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1

Intracochlear Drug Delivery Systems  

PubMed Central

Introduction Advances in molecular biology and in the basic understanding of the mechanisms associated with sensorineural hearing loss and other diseases of the inner ear, are paving the way towards new approaches for treatments for millions of patients. However, the cochlea is a particularly challenging target for drug therapy, and new technologies will be required to provide safe and efficacious delivery of these compounds. Emerging delivery systems based on microfluidic technologies are showing promise as a means for direct intracochlear delivery. Ultimately, these systems may serve as a means for extended delivery of regenerative compounds to restore hearing in patients suffering from a host of auditory diseases. Areas covered in this review Recent progress in the development of drug delivery systems capable of direct intracochlear delivery is reviewed, including passive systems such as osmotic pumps, active microfluidic devices, and systems combined with currently available devices such as cochlear implants. The aim of this article is to provide a concise review of intracochlear drug delivery systems currently under development, and ultimately capable of being combined with emerging therapeutic compounds for the treatment of inner ear diseases. Expert Opinion Safe and efficacious treatment of auditory diseases will require the development of microscale delivery devices, capable of extended operation and direct application to the inner ear. These advances will require miniaturization and integration of multiple functions, including drug storage, delivery, power management and sensing, ultimately enabling closed-loop control and timed-sequence delivery devices for treatment of these diseases. PMID:21615213

Borenstein, Jeffrey T.

2011-01-01

2

Mucoadhesive drug delivery systems  

PubMed Central

Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Over the past few decades, mucosal drug delivery has received a great deal of attention. Mucoadhesive dosage forms may be designed to enable prolonged retention at the site of application, providing a controlled rate of drug release for improved therapeutic outcome. Application of dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, and finally various mucoadhesive drug delivery systems (buccal, nasal, ocular, gastro, vaginal, and rectal). PMID:21430958

Shaikh, Rahamatullah; Raj Singh, Thakur Raghu; Garland, Martin James; Woolfson, A David; Donnelly, Ryan F.

2011-01-01

3

Bioinspired drug delivery systems.  

PubMed

The way Nature designs, processes and assembles molecular building blocks to fabricate high performance materials with a minimum of resources is a suitable model for the design of drug delivery systems (DDS) with advanced functionalities. Bioinspired preparation methods that involve the use of superhydrophobic surfaces, layer-by-layer assembly or protein-driven growth are being successfully implemented to create a wide range of polymeric and hybrid structures. Mimicking the surface, shape, texture and movement of cells and microorganisms help to overcome phagocytosis and attain efficient targeting of the drug carriers, while transposition of the feed-back regulation mechanisms and the functions of membrane channels and physiological receptors may notably enhance the spatiotemporal control of drug release. These aspects are addressed in the present review. PMID:23465754

Alvarez-Lorenzo, Carmen; Concheiro, Angel

2013-12-01

4

Drug Delivery Systems for Platinum Drugs  

NASA Astrophysics Data System (ADS)

Since the discovery of cisplatin, drugs based on platinum, have made a significant impact on the treatment of various cancers. The administration of platinum drugs is however accompanied by significant side effects. This chapter discusses the types of drug delivery systems that have been developed in order to enable the targeted delivery while maintaining controlled temporal supply of the drug. The sizes of carriers range from nanometer to micrometer sized particles. The most common types of drug carriers are micelles, liposomes, nanoparticles, and dendrimers, but also a few microspheres have been developed. Most striking aspect of the delivery of platinum drugs is the possibility of physical encapsulation but also the binding of the drug to the polymer carrier coordinate covalent bond. Since platinum drugs have typically two permanent and two leaving ligands, the polymer can be part of either ligand. As the leaving ligand, the platinum drug is released often as cisplatin. If the polymer provides the functionality for the permanent ligand, a new macromolecular drug has been formed. In addition to the attachment of pt(II) drugs, recent offorts are devoted to the conjugation via the Pt((IV) prodrug.

Huynh, Vien T.; Scarano, Wei; Stenzel, Martina H.

2013-09-01

5

Packaging for a drug delivery microelectromechanical system  

E-print Network

Local drug delivery is a fast expanding field, and has been a center of attention for researchers in medicine in the last decade. Its advantages over systemic drug delivery are clear in cancer therapy, with localized tumors. ...

Ho Duc, Hong Linh, 1978-

2005-01-01

6

Colloidal drug delivery systems in vaccine delivery.  

PubMed

Vaccines play a vital role in the field of community medicine to combat against several diseases of human existence. Vaccines primarily trigger the acquired immune system to develop long-lasting immunity against pathogens. Conventional approaches for vaccine delivery lacks potential to target a particular antigen to develop acquired immunity by specific antibodies. Recent advancements in vaccine delivery showed that inclusion of adjuvants in vaccine formulations or delivery of them in a carrier helps in achieving desired targeting ability, reducing the immunogenicity and significant augmentation in the immune response. Colloidal carriers (liposomes, niosomes, microspheres, proteosomes, virosomes and virus like particles (VLPs), antigen cochleates, dendrimers and carbon nanotubes) have been widely explored for vaccine delivery. Further, surface engineering of these carriers with ligands, functional moieties and monoclonal antibodies tend to enhance the immune recognition potential of vaccines by differentiation of antigen specific memory T-cells. The current review, therefore, provides an updated account on the recent advancements in various colloidal delivery systems in vaccine delivery, outlining the mechanism of immune response initiated by them along with potential applications and marketed instances in an explicit manner. PMID:23072326

Beg, Sarwar; Samad, Abdus; Nazish, Iram; Sultana, Ruksar; Rahman, Mahfoozur; Ahmad, Md Zaki; Akbar, Md

2013-01-01

7

Physically facilitating drug-delivery systems  

PubMed Central

Facilitated/modulated drug-delivery systems have emerged as a possible solution for delivery of drugs of interest to pre-allocated sites at predetermined doses for predefined periods of time. Over the past decade, the use of different physical methods and mechanisms to mediate drug release and delivery has grown significantly. This emerging area of research has important implications for development of new therapeutic drugs for efficient treatments. This review aims to introduce and describe different modalities of physically facilitating drug-delivery systems that are currently in use for cancer and other diseases therapy. In particular, delivery methods based on ultrasound, electrical, magnetic and photo modulations are highlighted. Current uses and areas of improvement for these different physically facilitating drug-delivery systems are discussed. Furthermore, the main advantages and drawbacks of these technologies reviewed are compared. The review ends with a speculative viewpoint of how research is expected to evolve in the upcoming years. PMID:22485192

Rodriguez-Devora, Jorge I; Ambure, Sunny; Shi, Zhi-Dong; Yuan, Yuyu; Sun, Wei; Xu, Tao

2012-01-01

8

Radiation sterilization of new drug delivery systems  

PubMed Central

Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (?) and beta (?) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by ? irradiation. PMID:24936306

Abuhano?lu, Gürhan

2014-01-01

9

Nanotechnology-based drug delivery systems  

PubMed Central

Nanoparticles hold tremendous potential as an effective drug delivery system. In this review we discussed recent developments in nanotechnology for drug delivery. To overcome the problems of gene and drug delivery, nanotechnology has gained interest in recent years. Nanosystems with different compositions and biological properties have been extensively investigated for drug and gene delivery applications. To achieve efficient drug delivery it is important to understand the interactions of nanomaterials with the biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signalling involved in pathobiology of the disease under consideration. Several anti-cancer drugs including paclitaxel, doxorubicin, 5-fluorouracil and dexamethasone have been successfully formulated using nanomaterials. Quantom dots, chitosan, Polylactic/glycolic acid (PLGA) and PLGA-based nanoparticles have also been used for in vitro RNAi delivery. Brain cancer is one of the most difficult malignancies to detect and treat mainly because of the difficulty in getting imaging and therapeutic agents past the blood-brain barrier and into the brain. Anti-cancer drugs such as loperamide and doxorubicin bound to nanomaterials have been shown to cross the intact blood-brain barrier and released at therapeutic concentrations in the brain. The use of nanomaterials including peptide-based nanotubes to target the vascular endothelial growth factor (VEGF) receptor and cell adhesion molecules like integrins, cadherins and selectins, is a new approach to control disease progression. PMID:18053152

Suri, Sarabjeet Singh; Fenniri, Hicham; Singh, Baljit

2007-01-01

10

Chitosan microspheres in novel drug delivery systems.  

PubMed

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

Mitra, Analava; Dey, Baishakhi

2011-07-01

11

Chitosan Microspheres in Novel Drug Delivery Systems  

PubMed Central

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

Mitra, Analava; Dey, Baishakhi

2011-01-01

12

76 FR 51038 - Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...  

Federal Register 2010, 2011, 2012, 2013

...Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...industry entitled ``Residual Drug in Transdermal and Related Drug Delivery Systems...developers and manufacturers of transdermal drug delivery systems...

2011-08-17

13

Ion Exchange Resins Transforming Drug Delivery Systems.  

PubMed

Ion-exchange resins are light, porous, three-dimensional high molecular weight cross -linked matrix of hydrocarbon chains carrying positively or negatively charged sites that can attract an ion of opposite charge from the surrounding medium. There is stoichiometric exchange of mobile ions between the solid and the solution called as Ion-exchange which does not lead to any radical change in the properties and structure of the solid. Depending upon the type of Ionexchanged it can be either Cation-exchange or Anion-exchange. They are prepared in the form of granules, beads or sheets. As drug delivery systems they have received considerable attention after the 1950s due to their inertness, freedom from side effects, high drug loading capacity, ease of sterilization and the fact that their structure can be easily altered to achieve the desired drug release characteristics. Their use is revolutionizing all traditional delivery systems namely- oral, nasal, ophthalmic and parenteral. Ion- exchange resins have been used for the development of novel drug delivery systems (NDDSs), to modify the characteristics of the dosage form and various other biomedical applications. The present article deals with the varied applications of ion-exchange resins for taste making, as resinates (simple and microencapsulated or coated), Pennkinetic systems, in selective recovery of pharmaceuticals, in pH and ionic strength responsive systems, in gastro-retentive systems, in hollow fiber systems, as sigmoidal release systems, as site specific delivery systems and as inotophoretically assisted transdermal drug delivery systems. They also have an immense importance when used as disintegrants/ superdisintegrants in formulation of orodispersible tablets, powder processing aids and in the dissolution and stabilization of drugs. PMID:20497105

Gupta, Shweta; Benien, Parul; Sahoo, P K

2010-05-24

14

Ion Exchange Resins Transforming Drug Delivery Systems.  

PubMed

Ion-exchange resins are light, porous, three-dimensional high molecular weight cross -linked matrix of hydrocarbon chains carrying positively or negatively charged sites that can attract an ion of opposite charge from the surrounding medium. There is stoichiometric exchange of mobile ions between the solid and the solution called as Ion-exchange which does not lead to any radical change in the properties and structure of the solid. Depending upon the type of Ion-exchanged it can be either Cation-exchange or Anion-exchange. They are prepared in the form of granules, beads or sheets. As drug delivery systems they have received considerable attention after the 1950s due to their inertness, freedom from side effects, high drug loading capacity, ease of sterilization and the fact that their structure can be easily altered to achieve the desired drug release characteristics. Their use is revolutionizing all traditional delivery systems namely- oral, nasal, ophthalmic and parenteral. Ion- exchange resins have been used for the development of novel drug delivery systems (NDDSs), to modify the characteristics of the dosage form and various other biomedical applications. The present article deals with the varied applications of ion-exchange resins for taste making, as resinates (simple and microencapsulated or coated), Pennkinetic systems, in selective recovery of pharmaceuticals, in pH and ionic strength responsive systems, in gastro-retentive systems, in hollow fiber systems, as sigmoidal release systems, as site specific delivery systems and as inotophoretically assisted transdermal drug delivery systems. They also have an immense importance when used as disintegrants / superdisintegrants in formulation of orodispersible tablets, powder processing aids and in the dissolution and stabilization of drugs. PMID:20158479

Gupta, Shweta; Parul; Sahoo, P K

2010-02-17

15

Recent technologies in pulsatile drug delivery systems  

PubMed Central

Pulsatile drug delivery systems (PDDS) have attracted attraction because of their multiple benefits over conventional dosage forms. They deliver the drug at the right time, at the right site of action and in the right amount, which provides more benefit than conventional dosages and increased patient compliance. These systems are designed according to the circadian rhythm of the body, and the drug is released rapidly and completely as a pulse after a lag time. These products follow the sigmoid release profile characterized by a time period. These systems are beneficial for drugs with chronopharmacological behavior, where nocturnal dosing is required, and for drugs that show the first-pass effect. This review covers methods and marketed technologies that have been developed to achieve pulsatile delivery. Marketed technologies, such as PulsincapTM, Diffucaps®, CODAS®, OROS® and PULSYSTM, follow the above mechanism to render a sigmoidal drug release profile. Diseases wherein PDDS are promising include asthma, peptic ulcers, cardiovascular ailments, arthritis and attention deficit syndrome in children and hypercholesterolemia. Pulsatile drug delivery systems have the potential to bring new developments in the therapy of many diseases. PMID:23507727

Jain, Deepika; Raturi, Richa; Jain, Vikas; Bansal, Praveen; Singh, Ranjit

2011-01-01

16

Nanoparticulate delivery systems for antiviral drugs.  

PubMed

Nanomedicine opens new therapeutic avenues for attacking viral diseases and for improving treatment success rates. Nanoparticulate-based systems might change the release kinetics of antivirals, increase their bioavailability, improve their efficacy, restrict adverse drug side effects and reduce treatment costs. Moreover, they could permit the delivery of antiviral drugs to specific target sites and viral reservoirs in the body. These features are particularly relevant in viral diseases where high drug doses are needed, drugs are expensive and the success of a therapy is associated with a patient's adherence to the administration protocol. This review presents the current status in the emerging area of nanoparticulate delivery systems in antiviral therapy, providing their definition and description, and highlighting some peculiar features. The paper closes with a discussion on the future challenges that must be addressed before the potential of nanotechnology can be translated into safe and effective antiviral formulations for clinical use. PMID:21107015

Lembo, David; Cavalli, Roberta

2010-01-01

17

Kontrollierte therapeutische Systeme (Controlled drug delivery systems)  

NASA Astrophysics Data System (ADS)

Es gibt eine grosse Anzahl von Arzneistoffen, die nicht mit der höchsten Effizienz eingesetzt werden können, weil das geeignete therapeutische System (drug delivery system) für die optimale Applikation fehlt. Viele Arzneistoffe setzen eine häufige Anwendung voraus und sind oft mit mehr oder weniger starken Nebenwirkungen oder aber mit Beeinträchtigungen von Arbeits- und Lebensrhythmus der Patienten verbunden. Der therapeutische Erfolg einer medikamentösen Behandlung setzt eine korrekte Diagnose, die Wahl der richtigen Wirksubstanz sowie ihr Vorliegen in geeigneter Darreichungsform voraus. Zudem muss ein genauer Verabreichungsplan erstellt werden, dessen Einhaltung seitens der Patienten eine wesentliche Voraussetzung für die optimale Wirkung des Arzneistoffes ist. Das Mass, mit dem eine Wirksubstanz therapeutisch voll genutzt werden kann, korreliert direkt mit der Darreichungsform, in der sie angewandt wird. Da viele hochwirksame Arzneimittel bereits existieren, hat sich, neben Neuentwicklungen, das Interesse im vergangenen Jahrzehnt der Optimierung von Arzneimittelwirkungen durch neue Darreichungsformen zugewandt.

Ha, Suk-Woo; Wintermantel, Erich

18

Mucoadhesive drug delivery system: An overview  

PubMed Central

Mucoadhesive drug delivery systems interact with the mucus layer covering the mucosal epithelial surface, and mucin molecules and increase the residence time of the dosage form at the site of absorption. The drugs which have local action or those which have maximum absorption in gastrointestinal tract (GIT) require increased duration of stay in GIT. Thus, mucoadhesive dosage forms are advantageous in increasing the drug plasma concentrations and also therapeutic activity. In this regard, this review covers the areas of mechanisms and theories of mucoadhesion, factors influencing the mucoadhesive devices and also various mucoadhesive dosage forms. PMID:22247877

Boddupalli, Bindu M.; Mohammed, Zulkar N. K.; Nath, Ravinder A.; Banji, David

2010-01-01

19

Bharatbook.com - Drug Delivery Systems forecasts for 2012 & 2017  

Microsoft Academic Search

Oral drug delivery systems will remain the largest method used for drug delivery. Orally disintegrating tablets and transmucosal drugs will generate strong growth opportunities in the delivery of pain control and other critical care medication. Ease of administration advantages will promote the widening use of chewable tablet dosages for nutritional, respiratory and central nervous system agents, especially pediatric preparations. Better

2008-01-01

20

In Situ Forming Polymeric Drug Delivery Systems  

PubMed Central

In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

Madan, M.; Bajaj, A.; Lewis, S.; Udupa, N.; Baig, J. A.

2009-01-01

21

Liposomes and Niosomes as Topical Drug Delivery Systems  

Microsoft Academic Search

The skin acts as a major target as well as a principle barrier for topical\\/transdermal (TT) drug delivery. The stratum corneum plays a crucial role in barrier function for TT drug delivery. Despite major research and development efforts in TT systems and the advantages of these routes, low stratum corneum permeability limits the usefulness of topical drug delivery. To overcome

M. J. Choi; H. I. Maibach

2005-01-01

22

Expert Review Functionalized Micellar Systems for Cancer Targeted Drug Delivery  

E-print Network

Expert Review Functionalized Micellar Systems for Cancer Targeted Drug Delivery Damon Sutton,1 targeting; cancer nanomedicine; micelle pharmacokinetics; polymer micelles; responsive drug release with greatly improved drug pharmacokinetics and efficacious response in cancer treatment. Typical

Gao, Jinming

23

Non-viral drug delivery systems for immune modulation  

E-print Network

Biodegradable polymer particles have diverse applications in drug delivery. The main objective of this thesis was to apply these delivery systems to modulating the immune system. We optimized particle formulations for the ...

Fuller, Jason E., Ph. D. Massachusetts Institute of Technology

2008-01-01

24

75 FR 45640 - Draft Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...  

Federal Register 2010, 2011, 2012, 2013

...Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...industry entitled ``Residual Drug in Transdermal and Related Drug Delivery Systems...developers and manufacturers of transdermal drug delivery systems...

2010-08-03

25

Importance of novel drug delivery systems in herbal medicines  

PubMed Central

Novel drug delivery system is a novel approach to drug delivery that addresses the limitations of the traditional drug delivery systems. Our country has a vast knowledge base of Ayurveda whose potential is only being realized in the recent years. However, the drug delivery system used for administering the herbal medicine to the patient is traditional and out-of-date, resulting in reduced efficacy of the drug. If the novel drug delivery technology is applied in herbal medicine, it may help in increasing the efficacy and reducing the side effects of various herbal compounds and herbs. This is the basic idea behind incorporating novel method of drug delivery in herbal medicines. Thus it is important to integrate novel drug delivery system and Indian Ayurvedic medicines to combat more serious diseases. For a long time herbal medicines were not considered for development as novel formulations owing to lack of scientific justification and processing difficulties, such as standardization, extraction and identification of individual drug components in complex polyherbal systems. However, modern phytopharmaceutical research can solve the scientific needs (such as determination of pharmacokinetics, mechanism of action, site of action, accurate dose required etc.) of herbal medicines to be incorporated in novel drug delivery system, such as nanoparticles, microemulsions, matrix systems, solid dispersions, liposomes, solid lipid nanoparticles and so on. This article summarizes various drug delivery technologies, which can be used for herbal actives together with some examples. PMID:22228938

Devi, V. Kusum; Jain, Nimisha; Valli, Kusum S.

2010-01-01

26

Herbal Excipients in Novel Drug Delivery Systems  

PubMed Central

The use of natural excipients to deliver the bioactive agents has been hampered by the synthetic materials. However advantages offered by these natural excipients are their being non-toxic, less expensive and freely available. The performance of the excipients partly determines the quality of the medicines. The traditional concept of the excipients as any component other than the active substance has undergone a substantial evolution from an inert and cheap vehicle to an essential constituent of the formulation. Excipients are any component other than the active substance(s) intentionally added to formulation of a dosage form. This article gives an overview of herbal excipients which are used in conventional dosage forms as well as novel drug delivery systems. PMID:20046764

Shirwaikar, A.; Shirwaikar, Annie; Prabu, S. Lakshmana; Kumar, G. Aravind

2008-01-01

27

Proniosome based drug delivery system of piroxicam  

Microsoft Academic Search

Piroxicam is a widely used potent non-steroidal anti-inflammatory drug, with due potential for dermal delivery. Permeation of piroxicam from proniosome based reservoir type transdermal gel formulation across excised rat abdominal skin was investigated using Keshery Chein diffusion cell. There was considerable improvement in flux over the control gel formulation. The lipid vesicles were evaluated for entrapment efficiency and vesicle size

A. Chandra; P. K. Sharma

2008-01-01

28

Controlled drug delivery systems: past forward and future back.  

PubMed

Controlled drug delivery technology has progressed over the last six decades. This progression began in 1952 with the introduction of the first sustained release formulation. The 1st generation of drug delivery (1950-1980) focused on developing oral and transdermal sustained release systems and establishing controlled drug release mechanisms. The 2nd generation (1980-2010) was dedicated to the development of zero-order release systems, self-regulated drug delivery systems, long-term depot formulations, and nanotechnology-based delivery systems. The latter part of the 2nd generation was largely focused on studying nanoparticle formulations. The Journal of Controlled Release (JCR) has played a pivotal role in the 2nd generation of drug delivery technologies, and it will continue playing a leading role in the next generation. The best path towards a productive 3rd generation of drug delivery technology requires an honest, open dialog without any preconceived ideas of the past. The drug delivery field needs to take a bold approach to designing future drug delivery formulations primarily based on today's necessities, to produce the necessary innovations. The JCR provides a forum for sharing the new ideas that will shape the 3rd generation of drug delivery technology. PMID:24794901

Park, Kinam

2014-09-28

29

Pulmonary drug delivery systems: recent developments and prospects.  

PubMed

Targeting drug delivery into the lungs has become one of the most important aspects of systemic or local drug delivery systems. Consequently, in the last few years, techniques and new drug delivery devices intended to deliver drugs into the lungs have been widely developed. Currently, the main drug targeting regimens include direct application of a drug into the lungs, mostly by inhalation therapy using either pressurized metered dose inhalers (pMDI) or dry powder inhalers (DPI). Intratracheal administration is commonly used as a first approach in lung drug delivery in vivo. To convey a sufficient dose of drug to the lungs, suitable drug carriers are required. These can be either solid, liquid, or gaseous excipients. Liposomes, nano- and microparticles, cyclodextrins, microemulsions, micelles, suspensions, or solutions are all examples of this type of pharmaceutical carrier that have been successfully used to target drugs into the lungs. The use of microreservoir-type systems offers clear advantages, such as high loading capacity and the possibility of controlling size and permeability, and thus of controlling the release kinetics of the drugs from the carrier systems. These systems make it possible to use relatively small numbers of vector molecules to deliver substantial amounts of a drug to the target. This review discusses the drug carriers administered or intended to be administered into the lungs. The transition to CFC-free inhalers and drug delivery systems formulated with new propellants are also discussed. Finally, in addition to the various advances made in the field of pulmonary-route administration, we describe new systems based on perfluorooctyl bromide, which guarantee oxygen delivery in the event of respiratory distress and drug delivery into the lungs. PMID:12661699

Courrier, H M; Butz, N; Vandamme, Th F

2002-01-01

30

[Research advances in brain-targeted nanoscale drug delivery system].  

PubMed

The blood-brain barrier (BBB) exerts its central nervous system (CNS) protective function as it hinders the delivery of diagnostic and therapeutic agents to the brain. With the development of nanotechnology during the last thirty years, the nanocarriers for delivering drugs make it possible to transport drugs across the BBB. The brain-targeted drug delivery system usually consists of two parts: nanocarriers and brain-targeted strategies. In this review, several kinds of nanocarriers are introduced for brain-targeted drug delivery. We focus on several possible strategies for brain-targeting and comment on their advantages and disadvantages in application. PMID:24417079

Liu, Yang; Jiang, Chen

2013-10-01

31

A water-powered micro drug delivery system  

Microsoft Academic Search

A plastic micro drug delivery system has been successfully demonstrated by utilizing the principle of osmosis without any electrical power consumption. The system has an osmotic microactuator (see Su, Lin, and Pisano, J. Microelectromech., vol. 11, pp. 736-7462, Dec. 2002) and a polydimethylsiloxane (PDMS) microfluidic cover compartment consisting of a reservoir, a microfluidic channel and a delivery port. The typical

Yu-Chuan Su; Liwei Lin

2004-01-01

32

Gastroretentive drug delivery systems for the treatment of Helicobacter pylori  

PubMed Central

Helicobacter pylori (H. pylori) is one of the most common pathogenic bacterial infections and is found in the stomachs of approximately half of the world’s population. It is the primary known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. However, combined drug therapy as the general treatment in the clinic, the rise of antibiotic-resistant bacteria, adverse reactions and poor patient compliance are major obstacles to the eradication of H. pylori. Oral site-specific drug delivery systems that could increase the longevity of the treatment agent at the target site might improve the therapeutic effect and avoid side effects. Gastroretentive drug delivery systems potentially prolong the gastric retention time and controlled/sustained release of a drug, thereby increasing the concentration of the drug at the application site, potentially improving its bioavailability and reducing the necessary dosage. Recommended gastroretentive drug delivery systems for enhancing local drug delivery include floating systems, bioadhesive systems and expandable systems. In this review, we summarize the important physiological parameters of the gastrointestinal tract that affect the gastric residence time. We then focus on various aspects useful in the development of gastroretentive drug delivery systems, including current trends and the progress of novel forms, especially with respect to their application for the treatment of H. pylori infections. PMID:25071326

Zhao, Shan; Lv, Yan; Zhang, Jian-Bin; Wang, Bing; Lv, Guo-Jun; Ma, Xiao-Jun

2014-01-01

33

Dendrimeric systems and their applications in ocular drug delivery.  

PubMed

Ophthalmic drug delivery is one of the most attractive and challenging research area for pharmaceutical scientists and ophthalmologists. Absorption of an ophthalmic drug in conventional dosage forms is seriously limited by physiological conditions. The use of nonionic or ionic biodegradable polymers in aqueous solutions and colloidal dosage forms such as liposomes, nanoparticles, nanocapsules, microspheres, microcapsules, microemulsions, and dendrimers has been studied to overcome the problems mentioned above. Dendrimers are a new class of polymeric materials. The unique nanostructured architecture of dendrimers has been studied to examine their role in delivery of therapeutics and imaging agents. Dendrimers can enhance drug's water solubility, bioavailability, and biocompatibility and can be applied for different routes of drug administration successfully. Permeability enhancer properties of dendrimers were also reported. The use of dendrimers can also reduce toxicity versus activity and following an appropriate application route they allow the delivery of the drug to the targeted site and provide desired pharmacokinetic parameters. Therefore, dendrimeric drug delivery systems are of interest in ocular drug delivery. In this review, the limitations related to eye's unique structure, the advantages of dendrimers, and the potential applications of dendrimeric systems to ophthalmology including imaging, drug, peptide, and gene delivery will be discussed. PMID:24396306

Yavuz, Burçin; Pehlivan, Sibel Bozda?; Unlü, Nur?en

2013-01-01

34

Transferosomes - A vesicular transdermal delivery system for enhanced drug permeation  

PubMed Central

Transdermal administration of drugs is generally limited by the barrier function of the skin. Vesicular systems are one of the most controversial methods for transdermal delivery of active substances. The interest in designing transdermal delivery systems was relaunched after the discovery of elastic vesicles like transferosomes, ethosomes, cubosomes, phytosomes, etc. This paper presents the composition, mechanisms of penetration, manufacturing and characterization methods of transferosomes as transdermal delivery systems of active substances. For a drug to be absorbed and distributed into organs and tissues and eliminated from the body, it must pass through one or more biological membranes/barriers at various locations. Such a movement of drug across the membrane is called as drug transport. For the drugs to be delivered to the body, they should cross the membranous barrier. The concept of these delivery systems was designed in an attempt to concentrate the drug in the tissues of interest, while reducing the amount of drug in the remaining tissues. Hence, surrounding tissues are not affected by the drug. In addition, loss of drug does not happen due to localization of drug, leading to get maximum efficacy of the medication. Therefore, the phospholipid based carrier systems are of considerable interest in this era. PMID:22171309

Rajan, Reshmy; Jose, Shoma; Mukund, V. P. Biju; Vasudevan, Deepa T.

2011-01-01

35

Pharmacosomes: An Emerging Novel Vesicular Drug Delivery System for Poorly Soluble Synthetic and Herbal Drugs  

PubMed Central

In the arena of solubility enhancement, several problems are encountered. A novel approach based on lipid drug delivery system has evolved, pharmacosomes. Pharmacosomes are colloidal, nanometric size micelles, vesicles or may be in the form of hexagonal assembly of colloidal drug dispersions attached covalently to the phospholipid. They act as befitting carrier for delivery of drugs quite precisely owing to their unique properties like small size, amphiphilicity, active drug loading, high entrapment efficiency, and stability. They help in controlled release of drug at the site of action as well as in reduction in cost of therapy, drug leakage and toxicity, increased bioavailability of poorly soluble drugs, and restorative effects. There has been advancement in the scope of this delivery system for a number of drugs used for inflammation, heart diseases, cancer, and protein delivery along with a large number of herbal drugs. Hence, pharmacosomes open new challenges and opportunities for improved novel vesicular drug delivery system. PMID:24106615

2013-01-01

36

Strategies for Enhanced Drug Delivery to the Central Nervous System  

PubMed Central

Treating central nervous system diseases is very challenging because of the presence of a variety of formidable obstacles that impede drug delivery. Physiological barriers like the blood-brain barrier and blood-cerebrospinal fluid barrier as well as various efflux transporter proteins make the entry of drugs into the central nervous system very difficult. The present review provides a brief account of the blood brain barrier, the P-glycoprotein efflux and various strategies for enhancing drug delivery to the central nervous system. PMID:20046703

Dwibhashyam, V. S. N. M.; Nagappa, A. N.

2008-01-01

37

Coacervate delivery systems for proteins and small molecule drugs.  

PubMed

Coacervates represent an exciting new class of drug delivery vehicles, developed in the past decade as carriers of small molecule drugs and proteins. This review summarizes several well-described coacervate systems, including: i) elastin-like peptides for delivery of anticancer therapeutics; ii) heparin-based coacervates with synthetic polycations for controlled growth factor delivery; iii) carboxymethyl chitosan aggregates for oral drug delivery; iv) Mussel adhesive protein and hyaluronic acid coacervates. Coacervates present advantages in their simple assembly and easy incorporation into tissue engineering scaffolds or as adjuncts to cell therapies. They are also amenable to functionalization such as for targeting or for enhancing the bioactivity of their cargo. These new drug carriers are anticipated to have broad applications and noteworthy impact in the near future. PMID:25138695

Johnson, Noah R; Wang, Yadong

2014-12-01

38

Acute Myeloid Leukemia: Nanomedicine drug delivery system could improve chemotherapy  

E-print Network

by their cardiotoxicity and the development of drug-resistance of tumors. In addition, the efficiency of anthracyclines the pharmacological properties of anthracyclines, a novel nanomedicine drug delivery system has been developed reputation for innovative research, interdisciplinarity and successful training. Its 4 faculties (Engineering

Pfeifer, Holger

39

Processing of polymer nanofibers through electrospinning as drug delivery systems  

Microsoft Academic Search

The use of electrospun fibers as drug carriers could be promising in the future for biomedical applications, especially postoperative local chemotherapy. In this research work, electrospun fibers were developed as a new system for the delivery of ketoprofen as non-steroidal anti-inflammatory drug (NSAID). The fibers were made either from polycaprolactone (PCL) as a biodegradable polymer or polyurethane (PU) as a

El-Refaie Kenawy; Fouad I. Abdel-Hay; Mohamed H. El-Newehy; Gary E. Wnek

2009-01-01

40

Chronopharmaceutics based modern colon specific drug delivery systems.  

PubMed

Colon-targeted delivery of bioactives has recently gained importance in addressing specific needs in the therapy of colon based diseases. Many approaches have been attempted for the development of colon-specific delivery systems, with not much success in the past. With the advancement in the field of chronobiology, modern drug delivery approaches have elevated to a new concept of chronopharmacology i.e. the ability to deliver the therapeutic agent to a patient in a staggered profile. The increasing research interest surrounding this delivery system has widened the areas of pharmaceutics in particular with many more sub-disciplines expected to coexist in the near future. Chronopharmaceutics based technology has eliminated the drawbacks associated with the conventional colon specific delivery systems. This review on chronopharmaceutics based delivery lays emphasis on the existing technologies and future development. PMID:22564168

Tiwari, Akanksha; Shukla, Raj Kumar; Tiwari, Suresh; Naazneen, Surti

2012-12-01

41

Pulsatile Drug Delivery System Based on Electrohydrodynamic Method  

E-print Network

Electrohydrodynamic (EHD) generation, a commonly used method in BioMEMS, plays a significant role in the pulsatile drug delivery system for a decade. In this paper, an EHD based drug delivery system is well designed, which can be used to generate a single drug droplet as small as 2.83 nL in 8.5 ms with a total device of 2\\times2\\times3 mm^3, and an external supplied voltage of 1500 V. Theoretically, we derive the expressions for the size and the formation time of a droplet generated by EHD method, while taking into account the drug supply rate, properties of liquid, gap between two electrodes, nozzle size, and charged droplet neutralization. This work proves a repeatable, stable and controllable droplet generation and delivery system based on EHD method experimentally as well as theoretically.

Zheng, Yi; Hu, Junqiang; Gao, Wenle

2012-01-01

42

Novel prospective in colon specific drug delivery system.  

PubMed

This review deals with the targeting of drugs to the lower gastrointestinal tract i.e. colon. Colonic drug delivery becomes important for localized action as well as for improved systemic availability of peptide and proteins. Drugs which have absorption window in the colonic region have been targeted using different novel technologies. pH sensitive polymers and prodrug based formulation have been used for the delivery of drugs into the colon. Different natural polymers have been used successfully for the delivery of drugs into the colon. Natural polymers are less toxic, biodegradable and easily available with a wide range of molecular weight and varying chemical compositions. One of the supporting properties associated with these polymers is that natural polymers can be used as approved pharmaceutical excipient. PMID:24967782

Bansal, Vipin; Malviya, Rishabha; Malaviya, Tanya; Sharma, Pramod Kumar

2014-01-01

43

Gastroretentive floating drug-delivery systems: a critical review.  

PubMed

The oral delivery of drugs with a narrow absorption window in the gastrointestinal tract (GIT) is often limited by poor bioavailability with conventional dosage forms due to incomplete drug release and short residence time at the site of absorption. To overcome this drawback and to maximize the oral absorption of these drugs, gastroretentive systems such as mucoadhesive, high-density, expandable, and floating systems have been developed. These systems provide controlled delivery of drugs with prolonged gastric residence time. However, in humans, differences in various physiological and biological factors can affect the gastric residence time and drug-delivery behavior from gastroretentive systems. Some floating drug-delivery systems (FDDS) have shown the capability to accommodate these variations without affecting drug release. This review mainly focuses on various physiological considerations for development of FDDS, and highlights recent technological developments including new dosage forms and their production techniques (e.g., holt-melt extrusion, melt pelletization, and pulsed plasma-irradiation processes). Alternatives to the existing in vitro compendial methods for evaluating floating dosage forms will be discussed, and a critical analysis of the existing literature on FDDS, identifying the potential areas for future research, is provided. PMID:21395515

Kotreka, Udaya K; Adeyeye, Moji Christianah

2011-01-01

44

Transdermal drug delivery  

Microsoft Academic Search

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, noncavitational ultrasound and iontophoresis have also resulted

Mark R Prausnitz; Robert Langer

2008-01-01

45

Targeting delivery of drugs in the vascular system  

PubMed Central

Delivery and effects of therapeutics remain suboptimal. Most drugs do not have affinity to their targets. Biotherapeutics including enzymes and genetic materials require specific sub-cellular addressing not attainable naturally. Endothelium, lining the luminal surface of blood vessels, represents a key therapeutic target in many diseases. Studies in cell culture and animal models revealed that targeted delivery of therapeutics to, into and across endothelium can be achieved using carriers targeted to specific molecules expressed on the surface of the endothelial cells. For example, cell adhesion molecules represent attractive targets for drug delivery. Rational design of the drug delivery systems (e.g., selection of optimal geometry and affinity to specific epitopes) provides an unprecedented level of control of such parameters of drug delivery as pharmacokinetics, circulation in blood, binding to selected endothelial cell phenotypes, anchoring on cell surface or internalization into the endothelium, subsequent intracellular addressing and duration of the effects. We discusse here key aspects of design of endothelium-targeted drug delivery systems with potential for translation into the clinical domain.

Muzykantov, Vladimir; Muro, Silvia

2014-01-01

46

Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier  

PubMed Central

Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods. PMID:25136634

Upadhyay, Ravi Kant

2014-01-01

47

Floating microspheres as drug delivery system: newer approaches.  

PubMed

A controlled drug delivery system with prolonged residence time in the stomach can be of great practical importance for drugs with an absorption window in the upper small intestine. The main limitations are attributed to the inter- and intra-subject variability of gastro-intestinal (GI) transit time and the non-uniformity of drug absorption throughout the alimentary canal. Floating drug delivery systems (FDDSs) are expected to remain buoyant in a lasting way upon the gastric contents and consequently to enhance the bioavailability of drugs. The various buoyant preparations include hollow microspheres, granules, powders, tablets, capsules, pills and laminated films. Floating microspheres are specially gaining attention due to their wide applicability in the targeting of drugs to stomach. These floating microspheres have the advantage that they remain buoyant and distributed uniformly over the gastric fluid to avoid the vagaries of gastric emptying and release the drug for prolonged period of time. A major drawback of low-density floating drug delivery systems is that their performance is strongly dependent upon the gastric emptying process of stomach. Multiparticulate low-density particles can successfully prolong the gastric retention time of drugs. This article is a review of two important approaches utilized to prepare and improve the performance of floating microspheres. PMID:18673266

Jain, Sunil K; Agrawal, Govind P; Jain, Narendra K

2008-07-01

48

Nanoscale drug delivery systems and the blood-brain barrier  

PubMed Central

The protective properties of the blood–brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain’s vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual’s age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS. PMID:24550672

Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

2014-01-01

49

[Drug delivery systems using nano-sized drug carriers].  

PubMed

Nanotechnology has attracted great attention all over the world in recent several years and has led to the establishment of the novel technical field of "nanomedicine" through collaboration with advanced medical technology. Particularly, site-specific drug targeting using particle drug carrier systems has made substantial progress and been actively developed. This review explains the essential factors (size and chemical character) of drug carriers to allow long circulation in the bloodstream avoiding the reticuloendothelial system, and shows the present status and future perspective of several types of nano-carrier systems (water-soluble polymer, liposome and polymeric micelle). We also introduce the novel concept of multi-targeting system (combination of two or more targeting methodologies) for ideal drug therapies. PMID:16044950

Nakayama, Masamichi; Okano, Teruo

2005-07-01

50

Multifunctional, stimuli-sensitive nanoparticulate systems for drug delivery.  

PubMed

The use of nanoparticulate pharmaceutical drug delivery systems (NDDSs) to enhance the in vivo effectiveness of drugs is now well established. The development of multifunctional and stimulus-sensitive NDDSs is an active area of current research. Such NDDSs can have long circulation times, target the site of the disease and enhance the intracellular delivery of a drug. This type of NDDS can also respond to local stimuli that are characteristic of the pathological site by, for example, releasing an entrapped drug or shedding a protective coating, thus facilitating the interaction between drug-loaded nanocarriers and target cells or tissues. In addition, imaging contrast moieties can be attached to these carriers to track their real-time biodistribution and accumulation in target cells or tissues. Here, I highlight recent developments with multifunctional and stimuli-sensitive NDDSs and their therapeutic potential for diseases including cancer, cardiovascular diseases and infectious diseases. PMID:25287120

Torchilin, Vladimir P

2014-11-01

51

Interpenetrating Polymer Networks as Innovative Drug Delivery Systems  

PubMed Central

Polymers have always been valuable excipients in conventional dosage forms, also have shown excellent performance into the parenteral arena, and are now capable of offering advanced and sophisticated functions such as controlled drug release and drug targeting. Advances in polymer science have led to the development of several novel drug delivery systems. Interpenetrating polymer networks (IPNs) have shown superior performances over the conventional individual polymers and, consequently, the ranges of applications have grown rapidly for such class of materials. The advanced properties of IPNs like swelling capacity, stability, biocompatibility, nontoxicity and biodegradability have attracted considerable attention in pharmaceutical field especially in delivering bioactive molecules to the target site. In the past few years various research reports on the IPN based delivery systems showed that these carriers have emerged as a novel carrier in controlled drug delivery. The present review encompasses IPNs, their types, method of synthesis, factors which affects the morphology of IPNs, extensively studied IPN based drug delivery systems, and some natural polymers widely used for IPNs. PMID:24949205

Lohani, Alka; Singh, Garima; Bhattacharya, Shiv Sankar; Verma, Anurag

2014-01-01

52

Microneedle-based drug delivery systems: microfabrication, drug delivery, and safety.  

PubMed

Many promising therapeutic agents are limited by their inability to reach the systemic circulation, due to the excellent barrier properties of biological membranes, such as the stratum corneum (SC) of the skin or the sclera/cornea of the eye and others. The outermost layer of the skin, the SC, is the principal barrier to topically-applied medications. The intact SC thus provides the main barrier to exogenous substances, including drugs. Only drugs with very specific physicochemical properties (molecular weight < 500 Da, adequate lipophilicity, and low melting point) can be successfully administered transdermally. Transdermal delivery of hydrophilic drugs and macromolecular agents of interest, including peptides, DNA, and small interfering RNA is problematic. Therefore, facilitation of drug penetration through the SC may involve by-pass or reversible disruption of SC molecular architecture. Microneedles (MNs), when used to puncture skin, will by-pass the SC and create transient aqueous transport pathways of micron dimensions and enhance the transdermal permeability. These micropores are orders of magnitude larger than molecular dimensions, and, therefore, should readily permit the transport of hydrophilic macromolecules. Various strategies have been employed by many research groups and pharmaceutical companies worldwide, for the fabrication of MNs. This review details various types of MNs, fabrication methods and, importantly, investigations of clinical safety of MN. PMID:20297904

Donnelly, Ryan F; Raj Singh, Thakur Raghu; Woolfson, A David

2010-05-01

53

Processing of Polymer Nanofibers Through Electrospinning as Drug Delivery Systems  

Microsoft Academic Search

The use of electrospun fibers as drug carriers could be promising in the future for biomedical applications, especially postoperative\\u000a local chemotherapy. In this research, electrospun fibers were developed as a new system for the delivery of ketoprofen as\\u000a non-steroidal anti-inflammatory drug (NSAID). The fibers were made either from polycaprolactone (PCL) as a biodegradable polymer\\u000a or polyurethane (PU) as a non-biodegradable

E. Kenawy; F. I. Abdel-Hay; M. H. El-Newehy; G. E. Wnek

54

Processing of Polymer Nanofibers Through Electrospinning as Drug Delivery Systems  

Microsoft Academic Search

The use of electrospun fibers as drug carriers could be promising in the future for biomedical applications, especially postoperative local chemotherapy. In this research, electrospun fibers were developed as a new system for the delivery of ketoprofen as non-steroidal anti-inflammatory drug (NSAID). The fibers were made either from polycaprolactone (PCL) as a biodegradable polymer or polyurethane (PU) as a non-biodegradable

E. Kenawy; F. I. Abdel-Hay; M. H. El-Newehy; G. E. Wnek

2009-01-01

55

Development and characterization of chronomodulated drug delivery system of captopril  

PubMed Central

Background: Hypertension shows circadian rhythm that there is a rise in pressure from the time of waking or before (about 4 to 8 a.m.), in most people. Conventional drug delivery system of captopril is inappropriate for the delivery of drug, as they cannot be administered just before the symptoms are worsened, because during this time the patients are asleep, bedtime dosing of captopril will not provide a therapeutic plasma drug concentration at the early hours of morning because of poor pharmacokinetic profile and shorter half-life of 1.9 hours. Thus, this study attempts to design and evaluate a chronomodulated pulsatile drug delivery system of captopril which was aimed to release the drug after a lag time of 6 hours. Materials and Methods: Present delivery system was prepared by rupturable coating method. The core containing captopril as a bioactive compound were prepared by direct compression method and then coated sequentially with an inner swelling layer containing hydrocolloid HPMC E5 and an outer rupturable layer consisted of Eudragit RL/RS (1 : 1). Total 12 formulations with different levels of inner swelling layer and outer polymeric layer were prepared and subjected to various processing and formulative parameters like the effect of core composition, level of swelling layer, and rupturable coating on lag time was investigated. In vitro drug release and rupture tests were performed using United States Pharmacopoeia paddle method at 50 rpm in 0.1N HCl and phosphate buffer of pH 6.8. Results: The results showed that as the amount of inner swelling layer increases, the lag time decreases and as the Eudragit coating level increases, the lag time increases and percent water uptake of time-dependent pulsatile release system decreases. The presence of an osmotic agent and effervescent agent helped in shortening of lag time. Conclusion: The system was found to be satisfactory in terms of release of the drug after the lag time of 6 hours. PMID:23071948

Patil, Archana S; Dandagi, Panchaxari M; Masthiholimath, Vinayak S; Gadad, Anand P; Najwade, Basavaraj K

2011-01-01

56

Advances in topical drug delivery system: micro to nanofibrous structures.  

PubMed

This paper is a review of the latest developments in the field of topical drug delivery via which the drug is directly applied onto the skin with high selectivity and efficiency. Advances in microfiber-based medical textiles such as sutures and wound dressings, especially those containing a drug or an antimicrobial agent, have been covered briefly. A special focus is on recent developments in the area of nanofibrous drug delivery systems, which have several advantages due to their large surface area to volume ratio, high porosity and flexibility. The electrospinning technique to produce nanofibers has also been discussed with reference to latest advances such as multiple needles, needleless and coaxial forms of electrospinning. The applications of nanofibers in different areas such as wound dressing, periodontal and anticancer treatment have also been discussed. PMID:24730303

Joshi, Mangala; Butola, B S; Saha, Kasturi

2014-01-01

57

The ophthalmic rod: a new ophthalmic drug delivery system I.  

PubMed

The ophthalmic rod (OR) is a new drug delivery system, intended as an alternative to conventional therapy in ophthalmology. The rod is made of a nontoxic plastic. It is dipped into a drug solution which after drying forms a thin homogeneous coating. The OR is then packed and sterilized by gamma radiation. The effects of radiation on the contents of the drugs were studied using IR, UV, and thin-layer chromatography (TLC). Sterility, dose variation, and simulated drug delivery in vitro were tested. Pure drugs were used; no preservatives were included. To deliver the drug, the tip of the rod is introduced into the conjunctival sac and rubbed against the palpebral conjunctiva of the lower lid. ORs with tropicamide, oxybuprocaine HCl, pilocarpine HCl, and fluorescein sodium were used. The behavior of the drugs administered by this system was compared with eyedrops. Results of trials with three drugs, i.e., tropicamide, oxybuprocaine HCl, and fluorescein sodium on ORs applied to the eyes of humans and those of the rabbit are discussed. PMID:2205544

Alani, S D

1990-01-01

58

Packaged Au-PPy valves for drug delivery systems  

NASA Astrophysics Data System (ADS)

The most common methods for the drug delivery are swallowing pills or receiving injections. However, formulations that control the rate and period of medicine (i.e., time-release medications) are still problematic. The proposed implantable devices which include batteries, sensors, telemetry, valves, and drug storage reservoirs provide an alternative method for the responsive drug delivery system [1]. Using this device, drug concentration can be precisely controlled which enhances drug efficiency and decreases the side effects. In order to achieve responsive drug delivery, a reliable release valve has to be developed. Biocompatibility, low energy consumption, and minimized leakage are the main requirements for such release method. A bilayer structure composed of Au/PPy film is fabricated as a flap to control the release valve. Optimized potentiostatic control to synthesize polypyrrole (PPy) is presented. The release of miniaturize valve is tested and showed in this paper. A novel idea to simultaneously fabricate the device reservoirs as well as protective packaging is proposed in this paper. The solution of PDMS permeability problem is also mentioned in this article.

Tsai, Han-Kuan A.; Ma, Kuo-Sheng; Zoval, Jim; Kulinsky, Lawrence; Madou, Marc

2006-03-01

59

Catheter systems for intrathecal drug delivery.  

PubMed

A prospective study of intrathecal catheter reliability was performed at Rush-Presbyterian-St. Luke's Medical Center. All 102 patients who had baclofen administered chronically for spasticity via an implanted drug pump were included. Sixty percent of the patients had no catheter complications; the remaining patients had one to five complications over their course of treatment. Survival analysis demonstrated a steady rate of malfunction up to 80 months, with the mean time to first failure recorded at 20 months. Kinks, holes, breaks, dislodgments, and disconnections were the most common complications. On the basis of their research the authors conclude that the thin-walled silastic catheter does not perform well and that larger, thick-walled catheters should be used. PMID:7616263

Penn, R D; York, M M; Paice, J A

1995-08-01

60

Floating Drug Delivery of Nevirapine as a Gastroretentive System  

PubMed Central

A multiple-unit floating drug delivery system based on gas formation technique was developed, in order to prolong the gastric residence time and to increase the overall bioavailability of the dosage form. The floating bead formulations were prepared by dispersing nevirapine together with calcium carbonate in a mixture of sodium alginate and hydroxypropyl methylcellulose solution and then dripping the dispersion into an acidified solution of calcium chloride. Calcium alginate beads were formed, as the alginate underwent ionotropic gelation by calcium ions, and carbon dioxide developed from the reaction of carbonate salts with acid. The obtained beads were able to float due to CO2-gas formation and the gas entrapment by the polymeric membrane. The prepared beads were evaluated for percent drug loading, drug entrapment efficiency, morphology, surface topography, buoyancy, in-vitro release, and release kinetics. The formulations were optimized for different weight ratios of the gas-forming agent and sodium alginate. The beads containing higher amounts of calcium carbonate demonstrated an instantaneous, complete, and excellent floating ability over a period of 24 hours. The increased amount of the gas forming agent did not affect the time to float, but increased the drug release from the floating beads, while increasing the coating level of the gas-entrapped membrane, increased the time to float, and slightly retarded the drug release. Good floating properties and sustained drug release were achieved. Finally, these floating beads seemed to be a promising gastroretentive drug delivery system. PMID:21264092

Vedha, Hari BN; Brahma, Reddy A; Samyuktha, Rani B

2010-01-01

61

Which drug or drug delivery system can change clinical practice for brain tumor therapy?  

PubMed Central

The prognosis and treatment outcome for primary brain tumors have remained unchanged despite advances in anticancer drug discovery and development. In clinical trials, the majority of promising experimental agents for brain tumors have had limited impact on survival or time to recurrence. These disappointing results are partially explained by the inadequacy of effective drug delivery to the CNS. The impediments posed by the various specialized physiological barriers and active efflux mechanisms lead to drug failure because of inability to reach the desired target at a sufficient concentration. This perspective reviews the leading strategies that aim to improve drug delivery to brain tumors and their likelihood to change clinical practice. The English literature was searched for defined search items. Strategies that use systemic delivery and those that use local delivery are critically reviewed. In addition, challenges posed for drug delivery by combined treatment with anti-angiogenic therapy are outlined. To impact clinical practice and to achieve more than just a limited local control, new drugs and delivery systems must adhere to basic clinical expectations. These include, in addition to an antitumor effect, a verified favorable adverse effects profile, easy introduction into clinical practice, feasibility of repeated or continuous administration, and compatibility of the drug or delivery system with any tumor size and brain location. PMID:23502426

Siegal, Tali

2013-01-01

62

Novel Drug Delivery System Shows Early Promise for Treating Lupus in Mice  

MedlinePLUS

... Lupus in Mice A drug delivery system using nanoparticle technology that allows for better targeting of specific ... be effectively programmed to seek specific cells. Although nanoparticle drug delivery systems have been used experimentally to ...

63

Liposome drug delivery system for murine neuroblastoma  

Microsoft Academic Search

Purpose: The effects of liposome-infused doxorubicin on C-1300 murine neuroblastoma were studied. The liposome surface was covered with polyethylene glycol to avoid migration toward the reticuloendothelial system and to prolong its presence in the bloodstream. Liposome-infused doxorubicin hydrochloride (DXR), an anthracycline was used as an anticancer antibiotic substance.Methods: Each AJ mouse was transplanted with 1 × 105 C-1300 murine neuroblastoma

Itsuro Nagae; Yasuhisa Koyanagi; Shinichi Ito; Yoshihide Tanabe; Sakae Unezaki

1998-01-01

64

Transdermal drug delivery system (TDDS) adhesion as a critical safety, efficacy and quality attribute  

Microsoft Academic Search

Transdermal drug delivery systems (TDDS), also known as “patches,” are dosage forms designed to deliver a therapeutically effective amount of drug across a patient’s skin. The adhesive of the transdermal drug delivery system is critical to the safety, efficacy and quality of the product. In the Drug Quality Reporting System (DQRS), the United States Food and Drug Administration (FDA) has

Anna M. Wokovich; Suneela Prodduturi; William H. Doub; Ajaz S. Hussain; Lucinda F. Buhse

2006-01-01

65

Ocular drug delivery.  

PubMed

Ocular drug delivery has been a major challenge to pharmacologists and drug delivery scientists due to its unique anatomy and physiology. Static barriers (different layers of cornea, sclera, and retina including blood aqueous and blood-retinal barriers), dynamic barriers (choroidal and conjunctival blood flow, lymphatic clearance, and tear dilution), and efflux pumps in conjunction pose a significant challenge for delivery of a drug alone or in a dosage form, especially to the posterior segment. Identification of influx transporters on various ocular tissues and designing a transporter-targeted delivery of a parent drug has gathered momentum in recent years. Parallelly, colloidal dosage forms such as nanoparticles, nanomicelles, liposomes, and microemulsions have been widely explored to overcome various static and dynamic barriers. Novel drug delivery strategies such as bioadhesive gels and fibrin sealant-based approaches were developed to sustain drug levels at the target site. Designing noninvasive sustained drug delivery systems and exploring the feasibility of topical application to deliver drugs to the posterior segment may drastically improve drug delivery in the years to come. Current developments in the field of ophthalmic drug delivery promise a significant improvement in overcoming the challenges posed by various anterior and posterior segment diseases. PMID:20437123

Gaudana, Ripal; Ananthula, Hari Krishna; Parenky, Ashwin; Mitra, Ashim K

2010-09-01

66

Intrathecal Drug Delivery (ITDD) systems for cancer pain  

PubMed Central

Intrathecal drug delivery is an effective pain management option for patients with chronic and cancer pain. The delivery of drugs into the intrathecal space provides superior analgesia with smaller doses of analgesics to minimize side effects while significantly improving quality of life. This article aims to provide a general overview of the use of intrathecal drug delivery to manage pain, dosing recommendations, potential risks and complications, and growing trends in the field. PMID:24555051

Bhatia, Gaurav; Lau, Mary E; Koury, Katharine M; Gulur, Padma

2014-01-01

67

ATTEMPTS system: a macromolecular prodrug strategy for cancer drug delivery.  

PubMed

In order to reduce systemic toxicity and effectively deliver macromolecular drug into tumor cells, a system termed "ATTEMPTS" (antibody targeted, [protamine] triggered, electrically modified prodrug-type strategy) was developed in our laboratory. This approach was adapted from our previously reported heparin/protamine-based system for controlled delivery of protease drugs such as tissue- specific plasminogen activator (tPA). In this "ATTEMPTS" system, the cell-permeable protein drugs are synthesized by conjugating proteins to cell-penetrating peptides (CPPs). Cell penetration ability of such CPP-protein conjugates would initially be disabled, acting as a "prodrug", by forming polyelectrolyte complexes with a functionalized heparin-antibody moiety. The complexes would accumulate in tumor sites by the antibody targeting function, and then the local release of CPP-protein conjugates would be triggered by protamine. We applied this system to the macromolecular anticancer agents, such as the protein drugs (gelonin and asparaginase) as well as the polymerdrugs (polyrotaxane-doxorubicin and polyrotaxane-camptothecin). Both in vitro and preliminary in vivo studies demonstrated the regulable cell penetration behavior based on the competitive ionic interactions between CPP/heparin and heparin/protamine. Thus, this ATTEMPTS approach provides a multi-functionalized system incorporating the features of targeting, prodrug-like, triggerable release, and cell penetration ability for the delivery of macromolecular anticancer agents. A summary of our work on "ATTEMPTS" is presented in this review. PMID:20618157

Huang, Yongzhuo; Park, Yoon Shin; Wang, Jianxin; Moon, Cheol; Kwon, Young Min; Chung, Hee Sun; Park, Yoon Jeong; Yang, Victor C

2010-07-01

68

STOMACH SPECIFIC FLOATING DRUG DELIVERY SYSTEM: A REVIEW  

Microsoft Academic Search

Technological attempts have been made in the research and development of rate-controll ed oral drug delivery systems to overcome physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying times (GET). It is known that differences in gastric physiology, such as, gastric pH, and motility exhibit both intra-as well as inter-subject variability demonstrating significant impact on gastric

69

Formulation and Evaluation of Floating Drug Delivery System of Famotidine  

PubMed Central

A multiple unit oral floating drug delivery system of famotidine was developed to prolong gastric residence time, target stomach mucosa and increase drug bioavailability. Drug and polymer compatibility was studied by subjecting physical mixtures of drug and polymers to differential scanning calorimetry. Cod liver oil entrapped calcium alginate beads containing famotidine, capable of floating in the gastric condition were formulated and evaluated. The gel beads were prepared by emulsion gelation method by employing sodium alginate alone and mixture of sodium alginate and hydrophilic copolymers such as carbopol 934P and hydroxypropylmethylcellulose K15M grade in three different ratios. The effect of selected factors, such as percentage of oil and amount of copolymers on floating properties was investigated. The beads were evaluated for percent drug loading, drug entrapment efficiency, buoyancy and in vitro drug release. The in vitro drug release study of the beads was carried out in simulated gastric media employing a modified Rosette-Rice test apparatus. Wherein, the apparatus was further modified by incorporating a water jacket to the apparatus to circulate hot water to maintain 37±2° for throughout the release study. All the oil entrapped calcium alginate beads floated if a sufficient amount of oil was used. Beads formulated employing sodium alginate alone could not sustain the drug release up to 8 h, whereas beads formulated with mixture of sodium alginate and copolymers demonstrated sustained release of famotidine up to 8 h. The results suggested that cod liver oil entrapped calcium alginate beads were promising as a carrier for intragastric floating drug delivery of famotidine. PMID:21969746

Satishbabu, B. K.; Sandeep, V. R.; Ravi, R. B.; Shrutinag, R.

2010-01-01

70

Formulation and evaluation of floating drug delivery system of famotidine.  

PubMed

A multiple unit oral floating drug delivery system of famotidine was developed to prolong gastric residence time, target stomach mucosa and increase drug bioavailability. Drug and polymer compatibility was studied by subjecting physical mixtures of drug and polymers to differential scanning calorimetry. Cod liver oil entrapped calcium alginate beads containing famotidine, capable of floating in the gastric condition were formulated and evaluated. The gel beads were prepared by emulsion gelation method by employing sodium alginate alone and mixture of sodium alginate and hydrophilic copolymers such as carbopol 934P and hydroxypropylmethylcellulose K15M grade in three different ratios. The effect of selected factors, such as percentage of oil and amount of copolymers on floating properties was investigated. The beads were evaluated for percent drug loading, drug entrapment efficiency, buoyancy and in vitro drug release. The in vitro drug release study of the beads was carried out in simulated gastric media employing a modified Rosette-Rice test apparatus. Wherein, the apparatus was further modified by incorporating a water jacket to the apparatus to circulate hot water to maintain 37±2° for throughout the release study. All the oil entrapped calcium alginate beads floated if a sufficient amount of oil was used. Beads formulated employing sodium alginate alone could not sustain the drug release up to 8 h, whereas beads formulated with mixture of sodium alginate and copolymers demonstrated sustained release of famotidine up to 8 h. The results suggested that cod liver oil entrapped calcium alginate beads were promising as a carrier for intragastric floating drug delivery of famotidine. PMID:21969746

Satishbabu, B K; Sandeep, V R; Ravi, R B; Shrutinag, R

2010-11-01

71

Design of a multiple drug delivery system directed at periodontitis.  

PubMed

Periodontal disease is highly prevalent, with 90% of the world population affected by either periodontitis or its preceding condition, gingivitis. These conditions are caused by bacterial biofilms on teeth, which stimulate a chronic inflammatory response that leads to loss of alveolar bone and, ultimately, the tooth. Current treatment methods for periodontitis address specific parts of the disease, with no individual treatment serving as a complete therapy. The present research sought to demonstrate development of a multiple drug delivery system for stepwise treatment of different stages of periodontal disease. More specifically, multilayered films were fabricated from an association polymer comprising cellulose acetate phthalate and Pluronic F-127 to achieve sequential release of drugs. The four types of drugs used were metronidazole, ketoprofen, doxycycline, and simvastatin to eliminate infection, inhibit inflammation, prevent tissue destruction, and aid bone regeneration, respectively. Different erosion times and adjustable sequential release profiles were achieved by modifying the number of layers or by inclusion of a slower-eroding polymer layer. Analysis of antibiotic and anti-inflammatory bioactivity showed that drugs released from the devices retained 100% bioactivity. The multilayered CAPP delivery system offers a versatile approach for releasing different drugs based on the pathogenesis of periodontitis and other conditions. PMID:23948165

Sundararaj, Sharath C; Thomas, Mark V; Peyyala, Rebecca; Dziubla, Thomas D; Puleo, David A

2013-11-01

72

Microemulsion drug delivery system: for bioavailability enhancement of ampelopsin.  

PubMed

Ampelopsin, one of the most common flavonoids, reported to possess numerous pharmacological activities and shows poor aqueous solubility. The purpose of this study was to enhance the dissolution rate and bioavailability of this drug by developing a novel delivery system that is microemulsion (ME) and to study the effect of microemulsion (ME) on the oral bioavailability of ampelopsin. Capmul MCM-based ME formulation with Cremophor EL as surfactant and Transcutol as cosurfactant was developed for oral delivery of ampelopsin. Optimised ME was evaluated for its transparency, viscosity, percentage assay and so forth. Solubilisation capacity of the ME system was also determined. The prepared ME was compared with the pure drug solution and commercially available tablet for in vitro drug release. The optimised ME formulation containing ampelopsin, Capmul MCM (5.5%), Cremophor EL (25%), Transcutol P (8.5%), and distilled water showed higher in vitro drug release, as compared to plain drug suspension and the suspension of commercially available tablet. These results demonstrate the potential use of ME for improving the bioavailability of poor water soluble compounds, such as ampelopsin. PMID:22830055

Solanki, Shailendra Singh; Sarkar, Brajesh; Dhanwani, Rakesh Kumar

2012-01-01

73

Design of a Multiple Drug Delivery System Directed at Periodontitis  

PubMed Central

Periodontal disease is highly prevalent, with 90% of the world population affected by either periodontitis or its preceding condition, gingivitis. These conditions are caused by bacterial biofilms on teeth, which stimulate a chronic inflammatory response that leads to loss of alveolar bone and, ultimately, the tooth. Current treatment methods for periodontitis address specific parts of the disease, with no individual treatment serving as a complete therapy. The present research sought to demonstrate development of a multiple drug delivery system for stepwise treatment of different stages of periodontal disease. More specifically, multilayered films were fabricated from an association polymer comprising cellulose acetate phthalate and Pluronic F-127 to achieve sequential release of drugs. The four types of drugs used were metronidazole, ketoprofen, doxycycline, and simvastatin to eliminate infection, inhibit inflammation, prevent tissue destruction, and aid bone regeneration, respectively. Different erosion times and adjustable sequential release profiles were achieved by modifying the number of layers or by inclusion of a slower-eroding polymer layer. Analysis of antibiotic and anti-inflammatory bioactivity showed that drugs released from the devices retained 100% bioactivity. The multilayered CAPP delivery system offers a versatile approach for releasing different drugs based on the pathogenesis of periodontitis and other conditions. PMID:23948165

Sundararaj, Sharath C.; Thomas, Mark V.; Peyyala, Rebecca; Dziubla, Thomas D.; Puleo, David A.

2013-01-01

74

Fundamental study for development magnetic drug delivery system  

NASA Astrophysics Data System (ADS)

Side-effects and lowering effects by diffusion of drugs such as anticancer agents is one of the serious issues in medication. To solve this problem, it is necessary to control the drugs quantitatively, spatially and temporally within the human body. Magnetic drug delivery system (MDDS) is one of the technologies to make it possible, in which the ferromagnetic drug injected into the blood vessel is conducted to diseased part by external magnetic force. As a fundamental experiment, the accumulation experiment using ferromagnetic particles were performed with simulated capillary vessels composed of glass beads channels in this work. Additionally, accumulation calculation of ferromagnetic particles was conducted to check the validity of accumulation experiment. From these result, the 2D distribution of particle accumulation in the experiment corresponded with that of particle accumulation in the calculation. It was suggested that the proper position of magnet should be changed according to the depth of diseased part.

Hirota, Y.; Akiyama, Y.; Izumi, Y.; Nishijima, S.

2009-10-01

75

Generic leak-free drug storage and delivery for microneedle-based systems  

Microsoft Academic Search

We present a generic liquid packaging method for micro-machined drug delivery systems with microneedles. Hollow microneedles are sealed with thin gold membranes at the openings on the needle tip on wafer level. This provides both a seal and an evaporation barrier to the drug delivery system on chip level. In addition, the membranes may also prevent drug delivery through needles

N. Roxhed; P. Griss; G. Stemme

2005-01-01

76

Small-scale systems for in vivo drug delivery  

Microsoft Academic Search

Recent developments in the application of micro- and nanosystems for drug administration include a diverse range of new materials and methods. New approaches include the on-demand activation of molecular interactions, novel diffusion-controlled delivery devices, nanostructured 'smart' surfaces and materials, and prospects for coupling drug delivery to sensors and implants. Micro- and nanotechnologies are enabling the design of novel methods such

David A LaVan; Terry McGuire; Robert Langer

2003-01-01

77

Chemical delivery systems and soft drugs: Retrometabolic approaches of drug design  

PubMed Central

Inclusion of metabolic considerations in the drug design process leads to significant development in the field of chemical drug targeting and the design of safer drugs during past few years which is a part of an approach now designated as Retro metabolic drug design (RMDD). This approach represents systematic methodologies that integrate structure–activity and structure–metabolism relationships and are aimed to design safe, locally active compounds with an improved therapeutic index. It embraces two distinct methods, chemical delivery systems and a soft drug approach. Present review recapitulates an impression of RMDD giving reflections on the chemical delivery system and the soft drug approach and provides a variety of examples to embody its concepts. Successful application of such design principles has already been applied to a number of marketed drugs like esmolol; loteprednol etc., and many other candidates like beta blockers, ACE inhibitors, alkylating agents, antimicrobials etc., are also under investigation. PMID:25161372

Bhardwaj, Yashumati Ratan; Pareek, Ashutosh; Jain, Vivek; Kishore, Dharma

2013-01-01

78

Design and Optimization of Floating Drug Delivery System of Acyclovir  

PubMed Central

The purpose of the present work was to design and optimize floating drug delivery systems of acyclovir using psyllium husk and hydroxypropylmethylcellulose K4M as the polymers and sodium bicarbonate as a gas generating agent. The tablets were prepared by wet granulation method. A 32 full factorial design was used for optimization of drug release profile. The amount of psyllium husk (X1) and hydroxypropylmethylcellulose K4M (X2) were selected as independent variables. The times required for 50% (t50%) and 70% (t70%) drug dissolution were selected as dependent variables. All the designed nine batches of formulations were evaluated for hardness, friability, weight variation, drug content uniformity, swelling index, in vitro buoyancy, and in vitro drug release profile. All formulations had floating lag time below 3 min and constantly floated on dissolution medium for more than 24 h. Validity of the developed polynomial equation was verified by designing two check point formulations (C1 and C2). The closeness of predicted and observed values for t50% and t70% indicates validity of derived equations for the dependent variables. These studies indicated that the proper balance between psyllium husk and hydroxypropylmethylcellulose K4M can produce a drug dissolution profile similar to the predicted dissolution profile. The optimized formulations followed Higuchi's kinetics while the drug release mechanism was found to be anomalous type, controlled by diffusion through the swollen matrix. PMID:21694992

Kharia, A. A.; Hiremath, S. N.; Singhai, A. K.; Omray, L. K.; Jain, S. K.

2010-01-01

79

Design and optimization of floating drug delivery system of acyclovir.  

PubMed

The purpose of the present work was to design and optimize floating drug delivery systems of acyclovir using psyllium husk and hydroxypropylmethylcellulose K4M as the polymers and sodium bicarbonate as a gas generating agent. The tablets were prepared by wet granulation method. A 3(2) full factorial design was used for optimization of drug release profile. The amount of psyllium husk (X1) and hydroxypropylmethylcellulose K4M (X2) were selected as independent variables. The times required for 50% (t(50%)) and 70% (t(70%)) drug dissolution were selected as dependent variables. All the designed nine batches of formulations were evaluated for hardness, friability, weight variation, drug content uniformity, swelling index, in vitro buoyancy, and in vitro drug release profile. All formulations had floating lag time below 3 min and constantly floated on dissolution medium for more than 24 h. Validity of the developed polynomial equation was verified by designing two check point formulations (C1 and C2). The closeness of predicted and observed values for t(50%) and t(70%) indicates validity of derived equations for the dependent variables. These studies indicated that the proper balance between psyllium husk and hydroxypropylmethylcellulose K4M can produce a drug dissolution profile similar to the predicted dissolution profile. The optimized formulations followed Higuchi's kinetics while the drug release mechanism was found to be anomalous type, controlled by diffusion through the swollen matrix. PMID:21694992

Kharia, A A; Hiremath, S N; Singhai, A K; Omray, L K; Jain, S K

2010-09-01

80

Chitosan in nasal delivery systems for therapeutic drugs.  

PubMed

There is an obvious need for efficient and safe nasal absorption enhancers for the development of therapeutically efficacious nasal products for small hydrophilic drugs, peptides, proteins, nucleic acids and polysaccharides, which do not easily cross mucosal membranes, including the nasal. Recent years have seen the development of a range of nasal absorption enhancer systems such as CriticalSorb (based on Solutol HS15) (Critical Pharmaceuticals Ltd), Chisys based on chitosan (Archimedes Pharma Ltd) and Intravail based on alkylsaccharides (Aegis Therapeutics Inc.), that is presently being tested in clinical trials for a range of drugs. So far, none of these absorption enhancers have been used in a marketed nasal product. The present review discusses the evaluation of chitosan and chitosan derivatives as nasal absorption enhancers, for a range of drugs and in a range of formulations such as solutions, gels and nanoparticles and finds that chitosan and its derivatives are able to efficiently improve the nasal bioavailability. The revirtew also questions whether chitosan nanoparticles for systemic drug delivery provide any real improvement over simpler chitosan formulations. Furthermore, the review also evaluates the use of chitosan formulations for the improvement of transport of drugs directly from the nasal cavity to the brain, based on its mucoadhesive characteristics and its ability to open tight junctions in the olfactory and respiratory epithelia. It is found that the use of chitosan nanoparticles greatly increases the transport of drugs from nose to brain over and above the effect of simpler chitosan formulations. PMID:24818769

Casettari, Luca; Illum, Lisbeth

2014-09-28

81

Sponges carrying self-microemulsifying drug delivery systems.  

PubMed

Self-microemulsifying drug delivery systems (SMEDDS) increase the solubility of lipophilic drugs. One barrier to their wide application is their liquid nature. We report on a new method to solidify SMEDDS-their incorporation in sponges made from a hydrophilic natural polymer. Using different freeze-drying schemes, sponges were prepared from alginate gels containing microemulsions. The sponges' structures were studied with scanning electron microscopy and small angle X-ray scattering. The oil droplets survived the drying process, and SMEDDS were present as 9 nm-sized objects in the dried sponges. The sponges were rehydrated in water, and evidence of the presence of SMEDDS in the rehydrated sponges was found. A model hydrophobic molecule, Nile red, was soluble in all dry and rehydrated sponges. SMEDDS containing Nile red were gradually released from the sponges, at a rate that depended on the drying method. The equilibrium water uptake of the sponges was also found to be influenced by the drying scheme. The combination of SMEDDS and sponges may be a way to overcome the disadvantages of each component separately, provide a solid dosage form for SMEDDS that can sustain the release of drugs and also enable utilization of hydrophilic sponges for the delivery of hydrophobic drugs. PMID:24096300

Josef, Elinor; Bianco-Peled, Havazelet

2013-12-15

82

A novel liquefied gas based oral controlled release drug delivery system for liquid drug formulations.  

PubMed

A novel liquefied gas based drug delivery system for the oral delivery of liquid and semi-solid drug formulations is presented. The capsule-shaped system is equipped with a capillary as an element controlling the release rate. The delivery mechanism is based on a constant vapor pressure produced by isopentane as a low-boiling liquefied gas. The liquid drug valproic acid (VA) was used as a model compound. The viscosity was increased by the addition of povidone (PVP). The VA-PVP gel exhibited pseudoplastic rheological properties, the shear rate was above 0.1s(-1), similar to a Newtonian liquid. The gels tested in the gas based delivery system provided near-zero-order release kinetics. The longest delivery time was up to ca. 8h. The system is characterized by high flexibility of the delivery rate, which can be achieved by adjusting system parameters such as the diameter and length of the capillary, the vapor pressure of the propellant and the viscosity of the drug formulation. PMID:22426133

Haznar-Garbacz, Dorota; Garbacz, Grzegorz; Eisenächer, Friederike; Klein, Sandra; Weitschies, Werner

2012-06-01

83

Formulation and evaluation of Ketoconazole niosomal gel drug delivery system  

PubMed Central

Purpose: Niosomes play an increasingly important role in drug delivery as they can reduce toxicity and modify pharmacokinetic and bio-availability. Topically applied niosomes can increase the residence time of drugs in the stratum corneum and epidermis, while reducing the systemic absorption of the drug. It can act as drug containing reservoirs and the modification of the vesicular compositions or surface properties can adjust the drug release rate and the affinity for the target site. Ketoconazole is a broad spectrum Imidazole derivative useful in the treatment of superficial and systemic fungal infections. Materials and Methods: In order to improve the low skin penetration and to minimize the side effects associated with topical conventional drug administration, Ketoconazole niosomes were prepared by a thin film hydration method using different ratios of non-ionic surfactants (Span 40, 60 and Tween 60) along with cholesterol (CHO). The formulations were evaluated for size, shape, entrapment efficiency and in vitro drug release. Results: Niosomes appeared spherical in shape and size range was found to be 4.86 ± 1.24-7.38 ± 3.64 ?m. The entrapment efficiency was found in the range of 55.14 ± 2.29-78.63 ± 0.91% and in vitro drug release in the range of 46.63 ± 0.95-72.37 ± 0.59% in 24 h. Ketoconazole niosomes formulated with Span 60 and CHO in the ratio of 1:0.2 were found to be promising and were incorporated into 1% Carbopol gel. The formulated gel was evaluated for various physicochemical parameters and antifungal activity. The in vitro drug release study was carried out using phosphate buffer saline pH 7.4 and was found to be 36.18 ± 1.50% in 12 h. Conclusion: Gel formulation containing niosomes loaded with Ketoconazole showed prolonged action than formulations containing Ketoconazole in non-niosomal form and it can be developed successfully to improve the antifungal activity. PMID:23580936

Shirsand, SB; Para, MS; Nagendrakumar, D; Kanani, KM; Keerthy, D

2012-01-01

84

Application of In Situ Polymerization for Design and Development of Oral Drug Delivery Systems  

Microsoft Academic Search

Although preformed polymers are commercially available for use in the design and development of drug delivery systems, in situ polymerization has also been employed. In situ polymerization affords the platform to tailor and optimize the drug delivery properties of polymers. This review brings to\\u000a light the benefits of in situ polymerization for oral drug delivery and the possibilities it provides

Ndidi Ngwuluka; Joseph Reo; Linda Felton; Stephen Howard

2010-01-01

85

A thermal microjet system with tapered micronozzles fabricated by inclined UV lithography for transdermal drug delivery  

E-print Network

for transdermal drug delivery This article has been downloaded from IOPscience. Please scroll down to see the full/025014 Abstract Transdermal drug delivery can be enabled by various methods that increase the permeability. This thermal microjet system can serve as a tool not only for transdermal drug delivery, but also for a variety

86

Progress in Psoriasis Therapy via Novel Drug Delivery Systems  

PubMed Central

Psoriasis is a lifelong condition which is caused by the negative signals produced by immune system, which leads to hyper proliferation and other inflammatory reactions on the skin. In this case, keratinocytes which are the outermost layer of skin possess shortened life cycle and results in the alteration of desquamation process where the cytokines will come out through lesions of affected patients and as a result, scaling marks appears on the skin. These conditions may negatively affect the patient’s quality of life and lead to psychosocial stress. Psoriasis can be categorized as mild, moderate and severe conditions. Mild psoriasis leads to the formation of rashes, and when it becomes moderate, the skin turns into scaly. In severe conditions, red patches may be present on skin surface and becomes itchy. Topical therapy continues to be one of the pillars for psoriasis management. Drug molecules with target effect on the skin tissues and other inflammations should be selected for the treatment of psoriasis. Most of the existing drugs lead to systemic intoxication and dryness when applied in higher dose. Different scientific approaches for topical delivery are being explored by researches including emollient, modified gelling system, transdermal delivery, spray, nanogels, hydrogels, micro/nano emulsion, liposomes, nano capsules etc. These topical dosage forms are evaluated for various physico chemical properties such as drug content, viscosity, pH, extrudability, spreadability, toxicity, irritancy, permeability and drug release mechanism. This review paper focus attention to the impact of these formulation approaches on various anti-psoriasis drugs for their successful treatment. PMID:25386329

Vincent, Nitha; Ramya, Devi D; Vedha, Hari BN

2014-01-01

87

Cubic and Hexagonal Liquid Crystals as Drug Delivery Systems  

PubMed Central

Lipids have been widely used as main constituents in various drug delivery systems, such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-based lyotropic liquid crystals. Among them, lipid-based lyotropic liquid crystals have highly ordered, thermodynamically stable internal nanostructure, thereby offering the potential as a sustained drug release matrix. The intricate nanostructures of the cubic phase and hexagonal phase have been shown to provide diffusion controlled release of active pharmaceutical ingredients with a wide range of molecular weights and polarities. In addition, the biodegradable and biocompatible nature of lipids demonstrates the minimum toxicity and thus they are used for various routes of administration. Therefore, the research on lipid-based lyotropic liquid crystalline phases has attracted a lot of attention in recent years. This review will provide an overview of the lipids used to prepare cubic phase and hexagonal phase at physiological temperature, as well as the influencing factors on the phase transition of liquid crystals. In particular, the most current research progresses on cubic and hexagonal phases as drug delivery systems will be discussed. PMID:24995330

Chen, Yulin; Ma, Ping; Gui, Shuangying

2014-01-01

88

Advances in the Applications of Polyhydroxyalkanoate Nanoparticles for Novel Drug Delivery System  

PubMed Central

Drug delivery technology is emerging as an interdisciplinary science aimed at improving human health. The controlled delivery of pharmacologically active agents to the specific site of action at the therapeutically optimal rate and dose regimen has been a major goal in designing drug delivery systems. Over the past few decades, there has been considerable interest in developing biodegradable drug carriers as effective drug delivery systems. Polymeric materials from natural sources play an important role in controlled release of drug at a particular site. Polyhydroxyalkanoates, due to their origin from natural sources, are given attention as candidates for drug delivery materials. Biodegradable and biocompatible polyhydroxyalkanoates are linear polyesters produced by microorganisms under unbalanced growth conditions, which have emerged as potential polymers for use as biomedical materials for drug delivery due to their unique physiochemical and mechanical properties. This review summarizes many of the key findings in the applications of polyhydroxyalkanoates and polyhydroxyalkanoate nanoparticles for drug delivery system. PMID:23984383

Shrivastav, Anupama; Kim, Hae-Yeong; Kim, Young-Rok

2013-01-01

89

Exploring the use of novel drug delivery systems for antiretroviral drugs.  

PubMed

Novel drug delivery systems present an opportunity for formulation scientists to overcome the many challenges associated with antiretroviral (ARV) drug therapy, thereby improving the management of patients with HIV/AIDS. This paper provides a comprehensive review of the various ARV delivery systems that have been developed for achieving sustained drug release kinetics, specifically targeting drugs to the macrophages, brain and gastric mucosa, and for addressing formulation difficulties such as poor solubility, stability and drug entrapment. Studies on the potential of systems for alternative routes of ARV drug administration, i.e., transdermal, buccal and rectal, are also highlighted. The physico-chemical properties and the in vitro/in vivo performances of various systems such as sustained release tablets, ceramic implants, nanoparticles, nanocontainers, liposomes, emulsomes, aspasomes, microemulsions, nanopowders and Pheroid(TM) are summarised. Further studies that remain to be undertaken for formulation optimisation are also identified. This review highlights the significant potential that novel drug delivery systems have for the future effective treatment of HIV/AIDS patients on ARV drug therapy. PMID:18655830

Ojewole, Elizabeth; Mackraj, Irene; Naidoo, Panjasaram; Govender, Thirumala

2008-11-01

90

Ionic liquids as ingredients in topical drug delivery systems.  

PubMed

Because of their properties, ionic liquids (ILs) (Ranke et al.) offer many advantages in topical drug delivery systems. For example, ionic liquids can be used to increase the solubility of sparingly soluble drugs and to enhance their topical and transdermal delivery. Furthermore, ILs can be used either to synthesize active pharmaceutical ingredients or as antimicrobial ingredients. In the present work, the conventional oil-in-water (O/W) and water-in-oil (W/O) emulsions containing the hydrophilic IL [HMIM] [Cl] and the hydrophobic IL [BMIM] [PF6] were prepared, and the influence of the ILs on emulsion properties was evaluated. It was found that ILs could be successfully incorporated into the emulsion structure, resulting in stable formulations. The antimicrobial activity of ILs in the formulations was estimated, and their application as preservatives was confirmed by performing preservative efficacy tests. Evaluation of the in vitro cytotoxicity of the emulsions containing hydrophilic or hydrophobic ILs showed the low cytotoxicity of the carriers. Finally, penetration enhancement of a fluorescent dye as a model drug in the presence of ionic liquids was shown. PMID:23123180

Dobler, Dorota; Schmidts, Thomas; Klingenhöfer, Ines; Runkel, Frank

2013-01-30

91

Synthesis and characterization of modified starch/polybutadiene as novel transdermal drug delivery system.  

PubMed

Transdermal drug delivery systems are topically administered medicaments in the form of patches that deliver drugs for systemic effects at a predetermined and controlled rate. It works very simply in which drug is applied inside the patch and it is worn on skin for long period of time. Polymer matrix, drug, permeation enhancers are the main components of transdermal drug delivery systems. The objective of the present study was to develop the modified starch and 1,4-cis polybutadiene nanoparticles as novel polymer matrix system. We have been studied the properties of a novel transdermal drug delivery system with clonidine as drug model. PMID:24887550

Saboktakin, Mohammad Reza; Akhyari, Shahab; Nasirov, Fizuli A

2014-08-01

92

Recent patents survey on self emulsifying drug delivery system.  

PubMed

Self-Emulsifying Drug Delivery System is a unique feasible approach to overcome low oral bioavailability problem which is associated with the hydrophobic drugs due to their unparalleled potential as a drug delivery with the broad range of application. The estimated 40% of active pharmaceuticals are poorly water soluble. Now recently, formulation containing oral SEDDS has received much interest as it solve problems related to oral bioavailability, intra and inter-subject variability and lack of dose proportionality of hydrophobic drugs. Now a days, it is the first way to investigate the development of any kind of innovative dosage forms. Many important in-vitro characteristics such as surfactant concentration, oil/surfactant ratio, emulsion polarity, droplet size and zeta potential play an important role in oral absorption of drug from SEEDS. It can be orally administered in the form of SGC or HGC and also enhances bioavailability of drugs to increase solubility and minimizes the gastric irritation. After administration the drug remains entrapped in the oily droplets (inside the droplet or in the surfactant`s film at the interface) of the emulsion that are formed in the GIT upon self-emulsification process. It is also a bit problematic to say that the drug is being released from SMEDDS, it would be more precise to say that it diffuses out of oily droplets into the GIT media resulting in the formation of an equilibrium between the drug dissolved in oily droplets and the outer dispersed media (e.g. GIT fluids). Many of the application and preparation methods of SEDDS are reported by research articles and patents in different countries. We present an exhaustive and updated account of numerous literature reports and more than 150 patents published on SEDDS in the recent period. This current patent review is useful in knowledge of SEDDS for its preparations and patents in different countries with emphasis on their formulation, characterization and systematic optimization strategies, thus paving the way for accelerated progress into the SEDDS application in pharmaceutical research as well as patents on SEDDS methods. PMID:25146965

Jethara, Sahilhusen I; Patel, Alpesh D; Patel, Mukesh R

2014-01-01

93

NMR characterisation and transdermal drug delivery potential of microemulsion systems  

Microsoft Academic Search

The purpose of this study was to investigate the influence of structure and composition of microemulsions (Labrasol\\/Plurol Isostearique\\/isostearylic isostearate\\/water) on their transdermal delivery potential of a lipophilic (lidocaine) and a hydrophilic model drug (prilocaine hydrochloride), and to compare the drug delivery potential of microemulsions to conventional vehicles. Self-diffusion coefficients determined by pulsed-gradient spin-echo NMR spectroscopy and T1 relaxation times were

Mads Kreilgaard; Erik J Pedersen; Jerzy W Jaroszewski

2000-01-01

94

Processing of Polymer Nanofibers Through Electrospinning as Drug Delivery Systems  

NASA Astrophysics Data System (ADS)

The use of electrospun fibers as drug carriers could be promising in the future for biomedical applications, especially postoperative local chemotherapy. In this research, electrospun fibers were developed as a new system for the delivery of ketoprofen as non-steroidal anti-inflammatory drug (NSAID). The fibers were made either from polycaprolactone (PCL) as a biodegradable polymer or polyurethane (PU) as a non-biodegradable polymer, or from the blends of the two. The release of the ketoprofen was followed by UV—VIS spectroscopy in phosphate buffer of pH 7.4 at 37°C and 20°C. The results showed that the release rates from the polycaprolactone, polyurethane and their blend were similar. However, the blend of the polycaprolactone with polyurethane improved its visual mechanical properties. Release profiles from the electrospun mats were compared to cast films of the various formulations.

Kenawy, E.; Abdel-Hay, F. I.; El-Newehy, M. H.; Wnek, G. E.

95

Gastroretentive drug delivery systems for therapeutic management of peptic ulcer.  

PubMed

A peptic ulcer, stomach ulcer, or gastric ulcer, also known as peptic ulcer disease (PUD), is a very common chronic disorder of the stomach which is mainly caused by damage or impairment of the stomach lining. Various factors such as pepsin, gastric acid, H. pylori, NSAIDs, prostaglandins, mucus, bicarbonate, and blood flow to mucosa play an important role in causing peptic ulcers. In this review article, our main focus is on some important gastroretentive drug delivery systems (GRDDS) (floating, bioadhesive, high density, swellable, raft forming, superporous hydrogel, and magnetic systems) which will be helpful in gastroretention of different dosage forms for treatment of peptic ulcer. GRDDS provides a mean for controlled release of compounds that are absorbed by active transport in the upper intestine. It also enables controlled delivery for paracellularly absorbed drugs without a decrease in bioavailability. The above approaches are specific for targeting and leading to a marked improvement in the quality of life for a large number of patients. In the future, it is expected that they will become of growing significance, finally leading to improved efficiencies of various types of pharmacotherapies. PMID:25271775

Garg, Tarun; Kumar, Animesh; Rath, Goutam; Goyal, Amit Kumar

2014-01-01

96

Bionanocomposites based on layered double hydroxides as drug delivery systems  

NASA Astrophysics Data System (ADS)

The present work introduces new biohybrid materials involving layered double hydroxides (LDH) and biopolymers to produce bionanocomposites, able to act as effective drug delivery systems (DDS). Ibuprofen (IBU) and 5-aminosalicylic acid (5-ASA) have been chosen as model drugs, being intercalated in a Mg-Al LDH matrix. On the one side, the LDHIBU intercalation compound prepared by ion-exchange reaction was blended with the biopolymers zein, a highly hydrophobic protein, and alginate, a polysaccharide widely applied for encapsulating drugs. On the other side, the LDH- 5-ASA intercalation compound prepared by co-precipitation was assembled to the polysaccharides chitosan and pectin, which show mucoadhesive properties and resistance to acid pH values, respectively. Characterization of the intercalation compounds and the resulting bionanocomposites was carried out by means of different experimental techniques: X-ray diffraction, infrared spectroscopy, chemical and thermal analysis, as well as optical and scanning electron microscopies. Data on the swelling behavior and drug release under different pH conditions are also reported.

Aranda, Pilar; Alcântara, Ana C. S.; Ribeiro, Ligia N. M.; Darder, Margarita; Ruiz-Hitzky, Eduardo

2012-10-01

97

Development of self-microemulsifying drug delivery system and solid-self-microemulsifying drug delivery system of telmisartan  

PubMed Central

Objective: Self-microemulsifying drug delivery system (SMEDDS) and solid-SMEDDS of telmisartan was aimed at overcoming the problems of poor solubility and bioavailability. Methodology: The formulation strategy included selection of oil phase based on saturated solubility studies and surfactant and co-surfactant screening on the basis of their emulsification ability. Ternary phase diagrams were constructed to identify the self-emulsifying region using a dilution method. The prepared formulations of SMEDDS were evaluated for their drug content, loading efficiency, morphology, globule size determination. Solid-SMEDDS were prepared by adsorption technique using microcrystalline cellulose (1% w/w) and were evaluated for micromeritic properties, scanning electron microscopy, differential scanning calorimetry, X-ray diffraction. Results: The formulation containing telmisartan (20 mg), castor oil (30% w/w), tween 20 (55% w/w), propylene glycol (15% w/w) was concluded to be optimized. The optimized SMEDDS and solid-SMEDDS exhibited 100% in vitro drug release up to 120 min, which was significantly higher (P < 0.05, t-test) than that of the pure drug. Solid-SMEDDS may be considered as a better solid dosage form as solidified formulations are more ideal than liquid ones in terms of its stability. Conclusion: These results suggest the potential use of SMEDDS and solid-SMEDDS to improve the dissolution and hence oral bioavailability of poorly water-soluble drugs like telmisartan through oral route.

Jaiswal, Parul; Aggarwal, Geeta; Harikumar, Sasidharan Leelakumari; Singh, Kashmir

2014-01-01

98

Preparation and characterization of floating drug delivery system of azithromycin.  

PubMed

The objective of present study was to develop a stomach drug delivery system of azithromycin (AZH) as a model drug for eradication of Helicobacter pyloni (H. pylori). Floating microspheres of AZH were prepared by the solvent evaporation method. The prepared microspheres were subjected to evaluation for particle size, incorporation efficiency, in vitro buoyancy and in vitro drug release characteristics. The formulations were prepared at a variable stirring rate (300 to 500 rpm) and temperature (30-50 degrees C). Surface morphology characteristics were studied using scanning electron microscopy (SEM). The mean particle size of the microspheres significantly increased with increasing polymer concentration and was in the range 252.26 +/- 6.50 to 380.91 +/- 4.59 microm. Angle of repose was between 26.42 to 35.83 degrees. Tapped density ranged between 0.493 to 0.612 g/cm3. The compressibility index of all formulations was found to be in the range of 12.41 to 17.16%, which was < 20 indicating good flow characteristics. The encapsulation efficiency of the prepared microspheres was in the range of 27.8 +/- 4.30 to 66.23 +/- 2.08%. The physical state of the drug, before and after formulation was determined by differential scanning calorimetry (DSC). Percentage buoyancy of the microspheres was in the range 45.52 +/- 0.69 to 68.71 +/- 0.61% for 8 h. In vitro drug release studies were performed in simulated gastrointestinal fluid (SGF), pH 2.0 as dissolution medium (900 mL) for 8 h. Effects of stirring rate during preparation, polymer concentration and temperature on the size of microspheres and drug release were also observed. The results of the present studies indicated that the floating microspheres of AZH were formulated to provide site specific delivery of drug with a view to provide an effective and safe therapy for eradication of H. pylori with a reduced dose and reduced duration of therapy. PMID:22594266

Wasnik, Shailendra; Parmar, Poonam; Singh, Deepika; Ram, Alpana

2012-01-01

99

Chemoradiotherapy of ME180 Tumors with an Intratumoral Cisplatin\\/Calcium Phosphate Drug Delivery System  

Microsoft Academic Search

Drug delivery systems are able to concentrate cancer drugs in a localized region, thereby increasing drug effectiveness. Side effects are decreased due to reduced systemic drug exposure. This in vivo study investigates the use of a calcium phosphate (CaP) crystal drug delivery system to deliver cisplatin (CDDP) into murine ME-180 tumors. Forty-two athymic Ner-nu\\/nu mice were put into six groups:

Felix Santiago; Stacha Campbell; Robert Dowsett; Liisa Kuhn

2006-01-01

100

Nanoparticle: Monoclonal Antibody Conjugates: A Novel Drug Delivery System in Human Breast Cancer.  

National Technical Information Service (NTIS)

The goal of this research project was to develop a novel targeted drug delivery system which would allow delivery of drugs directly to cancerous breast tissue without delivering significant amounts of drug to other parts of the body. The systems described...

G. W. Sledge

2002-01-01

101

Precise control of the drug kinetics by means of non-invasive magnetic drug delivery system  

NASA Astrophysics Data System (ADS)

In order to solve the problems of the side effects and medical lowering, has been advanced a study on the drug delivery system (DDS) to accumulate the drugs locally in the body with minimum dosage. The DDS is a system that controls the drug kinetics in the body precisely and accumulates the drug locally at the target part, keeping the drugs at high density. Among the DDS, the magnetic drug delivery system (MDDS) is the one that we studied. This is a technique to accumulate drugs by using the magnetic force as the physical driving force. Our previous researches showed the possibility of the technique of MDDS to accumulate the drugs with higher accumulation rate and locality than the traditional methods. It is necessary to apply a strong external magnetic field and a high magnetic gradient to accumulate the ferromagnetic drugs at a deep diseased part non-invasively. However, by applying a static magnetic field from one direction, the drug accumulates only at the surface of the body locates near the magnet. In this study, we tried to change the magnetic field applied by a superconducting bulk magnet with time, in order to make a constant and strong magnetic field applied in the center of the body and to accumulate the ferromagnetic drugs at the deep target part in the body. First of all, the effect of the surface treatment of the ferromagnetic drugs to prevent its absorption in the normal tissue was examined. Then, to increase the accumulation rate of the ferromagnetic drugs at the target part, the distribution of magnetic field was changed, and the optimum spatial and temporal conditions of magnetic field were examined.

Chuzawa, M.; Mishima, F.; Akiyama, Y.; Nishijima, S.

2013-01-01

102

Advanced drug delivery systems of curcumin for cancer chemoprevention.  

PubMed

Since ancient times, chemopreventive agents have been used to treat/prevent several diseases including cancer. They are found to elicit a spectrum of potent responses including anti-inflammatory, antioxidant, antiproliferative, anticarcinogenic, and antiangiogenic activity in various cell cultures and some animal studies. Research over the past 4 decades has shown that chemopreventives affect a number of proteins involved in various molecular pathways that regulate inflammatory and carcinogenic responses in a cell. Various enzymes, transcription factors, receptors, and adhesion proteins are also affected by chemopreventives. Although, these natural compounds have shown significant efficacy in cell culture studies, they elicited limited efficacy in various clinical studies. Their introduction into the clinical setting is hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration. Therefore, to circumvent these limitations and to ease their transition to clinics, alternate strategies should be explored. Drug delivery systems such as nanoparticles, liposomes, microemulsions, and polymeric implantable devices are emerging as one of the viable alternatives that have been shown to deliver therapeutic concentrations of various potent chemopreventives such as curcumin, ellagic acid, green tea polyphenols, and resveratrol into the systemic circulation. In this review article, we have attempted to provide a comprehensive outlook for these delivery approaches, using curcumin as a model agent, and discussed future strategies to enable the introduction of these highly potent chemopreventives into a physician's armamentarium. PMID:21546540

Bansal, Shyam S; Goel, Mehak; Aqil, Farrukh; Vadhanam, Manicka V; Gupta, Ramesh C

2011-08-01

103

In situ drug delivery.  

PubMed Central

Drug delivery to tumours and the accessibility of tumour cells to drugs remains a problem of foremost importance and is affected by many factors. We will discuss models we have developed for drug delivery from tumour capillaries to tumour cells, and drug delivery from well perfused, well oxygenated tumour regions to less well perfused hypoxic regions in terms of computer simulation of drug delivery for the anticancer agent BCNU and the hypoxic cell radiosensitizer misonidazole. PMID:6932949

Levin, V. A.; Wright, D. C.; Landahl, H. D.; Patlak, C. S.; Csejtey, J.

1980-01-01

104

Microneedle-based drug delivery systems for transdermal route.  

PubMed

Transdermal delivery offers an attractive, noninvasive administration route but it is limited by the skin's barrier to penetration. Minimally invasive techniques, such as the use of microneedles (MNs), bypass the stratum corneum (SC) barrier to permit the drug's direct access to the viable epidermis. These novel micro devices have been developed to puncture the skin for the transdermal delivery of hydrophilic drugs and macromolecules, including peptides, DNA and other molecules, that would otherwise have difficulty passing the outermost layer of the skin, the SC. Using the tools of the microelectronics industry, MNs have been fabricated with a range of sizes, shapes and materials. MNs have been shown to be robust enough to penetrate the skin and dramatically increase the skin permeability of several drugs. Moreover, MNs have reduced needle insertion pain and tissue trauma and provided controlled delivery across the skin. This review focuses on the current state of the art in the transdermal delivery of drugs using various types of MNs and developments in the field of microscale devices, as well as examples of their uses and clinical safety. PMID:24144208

Pierre, Maria Bernadete Riemma; Rossetti, Fabia Cristina

2014-03-01

105

Sugar Micro Needles as Transdermic Drug Delivery System  

Microsoft Academic Search

We designed and fabricated an array of sugar micro needles of the length ranging from 150 ? m to 2 mm for transdermic delivery of drugs. Micro needles were molded out of maltose mixed with pharmaceutical material, being expected bio-degradable in the human skin. To test basic tolerance to the healthy human skin, a clinical experiment was carried out for

Takaya Miyano; Yoshikazu Tobinaga; Takahiro Kanno; Yasushi Matsuzaki; Hitoshi Takeda; Makoto Wakui; Katsumi Hanada

2005-01-01

106

Synthesis and Characterization of a Magnetically Responsive Polymeric Drug Delivery System  

E-print Network

A magnetic target drug delivery system consisting of biodegradable polymeric microspheres (poly D, L-lactic acid) loaded with magnetite nanoparticles (10-100 nm) and anticancer drug (paclitaxel) was studied. The magnetite ...

Yu, Shi

107

A novel liquid effervescent floating delivery system for sustained drug delivery.  

PubMed

An effervescent floating liquid formulation with in situ gelling properties has been assessed for its potential for sustaining drug delivery and targeting. The formulation consisted of sodium alginate and glyceryl monooleate (GMO). The developed formulation met all pre-requisites to become an in situ gelling floating system and it gelled and floated instantaneously in the pH conditions of the stomach. Moreover, the gels formed in situ remained intact for more than 48 h to facilitate sustained release of drugs. Increasing the mannuronic acid ratio of sodium alginate and the GMO concentration significantly retarded the release rate and extent. The in vitro release of both hydrophilic and hydrophobic drugs from the prepared formulations followed root-time kinetics during the sustained release period. Replacing the free drug with drug encapsulated microspheres enabled tailoring of the release profile and achieved zero-order release kinetics. The system retained its appearance and rheological properties for 12 months at ambient conditions. The values of the similarity factor Sd proved the absence of any significant difference in the release profile upon storage. PMID:22495603

Ibrahim, H K

2009-08-01

108

Gold nanoparticle platforms as drug and biomacromolecule delivery systems  

PubMed Central

Gold nanoparticles (AuNPs) are a suitable platform for development of efficient delivery systems. AuNPs can be easily synthesized, functionalized, and are biocompatible. The tunability of the AuNP monolayer allows for complete control of surface properties for targeting and stability/release using these nanocarriers. This review will discuss several delivery strategies utilizing AuNPs. PMID:20547192

Duncan, Bradley; Kim, Chaekyu; Rotello, Vincent M.

2010-01-01

109

Development and in vitro evaluation of chitosan-based transdermal drug delivery systems for the controlled delivery of propranolol hydrochloride  

Microsoft Academic Search

Membrane permeation-controlled transdermal drug delivery systems were prepared using the natural polymer, chitosan. An adhesive sealing technique was used to construct the devices. Propranolol hydrochloride was selected as the model drug for the present study. Chitosan membranes with different permeability to propranolol hydrochloride obtained by controlled cross-linking with glutaraldehyde were used to regulate the drug release in the devices. Chitosan

D. Thacharodi; K. Panduranga Rao

1995-01-01

110

Floating drug delivery systems for prolonging gastric residence time: a review.  

PubMed

Oral delivery of the drug is the most preferable route of drug delivery due to the ease of administration, patient compliance and flexibility in the formulations. Recent technological advancements have been made in controlled oral drug delivery systems by overcoming physiological difficulties, such as short gastric residence time and highly variable gastric emptying time. Gastroretentive dosage forms have been designed over the past three decades to overcome these difficulties. Several technical approaches are currently utilized in the prolongation of gastric residence time, including highdensity, swelling and expanding, polymeric mucoadhesive, ion-exchange, raft forming, magnetic and floating drug delivery systems (FDDS), as well as other delayed gastric emptying devices. In this review, the current technological developments of FDDS including patented delivery systems and marketed products, and their advantages and future potential for oral controlled drug delivery are discussed. PMID:21696354

Sathish, D; Himabindu, S; Kumar, Y Shravan; Shayeda; Rao, Y Madhusudan

2011-09-01

111

Thermosensitive liposomal drug delivery systems: state of the art review  

PubMed Central

Thermosensitive liposomes are a promising tool for external targeting of drugs to solid tumors when used in combination with local hyperthermia or high intensity focused ultrasound. In vivo results have demonstrated strong evidence that external targeting is superior over passive targeting achieved by highly stable long-circulating drug formulations like PEGylated liposomal doxorubicin. Up to March 2014, the Web of Science listed 371 original papers in this field, with 45 in 2013 alone. Several formulations have been developed since 1978, with lysolipid-containing, low temperature-sensitive liposomes currently under clinical investigation. This review summarizes the historical development and effects of particular phospholipids and surfactants on the biophysical properties and in vivo efficacy of thermosensitive liposome formulations. Further, treatment strategies for solid tumors are discussed. Here we focus on temperature-triggered intravascular and interstitial drug release. Drug delivery guided by magnetic resonance imaging further adds the possibility of performing online monitoring of a heating focus to calculate locally released drug concentrations and to externally control drug release by steering the heating volume and power. The combination of external targeting with thermosensitive liposomes and magnetic resonance-guided drug delivery will be the unique characteristic of this nanotechnology approach in medicine.

Kneidl, Barbara; Peller, Michael; Winter, Gerhard; Lindner, Lars H; Hossann, Martin

2014-01-01

112

Influence of Drug Lipophilicity on Drug Release from Sclera After Iontophoretic Delivery of Mixed Micellar Carrier System to Human Sclera  

PubMed Central

Mixed micelles prepared using sodium taurocholate (TA) and egg lecithin (LE) were previously found to be an effective carrier for sustained release of a poorly water-soluble drug in transscleral iontophoretic delivery. The objectives of the present study were to investigate the effects of drug lipophilicity upon micellar carrier solubilization potential and drug release profiles from the sclera after iontophoretic delivery of model lipophilic drugs dexamethasone (DEX), triamcinolone acetonide (TRIAM), and ?-estradiol (E2?) with a mixed micellar carrier system of TA–LE (1:1 mole ratio). In this study, the micellar carrier system was characterized for drug solubilization. The micelles encapsulating these drugs were evaluated for transscleral passive and 2-mA iontophoretic delivery (both cathodal and anodal) and drug release from excised human sclera in vitro. The results show that drug solubility enhancement of the micellar carrier system increased with increasing drug lipophilicity. The more lipophilic drugs E2? and TRIAM displayed slower drug release from the sclera compared with the less lipophilic drug DEX after iontophoretic drug delivery with the mixed micelles. These results suggest that the combination of transscleral iontophoresis and micellar carriers is more effective in sustaining transscleral delivery of the more lipophilic drugs studied in this investigation. PMID:23150488

Chopra, Poonam; Hao, Jinsong; Li, S. Kevin

2013-01-01

113

Influence of drug lipophilicity on drug release from sclera after iontophoretic delivery of mixed micellar carrier system to human sclera.  

PubMed

Mixed micelles prepared using sodium taurocholate (TA) and egg lecithin (LE) were previously found to be an effective carrier for sustained release of a poorly water-soluble drug in transscleral iontophoretic delivery. The objectives of the present study were to investigate the effects of drug lipophilicity upon micellar carrier solubilization potential and drug release profiles from the sclera after iontophoretic delivery of model lipophilic drugs dexamethasone (DEX), triamcinolone acetonide (TRIAM), and ?-estradiol (E2?) with a mixed micellar carrier system of TA-LE (1:1 mole ratio). In this study, the micellar carrier system was characterized for drug solubilization. The micelles encapsulating these drugs were evaluated for transscleral passive and 2-mA iontophoretic delivery (both cathodal and anodal) and drug release from excised human sclera in vitro. The results show that drug solubility enhancement of the micellar carrier system increased with increasing drug lipophilicity. The more lipophilic drugs E2? and TRIAM displayed slower drug release from the sclera compared with the less lipophilic drug DEX after iontophoretic drug delivery with the mixed micelles. These results suggest that the combination of transscleral iontophoresis and micellar carriers is more effective in sustaining transscleral delivery of the more lipophilic drugs studied in this investigation. PMID:23150488

Chopra, Poonam; Hao, Jinsong; Li, S Kevin

2013-02-01

114

Design and development of a self-nanoemulsifying drug delivery system for telmisartan for oral drug delivery  

PubMed Central

Background and Aim: Telmisartan (TEL) is an angiotensin II receptor blocker (ARB) antihypertensive agent. The aim of the present investigation was to develop a self-nanoemulsifying drug delivery system (SNEDDS) to enhance the oral bioavailability of poorly water soluble TEL. Materials and Methods: The solubility of TEL in various oils was determined to identify the oil phase of a SNEDDS. Various surfactants and co-surfactants were screened for their ability to emulsify the selected oil. Pseudoternary phase diagrams were constructed to identify the efficient self-emulsifying region. A SNEDDS was further evaluated for its percentage transmittance, emulsification time, drug content, phase separation, dilution, droplet size, zeta potential, pH, refractive index, and viscosity. Results: The developed SNEDDS formulation contained TEL (20 mg), Tween® 20 (43.33%w/w), Carbitol® (21.67%w/w), and Acrysol® EL 135 (32%w/w). The optimized formulation of the TEL-loaded SNEDDS exhibited a complete in vitro drug release in 15 min as compared with the plain drug, which had a limited dissolution rate. It was also compared with the pure drug suspension by oral administration in male Wister rats. The in vivo study exhibited a 7.5-fold increase in the oral bioavailability of TEL from the SNEDDS compared with the pure drug suspension. Conclusions: These results suggest the potential use of the SNEDDS to improve the dissolution and oral bioavailability of poorly water soluble TEL. PMID:23071930

Patel, Jaydeep; Kevin, Garala; Patel, Anjali; Raval, Mihir; Sheth, Navin

2011-01-01

115

Targeted delivery of doxorubicin: drug delivery system based on PAMAM dendrimers.  

PubMed

Polyamidoamine (PAMAM) dendrimers of the second generation (G2) are branched polymers containing 16 surface amino groups that allow them to be used as universal carriers on creating systems for drug delivery. G2 labeled with fluorescein isothiocyanate (FITC) efficiently bound with the surface of tumor cells at 4°C and was absorbed by the cells at 37°C. The covalent binding to G2-FITC of a vector protein, a recombinant fragment of the human alpha-fetoprotein receptor-binding domain (rAFP3D), increased the binding and endocytosis efficiency more than threefold. Covalent conjugates of G2 with doxorubicin (Dox) obtained by acid-labile linking of cis-aconitic anhydride (CAA) without the vector protein (G2-Dox) and with the vector protein rAFP3D (rAFP3D-G2-Dox) were accumulated by the tumor cells with high efficiency. However, a selective effect was observed only in rAFP3D-G2-Dox, which also demonstrated high cytotoxic activity against the human ovarian adenocarcinoma SKOV3 cells and low cytotoxicity against human peripheral blood lymphocytes. Based on these results, rAFP3D-G2 conjugate is promising for selective delivery of antitumor drugs. PMID:24228876

Yabbarov, N G; Posypanova, G A; Vorontsov, E A; Popova, O N; Severin, E S

2013-08-01

116

Raft forming system-an upcoming approach of gastroretentive drug delivery system.  

PubMed

In recent era various technologies have been made in research and development of controlled release oral drug delivery system to overcome various physiological difficulties such as variation in gastric retention and emptying time. To overcome this drawback and to maximize the oral absorption of various drugs, novel drug delivery systems have been developed. Gastroretentive drug delivery system is facing many challenges which can be overcome by upcoming newly emerging approach i.e. raft forming system. The purpose of writing this review is to focus on recent development of stomach specific floating drug delivery system to circumvent the difficulties associated with formulation design. Various gastroretentive approaches that have been developed till now are also discussed. The present study provides valuable information & highlights advances in this raft forming system. This review attempts to discuss various factors like physiological factors, physicochemical factors and formulation factors to be considered in the development of the raft forming system. Different types of smart polymers used for their formulation have also been summarized. The review focuses on the mechanism, formulation and development of the raft forming system. This review also summarizes the studies to evaluate the performance and application of these systems. The study finally highlights advantages, disadvantages, and marketed preparation of the raft forming system. PMID:23500062

Prajapati, Vipul D; Jani, Girish K; Khutliwala, Tohra A; Zala, Bhumi S

2013-06-10

117

JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 1, FEBRUARY 2004 75 A Water-Powered Micro Drug Delivery System  

E-print Network

the late 1960s aiming to improve drug performance [7]. However, the most common drug delivery methods today presented in this paper) can result in enhanced drug efficiency and minimized side effects. Further- more Drug Delivery System Yu-Chuan Su and Liwei Lin, Member, IEEE, Member, ASME Abstract--A plastic micro

Lin, Liwei

118

An overview of clinical and commercial impact of drug delivery systems.  

PubMed

Drug delivery systems are widely researched and developed to improve the delivery of pharmaceutical compounds and molecules. The last few decades have seen a marked growth of the field fueled by increased number of researchers, research funding, venture capital and the number of start-ups. Collectively, the growth has led to novel systems that make use of micro/nano-particles, transdermal patches, inhalers, drug reservoir implants and antibody-drug conjugates. While the increased research activity is clearly an indication of proliferation of the field, clinical and commercial translation of early-stage research ideas is critically important for future growth and interest in the field. Here, we will highlight some of the examples of novel drug delivery systems that have undergone such translation. Specifically, we will discuss the developments, advantages, limitations and lessons learned from: (i) microparticle-based depot formulations, (ii) nanoparticle-based cancer drugs, (iii) transdermal systems, (iv) oral drug delivery systems, (v) pulmonary drug delivery, (vi) implants and (vii) antibody-drug conjugates. These systems have impacted treatment of many prevalent diseases including diabetes, cancer and cardiovascular diseases, among others. At the same time, these systems are integral and enabling components of products that collectively generate annual revenues exceeding US $100 billion. These examples provide strong evidence of the clinical and commercial impact of drug delivery systems. PMID:24747160

Anselmo, Aaron C; Mitragotri, Samir

2014-09-28

119

Colon Targeted Drug Delivery Systems: A Review on Primary and Novel Approaches  

PubMed Central

The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. This review, mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process. PMID:22125706

Philip, Anil K.; Philip, Betty

2010-01-01

120

The Benefits and Challenges Associated with the Use of Drug Delivery Systems in Cancer Therapy  

PubMed Central

The use of Drug Delivery Systems as nanocarriers for chemotherapeutic agents can improve the pharmacological properties of drugs by altering drug pharmacokinetics and biodistribution. Among the many drug delivery systems available, both micelles and liposomes have gained the most attention in recent years due to their clinical success. There are several formulations of these nanocarrier systems in various stages of clinical trials, as well as currently clinically approved liposomal-based drugs. In this review, we discuss these drug carrier systems, as well as current efforts that are being made in order to further improve their delivery efficacy through the incorporation of targeting ligands. In addition, this review discusses aspects of drug resistance attributed to the remodeling of the extracellular matrix that occurs during tumor development and progression, as well as to the acidic, hypoxic, and glucose deprived tumor microenvironment. Finally, we address future prospective approaches to overcoming drug resistance by further modifications made to these drug delivery systems, as well as the possibility of coencapsulation/coadministration of various drugs aimed to surmount some of these microenvironmental-influenced obstacles for efficacious drug delivery in chemotherapy. PMID:20417189

Cukierman, Edna; Khan, David R.

2010-01-01

121

Formulation and evaluation of multiple tablets as a biphasic gastroretentive floating drug delivery system for fenoverine.  

PubMed

A biphasic gastroretentive drug delivery system of fenoverine was developed to maintain constant plasma concentration. The delivery system consisted of a loading-dose tablet and a floating multiple matrix tablet prepared by the direct compression process. The drug release from biphasic GRDDS in 0.1 mol L(-1) HCl and SGF (enzyme free) was sustained over 12 h with buoyant properties. Stability studies showed no significant change in dissolution profiles (f2 value > 50). Based on the release kinetics, it can be concluded that the floating multiple matrix tablet containing HPMC was a particularly suitable gastroretentive drug delivery system with a zero-order release profile. PMID:20228043

Bandari, Suresh; Eaga, Chandra Mohan; Thadishetty, Ashok; Yamsani, Madhusudan Rao

2010-03-01

122

Two cholesterol derivative-based PEGylated liposomes as drug delivery system, study on pharmacokinetics and drug delivery to retina  

NASA Astrophysics Data System (ADS)

In this study, two cholesterol derivatives, (4-cholesterocarbonyl-4?-(N,N,N-triethylamine butyloxyl bromide) azobenzene (CAB) and 4-cholesterocarbonyl-4?-(N,N-diethylamine butyloxyl) azobenzene (ACB), one of which is positively charged while the other is neutral, were synthesized and incorporated with phospholipids and cholesterol to form doxorubicin (DOX)-loaded liposomes. PEGylation was achieved by including 1,2-distearoyl-sn-glycero-3-phosphatiylethanol-amine-N-[methoxy-(polyethylene glycol)-2000 (DSPE-PEG2000). Our results showed that PEGylated liposomes displayed significantly improved stability and the drug leakage was decreased compared to the non-PEGylated ones in vitro. The in vivo study with rats also revealed that the pharmacokinetics and circulation half-life of DOX were significantly improved when liposomes were PEGylated (p < 0.05). In particular, the neutral cholesterol derivative ACB played some role in improving liposomes’ stability in systemic circulation compared to the conventional PC liposome and the positively charged CAB liposome, with or without PEGylation. In addition, in the case of local drug delivery, the positively charged PEG-liposome not only delivered much more of the drug into the rats’ retinas (p < 0.001), but also maintained much longer drug retention time compared to the neutral PEGylated liposomes.

Geng, Shengyong; Yang, Bin; Wang, Guowu; Qin, Geng; Wada, Satoshi; Wang, Jin-Ye

2014-07-01

123

Two cholesterol derivative-based PEGylated liposomes as drug delivery system, study on pharmacokinetics and drug delivery to retina.  

PubMed

In this study, two cholesterol derivatives, (4-cholesterocarbonyl-4'-(N,N,N-triethylamine butyloxyl bromide) azobenzene (CAB) and 4-cholesterocarbonyl-4'-(N,N-diethylamine butyloxyl) azobenzene (ACB), one of which is positively charged while the other is neutral, were synthesized and incorporated with phospholipids and cholesterol to form doxorubicin (DOX)-loaded liposomes. PEGylation was achieved by including 1,2-distearoyl-sn-glycero-3-phosphatiylethanol-amine-N-[methoxy-(polyethylene glycol)-2000 (DSPE-PEG2000). Our results showed that PEGylated liposomes displayed significantly improved stability and the drug leakage was decreased compared to the non-PEGylated ones in vitro. The in vivo study with rats also revealed that the pharmacokinetics and circulation half-life of DOX were significantly improved when liposomes were PEGylated (p < 0.05). In particular, the neutral cholesterol derivative ACB played some role in improving liposomes' stability in systemic circulation compared to the conventional PC liposome and the positively charged CAB liposome, with or without PEGylation. In addition, in the case of local drug delivery, the positively charged PEG-liposome not only delivered much more of the drug into the rats' retinas (p < 0.001), but also maintained much longer drug retention time compared to the neutral PEGylated liposomes. PMID:24960297

Geng, Shengyong; Yang, Bin; Wang, Guowu; Qin, Geng; Wada, Satoshi; Wang, Jin-Ye

2014-07-11

124

MRI in ocular drug delivery  

PubMed Central

Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed. PMID:18186077

Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

2008-01-01

125

Nano-sized melphalan and sarcolysine drug delivery systems: synthesis and prospects of application  

NASA Astrophysics Data System (ADS)

The results of experimental studies concerned with the development of nano-sized drug delivery systems for the antitumour drugs sarcolysine and melphalan are generalized. The structures and biological activities of nanocarriers in comparison with unmodified drugs are discussed. Particular attention is given to the liposomes containing lipid derivatives of sarcolysine and melphalan in the lipid bilayer. The bibliography includes 196 references.

Krasnov, V. P.; Korolyova, M. A.; Vodovozova, E. L.

2013-08-01

126

Development of Bioadhesive Chitosan Superporous Hydrogel Composite Particles Based Intestinal Drug Delivery System  

PubMed Central

Bioadhesive superporous hydrogel composite (SPHC) particles were developed for an intestinal delivery of metoprolol succinate and characterized for density, porosity, swelling, morphology, and bioadhesion studies. Chitosan and HPMC were used as bioadhesive and release retardant polymers, respectively. A 32 full factorial design was applied to optimize the concentration of chitosan and HPMC. The drug loaded bioadhesive SPHC particles were filled in capsule, and the capsule was coated with cellulose acetate phthalate and evaluated for drug content, in vitro drug release, and stability studies. To ascertain the drug release kinetics, the drug release profiles were fitted for mathematical models. The prepared system remains bioadhesive up to eight hours in intestine and showed Hixson-Crowell release with anomalous nonfickian type of drug transport. The application of SPHC polymer particles as a biomaterial carrier opens a new insight into bioadhesive drug delivery system and could be a future platform for other molecules for intestinal delivery. PMID:23984380

Modhia, Ishan; Mehta, Anant; Patel, Rupal; Patel, Chhagan

2013-01-01

127

A polyvalent aptamer system for targeted drug delivery.  

PubMed

Poor efficacy and off-target systemic toxicity are major problems associated with current chemotherapeutic approaches to treat cancer. We developed a new form of polyvalent therapeutics that is composed of multiple aptamer units synthesized by rolling circle amplification and physically intercalated chemotherapy agents (termed as "Poly-Aptamer-Drug"). Using a leukemia cell-binding aptamer and doxorubicin as a model system, we have successfully constructed Poly-Aptamer-Drug systems and demonstrated that the Poly-Aptamer-Drug is significantly more effective than its monovalent counterpart in targeting and killing leukemia cells due to enhanced binding affinity (? 40 fold greater) and cell internalization via multivalent effects. We anticipate that our Poly-Aptamer-Drug approach will yield new classes of tunable therapeutics that can be utilized to effectively target and treat cancers while minimizing the side effects of chemotherapy. PMID:24044994

Zhang, Zhiqing; Ali, M Monsur; Eckert, Mark A; Kang, Dong-Ku; Chen, Yih Yang; Sender, Leonard S; Fruman, David A; Zhao, Weian

2013-12-01

128

Colonic drug delivery systems based on natural polysaccharides and their evaluation.  

PubMed

Natural polysaccharides are found in abundance, are inexpensive, safe and available in a variety of structures which can easily be modified chemically and biochemically. A number of natural gums and mucilages along with their chemically modified forms have been evaluated as controlled drug delivery devices. They are reported to be capable of providing the desired drug release profiles and in some cases, have shown comparable drug release properties with currently available sustained release products in the market. Colon specific drug delivery based on natural polysaccharides has highly been acclaimed in recent years. A colon specific drug delivery system should prevent drug release in the stomach as well as the small intestine. Several polysaccharides have been reported to be capable of preventing drug release in the upper GI tract while being susceptible to enzymatic degradation by colonic bacterial enzymes. A wide range of natural or modified polysaccharides has been investigated for peroral delivery of drugs to the colon. As the release of drug from these polysaccharides based systems is independent of pH and gastric emptying time these polysaccharides based systems are considered the most effective and preferable means for colonic drug delivery in terms of target specificity. PMID:24032514

Pachuau, Lalduhsanga; Mazumder, Bhaskar

2013-11-01

129

Osmotic micropumps for drug delivery.  

PubMed

This paper reviews miniaturized drug delivery systems applying osmotic principles for pumping. Osmotic micropumps require no electrical energy and consequently enable drug delivery systems of smallest size for a broad field of new applications. In contrast to common tablets, these pumps provide constant (zero-order) drug release rates. This facilitates systems for long term use not limited by gastrointestinal transit time and first-pass metabolism. The review focuses on parenteral routes of administration targeting drug delivery either in a site-specific or systemic way. Osmotic pumps consist of three building blocks: osmotic agent, solvent, and drug. This is used to categorize pumps into (i) single compartment systems using water from body fluids as solvent and the drug itself as the osmotic agent, (ii) two compartment systems employing a separate osmotic agent, and (iii) multi-compartment architectures employing solvent, drug and osmotic agent separately. In parallel to the micropumps, relevant applications and therapies are discussed. PMID:22370615

Herrlich, Simon; Spieth, Sven; Messner, Stephan; Zengerle, Roland

2012-11-01

130

Osmotic Drug Delivery System as a Part of Modified Release Dosage Form  

PubMed Central

Conventional drug delivery systems are known to provide an immediate release of drug, in which one can not control the release of the drug and can not maintain effective concentration at the target site for longer time. Controlled drug delivery systems offer spatial control over the drug release. Osmotic pumps are most promising systems for controlled drug delivery. These systems are used for both oral administration and implantation. Osmotic pumps consist of an inner core containing drug and osmogens, coated with a semipermeable membrane. As the core absorbs water, it expands in volume, which pushes the drug solution out through the delivery ports. Osmotic pumps release drug at a rate that is independent of the pH and hydrodynamics of the dissolution medium. The historical development of osmotic systems includes development of the Rose-Nelson pump, the Higuchi-Leeper pumps, the Alzet and Osmet systems, the elementary osmotic pump, and the push-pull system. Recent advances include development of the controlled porosity osmotic pump, and systems based on asymmetric membranes. This paper highlights the principle of osmosis, materials used for fabrication of pumps, types of pumps, advantages, disadvantages, and marketed products of this system. PMID:22852100

Keraliya, Rajesh A.; Patel, Chirag; Patel, Pranav; Keraliya, Vipul; Soni, Tejal G.; Patel, Rajnikant C.; Patel, M. M.

2012-01-01

131

Nanoparticles as Drug Delivery Systems in Cancer Medicine: Emphasis on RNAi-Containing Nanoliposomes  

PubMed Central

Nanomedicine is a growing research field dealing with the creation and manipulation of materials at a nanometer scale for the better treatment, diagnosis and imaging of diseases. In cancer medicine, the use of nanoparticles as drug delivery systems has advanced the bioavailability, in vivo stability, intestinal absorption, solubility, sustained and targeted delivery, and therapeutic effectiveness of several anticancer agents. The expansion of novel nanoparticles for drug delivery is an exciting and challenging research filed, in particular for the delivery of emerging cancer therapies, including small interference RNA (siRNA) and microRNA (miRNAs)-based molecules. In this review, we focus on the currently available drug delivery systems for anticancer agents. In addition, we will discuss the promising use of nanoparticles for novel cancer treatment strategies. PMID:24287462

Rivera Diaz, Monica; Vivas-Mejia, Pablo E.

2013-01-01

132

Photomechanical drug delivery  

NASA Astrophysics Data System (ADS)

Photomechanical waves (PW) are generated by Q-switched or mode-locked lasers. Ablation is a reliable method for generating PWs with consistent characteristics. Depending on the laser wavelength and target material, PWs with different parameters can be generated which allows the investigation of PWs with cells and tissue. PWs have been shown to permeabilize the stratum corneum (SC) in vivo and facilitate the transport of drugs into the skin. Once a drug has diffused into the dermis it can enter the vasculature, thus producing a systemic effect. Fluorescence microscopy of biopsies show that 40-kDa molecules can be delivered to a depth of > 300 micrometers into the viable skin of rats. Many important drugs such as insulin, and erythropoietin are smaller or comparable in size, making the PWs attractive for transdermal drug delivery. There are three possible pathways through the SC: Transappendageal via hair follicles or other appendages, transcellular through the corneocytes, and intercellular via the extracellular matrix. The intracellular route appears to be the most likely pathway of drug delivery through the SC.

Doukas, Apostolos G.; Lee, Shun

2000-05-01

133

Innovative Liposomes as a Transfollicular Drug Delivery System: Penetration into Porcine Hair Follicles  

Microsoft Academic Search

Liposomes had been widely used for drug delivery in the past. In this study, five different liposomes were used as a follicular delivery system in pig ear skin. The liposomes mainly differed in their sphere diameter, lipid composition, and surface charge. A novel class of liposomes being amphoteric in their charge behavior are compared to established anionic and cationic liposomes.

Sascha Jung; Nina Otberg; Gisela Thiede; Heike Richter; Wolfram Sterry; Steffen Panzner; Jürgen Lademann

2006-01-01

134

Polymeric micelle-templated synthesis of hydroxyapatite hollow nanoparticles for a drug delivery system  

Microsoft Academic Search

Hydroxyapatite (HA) hollow nanoparticles (HNPs) have great potential in nanoscaled delivery devices due to their small size, excellent biocompatibility and expected high capacity. However, the preparation of HA HNPs for their application in a drug delivery system has rarely been reported because HA has a complicated crystal structure and it is difficult to obtain stable HA HNPs with hollows that

Feng Ye; Haifeng Guo; Haijiao Zhang; Xiulan He

2010-01-01

135

Development of an injectable two-phase drug delivery system for sequential release of antiresorptive and osteogenic drugs.  

PubMed

Unlike controlled release systems that deliver a single drug, dual or multidrug delivery systems with distinct release profiles are more likely to promote timely and effective tissue regeneration as they provide both temporally and concentration-dependent release of different molecules to mimic natural biological events. In this study, an injectable and biodegradable delivery system was developed to sequentially release an antiresorptive drug (clodronate) followed by an osteogenic agent (simvastatin) to treat bone disease. The injectable delivery system comprised simvastatin-loaded gelatin microspheres suspended in a viscous solution of carboxymethylcellulose (CMC) containing clodronate. Several factors (CMC concentration, glutaraldehyde concentration, simvastatin loading, and gelatin microsphere processing conditions) were investigated for their effects on drug release. Clodronate release was not affected by CMC concentration, with complete delivery within 12 hr, and simvastatin release could be modulated by cross-linking of the gelatin microspheres, loading, and washing conditions. Burst release of simvastatin was reduced from 70% to 6% in conjunction with sustained release for up to 3 weeks. The combined system showed early release of the antiresorptive clodronate sequentially followed by sustained delivery of the osteogenic simvastatin. This robust and flexible two-phase delivery system may prove useful for applications in which multiple drug delivery is desired. PMID:22102375

Zou, Y; Brooks, J L; Talwalkar, V; Milbrandt, T A; Puleo, D A

2012-01-01

136

Fast disintegrating tablets: Opportunity in drug delivery system  

PubMed Central

Fast disintegrating tablets (FDTs) have received ever-increasing demand during the last decade, and the field has become a rapidly growing area in the pharmaceutical industry. Oral drug delivery remains the preferred route for administration of various drugs. Recent developments in the technology have prompted scientists to develop FDTs with improved patient compliance and convenience. Upon introduction into the mouth, these tablets dissolve or disintegrate in the mouth in the absence of additional water for easy administration of active pharmaceutical ingredients. The popularity and usefulness of the formulation resulted in development of several FDT technologies. FDTs are solid unit dosage forms, which disintegrate or dissolve rapidly in the mouth without chewing and water. FDTs or orally disintegrating tablets provide an advantage particularly for pediatric and geriatric populations who have difficulty in swallowing conventional tablets and capsules. This review describes various formulations and technologies developed to achieve fast dissolution/dispersion of tablets in the oral cavity. In particular, this review describes in detail FDT technologies based on lyophilization, molding, sublimation, and compaction, as well as approaches to enhancing the FDT properties, such as spray drying and use of disintegrants. In addition, taste-masking technologies, experimental measurements of disintegration times, and dissolution are also discussed. PMID:22247889

Parkash, Ved; Maan, Saurabh; Deepika; Yadav, Shiv Kumar; Hemlata; Jogpal, Vikas

2011-01-01

137

Liposomal systems as drug delivery vehicles for dermal and transdermal applications  

Microsoft Academic Search

Enhancement strategies are necessary to improve the dermal\\/transdermal bioavailability of drugs applied to the skin due to\\u000a its amazing barrier, the stratum corneum. Strategies to overcome this barrier, thus improving drug release to the skin include\\u000a the use of penetration enhancers, specific delivery systems, supersaturated solutions and physical methods (iontophoresis,\\u000a electroporation and ultrasound). Delivery of active agents to the skin

Maria Bernadete Riemma Pierre; Irina dos Santos Miranda Costa

138

Topical Delivery of Aceclofenac: Challenges and Promises of Novel Drug Delivery Systems  

PubMed Central

Osteoarthritis (OA), a common musculoskeletal disorder, is projected to affect about 60 million people of total world population by 2020. The associated pain and disability impair the quality of life and also pose economic burden to the patient. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed in OA, while diclofenac is the most prescribed one. Oral NSAIDs are not very patient friendly, as they cause various gastrointestinal adverse effects like bleeding, ulceration, and perforation. To enhance the tolerability of diclofenac and decrease the common side effects, aceclofenac (ACE) was developed by its chemical modification. As expected, ACE is more well-tolerated than diclofenac and possesses superior efficacy but is not completely devoid of the NSAID-tagged side effects. A series of chemical modifications of already planned drug is unjustified as it consumes quanta of time, efforts, and money, and this approach will also pose stringent regulatory challenges. Therefore, it is justified to deliver ACE employing tools of drug delivery and nanotechnology to refine its safety profile. The present review highlights the constraints related to the topical delivery of ACE and the various attempts made so far for the safe and effective topical delivery employing the novel materials and methods. PMID:25045671

Kumar, Manish; Kumar, Pramod; Malik, Ruchi; Sharma, Gajanand; Kaur, Manmeet; Katare, O. P.

2014-01-01

139

Topical delivery of aceclofenac: challenges and promises of novel drug delivery systems.  

PubMed

Osteoarthritis (OA), a common musculoskeletal disorder, is projected to affect about 60 million people of total world population by 2020. The associated pain and disability impair the quality of life and also pose economic burden to the patient. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed in OA, while diclofenac is the most prescribed one. Oral NSAIDs are not very patient friendly, as they cause various gastrointestinal adverse effects like bleeding, ulceration, and perforation. To enhance the tolerability of diclofenac and decrease the common side effects, aceclofenac (ACE) was developed by its chemical modification. As expected, ACE is more well-tolerated than diclofenac and possesses superior efficacy but is not completely devoid of the NSAID-tagged side effects. A series of chemical modifications of already planned drug is unjustified as it consumes quanta of time, efforts, and money, and this approach will also pose stringent regulatory challenges. Therefore, it is justified to deliver ACE employing tools of drug delivery and nanotechnology to refine its safety profile. The present review highlights the constraints related to the topical delivery of ACE and the various attempts made so far for the safe and effective topical delivery employing the novel materials and methods. PMID:25045671

Raza, Kaisar; Kumar, Manish; Kumar, Pramod; Malik, Ruchi; Sharma, Gajanand; Kaur, Manmeet; Katare, O P

2014-01-01

140

[Development of a novel transdermal delivery system of peptide and protein drugs using microneedle arrays].  

PubMed

Transdermal delivery of peptide and protein drugs may be limited by the stratum corneum, which is a protective barrier against the entry of microorganisms and water. Many approaches have been utilized to promote peptide and protein drugs delivery across the stratum corneum, including chemical enhancer modification and physical disruption of barrier function. However, it has been difficult to achieve therapeutic levels of peptide and protein drugs via this route without any skin irritation. Recently, attention has been paid to the possibility of using microneedle arrays in delivering peptide and protein drugs into the skin. As a novel and minimally invasive approach, microneedle arrays are capable of creating superficial pathways across the skin for peptide and protein drugs to achieve enhanced transdermal drug delivery. This method combines the efficacy of conventional injection needles with the convenience of transdermal patches, while minimizing the disadvantages of these administration methods. Therefore, microneedle arrays are a very useful alternative method for delivering peptide and protein drugs from the skin into the systemic circulation without any serious damage to skin. In this review, recent challenges in the developments of microneedle arrays for the delivery of peptide and protein drugs are summarized. Then, future developments of microneedle arrays for the delivery of peptide and protein drugs are also discussed in order to improve their therapeutic efficacy and safety. PMID:24389619

Katsumi, Hidemasa; Quan, Ying-Shu; Kamiyama, Fumio; Kusamori, Kosuke; Sakane, Toshiyasu; Yamamoto, Akira

2014-01-01

141

Organ-on-a-chip platforms for studying drug delivery systems.  

PubMed

Novel microfluidic tools allow new ways to manufacture and test drug delivery systems. Organ-on-a-chip systems - microscale recapitulations of complex organ functions - promise to improve the drug development pipeline. This review highlights the importance of integrating microfluidic networks with 3D tissue engineered models to create organ-on-a-chip platforms, able to meet the demand of creating robust preclinical screening models. Specific examples are cited to demonstrate the use of these systems for studying the performance of drug delivery vectors and thereby reduce the discrepancies between their performance at preclinical and clinical trials. We also highlight the future directions that need to be pursued by the research community for these proof-of-concept studies to achieve the goal of accelerating clinical translation of drug delivery nanoparticles. PMID:24818770

Bhise, Nupura S; Ribas, João; Manoharan, Vijayan; Zhang, Yu Shrike; Polini, Alessandro; Massa, Solange; Dokmeci, Mehmet R; Khademhosseini, Ali

2014-09-28

142

An updated patent review on ocular drug delivery systems with potential for commercial viability.  

PubMed

The eye due to its special attributes is an effortlessly accessible location for topical drug administration. Topical administration not only provides local targeting of drugs but also offers a better control over the systemic delivery. Bioavailability of drugs from ocular dosage forms is dependent to the precorneal loss factors (physiological and anatomical constraints of eye) thus, very small fraction of the drug is absorbed through ocular route. The effective dose of medication administered ophthalmically may be altered by changing the formulation. Various research reports have been documented for ocular drug delivery, both on academic level as well as commercial level resulting in augmented increase in the numbers of patents in this field. The primary objective of the present review is to provide an overview of the ocular drug delivery systems with special emphasis on the intellectual aspects of these systems. This paper also attempts to extend the information on ocular drug delivery systems already existing in the literature by focusing on the update on the patents granted as well as applications published for these systems during the last decade. PMID:21453249

Srivastava, Rishabh; Pathak, Kamla

2011-05-01

143

Development and optimization of metoprolol succinate gastroretentive drug delivery system.  

PubMed

Metoprolol succinate (MS) gastroretentive (GR) controlled release system was formulated to increase gastric residence time leading to improved drug bioavailability. Box-Behnken model was followed using novel combinations of sodium alginate (SA), sodium carboxymethylcellulose (NaCMC), magnesium alumino metasilicate (MAS) as independent variables. Floating lag time (Flag), t25, t50, t75, diffusion exponent as dependent variables revealed that the amount of SA, NaCMC and MAS have a significant effect (p < 0.05) on t25, t50, t75 and Flag. MSGR tablets were prepared and evaluated for mass, thickness, hardness, friability, drug content and floating property. Tablets were studied for dissolution for 24 h and exhibited controlled release of MS with floating for 16 h. The release profile of the optimized batch MS01 fitted first-order kinetics (R2 = 0.9868, n = 0.543), indicating non-Fickian diffusion or anomalous transport by diffusion and swelling. PMID:21169134

Boldhane, Sanjay P; Kuchekar, Bhanudas S

2010-12-01

144

The application of carbon nanotubes in target drug delivery systems for cancer therapies  

PubMed Central

Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies. PMID:21995320

2011-01-01

145

The application of carbon nanotubes in target drug delivery systems for cancer therapies  

NASA Astrophysics Data System (ADS)

Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies.

Zhang, Wuxu; Zhang, Zhenzhong; Zhang, Yingge

2011-10-01

146

Bioactive and bioresponsive nanoparticle surface modifications for vaccine and systemic drug delivery  

E-print Network

the most common transdermal drug delivery device availableuse of a transdermal patch that elutes drugs continuouslytransdermal patch is one of its major advantages. Transmucosal delivery refers to the absorption of a drug

Clawson, Corbin Zean

2011-01-01

147

Liquid crystalline systems for transdermal delivery of celecoxib: in vitro drug release and skin permeation studies.  

PubMed

Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution. PMID:24980082

Estracanholli, Eder André; Praça, Fabíola Silva Garcia; Cintra, Ana Beatriz; Pierre, Maria Bernadete Riemma; Lara, Marilisa Guimarães

2014-12-01

148

Modular reservoir concept for MEMS-based transdermal drug delivery systems  

NASA Astrophysics Data System (ADS)

While MEMS-based transdermal drug delivery device development efforts have typically focused on tightly-integrated solutions, we propose an alternate conception based upon a novel, modular drug reservoir approach. By decoupling the drug storage functionality from the rest of the delivery system, this approach seeks to minimize cold chain storage volume, enhance compatibility with conventional pharmaceutical practices, and allow independent optimization of reservoir device design, materials, and fabrication. Herein, we report the design, fabrication, and preliminary characterization of modular reservoirs that demonstrate the virtue of this approach within the application context of transdermal insulin administration for diabetes management.

Cantwell, Cara T.; Wei, Pinghung; Ziaie, Babak; Rao, Masaru P.

2014-11-01

149

Electrospun zein/eudragit nanofibers based dual drug delivery system for the simultaneous delivery of aceclofenac and pantoprazole.  

PubMed

Electrospun composite zein/eudragit nanofibers were developed with an aim to deliver two different classes of drugs simultaneously that would restrict/compensate the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs). Co-administration of proton pump inhibitors is beneficial for patients consuming NSAIDs for treating chronic ailments like arthritis. In this study, aceclofenac/pantoprazole loaded zein/eudragit S 100 nanofibers were developed using a single nozzle electrospinning process. The morphological analysis revealed the uniform and smooth surface of the drug loaded nanofibers. The physico-thermal characterization of nanofibers depicted the molecular integration of the drugs with the polymers and also confirmed that the drugs were evenly distributed in the nanofibers in an amorphous state. In vitro release studies ensure the efficiency of the developed fibers in sustaining the release of both the drugs up to 8h. In vivo animal experiments further confirmed that the co-administration of pantoprazole along with aceclofenac reduced the gastro-intestinal toxicity induced by NSAIDs. The histological evaluation revealed the preserved mucosal architecture of rat gastric tissue treated with drug loaded composite nanofibers. Thus, dual drug delivery system comprising polymers with different release characteristics has been successfully developed and further, oral delivery of aceclofenac with reduced side effects was achieved. PMID:22960320

Karthikeyan, K; Guhathakarta, Soma; Rajaram, Rama; Korrapati, Purna Sai

2012-11-15

150

Cell-penetrating peptides as a novel transdermal drug delivery system.  

PubMed

In the last decade, almost one-third of the newly discovered drugs approved by the US FDA were biomolecules and biologics. Effective delivery of therapeutic biomolecules to their target is a challenging issue. Innovations in drug delivery systems have improved the efficiency of many of new biopharmaceuticals. Designing of novel transdermal delivery systems has been one of the most important pharmaceutical innovations, which offers a number of advantages. The cell-penetrating peptides have been increasingly used to mediate delivery of bimolecular cargoes such as small molecules, small interfering RNA nucleotides, drug-loaded nanoparticles, proteins, and peptides, both in vitro and in vivo, without using any receptors and without causing any significant membrane damage. Among several different drug delivery routes, application of cell-penetrating peptides in the topical and transdermal delivery systems has recently garnered tremendous attention in both cosmeceutical and pharmaceutical research and industries. In this review, we discuss history of cell-penetrating peptides, cell-penetrating peptide/cargo complex formation, and their mechanisms of cell and skin transduction. PMID:22846609

Nasrollahi, Saman A; Taghibiglou, Changiz; Azizi, Ebrahim; Farboud, Effat S

2012-11-01

151

Implications of nanoscale based drug delivery systems in delivery and targeting tubulin binding agent, noscapine in cancer cells.  

PubMed

Noscapine, a tubulin binding anticancer agent undergoing Phase I/II clinical trials, inhibits tumor growth in nude mice bearing human xenografts of breast, lung, ovarian, brain, and prostrate origin. The analogues of noscapine like 9-bromonoscapine (EM011) are 5 to 10-fold more active than parent compound, noscapine. Noscapinoids inhibit the proliferation of cancer cells that are resistant to paclitaxel and epothilone. Noscapine also potentiated the anticancer activity of doxorubicin in a synergistic manner against triple negative breast cancer (TNBC). However, physicochemical and pharmacokinetic (ED50˜300-600 mg/kg bodyweight) limitations of noscapine present hurdle in development of commercial anticancer formulations. Therefore, objectives of the present review are to summarize the chemotherapeutic potential of noscapine and implications of nanoscale based drug delivery systems in enhancing the therapeutic efficacy of noscapine in cancer cells. We have constructed noscapine-enveloped gelatin nanoparticles, NPs and poly (ethylene glycol) grafted gelatin NPs as well as inclusion complex of noscapine in ?-cyclodextrin (?-CD) and evaluated their physicochemical characteristics. The Fe3O4 NPs were also used to incorporate noscapine in its polymeric nanomatrix system where molecular weight of the polymer governed the encapsulation efficiency of drug. The enhanced noscapine delivery using ?PAR-targeted optical-MR imaging trackable NPs offer a great potential for image directed targeted delivery of noscapine. Human Serum Albumin NPs (150-300 nm) as efficient noscapine drug delivery systems have also been developed for potential use in breast cancer. PMID:22571485

Chandra, Ramesh; Madan, Jitender; Singh, Prashant; Chandra, Ankush; Kumar, Pradeep; Tomar, Vartika; Dass, Sujata K

2012-12-01

152

A gastroretentive drug delivery system of lisinopril imbibed on isabgol-husk.  

PubMed

The gastroretentive drug delivery system is site-specific and allows the drug to remain in the stomach for a prolonged period of time so that it can be released in a controlled manner in gastrointestinal tract. The present study was carried out to develop a gastroretentive drug delivery system using isabgol as an excipient to prolong the residence time of the model drug lisinopril in the stomach. The gastroretentive ability of isabgol was increased by addition of NaHCO3 as a gas-generating agent while its mucoadhesive property was enhanced by incorporation of HPMC-K4M. The drug, NaHCO3 and HPMC-K3M were imbibed on isabgol-husk as per entrapment efficiency of the isabgol-husk. After drying, the product was filled in a hard gelatin capsule and evaluated for its buoyancy, mucoadhesive properties, swelling index and in vitro drug release. The lisinopril released through isabgol was delayed by 12 hours when compared to a preparation available on the market which released the complete drug in 0.5 hours. The drug release study of lisinopril from the formulation follows first order kinetics using a diffusion controlled mechanism. The results from the present study revealed that isabgol can be used as a potential excipient for the formulation of gastroretentive drug delivery systems in the near future. PMID:24144200

Semwal, Ravindra; Semwal, Ruchi Badoni; Semwal, Deepak Kumar

2014-01-01

153

Calcium phosphate ceramic systems in growth factor and drug delivery for bone tissue engineering: A review  

PubMed Central

Calcium phosphates (CaPs) are the most widely used bone substitutes in bone tissue engineering due to their compositional similarities to bone mineral and excellent biocompatibility. In recent years, CaPs, especially hydroxyapatite and tricalcium phosphate, have attracted significant interest in simultaneous use as bone substitute and drug delivery vehicle, adding a new dimension to their application. CaPs are more biocompatible than many other ceramic and inorganic nanoparticles. Their biocompatibility and variable stoichiometry, thus surface charge density, functionality, and dissolution properties, make them suitable for both drug and growth factor delivery. CaP matrices and scaffolds have been reported to act as delivery vehicles for growth factors and drugs in bone tissue engineering. Local drug delivery in musculoskeletal disorder treatments can address some of the critical issues more effectively and efficiently than the systemic delivery. CaPs are used as coatings on metallic implants, CaP cements, and custom designed scaffolds to treat musculoskeletal disorders. This review highlights some of the current drug and growth factor delivery approaches and critical issues using CaP particles, coatings, cements, and scaffolds towards orthopedic and dental applications. PMID:22127225

Bose, Susmita; Tarafder, Solaiman

2012-01-01

154

Alginate drug delivery systems: application in context of pharmaceutical and biomedical research.  

PubMed

Abstract Alginates are natural polymers widely used in the food industry because of their biocompatible, biodegradable character, nontoxicity and easy availability. The bioadhesive character of alginates makes them useful in the pharmaceutical industry as well. The application areas of sodium alginate-based drug delivery systems are many and these systems can be formulated as gels, matrices, membranes, nanospheres, microspheres, etc. Worldwide researchers are exploring possible applications of alginates as coating material, preparation of controlled-release drug delivery systems such as microspheres, beads, pellets, gels, fibers, membranes, etc. In the present review, such applications of alginates are discussed. PMID:25109399

Jain, Dharmendra; Bar-Shalom, Daniel

2014-12-01

155

The recent progresses on the improved therapy of melanoma by novel drug delivery systems.  

PubMed

Melanoma is a life threatening disease with a growing incidence rate. It is estimated that 9840 patients will die from melanoma in 2014. Despite numerous attempts for treating metastatic melanoma, conventional therapies including systemic chemotherapy or immunotherapy, either as single agents or combined, have not been promising. The most cytotoxic agents have low molecular weight, which leads to rapid excretion, nonspecific distribution, and poor therapeutic index. Therefore, they may even increase toxicity due to their non-specific action on healthy tissue that can exacerbate the malady. To provide optimum effective concentration, multiple-dose drug administration is required, which again can increase the incidence of adverse effects. Recent developments in drug delivery systems are able to improve the drug efficacy and safety, and offer more promising approaches in treating melanoma. Recent researches have shed more light on the advantages of novel drug loaded carrier systems versus free drugs. Most of these animal studies, reported improvement in treatment efficacy and survival rate using novel carrier systems. This is related to the ability of these systems in enhancing the anticancer effect by modifying drug pharmacokinetics and biodistribution, selective target delivery of the agents to the diseased tissue and their ability to cross the biological barriers. In this paper, it is attempted to illustrate the potentials of novel strategies in treatment of melanoma incorporating drug delivery systems versus conventional therapies. PMID:24947545

Taymouri, Somayeh; Varshosaz, Jaleh

2014-01-01

156

Heterostructured layered aluminosilicate-itraconazole nanohybrid for drug delivery system.  

PubMed

A nanohybrid, consisting of layered aluminosilicate as a host material and itraconazole as a guest molecule, was successfully synthesized through the interfacial intercalation reaction across the boundary between water and water-immiscible liquid at the various pH. According to the powder X-ray diffraction pattern, the basal spacing of the intraconazole-layered aluminosilicate nanohybrid increased from 14.7 to 22.7 A depending on the pH of the aqueous suspension. The total amounts of itraconazole in the hybrids were determined to be 2.3-25.4 wt% by HPLC analysis. The in vivo pharmacokinetics study was performed in rats in order to compare the absorptions of itraconazole for the itraconazole-layered aluminosilicate nanohybrid and a commercial product, Sporanox. The pharmacokinetic data for the nanohybrid and Sporanox showed that the mean area under the plasma concentration-time curve (AUC, 2477 +/- 898 ng x hr/mL and 2630 +/- 953 ng x hr/mL, respectively) and maximum concentration (Cmax, 225.4 +/- 77.4 ng x hr/mL and 223.6 +/- 51.9 ng x hr/mL, respectively), were within the bioequivalence (BE) range. Therefore, we concluded that this drug-layered aluminosilicate nanohybrid system has a great potential for its application in formulation of poorly soluble drugs. PMID:24245252

Yang, Jae-Hun; Jung, Hyun; Kim, Su Yeon; Yo, Chul Hyun; Choy, Jin-Ho

2013-11-01

157

Bioactive electrospun fish sarcoplasmic proteins as a drug delivery system.  

PubMed

Nano-microfibers were made from cod (Gadus morhua) sarcoplasmic proteins (FSP) (Mw<200kDa) using the electrospinning technique. The FSP fibers were studied by scanning electron microscopy, and the fiber morphology was found to be strongly dependent on FSP concentration. Interestingly, the FSP fibers were insoluble in water. However, when exposed to proteolytic enzymes, the fibers were degraded. The degradation products of the FSP fibers proved to be inhibitors of the diabetes-related enzyme DPP-IV. The FSP fibers may have biomedical applications, among others as a delivery system. To demonstrate this, a dipeptide (Ala-Trp) was encapsulated into the FSP fibers, and the release properties were investigated in gastric buffer and in intestinal buffer. The release profile showed an initial burst release, where 30% of the compound was released within the first minute, after which an additional 40% was released (still exponential) within the next 30min (gastric buffer) or 15min (intestinal buffer). The remaining 30% was not released in the timespan of the experiment. PMID:25033436

Stephansen, Karen; Chronakis, Ioannis S; Jessen, Flemming

2014-10-01

158

Application of mesoporous silicon dioxide and silicate in oral amorphous drug delivery systems.  

PubMed

Aqueous solubility of an active pharmaceutical ingredient is an important consideration to ensure successful drug development. Mesoporous materials have been investigated as an amorphous drug delivery system owing to their nanosized capillaries and large surface areas. The complex interactions of crystalline compounds with mesoporous media and their implication in drug delivery are not well understood. Molecules interacting with porous media behave very differently than those in bulk phase. Their altered dynamics and thermodynamics play an important role in the properties and product performance of the amorphous system. In this review, application of mesoporous silicon dioxide and silicates in drug amorphization is the main focus. First, as background, the nature of gas-porous media interactions is summarized. The synthesis of various types of mesoporous silica, which are used by many investigators in this field, is described. Second, the behavior of molecules confined in mesopores is compared with those in bulk, crystalline phase. The molecular dynamics of compounds due to confinement, analyzed using various techniques, and their consequences in drug delivery are discussed. Finally, the preparation and performance of drug delivery systems using mesoporous silica are examined. PMID:21976048

Qian, Ken K; Bogner, Robin H

2012-02-01

159

Drug delivery system design and development for boron neutron capture therapy on cancer treatment.  

PubMed

We have already synthesized a boron-containing polymeric micellar drug delivery system for boron neutron capture therapy (BNCT). The synthesized diblock copolymer, boron-terminated copolymers (Bpin-PLA-PEOz), consisted of biodegradable poly(D,l-lactide) (PLA) block and water-soluble polyelectrolyte poly(2-ethyl-2-oxazoline) (PEOz) block, and a cap of pinacol boronate ester (Bpin). In this study, we have demonstrated that synthesized Bpin-PLA-PEOz micelle has great potential to be boron drug delivery system with preliminary evaluation of biocompatibility and boron content. PMID:24447933

Sherlock Huang, Lin-Chiang; Hsieh, Wen-Yuan; Chen, Jiun-Yu; Huang, Su-Chin; Chen, Jen-Kun; Hsu, Ming-Hua

2014-06-01

160

Transducer design for a portable ultrasound enhanced transdermal drug-delivery system  

Microsoft Academic Search

For application in a portable transdermal drug-delivery system, novel transducers have been designed to enhance insulin transmission across skin using ultrasound. Previous research has shown transdermal delivery of insulin across skin using commercial sonicators operating at 20 kHz with intensities ranging from 12.5 to 225 mW\\/cm2. The goal of this research was to design and construct a small, lightweight transducer

Emiliano Maione; K. Kirk Shung; Richard J. Meyer; Jack W. Hughes; Robcrt E. Newnham; Nadine Barrie Smith

2002-01-01

161

Distinctive features of "chronotherapeutic" and "pulsatile" drug delivery systems negating the practice of their interchangeable terminology.  

PubMed

The term pulsatile drug delivery has often been used as a synonym to chronotherapeutic drug delivery. This needs to be given a thought as both the drug delivery systems are entirely addressing different needs of the patients as well as the intentions of the formulators being different. Chronotherapeutic systems are based completely on circadian needs and response of the body and the need of the drug to be in its maximum concentrations at a particular time of the day, the fact being supported by endless list of ailments which elicit the related symptoms at a particular time of the day. Considering the formulation approach, one does not find major differences among site-specific chronotherapeutic systems and the basic and more conventional intestinal or colon targeted systems due to the mechanism and the site of landing of drug of both being almost similar even though the intention of the formulator being different. An ideal pulsatile system is the one delivering drug in different pulses with multiple troughs in release profile. The article explores the major differences in between the two systems and highlights the need of using appropriate terminology for these individual and distinct systems catering different needs. PMID:20132094

Ali, Javed; Baboota, Sanjula; Ahuja, Alka; Saigal, Nitin

2010-07-01

162

Towards multifunctional, targeted drug delivery systems using mesoporous silica nanoparticles - opportunities & challenges  

NASA Astrophysics Data System (ADS)

One of the big challenges of medicine today is to deliver drugs specifically to defected cells. Nanoparticulate drug carriers have the potential to answer to this call, as nanoparticles can cross physiological barriers and access different tissues, and also be provided in a targetable form aimed at enhancing cell specificity of the carrier. Recent developments within material science and strong collaborative efforts crossing disciplinary borders have highlighted the potential of mesoporous silica nanoparticles (MSNs) for such targeted drug delivery. Here we outline recent advances which in this sense push MSNs to the forefront of drug delivery development. Relatively straightforward inside-out tuning of the vehicles, high flexibility, and potential for sophisticated release mechanisms make these nanostructures promising candidates for targeted drug delivery such as `smart' cancer therapies. Moreover, due to the large surface area and the controllable surface functionality of MSNs, they can be controllably loaded with large amounts of drugs and coupled to homing molecules to facilitate active targeting, simultaneously carrying traceable (fluorescent or magnetically active) modalities, also making them highly interesting as theragnostic agents. However, the increased relative surface area and small size, and flexible surface functionalization which is beneficially exploited in nanomedicine, consequently also includes potential risks in their interactions with biological systems. Therefore, we also discuss some safety issues regarding MSNs and highlight how different features of the drug delivery platform influence their behaviour in a biological setting. Addressing these burning questions will facilitate the application of MSNs in nanomedicine.

Rosenholm, Jessica M.; Sahlgren, Cecilia; Lindén, Mika

2010-10-01

163

Dynamic Feedback and the Design of Closed-loop Drug Delivery Systems  

E-print Network

regulates hormone concentration. This results in a control system composed of two time-delayed negative are most commonly employed, for To whom correspondence should be addressed. 1 #12;example, pills-loop drug delivery systems We assume that the in vivo regulation of hormone concentration, x, can

Campbell, Sue Ann

164

Microfabricated Engineered Particle Systems for Respiratory Drug Delivery and Other Pharmaceutical Applications  

PubMed Central

Particle Replication in Non-Wetting Templates (PRINT®) is a platform particle drug delivery technology that coopts the precision and nanoscale spatial resolution inherently afforded by lithographic techniques derived from the microelectronics industry to produce precisely engineered particles. We describe the utility of PRINT technology as a strategy for formulation and delivery of small molecule and biologic therapeutics, highlighting previous studies where particle size, shape, and chemistry have been used to enhance systemic particle distribution properties. In addition, we introduce the application of PRINT technology towards respiratory drug delivery, a particular interest due to the pharmaceutical need for increased control over dry powder characteristics to improve drug delivery and therapeutic indices. To this end, we have produced dry powder particles with micro- and nanoscale geometric features and composed of small molecule and protein therapeutics. Aerosols generated from these particles show attractive properties for efficient pulmonary delivery and differential respiratory deposition characteristics based on particle geometry. This work highlights the advantages of adopting proven microfabrication techniques in achieving unprecedented control over particle geometric design for drug delivery. PMID:22518316

Garcia, Andres; Mack, Peter; Williams, Stuart; Fromen, Catherine; Shen, Tammy; Tully, Janet; Pillai, Jonathan; Kuehl, Philip; Napier, Mary; DeSimone, Joseph M.; Maynor, Benjamin W.

2012-01-01

165

An Implantable MEMS Micropump System for Drug Delivery in Small Animals  

PubMed Central

We present the first implantable drug delivery system for controlled dosing, timing, and location in small animals. Current implantable drug delivery devices do not provide control over these factors or are not feasible for implantation in research animals as small as mice. Our system utilizes an integrated electrolysis micropump, is refillable, has an inert drug reservoir for broad drug compatibility, and is capable of adjustment to the delivery regimen while implanted. Electrochemical impedance spectroscopy (EIS) was used for characterization of electrodes on glass substrate and a flexible Parylene substrate. Benchtop testing of the electrolysis actuator resulted in flow rates from 1 to 34 ?L/min on glass substrate and up to 6.8 ?L/min on Parylene substrate. The fully integrated system generated a flow rate of 4.72 ± 0.35 ?L/min under applied constant current of 1.0 mA while maintaining a power consumption of only ~3 mW. Finally, we demonstrated in vivo application of the system for anti-cancer drug delivery in mice. PMID:22273985

Gensler, Heidi; Sheybani, Roya; Li, Po-Ying; Lo, Ronalee; Meng, Ellis

2012-01-01

166

A Microparticle/Hydrogel Combination Drug-Delivery System for Sustained Release of Retinoids  

PubMed Central

Purpose. To design and develop a drug-delivery system containing a combination of poly(d,l-lactide-co-glycolide) (PLGA) microparticles and alginate hydrogel for sustained release of retinoids to treat retinal blinding diseases that result from an inadequate supply of retinol and generation of 11-cis-retinal. Methods. To study drug release in vivo, either the drug-loaded microparticle–hydrogel combination was injected subcutaneously or drug-loaded microparticles were injected intravitreally into Lrat?/? mice. Orally administered 9-cis-retinoids were used for comparison and drug concentrations in plasma were determined by HPLC. Electroretinography (ERG) and both chemical and histologic analyses were used to evaluate drug effects on visual function and morphology. Results. Lrat?/? mice demonstrated sustained drug release from the microparticle/hydrogel combination that lasted 4 weeks after subcutaneous injection. Drug concentrations in plasma of the control group treated with the same oral dose rose to higher levels for 6?7 hours but then dropped markedly by 24 hours. Significantly increased ERG responses and a markedly improved retinal pigmented epithelium (RPE)–rod outer segment (ROS) interface were observed after subcutaneous injection of the drug-loaded delivery combination. Intravitreal injection of just 2% of the systemic dose of drug-loaded microparticles provided comparable therapeutic efficacy. Conclusions. Sustained release of therapeutic levels of 9-cis-retinoids was achieved in Lrat?/? mice by subcutaneous injection in a microparticle/hydrogel drug-delivery system. Both subcutaneous and intravitreal injections of drug-loaded microparticles into Lrat?/? mice improved visual function and retinal structure. PMID:22918645

Gao, Song-Qi; Maeda, Tadao; Okano, Kiichiro; Palczewski, Krzysztof

2012-01-01

167

Development of Drug Delivery Systems Based on Layered Hydroxides for Nanomedicine  

PubMed Central

Layered hydroxides (LHs) have recently fascinated researchers due to their wide application in various fields. These inorganic nanoparticles, with excellent features as nanocarriers in drug delivery systems, have the potential to play an important role in healthcare. Owing to their outstanding ion-exchange capacity, many organic pharmaceutical drugs have been intercalated into the interlayer galleries of LHs and, consequently, novel nanodrugs or smart drugs may revolutionize in the treatment of diseases. Layered hydroxides, as green nanoreservoirs with sustained drug release and cell targeting properties hold great promise of improving health and prolonging life. PMID:24802876

Barahuie, Farahnaz; Hussein, Mohd Zobir; Fakurazi, Sharida; Zainal, Zulkarnain

2014-01-01

168

Novel gel-niosomes formulations as multicomponent systems for transdermal drug delivery.  

PubMed

The percutaneous permeation profiles of sulfadiazine sodium salt, propranolol hydrochloride and tyrosol from novel liquid crystal-niosomes formulations as multicomponent systems, were investigated. The new carriers were prepared from mixture of water/surfactant, AOT or Pluronic L64 as anionic and nonionic surfactants, respectively, in order to obtain lamellar LLC phases. The same surfactants were used to prepare also the vesicular systems (niosomes) that were added to the corresponding gel. The obtained multicomponent drug carrier was characterized by deuterium nuclear magnetic resonance spectroscopy, in order to understand if the introduction of the drug or drug-loaded niosomal suspension, as third component in the formulations, could influence the microstructure of the system and then the drug delivery across the skin. Simple AOT and L64-based niosomal formulations and LLCs phases were then prepared and used as control. Different drugs percutaneous availability was achieved, and the results revealed that the obtained gel-niosomes carriers were affected by the chemical structure of the drugs and by their affinity for the components. As a consequence these systems could be proposed as novel transdermal drug delivery systems, since they were found able to control the percutaneous permeation of small drugs across the skin. PMID:23732806

Tavano, Lorena; Gentile, Luigi; Oliviero Rossi, Cesare; Muzzalupo, Rita

2013-10-01

169

Drug delivery Combinatorial Drug Conjugation Enables Nanoparticle  

E-print Network

Drug delivery Combinatorial Drug Conjugation Enables Nanoparticle Dual-Drug Delivery Santosh Aryal, Che-Ming Jack Hu, and Liangfang Zhang* A new approach to loading multiple drugs onto the same drug through hydrolyzable linkers to form drug conjugates, is reported. In contrast to loading individual types

Zhang, Liangfang

170

Pharmacokinetics of CNT-based drug delivery systems.  

PubMed

Carbon nanotubes (CNT) are allotropes of carbon with a cylindrical nanostructure. They have recently aroused great interests as drug carriers, but their pharmacokinetic profiles which determine their potentials in clinical application are yet to be fully understood. Therefore, this overview attempts to outline the processes of absorption, distribution, metabolism and excretion (ADME) that govern the pharmacokinetics of CNT. In addition, the molecular mechanisms of intracellular internalization and drug release are also discussed. PMID:24016105

Ye, Rui; Wang, Sheng; Wang, Jing; Luo, Zhiqiang; Peng, Qiang; Cai, Xiaoxiao; Lin, Yunfeng

2013-10-01

171

Poly(fumaric-co-sebacic) microspheres as oral drug delivery systems.  

PubMed

The current study focuses on the development of bioadhesive oral delivery systems based on bioerodible polyanhydrides. The polymers were studied and characterized using a novel tensiometer based on a very sensitive electrobalance. The system was designed to mimic in vivo interactions, thus all experiments were conducted with freshly excised tissue immersed in physiological saline at 37 degrees C. Poly(fumaric-co-sebacic) [P(FA:SA)] was found to be the most bioadhesive polymer from a series of different thermoplastic materials evaluated. Correlation with in vivo performance was investigated by determining gastrointestinal (GI) residence time of barium-loaded microspheres. Residence times of 24 to 36 h provided a strong indication that these microspheres were good candidates for bioadhesive drug delivery systems. To evaluate the effect of these materials on bioavailability, the anticoagulant drug, dicumarol, was encapsulated. Systemic blood levels demonstrated increased bioavailability for the encapsulated dicumarol formulation as compared with unencapsulated drug. (c) 1996 John Wiley & Sons, Inc. PMID:18629855

Chickering, D; Jacob, J; Mathiowitz, E

1996-10-01

172

Experimental characterization of a robotic drug delivery system based on magnetic propulsion  

Microsoft Academic Search

This paper reports on the experimental characterization of a robotic drug delivery system based on an endoscopic capsule propelled in water and silicone oil using electromagnetic actuation. Silicon oil is specifically chosen to mimic the viscous environment in the gastrointestinal (GI) tract within the human body. A permanent magnet is embedded inside the capsule to make it responsive to the

Hao Zhou; Gursel Alici; Weihua Li; Shaya Ghanbar

2011-01-01

173

A review of integrating electroactive polymers as responsive systems for specialized drug delivery applications.  

PubMed

Electroactive polymers (EAPs) are promising candidate materials for the design of drug delivery technologies, especially in conditions where an "on-off" drug release mechanism is required. To achieve this, EAPs such as polyaniline, polypyrrole, polythiophene, ethylene vinyl acetate, and polyethylene may be blended into responsive hydrogels in conjunction with the desired drug to obtain a patient-controlled drug release system. The "on-off" drug release mechanism can be achieved through the environmental-responsive nature of the interpenetrating hydrogel-EAP complex via (i) charged ions initiated diffusion of drug molecules; (ii) conformational changes that occur during redox switching of EAPs; or (iii) electroerosion. These release mechanisms are not exhaustive and new release mechanisms are still under investigation. Therefore, this review seeks to provide a concise incursion and critical overview of EAPs and responsive hydrogels as a strategy for advanced drug delivery, for example, controlled release of neurotransmitters, sulfosalicyclic acid from cross-linked hydrogel, and vaccine delivery. The review further discusses techniques such as linear sweep voltammetry, cyclic voltammetry, impedance spectroscopy, and chronoamperometry for the determination of the redox capability of EAPs. The future implications of the hydrogel-EAP composites include, but not limited to, application toward biosensors, DNA hybridizations, microsurgical tools, and miniature bioreactors and may be utilized to their full potential in the form of injectable devices as nanorobots or nanobiosensors. PMID:23852673

Pillay, Viness; Tsai, Tong-Sheng; Choonara, Yahya E; du Toit, Lisa C; Kumar, Pradeep; Modi, Girish; Naidoo, Dinesh; Tomar, Lomas K; Tyagi, Charu; Ndesendo, Valence M K

2014-06-01

174

Itraconazole Niosomes Drug Delivery System and Its Antimycotic Activity against Candida albicans  

PubMed Central

Niosomes have potential applications in topical drug delivery system. The objective of the study was to formulate and evaluate the niosome of Itraconazole. Surfactant?:?cholesterol ratio and quantity of ethanol used were studied by applying factorial design. Formulated niosomes were evaluated for vesicle size, entrapment efficiency, drug release, skin permeation, and antimycotic activity. Vesicle size, entrapment efficiency, and drug release were markedly dependent on surfactant?:?cholesterol ratio and quantity of ethanol used. Permeation of the drug through the skin was affected by cholesterol content in formulation. Itraconazole niosome were having larger zone of inhibition than marketed formulation when activity was checked against C. albicans. Niosomes may be a promising carrier for topical delivery of Itraconazole especially due to their simple production. PMID:23378932

Wagh, Vijay D.; Deshmukh, Onkar J.

2012-01-01

175

Biomedical Properties Study of Modified Chitosan Nanoparticles for Drug Delivery Systems  

NASA Astrophysics Data System (ADS)

The purpose of this review is to discuss and summarize some of the interesting findings and applications of modified chitosan (MCS) and their derivatives in different areas of drug delivery. This review highlights the important applications of MCS in the design of various novel delivery systems like liposomes, microspheres, microcapsules, and nanoparticles. In addition to their well-known effects on drug solubility and dissolution, bioavailability, safety, and stability, their uses as recipients in drug formulation are also discussed. This review also focuses on various factors influencing inclusion complex formation because an understanding of the same is necessary for proper handling of these versatile materials. Some important considerations in selecting MCS in drug formulation such as their commercial availability, regulatory status, and patent status are also summarized.

Saboktakin, Mohammad Reza

2013-09-01

176

Novel self-nanoemulsifying drug delivery systems (SNEDDS) for oral delivery of cinnarizine: design, optimization, and in-vitro assessment.  

PubMed

Due to its extreme lipophilicity, the oral delivery of cinnarizine (CN) encounters several problems such as poor aqueous solubility and pH-dependent dissolution, which result in low and erratic bioavailability. The current study aims to design self-nanoemulsifying drug delivery systems (SNEDDS) of CN that circumvent such obstacles. Equilibrium solubility of CN was determined in a range of anhydrous and diluted lipid-based formulations. Dynamic dispersion tests were carried out to investigate the efficiency of drug release and magnitude of precipitation that could occur upon aqueous dilution. Droplet sizes of selected formulations, upon (1:1,000) aqueous dilution, were presented. The optimal formulations were enrolled in subsequent dissolution studies. The results showed that increasing lipid chain length and surfactant lipophilicity raised the formulation solvent capacity, while adding co-solvents provoked a negative influence. The inclusion of mixed glycerides and/or hydrophilic surfactants improved the drug release efficiency. Generally, no significant precipitation was observed upon aqueous dilution of the formulations. Five formulations were optimal in terms of their superior self-emulsifying efficiency, drug solubility, dispersion characteristics, and lower droplet size. Furthermore, the optimal formulations showed superior dissolution profile compared to the marketed (Stugeron®) tablet. Most importantly, they could resist the intensive precipitation observed with the marketed tablet upon shifting from acidic to alkaline media. However, SNEDDS containing medium-chain mixed glycerides showed the highest drug release rate and provide great potential to enhance the oral CN delivery. Accordingly, the lipid portion seems to be the most vital component in designing CN self-nanoemulsifying systems. PMID:22760454

Shahba, Ahmad Abdul-Wahhab; Mohsin, Kazi; Alanazi, Fars Kaed

2012-09-01

177

New challenges for pharmaceutical formulations and drug delivery systems characterization using isothermal titration calorimetry.  

PubMed

Long viewed as the 'method of choice' for characterizing thermodynamics and stoichiometry of molecular interactions, with high sensitivity, isothermal titration calorimetry (ITC) has been applied to many areas of pharmaceutical analysis. This review highlights ITC employment to measure binding thermodynamics and their use for pharmaceutical formulations and drug delivery system characterization particularly cyclodextrin-guest interactions, investigation of micellar-based systems, polyelectrolytes, nucleic acid interactions with multivalent cations and the optimization of DNA targeting and delivery. Furthermore, the potential of ITC for the characterization of different functionalities carried by nanoparticles as well as their interaction with living systems was outlined. PMID:18617012

Bouchemal, Kawthar

2008-11-01

178

Multiunit floating drug delivery system of rosiglitazone maleate: development, characterization, statistical optimization of drug release and in vivo evaluation.  

PubMed

A multiunit floating drug delivery system of rosiglitazone maleate has been developed by encapsulating the drug into Eudragit RS100 through nonaqueous emulsification/solvent evaporation method. The in vitro performances of microspheres were evaluated by yield (%), particle size analysis, drug entrapment efficiency, in vitro floating behavior, surface topography, drug-polymer compatibility, crystallinity of the drug in the microspheres, and drug release studies. In vitro release was optimized by a {3, 3} simplex lattice mixture design to achieve predetermined target release. The in vivo performance of the optimized formulation was evaluated in streptozotocin-induced diabetic rats. The results showed that floating microspheres could be successfully prepared with good yields (69-75%), high entrapment (78-97%), narrow size distribution, and desired target release with the help of statistical design of experiments from very small number of formulations. In vivo evaluation in albino rats suggested that floating microspheres of rosiglitazone could be a promising approach for better glycemic control. PMID:19572199

Mohan Kamila, Madan; Mondal, Nita; Kanta Ghosh, Lakshmi; Kumar Gupta, Bijan

2009-01-01

179

Microfabricated drug delivery devices  

Microsoft Academic Search

We review newest developments in the design and fabrication of drug delivery devices based on micropatterned structures. Electronic devices have now reached a stage of dimensions comparable to those of biological macromolecules. This raises exciting possibilities for combining microelectronics and biotechnology to develop new technologies with unprecedented power and versatility. While molecular electronics use the unique self-assembly, switching and dynamic

J. Zachary Hilt; Nicholas A. Peppas

2005-01-01

180

Drug-loaded nano-microcapsules delivery system mediated by ultrasound-targeted microbubble destruction: A promising therapy method  

PubMed Central

The nano-microcapsules drug delivery system is currently a promising method for the treatment of many types of diseases, particularly tumors. However, the drug delivery efficiency does not reach a satisfactory level to meet treatment demands. Therefore, the effectiveness of delivery needs to be improved. Based on the alterations in the structure and modification of nano-microcapsules, ultrasound-targeted microbubble destruction (UTMD), a safe physical targeted method, may increase tissue penetration and cell membrane permeability, aiding the drug-loaded nano-microcapsules ingress the interior of targeted tissues and cells. The effectiveness and exact mechanism of action of the drug-loaded nano-microcapsules delivery system mediated by UTMD have yet to be fully elucidated. In this study, the latest advancement in UTMD-mediated drug loaded nano-microcapsules system technology was reviewed and the hindrances of UTMD-mediated drug delivery were assessed, in combination with a prospective study. The findings suggested that the drug delivery efficiency of nano-microcapsules mediated by UTMD was distinctly improved. Thus, the UTMD-mediated drug-loaded nano-microcapsules delivery system may significantly improve the efficiency of drug delivery, which may be a promising new therapeutic method. PMID:24648976

MA, JING; DU, LIAN FANG; CHEN, MING; WANG, HANG HUI; XING, LING XI; JING, LI FANG; LI, YUN HUA

2013-01-01

181

The biopolymer bacterial nanocellulose as drug delivery system: investigation of drug loading and release using the model protein albumin.  

PubMed

Although bacterial nanocellulose (BNC) has reached enormous interest for biomedical applications because of its outstanding material properties, investigations about its potential as drug delivery system are very rare. In the present study, for the first time, the applicability of BNC as drug delivery system for proteins using serum albumin as model drug was systematically investigated. Additionally, never-dried BNC was compared with freeze-dried BNC. For both types of BNC, a dependency of concentration, temperature, time, and preswelling for albumin loading and release could be demonstrated. These findings indicated an overlay of diffusion- and swelling-controlled processes, which could be confirmed by Ritger-Peppas equation. Freeze-dried samples showed a lower uptake capacity for albumin than native BNC, which was found to be related to changes of the fiber network during the freeze drying process as demonstrated by electron microscopy and protein staining experiments. The integrity and biological activity of proteins could be retained during the loading and release processes, which was demonstrated by gel electrophoresis and the use of luciferase as biologically active molecule. In conclusion, hydrophilicity, high biocompatibility, and controllable drug loading and release render BNC an innovative and attractive biopolymer for controlled drug delivery. PMID:23192666

Müller, Astrid; Ni, Zhixu; Hessler, Nadine; Wesarg, Falko; Müller, Frank A; Kralisch, Dana; Fischer, Dagmar

2013-02-01

182

[Mechanisms of hydroxypropyl methylcellulose for the precipitation inhibitor of supersaturatable self-emulsifying drug delivery systems].  

PubMed

Hydroxypropyl methylcellulose (HPMC) propels self-emulsifying drug delivery systems (SEDDS) to achieve the supersaturated state in gastrointestinal tract, which possesses important significance to enhance oral absorption for poorly water-soluble drugs. This study investigated capacities and mechanisms of HPMC with different viscosities (K4M, K15M and K100M) to inhibit drug precipitation of SEDDS in the simulated gastrointestinal tract environment in vitro. The results showed that HPMC inhibited drug precipitation during the dispersion of SEDDS under gastric conditions by inhibiting the formation of crystal nucleus and the growth of crystals. HPMC had evident effects on the rate of SEDDS lipolysis and benefited the distribution of drug molecules across into the aqueous phase and the decrease of drug sediment. The mechanisms were related to the formed network of HPMC and its viscosities and molecular weight. These results offered a reference for selecting appropriate type of HPMC as the precipitation inhibitor of supersaturatable SEDDS. PMID:23888703

Xiao, Lu; Yi, Tao

2013-05-01

183

The Designs, Syntheses and Medical Applications of Mesoporous Silica Nanoparticle Based Drug Delivery Systems  

E-print Network

of folic?acid?conjugated FMSNs and drug loading: To attachdual delivery of drugs and nucleic acids. 10,11 There are aacid binding properties. 19-21 Another crucial property that makes mesoporous silica materials promising for drug

Li, Zongxi

2012-01-01

184

Pluronic lecithin organogel as a topical drug delivery system.  

PubMed

The objective of this study was to formulate and evaluate the pluronic lecithin organogel containing flurbiprofen for topical application. Different formulations of pluronic lecithin organogels were prepared by using pluronic F127, lecithin, flurbiprofen, isopropyl palmitate, water, sorbic acid, and potassium sorbate. To study the in vitro potential of these formulations, permeation studies were performed with Keshary-Chien diffusion cells. The results of the in vitro permeation studies found that release of flurbiprofen from dialysis membrane-70 was more than excised dorsal rat skin. Gelation temperature study was carried out to determine the temperature where sol-gel transformation takes place. The viscosities of different formulations were determined by using Brookfield Viscometer at 25°C, the viscosity of formulations increases as the lecithin concentration increases. Also the formulations were tested for appearance and feel psychorheologically, pH, and drug content. Interactions between the components of the gel have been investigated by differential scanning calorimetry and X-ray powder diffractometry. The optimized formulation subjected to differential scanning calorimetry shows no drug-polymer interaction. To investigate the in vivo performance of the formulations, a carrageenan-induced rat paw edema model and skin irritation study was used. The stability studies and freeze-thaw thermal cyclic test were carried out, showing no phase separation of gel, and representing gel stability. Statistical analysis of the data of animal study (anti-inflammatory activity) was done by using one way analysis of variance (ANOVA) followed by Dunnett's test. The formulation shows a statistically significant anti-inflammatory activity and is non-irritant to skin. PMID:22747074

Pandey, Mohit; Belgamwar, Veena; Gattani, Surendra; Surana, Sanjay; Tekade, Avinash

2010-01-01

185

Potential for Layered Double Hydroxides-Based, Innovative Drug Delivery Systems  

PubMed Central

Layered Double Hydroxides (LDHs)-based drug delivery systems have, for many years, shown great promises for the delivery of chemical therapeutics and bioactive molecules to mammalian cells in vitro and in vivo. This system offers high efficiency and drug loading density, as well as excellent protection of loaded molecules from undesired degradation. Toxicological studies have also found LDHs to be biocompatible compared with other widely used nanoparticles, such as iron oxide, silica, and single-walled carbon nanotubes. A plethora of bio-molecules have been reported to either attach to the surface of or intercalate into LDH materials through co-precipitation or anion-exchange reaction, including amino acid and peptides, ATPs, vitamins, and even polysaccharides. Recently, LDHs have been used for gene delivery of small molecular nucleic acids, such as antisense, oligonucleotides, PCR fragments, siRNA molecules or sheared genomic DNA. These nano-medicines have been applied to target cells or organs in gene therapeutic approaches. This review summarizes current progress of the development of LDHs nanoparticle drug carriers for nucleotides, anti-inflammatory, anti-cancer drugs and recent LDH application in medical research. Ground breaking studies will be highlighted and an outlook of the possible future progress proposed. It is hoped that the layered inorganic material will open up new frontier of research, leading to new nano-drugs in clinical applications. PMID:24786098

Zhang, Kai; Xu, Zhi Ping; Lu, Ji; Tang, Zhi Yong; Zhao, Hui Jun; Good, David A.; Wei, Ming Qian

2014-01-01

186

Synthesis and characterization of novel dual-responsive nanogels and their application as drug delivery systems  

NASA Astrophysics Data System (ADS)

In this study, a temperature/pH dual-response nanogel based on NIPAm, MAA, and PEGMA was synthesized via emulsion polymerization and characterized by 1H-NMR, FT-IR, TEM and DLS. By introducing a novel initiator, through which PEG-AIBN-PEG was synthesized, it was revealed that the PEG segments from PEG-AIBN-PEG with a dosage of initiator had a significant influence over the macro-state and stability of the nanogels. In order to optimize the feeding prescription for better application as a drug delivery system, the effect of the co-monomer contents on the response to stimuli (temperature and pH value) and cytotoxicity of the nanogels has been studied in detail. The results demonstrated that the responsiveness, reversibility and volume phase transition critical value of the nanogels could be controlled by adjusting the feeding ratio of the co-monomers in the synthesis process. MTT assay results revealed that nanogels with appropriate compositions showed good biocompatibility and relatively low toxicity. Most importantly, by studying the drug loading behavior, it was found that the dimensions of the drug molecules had a considerable influence on the drug loading efficiency and loading capacity of the nanogels, and that the mechanism by which drug molecule sizes influence the drug loading behavior of nanogels needs further investigation. The results indicated that such PNMP nanogels might have potential applications in drug delivery and other medical applications, but that the drug loading mechanism must be further developed.

Peng, Jinrong; Qi, Tingting; Liao, Jinfeng; Fan, Min; Luo, Feng; Li, He; Qian, Zhiyong

2012-03-01

187

Ultrasound Enhanced Drug Delivery to the Brain and Central Nervous System  

PubMed Central

There is an increasing interest in the use of ultrasound to enhance drug delivery to the brain and central nervous system. Disorders of the brain and CNS historically have had poor response to drug therapy due to the presence of the Blood-Brain barrier (BBB). Techniques for circumventing the BBB are typically highly invasive or involve disrupting large portions of the BBB, exposing the brain to pathogens. Ultrasound can be non-invasively delivered to the brain through the intact skull. When combined with preformed microbubbles, ultrasound can safely induce transient, localized and reversible disruption of the BBB, allowing therapeutics to be delivered. Investigations to date have shown positive response to ultrasound BBB disruption combined with therapeutic agent delivery in rodent models of primary and metastatic brain cancer and Alzheimer’s disease. Recent work in non-human primates has demonstrated that the technique is feasible for use in humans. This review examines the current status of drug delivery to the brain and CNS both by disruption of the BBB, and by ultrasound enhancement of drug delivery through the already compromised BBB. Cellular and physical mechanisms of disruption are discussed, as well as treatment technique, safety and monitoring. PMID:22621739

O'Reilly, Meaghan A.; Hynynen, Kullervo

2014-01-01

188

[Influence of silica on intestinal absorption of solid self-microemulsifying drug delivery systems].  

PubMed

Solid carriers had important effects on the properties of solid self-microemulsifying drug delivery systems (S-SMEDDS). In order to make the basis for further development of S-SMEDDS, the influences of silica on the absorption of S-SMEDDS were investigated. An in vitro lipolysis model was used to evaluate the influence of silica on self-microemulsifying drug delivery system digestion from intestinal tract. S-SMEDDS containing silica were prepared by extrusion/spheronization. The drug release and absorption were investigated. The results showed that lipolysis rate and drug concentration in aqueous phase after intestinal lipolysis both increased by adding silica, which was benefit to drug absorption. And silica was not benefit to absorption for slowing drug release. Consistently, there was no significant influence of silica on intestinal absorption. This study implied that the influences of silica on lipolysis rate and drug release were both amount dependent and it is suggested that silica could be used as the solid carrier but the proportion needs to be optimized. PMID:21751501

Huan, Di; Yi, Tao; Liu, Ying; Xiao, Lu; He, Ji-kui

2011-04-01

189

Formulation development of smart gel periodontal drug delivery system for local delivery of chemotherapeutic agents with application of experimental design.  

PubMed

Smart gel periodontal drug delivery systems (SGPDDS) containing gellan gum (0.1-0.8% w/v), lutrol F127 (14, 16, and 18% w/v), and ornidazole (1% w/v) were designed for the treatment of periodontal diseases. Each formulation was characterized in terms of in vitro gelling capacity, viscosity, rheology, content uniformity, in vitro drug release, and syringeability. In vitro gelation time and the nature of the gel formed in simulated saliva for prepared formulations showed polymeric concentration dependency. Drug release data from all formulations was fitted to different kinetic models and the Korsemeyer-Peppas model was the best fit model. Drug release was significantly decreased as the concentration of each polymer component was increased. Increasing the concentration of each polymeric component significantly increased viscosity, syringeability, and time for 50%, 70%, and 90% drug release. In conclusion, the formulations described offer a wide range of physical and drug release characteristics. The formulation containing 0.8% w/v of gellan gum and 16% w/v of lutrol F127 exhibited superior physical characteristics. PMID:20553104

Dabhi, Mahesh R; Nagori, Stavan A; Gohel, Mukesh C; Parikh, Rajesh K; Sheth, Navin R

2010-01-01

190

A vision for cyclodextrin nanoparticles in drug delivery systems and pharmaceutical applications.  

PubMed

Cyclodextrins (CDs) have brought a revolution in the pharmaceutical field over the last decade. Natural and modified CDs (?-CD and ?-CD) have been studied and some have gained US FDA approval or achieved 'Generally Regarded as Safe' (GRAS) status. Another characteristic of CDs is the ease with which they can be induced to form supramolecular structures for its use in drug delivery. CDs, grafted or crosslinked with polymers, are now being developed into 'smart' systems for efficient targeted drug delivery, especially for hydrophobic drugs. Amphiphilic CDs have the ability to form nanospheres or nanocapsules via a simple nanoprecipitation technique. This review deals with different types of CDs, and their efficacy, physicochemical properties and transformation into nanoparticles with interesting in vitro and in vivo applications. PMID:24981652

Lakkakula, Jaya Raju; Maçedo Krause, Rui Werner

2014-05-01

191

A Transdermal Drug Delivery System Based on LIGA Technology and Soft Lithography  

NASA Astrophysics Data System (ADS)

This report presents a transdermal drug delivery system based on LIGA fabricated microparts. It is a portable device combining a magnetically actuated micro gear pump with a microneedle array. The fluidic behaviour of the system is analyzed in order to predict its performance according to the dimension of the microparts and then compared to experimental data. The manufacturing process of both micropump and microneedle array are described.

Matteucci, Marco; Perennes, Frederic; Marmiroli, Benedetta; Di Fabrizio, Enzo

2007-01-01

192

Diffusion-controlled drug delivery systems: calculation of the required composition to achieve desired release profiles.  

PubMed

The aim of this study was to investigate the effect of the composition of diffusion-controlled release devices (type and amount of plasticizer, type of polymer) on the drug diffusivity and the resulting release kinetics in a quantitative way. Diltiazem hydrochloride and theophylline were investigated in ethyl cellulose (EC) and Eudragit((R)) RS 100, plasticized with various amounts of acetyltributyl citrate (ATBC), acetyltriethyl citrate (ATEC), dibutyl phthalate (DBP), dibutyl sebacate (DBS), diethyl phthalate (DEP), and tributyl citrate (TBC). Thin drug-containing films (monolithic solutions) were used to determine the diffusion coefficients experimentally. The effect of the type and amount of plasticizer on the drug diffusivity was found to be significant, whereas the chain length of the polymer only played a minor rule in the investigated systems. Interestingly, a quantitative relationship between the diffusion coefficient of the drug and the plasticizer level could be established. Based on these results, the release kinetics of diffusion-controlled drug delivery systems could be predicted. In this study, the release patterns from microparticles were calculated and the significant effect of the composition of the device on the resulting release rate was simulated. The latter could be effectively modified by varying the type and amount of plasticizer. Independent experiments verified the theoretical predictions. The practical benefit of the presented method is to calculate the required composition of diffusion-controlled drug delivery systems (monolithic solutions) to achieve desired release profiles. PMID:10425342

Siepmann, J; Lecomte, F; Bodmeier, R

1999-08-01

193

Characterization of formulation parameters affecting low molecular weight drug release from in situ forming drug delivery systems  

PubMed Central

In situ forming implants (ISFI) have shown promise in delivering adjuvant chemotherapy following minimally invasive cancer therapies such as thermal ablation of tumors. While ISFI systems have been thoroughly investigated for delivery of high molecular weight (Mw) therapeutics, little research has been conducted to optimize their design for delivery of low Mw drugs. This study examined the effect of varying the formulation components on the low Mw drug release profile from a ISFI consisting of poly(D,L-lactide-co-glycolide), fluorescein (model drug), and excipient dissolved in 1-methyl-2-pyrrolidinone (NMP). Effects of varying PLGA Mw, excipient concentration, and drug loading were studied. Additionally, solubility studies were conducted to determine the critical water concentration required for phase inversion. Results demonstrated that PLGA Mw was the most significant factor in modulating low Mw drug release from the ISFI systems. ISFI formulations comprised of a low Mw (16 kDa) PLGA showed a significantly (p<0.05) lower burst release (after 24 hours), 28.2 ± 0.5%, compared to higher Mw PLGA (60 kDa), 55.1 ± 3.1%. Critical water concentration studies also demonstrated that formulations with lower Mw PLGA had increased solubility in water and may thus require more time to phase invert and release the drug. PMID:20186771

Patel, Ravi B.; Carlson, Angela; Solorio, Luis

2010-01-01

194

Treatment of intermediate stage hepatocellular carcinoma: a review of intrahepatic doxorubicin drug-delivery systems.  

PubMed

The biopharmaceutical properties of doxorubicin delivered via two drug-delivery systems (DDSs) for the palliative treatment of unresectable hepatocellular carcinoma were reviewed with relation to the associated liver and tumor (patho)physiology. These two DDSs, doxorubicin emulsified with Lipiodol(®) and doxorubicin loaded into DC Bead(®) are different regarding tumor delivery, release rate, local bioavailability, if and how they can be given repeatedly, biodegradability, length of embolization and safety profile. There have been few direct head-to-head comparisons of these DDSs, and in-depth investigations into their in vitro and in vivo performance is warranted. PMID:24856170

Dubbelboer, Ilse R; Lilienberg, Elsa; Ahnfelt, Emelie; Sjögren, Erik; Axén, Niklas; Lennernäs, Hans

2014-04-01

195

Design and characterization of colon-specific drug delivery system containing paracetamol microsponges.  

PubMed

The present work was aimed at designing microsponge based colon specific drug delivery system containing paracetamol. Eudragit S-100 based microsponges containing drug in varying amounts were prepared using quasi-emulsion solvent diffusion method. The microsponges were prepared by optimizing various process parameters. DSC and FTIR studies indicated compatibility of the drug in various formulations. Shape and surface morphology of the microsponges were examined using scanning electron microscopy. The formulations were subjected to in vitro release studies and the results were evaluated kinetically and statistically. The in vitro release data showed a bi-phasic pattern with an initial burst effect. In the first hour drug release from microsponges was found to be between 18-30%. The cumulative percent release at the end of 12(th) hour was noted to be between 74-98%. The release kinetics showed that the data followed Higuchi model and the main mechanism of drug release was diffusion. The colon specific tablets were prepared by compressing the microsponges followed by coating with pectin: hydroxypropylmethyl cellulose (HPMC) mixture. In vitro release studies exhibited that compression coated colon specific tablet formulations started releasing the drug at 6(th) hour corresponding to the arrival time at proximal colon. The study presents a new approach for colon specific drug delivery. PMID:21656358

Jain, Vikas; Singh, Ranjit

2011-05-01

196

Polymers for Colon Targeted Drug Delivery  

PubMed Central

The colon targeted drug delivery has a number of important implications in the field of pharmacotherapy. Oral colon targeted drug delivery systems have recently gained importance for delivering a variety of therapeutic agents for both local and systemic administration. Targeting of drugs to the colon via oral administration protect the drug from degradation or release in the stomach and small intestine. It also ensures abrupt or controlled release of the drug in the proximal colon. Various drug delivery systems have been designed that deliver the drug quantitatively to the colon and then trigger the release of drug. This review will cover different types of polymers which can be used in formulation of colon targeted drug delivery systems. PMID:21969739

Rajpurohit, H.; Sharma, P.; Sharma, S.; Bhandari, A.

2010-01-01

197

Evaluation of powder mixtures and hydrophilic gastroretentive drug delivery systems containing zinc acetate and sodium bicarbonate.  

PubMed

The aim of this study was to develop and study floating controlled drug delivery systems consisting of a model drug (zinc acetate dihydrate), different forms of a matrix-forming polymer (Metolose 90 SH) and sodium bicarbonate as an effervescent component. The proportions of Metolose and bicarbonate were varied, and the effects of the different ratios on the properties of the resulting powders and tablets were determined. The water uptakes of different powder mixtures were initially evaluated. These tests indicated the interaction of the active and effervescent agent, this phenomenon leading to an unpredicted increase in the amount of liquid taken up. This interaction was evaluated as concerns the degradation of the hydrophilic matrix system. The disintegration of tablets with different compositions revealed that this interaction increases the time required for the disintegration of these systems. The study demonstrated that the interaction of the components induced significant changes in the parameters of this new sensitive delivery system. In the last steps, the buoyancy and dissolution properties of tablets that appeared appropriate for the formulation of a controlled drug delivery system were investigated. PMID:21109379

Baki, Gabriella; Bajdik, János; Pintye-Hódi, Klára

2011-03-25

198

Hydroxyapatite-magnetite-MWCNT nanocomposite as a biocompatible multifunctional drug delivery system for bone tissue engineering.  

PubMed

New magnetic hydroxyapatite-based nanomaterials as bone-specific systems for controlled drug delivery have been synthesized. The synthesized hydroxyapatite, HA, decorated with magnetite nanoparticles by a deposition method (HA/Fe3O4) and the nanocomposite system obtained using magnetic multi-walled carbon nanotubes (HA/MWCNT/Fe3O4) as a filler for HA have been characterized by chemical and morphological analyses, and their biological behavior was investigated. The systems have also been doped with clodronate in order to combine the effect of bone biomineralization induced by hydroxyapatite-based composites with the decrease of osteoclast formation induced by the drug. An analysis of the preosteoclastic RAW264.7 cell proliferation by MTT assay confirmed the high biocompatibility of the three systems. TRAP staining of RAW 264.7 conditioned with sRAKL to induce osteoclastogenesis, cultured in the presence of the systems doped and undoped with clodronate, showed the inhibitory effect of clodronate after we counted the MNC TRAP(+)cells but only in the osteoclast formation; in particular, the system HA/Fe3O4-Clo exerted a high inhibitory effect compared to the drug alone. These results demonstrate that the synthesized nanocomposites are a biocompatible magnetic drug delivery system and can represent a useful multimodal platform for applications in bone tissue engineering. PMID:25265364

Pistone, Alessandro; Iannazzo, Daniela; Panseri, Silvia; Montesi, Monica; Tampieri, Anna; Galvagno, Signorino

2014-10-24

199

Hydroxyapatite-magnetite-MWCNT nanocomposite as a biocompatible multifunctional drug delivery system for bone tissue engineering  

NASA Astrophysics Data System (ADS)

New magnetic hydroxyapatite-based nanomaterials as bone-specific systems for controlled drug delivery have been synthesized. The synthesized hydroxyapatite, HA, decorated with magnetite nanoparticles by a deposition method (HA/Fe3O4) and the nanocomposite system obtained using magnetic multi-walled carbon nanotubes (HA/MWCNT/Fe3O4) as a filler for HA have been characterized by chemical and morphological analyses, and their biological behavior was investigated. The systems have also been doped with clodronate in order to combine the effect of bone biomineralization induced by hydroxyapatite-based composites with the decrease of osteoclast formation induced by the drug. An analysis of the preosteoclastic RAW264.7 cell proliferation by MTT assay confirmed the high biocompatibility of the three systems. TRAP staining of RAW 264.7 conditioned with sRAKL to induce osteoclastogenesis, cultured in the presence of the systems doped and undoped with clodronate, showed the inhibitory effect of clodronate after we counted the MNC TRAP+cells but only in the osteoclast formation; in particular, the system HA/Fe3O4-Clo exerted a high inhibitory effect compared to the drug alone. These results demonstrate that the synthesized nanocomposites are a biocompatible magnetic drug delivery system and can represent a useful multimodal platform for applications in bone tissue engineering.

Pistone, Alessandro; Iannazzo, Daniela; Panseri, Silvia; Montesi, Monica; Tampieri, Anna; Galvagno, Signorino

2014-10-01

200

The ideal drug delivery system: a look into the future.  

PubMed

In the very near future, the CFC manufacturers are going to be obliged to stop their production as a result of the "Montreal protocole on substances that deplete the ozone layer". The replacement of these propellants by other fluorinated ones will be possible as soon as their lack of toxicity has been demonstrated. Other substitution substances like haliphatic hydrocarbons (butane, propane) or compressed air generated by the device system itself or the user himself are also under development. The pulverisation can also be obtained by the pressure of a classical propellant onto an aluminum or plastic bag. The dispersion is achieved by means of a regulator which is positioned into the valve. The hand-operated spray pumps with or without compression will also allow the obtention of very small particles though the delivered doses are reduced. However, as few of the new devices have metered valves, they are not yet suitable for pulmonary administration. PMID:10147683

Aiache, J M

1991-01-01

201

Drug delivery system for the treatment of endometrial carcinoma  

NASA Astrophysics Data System (ADS)

It has been elaborated a polymer system containing medroxyprogesterone acetate (MPA), which is inserted by physicians into the womb in order to release the hormone inside only. The device has a shape of thin rod of diameter of 4 mm and length of 30 mm. It contains about 350 mg of MPA trapped in poly(ethylene oxide) matrix. The walls of the rod are covered with a few layers of latex, and the final product undergoes radiation sterilization. The rate of release of MPA to the physiological solution with respect to number of latex layers has been monitored by UV spectroscopy at 240 nm. The results of experiments in vitro have been compared to those obtained in vivo.

Rosiak, J. M.; Kowalski, A.; Dec, W.

1998-06-01

202

Preparation and characterization of superporous hydrogels as gastroretentive drug delivery system for rosiglitazone maleate  

PubMed Central

Background and the purpose of the study Many drugs which have narrow therapeutic window and are absorbed mainly in stomach have been developed as gastroretentive delivery system. Rosiglitazone maleate, an anti-diabetic, is highly unstable at basic pH and is extensively absorbed from the stomach. Hence there is a need to develop a gastroretentive system. In this study a superporous hydrogel was developed as a gastroretentive drug delivery system. Methods Chitosan/poly(vinyl alcohol) interpenetrating polymer network type superporous hydrogels were prepared using a gas foaming method employing glyoxal as the crosslinking agent for Rosiglitazone maleate. Sodium bicarbonate was applied as a foaming agent to introduce the porous structure. Swelling behaviors of superporous hydrogel in acidic solution were studied to investigate their applications for gastric retention device. The optimum preparation condition of superporous hydrogels was obtained from the gelation kinetics. FT-IR, scanning electron microscopy, porosity and swelling ratio studies were used to characterize these polymers. In vitro drug release studies were also carried out. Results The introduction of a small amount of Poly(Vinyl Alcohol) enhanced the mechanical strength but slightly reduced the swelling ratio. The prepared superporous hydrogels were highly sensitive to pH of swelling media, and showed reversible swelling and de-swelling behaviors maintaining their mechanical stability. The degradation kinetics in simulated gastric fluid showed that it had biodegradability. Swelling was dependent on the amount of chitosan and crosslinker. The drug release from superporous hydrogels was sustained for 6 hrs. Major Conclusion The studies showed that chitosan-based superporous hydrogels could be used as a gastroretentive drug delivery system for rosiglitazone maleate in view of their swelling and prolonged drug release characteristics in acidic pH. PMID:22615618

Vishal Gupta, N.; Shivakumar, H.G.

2010-01-01

203

Proliposomes as a drug delivery system to decrease the hepatic first-pass metabolism: Case study using a model drug.  

PubMed

Objective of the present study was to develop a proliposomal formulation to decrease the hepatic first-pass metabolism of a highly metabolized drug. Lovastatin was chosen as the model drug. Proliposomes were prepared by mixing different ratios of phospholipids such as soy phosphatidylcholine (SPC), hydrogenated egg phosphatidylcholine (HEPC) and dimyristoyl phosphatidylglycerol (DMPG) individually with drug and cholesterol in an organic solvent. Proliposomal powder was obtained following evaporation of the solvent. The proliposomal powder was either filled into capsules or compressed into tablets. Physical characterization, in vitro drug transport studies and in vitro dissolution of formulations and pure drug was carried out. In vitro transport across the membrane was evaluated using parallel artificial membrane permeability assay (PAMPA). The extent of drug released from various proliposomal formulations in the first 30min was 85%, 87% and 96% with DMPG, SPC and HEPC containing formulations respectively, while the pure drug formulation showed 48% drug release in the same period. In vivo studies were carried out in male Sprague-Dawley rats. Following single oral administration of the selected formulation (F9), a relative bioavailability of 162% was achieved compared to pure lovastatin. The study demonstrated that proliposomes can be used as a drug delivery system to decrease the hepatic first-pass metabolism. PMID:25159836

Yanamandra, Sarala; Venkatesan, Natarajan; Kadajji, Veeran Gowda; Wang, Zhijun; Issar, Manish; Betageri, Guru V

2014-11-20

204

Polypyrrole Film as a Drug Delivery System for the Controlled Release of Risperidone  

NASA Astrophysics Data System (ADS)

Conducting polymers are finding applications in medicine including drug delivery systems, biosensors and templates for the regeneration of nervous pathways. We aim to develop a novel system where the drug release rate can be controlled by electrical stimulation. Polypyrrole (PPY) is being used as a drug delivery system due to its inherent electrical conductivity, ease of preparation and apparent biocompatibility. Risperidone is an atypical antipsychotic drug used in the treatment of psychosis and related disorders, including schizophrenia. PPY was synthesised using p-toluene sulfonic acid as a primary dopant, in the presence of risperidone. A validated high performance liquid chromatography (HPLC) analytical method was used to quantify risperidone release. It has been demonstrated that the release rate of risperidone can be altered through the application, or absence, of electrical stimulation. Technology such as this would find use in drug-delivering implants where the dose could be adjusted through application of external stimulus, optimising benefit to side effect ratio, while simultaneously ensuring patient adherence (which is a particular challenge in mental health conditions).

Svirskis, Darren; Travas-Sejdic, Jadranka; Rodgers, Anthony; Garg, Sanjay

2009-07-01

205

Effect of Formulation Components on the In Vitro Permeation of Microemulsion Drug Delivery System of Fluconazole  

Microsoft Academic Search

The purpose of this study was to evaluate the effect of formulation components on the in vitro skin permeation of microemulsion drug delivery system containing fluconazole (FLZ). Lauryl alcohol (LA) was screened as the\\u000a oil phase of microemulsions. The pseudo-ternary phase diagrams for microemulsion regions were constructed using LA as the\\u000a oil, Labrasol (Lab) as the surfactant and ethanol (EtOH)

Mrunali R. Patel; Rashmin B. Patel; Jolly R. Parikh; Ajay B. Solanki; Bharat G. Patel

2009-01-01

206

Lyotropic liquid crystalline phases formed from glycerate surfactants as sustained release drug delivery systems.  

PubMed

A new class of surfactants with glycerate headgroups, that form viscous lyotropic liquid crystalline phases in excess water, have been investigated for their potential to provide sustained release matrices for depot drug delivery. Oleyl glycerate and phytanyl glycerate were used as representative surfactants of this new class, and their behaviour compared with that of glyceryl monooleate (GMO). The surfactants were found to form reverse hexagonal phase (H(II)) in excess water, and the matrices were loaded with a series of model hydrophobic and hydrophilic drugs, (paclitaxel, irinotecan, glucose, histidine and octreotide), and the release kinetics determined. In all cases, the release behaviour obeyed Higuchi kinetics, with linear drug release versus square root of time. The H(II) phases released model drugs slower than the GMO cubic phase matrix. The oleyl glycerate matrix was found to consistently release drug faster than the phytanyl glycerate matrix, despite both matrices being based on H(II) phase. To further demonstrate the potential utility of these materials as drug depot delivery systems, an injectable precursor formulation for octreotide was also prepared and demonstrated to provide controlled release for the peptide. The stability of the H(II) phase to likely in vivo breakdown products was also assessed. PMID:16413980

Boyd, Ben J; Whittaker, Darryl V; Khoo, Shui-Mei; Davey, Greg

2006-02-17

207

A Targeting Drug Delivery System for Ovarian Carcinoma: Transferrin Modified Lipid Coated Paclitaxel-loaded Nanoparticles.  

PubMed

The transferring modified lipid coated PLGA nanoparticles, as a targetable vector, were developed for the targeting delivery of anticancer drugs with paclitaxel (PTX) as a model drug to the ovarian carcinoma, which combines the advantages and avoids disadvantages of polymeric nanoparticles and liposomes in drug delivery. A transmission electron microscopy (TEM) confirmed the lipid coating on the polymeric core. Physicochemical characterizations of TFLPs, such as particle size, zeta potential, morphology, encapsulation efficiency, and in vitro PTX release, were also evaluated. In the cellular uptake study, the TFLPs were more efficiently endocytosed by the A2780 cells with high expression of transferrin receptors than HUVEC cells without the transferrin receptors. Furthermore, the anticancer efficacy of TFLPs on the tumor spheroids was stronger than that of lipid coated PLGA nanoparticles (LPs) and PLGA nanoparticles. In the in vivo study, the TFLPs showed the best inhibition effect of the tumor growth for the ovarian carcinoma-bearing mice. In brief, the TFLPs were proved to be an efficient targeting drug delivery system for ovarian carcinoma. PMID:24443309

Li, R; Zhang, Q; Wang, X-Y; Chen, X-G; He, Y-X; Yang, W-Y; Yang, X

2014-10-01

208

Design and in vitro evaluation of multiparticulate floating drug delivery system of zolpidem tartarate.  

PubMed

Zolpidem tartarate is a non-benzodiazepine, sedative-hypnotic, which finds its major use in various types of insomnia. The present work relates to development of multiparticulate floating drug delivery system based on gas generation technique to prolong the gastric residence time and to increase the overall bioavailability. Modified release dosage form of zolpidem tartarate adapted to release over a predetermined time period, according to biphasic profile of dissolution, where the first phase is immediate release phase for inducing the sleep and the second phase is modified release phase for maintaining the sleep up to 10 h. The system consists of zolpidem tartarate layered pellets coated with effervescent layer and polymeric membrane. The floating ability and in vitro drug release of the system were dependent on amount of the effervescent agent (sodium bicarbonate) layered onto the drug layered pellets, and coating level of the polymeric membrane (Eudragit(®) NE 30D). The system could float completely within 5 min and maintain the floating over a period of 10 h. The multiparticulate floating delivery system of zolpidem tartarate with rapid floating and modified drug release was obtained. PMID:21974910

Amrutkar, P P; Chaudhari, P D; Patil, S B

2012-01-01

209

The Biocompatibility of Nanodiamonds and Their Application in Drug Delivery Systems  

PubMed Central

Nanodiamonds (NDs), as a new member of the carbon nanoparticles family, have attracted more and more attention in biomedicine recently due to their excellent physical and chemical properties. This paper summarizes the main results from the in vitro and in vivo safety assessments of NDs and reports the application of NDs in the development of drug delivery systems. In view of the NDs' characteristics of easy formation of a porous cluster structure in solution, an adsorption model for a variety of functional molecules on the ND clusters is proposed, which provides new ideas for developing a novel smart drug with various features such as sustained-release, targeting, and fluorescence imaging. PMID:22509196

Zhu, Ying; Li, Jing; Li, Wenxin; Zhang, Yu; Yang, Xiafeng; Chen, Nan; Sun, Yanhong; Zhao, Yun; Fan, Chunhai; Huang, Qing

2012-01-01

210

Hydrogel-Based Colloidal Polymeric System for Protein and Drug Delivery: Physical and Chemical Characterization, Permeability Control and Applications  

Microsoft Academic Search

The use of polymeric nanoparticles as drug carriers is receiving an increasing amount of attention both in academia and industry.\\u000a The development of suitable delivery systems for protein drugs with high molecular weights and short half-lives is of current\\u000a interest. In addition, nanoparticles have a number of potential applications in drug and vaccine delivery as well as gene\\u000a therapy applications.

Ales Prokop; Evgenii Kozlov; Gianluca Carlesso; Jeffrey M. Davidson

211

An implantable device for localized drug delivery and sensing  

E-print Network

There are many potential clinical applications for localized drug delivery and sensing systems, such as cancer, vaccinations, pain management, and hormone therapy. Localized drug delivery systems reduce the amount of drug ...

Daniel, Karen D

2009-01-01

212

Enhancement of oral bioavailability of cyclosporine A: comparison of various nanoscale drug-delivery systems.  

PubMed

A variety of nanoscale delivery systems have been shown to enhance the oral absorption of poorly water-soluble and poorly permeable drugs. However, the performance of these systems has seldom been evaluated simultaneously. The aim of this study was to compare the bioavailability enhancement effect of lipid-based nanocarriers with poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to highlight the importance of the lipid composition, with cyclosporine A (CyA) as a model drug. CyA-loaded PLGA NPs, nanostructured lipid carriers (NLCs), and self-microemulsifying drug-delivery systems (SMEDDS) were prepared. The particle size of PLGA NPs (182.2 ± 12.8 nm) was larger than that of NLCs (89.7 ± 9.0 nm) and SMEDDS (26.9 ± 1.9 nm). All vehicles are charged negatively. The entrapment efficiency of PLGA NPs and NLCs was 87.6%± 1.6% and 80.3%± 0.6%, respectively. In vitro release tests indicated that the cumulative release of CyA was lower than 4% from all vehicles, including Sandimmun Neoral(®), according to the dialysis method. Both NLCs and SMEDDS showed high relative oral bioavailability, 111.8% and 73.6%, respectively, after oral gavage administration to beagle dogs, which was not statistically different from commercial Sandimmun Neoral(®). However, PLGA NPs failed to achieve efficient absorption, with relative bioavailability of about 22.7%. It is concluded that lipid-based nanoscale drug-delivery systems are superior to polymeric NPs in enhancing oral bioavailability of poorly water-soluble and poorly permeable drugs. PMID:25378925

Wang, Kai; Qi, Jianping; Weng, Tengfei; Tian, Zhiqiang; Lu, Yi; Hu, Kaili; Yin, Zongning; Wu, Wei

2014-01-01

213

Enhancement of oral bioavailability of cyclosporine A: comparison of various nanoscale drug-delivery systems  

PubMed Central

A variety of nanoscale delivery systems have been shown to enhance the oral absorption of poorly water-soluble and poorly permeable drugs. However, the performance of these systems has seldom been evaluated simultaneously. The aim of this study was to compare the bioavailability enhancement effect of lipid-based nanocarriers with poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to highlight the importance of the lipid composition, with cyclosporine A (CyA) as a model drug. CyA-loaded PLGA NPs, nanostructured lipid carriers (NLCs), and self-microemulsifying drug-delivery systems (SMEDDS) were prepared. The particle size of PLGA NPs (182.2±12.8 nm) was larger than that of NLCs (89.7±9.0 nm) and SMEDDS (26.9±1.9 nm). All vehicles are charged negatively. The entrapment efficiency of PLGA NPs and NLCs was 87.6%±1.6% and 80.3%±0.6%, respectively. In vitro release tests indicated that the cumulative release of CyA was lower than 4% from all vehicles, including Sandimmun Neoral®, according to the dialysis method. Both NLCs and SMEDDS showed high relative oral bioavailability, 111.8% and 73.6%, respectively, after oral gavage administration to beagle dogs, which was not statistically different from commercial Sandimmun Neoral®. However, PLGA NPs failed to achieve efficient absorption, with relative bioavailability of about 22.7%. It is concluded that lipid-based nanoscale drug-delivery systems are superior to polymeric NPs in enhancing oral bioavailability of poorly water-soluble and poorly permeable drugs. PMID:25378925

Wang, Kai; Qi, Jianping; Weng, Tengfei; Tian, Zhiqiang; Lu, Yi; Hu, Kaili; Yin, Zongning; Wu, Wei

2014-01-01

214

Floating or pulsatile drug delivery systems based on coated effervescent cores.  

PubMed

The objective of this study was to develop and evaluate floating and pulsatile drug delivery systems based on a reservoir system consisting of a drug-containing effervescent core and a polymeric coating. Preliminary studies identified important core and coating properties for the two systems. The mechanical properties (puncture strength and elongation) of acrylic (Eudragit RS, RL or NE) and cellulosic (cellulose acetate, ethyl cellulose) polymers, which primarily determined the type of delivery system, were characterized with a puncture test in the dry and wet state. For the floating system, a polymer coating with a high elongation value and high water- and low CO(2) permeabilities was selected (Eudragit RL/acetyltributyl citrate 20%, w/w) in order to initiate the effervescent reaction and the floating process rapidly, while for the pulsatile DDS, a weak, semipermeable film, which ruptured after a certain lag time was best (ethyl cellulose/dibutyl sebacate 20%, w/w). With the floating system, the polymeric coating did not retard the drug release. A polymer (cellulose acetate or hydroxypropylmethylcellulose) was added to the core to control the drug release. The time to flotation could be controlled by the composition (type of filler, concentration of effervescent agents) and hardness of the tablet core and the composition (type of polymer and plasticizer) and thickness of the coating. For the pulsatile system, a quick releasing core was formulated in order to obtain a rapid drug release after the rupture of the polymer coating. The lag time prior to the rapid drug release phase increased with increasing core hardness and coating level. PMID:10502623

Krögel, I; Bodmeier, R

1999-10-01

215

Formulation and evaluation of niosomal nasal drug delivery system of folic acid for brain targeting.  

PubMed

Nasal mucosa offers advantages to deliver drugs to brain via olfactory route thus provides rapid onset of drug action and hence faster therapeutic effect. Therefore, various strategies have been proposed to improve the delivery of different drugs to brain including liposomes, colloidal drug carriers, micelles, chimeric peptide technology and nanotechnology through nasal route. The low blood level of folates is the primary cause of depression in Alzheimer's disease. Folic acid is a water soluble vitamin showing difficulty in crossing the blood brain barrier and thus was formulated as niosomal nasal drug delivery systems to target the brain. In the present work, folic acid niosomes were prepared using different nonionic surfactants i.e., span 20, span 60, span 80, tween 20, tween 80 and cholesterol by using lipid layer hydration technique. These were evaluated for particle size, viscosity, osmotic shock, entrapment efficiency and in vitro drug release. The influence of different formulation variables such as surfactant type, surfactant concentration, and cholesterol concentration was optimized for required size distribution, viscosity, entrapment efficiency and in vitro release. The prepared niosomes were in the size range of 3.05-5.625 µm. Niosomes prepared with span 60 and cholesterol in the ratio of 1:1 (50 mg: 50 mg) shown higher entrapment efficiency of 69.42% and better in vitro drug release of 64.2% at the end of 12 hrs and therefore considered as optimized formulation. The stability studies were carried out by storing niosomes at 4±1°C and 25±1°C and showed good stability over the period of storage. The release of drug from niosomes followed anomalous diffusion and obeyed first order release kinetics. Ex-vivo perfusion studies were also performed by using rat model, about 48.15% of drug was found to be absorbed through nasal cavity at the end of 6 hrs. PMID:23863098

Ravouru, Nagaraju; Kondreddy, Pallavi; Korakanchi, Deepthy; Haritha, M

2013-12-01

216

Mechanism-based tumor-targeting drug delivery system. Validation of efficient vitamin receptor-mediated endocytosis and drug release.  

PubMed

An efficient mechanism-based tumor-targeting drug delivery system, based on tumor-specific vitamin-receptor mediated endocytosis, has been developed. The tumor-targeting drug delivery system is a conjugate of a tumor-targeting molecule (biotin: vitamin H or vitamin B-7), a mechanism-based self-immolative linker and a second-generation taxoid (SB-T-1214) as the cytotoxic agent. This conjugate (1) is designed to be (i) specific to the vitamin receptors overexpressed on tumor cell surface and (ii) internalized efficiently through receptor-mediated endocytosis, followed by smooth drug release via glutathione-triggered self-immolation of the linker. In order to monitor and validate the sequence of events hypothesized, i.e., receptor-mediated endocytosis of the conjugate, drug release, and drug-binding to the target protein (microtubules), three fluorescent/fluorogenic molecular probes (2, 3, and 4) were designed and synthesized. The actual occurrence of these processes was unambiguously confirmed by means of confocal fluorescence microscopy (CFM) and flow cytometry using L1210FR leukemia cells, overexpressing biotin receptors. The molecular probe 4, bearing the taxoid linked to fluorescein, was also used to examine the cell specificity (i.e., efficacy of receptor-based cell targeting) for three cell lines, L1210FR (biotin receptors overexpressed), L1210 (biotin receptors not overexpressed), and WI38 (normal human lung fibroblast, biotin receptor negative). As anticipated, the molecular probe 4 exhibited high specificity only to L1210FR. To confirm the direct correlation between the cell-specific drug delivery and anticancer activity of the probe 4, its cytotoxicity against these three cell lines was also examined. The results clearly showed a good correlation between the two methods. In the same manner, excellent cell-specific cytotoxicity of the conjugate 1 (without fluorescein attachment to the taxoid) against the same three cell lines was confirmed. This mechanism-based tumor-targeting drug delivery system will find a range of applications. PMID:20429547

Chen, Shuyi; Zhao, Xianrui; Chen, Jingyi; Chen, Jin; Kuznetsova, Larisa; Wong, Stanislaus S; Ojima, Iwao

2010-05-19

217

Ultrasound and transdermal drug delivery  

Microsoft Academic Search

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Application of ultrasound to the skin increases its permeability (sonophoresis) and enables the delivery of various substances into and through the skin. This review presents

Ilana Lavon; Joseph Kost

2004-01-01

218

Casein-based formulations as promising controlled release drug delivery systems.  

PubMed

Casein, the major milk protein, forms an integral part of the daily diet in many parts of the world. Casein possesses a number of interesting properties that make it a good candidate for conventional and novel drug delivery systems. This article reviews approaches aimed to associate bioactive molecules to casein and analyze the evidence of their efficacy in modifying the release and/or improving the bioavailability of the associated molecules. The ability of casein to modify drug dissolution from compacts was reported. The high tensile strength of casein films, favors its use as an acceptable film-coating for tablets. Naturally occurring genipin and a natural tissue enzyme, transglutaminase, were used as crosslinkers to prepare novel casein-based hydrogels for the controlled release of bioactives. Casein floating beads were developed to increase the residence time of drugs in the stomach based on its emulsifying and bubble-forming properties. Casein-based microparticles entrapping bioactive molecules were prepared via emulsification-chemical crosslinking with glutaraldehyde, enzymatic crosslinking by transglutaminase, simple coacervation and electrostatic complexation. Casein nano-formulations were also prepared to deliver nutraceuticals and synthetic drugs via enzymatic crosslinking, graft copolymerization, heat-gelation and polyelectrolyte ionic complexation. It can be concluded that casein-based formulations are promising materials for controlled drug delivery. PMID:21338636

Elzoghby, Ahmed O; El-Fotoh, Wael S Abo; Elgindy, Nazik A

2011-08-10

219

pH-responsive mesoporous silica nanoparticles employed in controlled drug delivery systems for cancer treatment  

PubMed Central

In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles (MSNs) with a functional surface possess obvious advantages and were thus rapidly developed for cancer treatment. Many stimuli-responsive materials, such as nanoparticles, polymers, and inorganic materials, have been applied as caps and gatekeepers to control drug release from MSNs. This review presents an overview of the recent progress in the production of pH-responsive MSNs based on the pH gradient between normal tissues and the tumor microenvironment. Four main categories of gatekeepers can respond to acidic conditions. These categories will be described in detail. PMID:24738037

Yang, Ke-Ni; Zhang, Chun-Qiu; Wang, Wei; Wang, Paul C.; Zhou, Jian-Ping; Liang, Xing-Jie

2014-01-01

220

Development and evaluation of pluronic- and methylcellulose-based thermoreversible drug delivery system for insulin.  

PubMed

Abstract The objective of the current work was to develop and evaluate thermoreversible subcutaneous drug delivery system for Insulin. Thermoreversible in-situ gel system was developed and evaluated both in-vitro and in-vivo comprising of pluronic F-127 alone or in combination with methylcellulose in different ratios. The drug release kinetics and mechanism was predicted by applying various mathematical models to the in-vitro dissolution data. Rabbits were used as animal model following subcutaneous injection to predict various pharmacokinetic parameters by applying Pk-Summit® software. The in-vitro and in-vivo data revealed that the formulation IPM 15/3 consisting of the pluronic F-127 (15% w/v) and methylcellulose (3% w/v) was the most robust and capable formulation for extending the drug release and maintaining basal plasma insulin level between 10 and 40?µU/ml for 240?h (10?d). PMID:23984755

Nasir, Fazli; Iqbal, Zafar; Khan, Amirzada; Khan, Jamshaid A; Khan, Abad; Khuda, Fazli; Zakir, Shahida; Yousaf, Nageen; Khan, Ismail; Shah, Yasar; Khan, Muhammad Imran; Shahbaz, Naila

2014-11-01

221

Preliminary Studies on Two Vegetable Oil Based Self Emulsifying Drug Delivery System (SEDDS) for the Delivery of Metronidazole, A Poorly Water Soluble Drug  

NASA Astrophysics Data System (ADS)

A preliminary evaluation was carried out on metronidazole-loaded Self Emulsifying Drug Delivery System (SEDDS) using two vegetable oils-Palm Kernel Oil (PKO) and Palm Oil (PO). Purification of oils, drug solubility in the oils, pre/post formulation isotropicity tests, emulsification times and release studies of metronidazole from the SEDDS were carried out. Results indicated solubility values of 4.441 and 4.654%w/w, respectively for metronidazole in PKO and PO. Preformulation isotropicity test revealed that out of the 24 batches evaluated 10 of the SEDDS formulations containing different oil: surfactant ratios and PKO:PO admixtures were found to be isotropic after 5 h. However when the SEDDS were loaded with metronidazole there was a reduction in the number (to 7) of formulations that maintained isotropicity and stability after 72 h. All the batches had emulsification times of less than two minutes except batch 4D with oil:surfactant concentration of 50:50. The release profile showed that most of the formulations released 50% of drug in less than 8 min and 85% of drug in less than 30 min. We therefore conclude that SEDDS containing the two vegetable oils are potential alternatives when immediate release and delivery of metronidazole is the primary motivation.

Obitte, N. C.; Ezeiruaku, H.; Onyishi, V. I.

222

Fabrication methods and performance of low-permeability microfluidic components for a miniaturized wearable drug delivery system  

E-print Network

In this paper, we describe low-permeability components of a microfluidic drug delivery system fabricated with versatile micromilling and lamination techniques. The fabrication process uses laminate sheets which are machined ...

Mescher, Mark J.

223

Nanoemulsion-templated shell-crosslinked nanocapsules as drug delivery systems.  

PubMed

A novel biocompatible shell-crosslinked nanocapsule system was developed based on nanoemulsion templates stabilized by a class of food proteins. The nanoemulsion templates were prepared using a combination of mechanical mixing and high-pressure homogenization, while the nanocapsule shell formed simultaneously through calcium ions-induced crosslinking of the food proteins. These core-shell structured nanocapsules with a particle size of about 200 nm showed high drug-loading capacity and well improved stability in comparison with their nanoemulsion counterpart. The nanocapsule suspension can be freeze-fried directly; and the solidified nanocapsules can be well reconstituted in water, retaining their original particle size. It is concluded that the nanoemulsion-templated core-shell structured nanocapsules can be used as novel drug delivery systems with high loading capacity for poorly water-soluble drugs as well as well improved long-term and storage stability. Furthermore, the presence of surface food proteins introduces carboxyl and amine moieties, which enables the nanocapsules to anchor ligands, suggesting its potential application in targeting drug delivery, bioimaging and therapeutics. PMID:23396257

He, Wei; Lu, Yi; Qi, Jianping; Chen, Lingyun; Hu, Fuqiang; Wu, Wei

2013-03-10

224

Light-sensitive intelligent drug delivery systems of coumarin-modified mesoporous bioactive glass.  

PubMed

Functionalized mesoporous bioactive glasses (MBG) with photoactive coumarin demonstrates photo-responsive dimerization resulting in reversible gate operation. Coumarin-modified MBG was used as a drug delivery carrier to investigate drug storage/release characteristics using phenanthrene as a model drug. Irradiation with UV light (>310 nm) induced photo-dimerization of the coumarin-modified MBG, which led to the pores' closing with cyclobutane dimers and trapping of the guest phenanthrene in the mesopores. However, irradiating the dimerized-coumarin-modified MBG with shorter wavelength UV light (approximately 250 nm) regenerates the coumarin monomer derivative by the photo-cleavage of cyclobutane dimers, such that trapped guest molecules are released from the mesopores. The structural, morphological, textural and optical properties are well characterized by X-ray diffraction, transmission electron microscopy, N(2) adsorption/desorption, and UV-visible spectroscopy. The results reveal that the MBG exhibits the typical ordered characteristics of the hexagonal mesostructure. The system demonstrates great potential in light-sensitive intelligent drug delivery systems and disease therapy fields. PMID:20152945

Lin, H-M; Wang, W-K; Hsiung, P-A; Shyu, S-G

2010-08-01

225

Gastroretentive dosage forms: a review with special emphasis on floating drug delivery systems.  

PubMed

In the present era, gastroretentive dosage forms (GRDF) receive great attention because they can improve the performance of controlled release systems. An optimum GRDF system can be defined as a system which retains in the stomach for a sufficient time interval against all the physiological barriers, releases active moiety in a controlled manner, and finally is easily metabolized in the body. Physiological barriers like gastric motility and gastric retention time (GRT) act as obstacles in developing an efficient GRDF. Gastroretention can be achieved by developing different systems like high density systems, floating drug delivery systems (FDDS), mucoadhesive systems, expandable systems, superporous systems, and magnetic systems. All these systems have their own merits and demerits. This review focused on the various aspects useful in development of GRDF including the current trends and advancements. PMID:20958237

Pawar, Vivek K; Kansal, Shaswat; Garg, Garima; Awasthi, Rajendra; Singodia, Deepak; Kulkarni, Giriraj T

2011-02-01

226

Targeted Drug Delivery in Pancreatic Cancer  

PubMed Central

Effective drug delivery in pancreatic cancer treatment remains a major challenge. Because of the high resistance to chemo and radiation therapy, the overall survival rate for pancreatic cancer is extremely low. Recent advances in drug delivery systems hold great promise for improving cancer therapy. Using liposomes, nanoparticles, and carbon nanotubes to deliver cancer drugs and other therapeutic agents such as siRNA, suicide gene, oncolytic virus, small molecule inhibitor and antibody has been a success in recent pre-clinical trials. However, how to improve the specificity and stability of the delivered drug using ligand or antibody directed delivery represent a major problem. Therefore, developing novel, specific, tumor-targeted drug delivery systems is urgently needed for this terrible disease. This review summarizes the current progress on targeted drug delivery in pancreatic cancer, and provides important information on potential therapeutic targets for pancreatic cancer treatment. PMID:19853645

Yu, Xianjun; Zhang, Yuqing; Chen, Changyi; Yao, Qizhi; Li, Min

2009-01-01

227

Eudraginated polymer blends: a potential oral controlled drug delivery system for theophylline.  

PubMed

Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (m/m) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for micromeritic properties, drug concentration and in vitro drug release. It was found that the in vitro drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to in vivo studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl(®)) formulation. Asmanyl(®) tablets showed faster absorption (t(max) 4.0 h) compared to the TPH formulation showing a t(max) value of 8.0 h. The C(max) and AUC values of TPH formulation were significantly (p < 0.05) higher than those for Asmanyl(®), revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline. PMID:22472450

Emeje, Martins; John-Africa, Lucy; Isimi, Yetunde; Kunle, Olobayo; Ofoefule, Sabinus

2012-03-01

228

Targeted drug delivery for brain cancer treatment  

Microsoft Academic Search

The blood brain barrier (BBB) and the systemic toxicity of conventional chemotherapy present obstacles to the success of future blood-borne drug therapies of brain tumors. The work with polymer-encapsulated cancer drugs suggests an alternative and more focused treatment approach. Our experimental strategy integrates direct intracerebral drug delivery, sustained drug release from liposomes or polymer implants, and increased targeting of the

Robert L Gutman; Gina Peacock; D. Robert Lu

2000-01-01

229

New Methods of Drug Delivery  

Microsoft Academic Search

Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions. Recently, a number of novel drug delivery approaches have been developed. These approaches include drug modification by chemical means, drug entrapment in small vesicles that are injected into the bloodstream, and drug entrapment within pumps or polymeric materials that are placed in desired bodily compartments

Robert Langer

1990-01-01

230

Molecular recognition and controlled release in drug delivery systems based on nanostructured lipid surfactants  

NASA Astrophysics Data System (ADS)

Several monoolein/water (MO/W) based liquid crystalline (LC) nanostructured mesophases have been revisited in view of the new trends of modern drug delivery formulations. The shape and amphiphilic character of the investigated lipid molecules address the preferential polar-apolar interfacial curvature and the delicate interplay of different intermolecular forces that drive self-assembly and thermodynamic stability of the nanostructures. Here some preliminary results related to the release of the antiviral drug 1-amine-adamantane hydrochloride, solubilized in the aqueous domain of bicontinuous cubic and reverse hexagonal LC phases, suggest these MO based LC phases as possible nano-depot systems for long term controlled release. Drug release was followed by conductivity measurements during a period of ten days. An effective and targeted drug delivery often requires a specific molecular recognition. With this aim, the possibility to entrap suitable molecules such as lauroylcholine (LCh, a cationic surfactant having a peptide-like polar head that can 'recognize' membrane proteins) and adenosine monophosphate disodium salt (NaAMP, an electrolyte that can 'recognize' purine receptors) has been tested. The addition of LCh to MO/W cubic gyroid (CG) LC phase causes a cubic-lamellar phase transition. The addition of NaAMP still allows the formation of the CG nanostructure. In the presence of both NaAMP and LCh again a CG LC phase forms. The bicontinuous CG LC phases have been characterized by NMR and SAXS.

Angius, R.; Murgia, S.; Berti, D.; Baglioni, P.; Monduzzi, M.

2006-08-01

231

Enhanced dissolution of celecoxib by supersaturating self-emulsifying drug delivery system (S-SEDDS) formulation.  

PubMed

A supersaturating self-emulsifying drug delivery system (S-SEDDS) was prepared and evaluated for enhanced dissolution of celecoxib (CXB), a poorly water-soluble drug. The selected CXB-dissolved SEDDS formulation consisting 10 % Capryol 90 (oil), 45 % Tween 20 (surfactant), and 45 % Tetraglycol (cosurfactant) had the characteristics of small droplet size and great solubility as 208 nm and 556.7 mg/mL in average, respectively. CXB dissolution from SEDDS in simulated gastric fluid was increased to about 20 % for the initial period of 5 min, but decreased to a half level as time elapsed. Thus, precipitation inhibitors were screened to stabilize the supersaturation. The stabilizing effect of Soluplus, an amphiphilic copolymer, was concentration-dependent, revealing the greatest dissolution of approximately 90 % level with delayed drug crystallization by the addition of the copolymer. CXB dissolution from S-SEDDS was pH-independent. We concluded that S-SEDDS formulation would be very useful in the future for developing oral delivery product of poorly water-soluble drugs. PMID:23325487

Song, Woo Heon; Park, Jong Hyeok; Yeom, Dong Woo; Ahn, Byeong Kil; Lee, Kyung Min; Lee, Sang Gon; Woo, Hye Seung; Choi, Young Wook

2013-01-01

232

Development and evaluation of a monolithic floating drug delivery system for acyclovir.  

PubMed

Acyclovir (ACV), a model drug for this study, is one of the most effective drugs against viruses of the herpes group. Absorption of orally administered ACV is variable and incomplete, with a bioavailability of ca. 15-30%. The drug is absorbed in the duodenum after oral administration and hence, preparation of a floating drug delivery system (FDDS) for ACV may increase oral absorption of the drug. ACV matrix tablets (200?mg) containing an effervescent base (sodium bicarbonate and citric acid) and a binary combination of hydroxypropyl methylcellulose (HPMC) K4M with carbopol or sodium carboxymethyl cellulose (Na CMC) or polyvinylpyrrolidone (PVP) and/or sodium alginate were prepared by the direct compression method. The tablets were evaluated for physicochemical properties and in vitro floating ability (floating lag-time and duration), bioadhesiveness and drug release. The drug release studies were carried out in 0.1?N HCl (pH 1.2) at 37±0.5°C. At appropriate time intervals, samples were withdrawn and assayed spectrophotometrically at ?(max)=259?nm. The floating test showed tablets containing 15% effervescent base had a floating lag time of 10-30?s and a duration of floating time of 24?h. The formulations containing HPMC-PVP, HPMC-Na CMC, HPMC-carbopol, and HPMC-sodium alginate released about 60-90% of their drug content during a 12-h period. Increasing carbopol caused slower drug release. We concluded that the proposed tablets with 15% effervescent base, 20-30% HPMC, 30% Na CMC (and/or 20% PVP or 20% sodium alginate) showed good floating and drug release properties in vitro, and should be considered as FDDS for ACV. PMID:22293475

Tavakoli, Naser; Varshosaz, Jaleh; Dorkoosh, Farid; Motaghi, Sedigheh; Tamaddon, Lana

2012-01-01

233

Ultrasound mediated nanoparticle drug delivery  

NASA Astrophysics Data System (ADS)

Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems. Ultrasound parameters are optimized to achieve maximum cell internalization of molecules and increased nanoparticle delivery to a cell layer on a coverslip. In-vivo studies demonstrate the possibility of using a lower dose of paclitaxel to slow tumor growth rates, increase doxorubicin concentration in tumor tissue, and enhance tumor delivery of fluorescent molecules through treatments that combine nanoparticles with ultrasound and microbubbles.

Mullin, Lee B.

234

Design, development and evaluation of chronomodulated drug delivery systems of amoxicillin trihydrate with enhanced antimicrobial activity.  

PubMed

The present studies entail the formulation development and evaluation of chronomodulated drug delivery system of amoxicillin trihydrate (AMT), which comprises of a bilayer tablet containing a delayed release and a sustained release layer. Direct compression method was employed for the preparation of bilayer matrix tablets containing rational blend of polymers, such as Eudragit-L100 D55 as delayed release polymer and HPMCK4M, HPMCK15 and HPMCK100 are sustained release polymers. In- vitro drug release studies of bilayer tablets observed a good sustained release action with time-dependent burst release after a lag-time of 3 hrs. Evaluation of drug release kinetics from sustained release layer of bilayer tablets followed Higuchi model via quasi-Fickian diffusion mechanism. SEM studies revealed formation of pores on sustained release layer, which confirmed the drug release through diffusion and predominantly by surface erosion mechanism. Evaluation of antimicrobial activity showed a decrease in minimum inhibitory concentration of optimized bilayer tablets vis-à-vis conventional marketed formulation. Accelerated stability studies revealed that the optimized bilayer tablet formulation was found to be stable upto the period of 6 months. Solid state characterization employing FT-IR and DSC studies indicated lack of significant interaction of drug with formulation excipients. Thus, the present studies ratify the suitability of chronomodulated bilayer tablets of AMT for effective management of bacterial infections owing to specific time-dependent drug release, higher gastric protection and enhanced antimicrobial activity. PMID:22998051

Beg, Sarwar; Swain, Suryakanta; Gahoi, Sachin; Kohli, Kanchan

2013-04-01

235

The application of EDTA in drug delivery systems: doxorubicin liposomes loaded via NH4EDTA gradient  

PubMed Central

The applications of ethylenediaminetetraacetic acid (EDTA) have been expanded from the treatment of heavy metal poisoning to chelation therapies for atherosclerosis, heart disease, and cancers, in which EDTA reduces morbidity and mortality by chelating toxic metal ions. In this study, EDTA was used in a drug delivery system by adopting an NH4EDTA gradient method to load doxorubicin into liposomes with the goal of increasing therapeutic effects and decreasing drug-related cytotoxicity. The particle size of the optimum NH4EDTA gradient liposomes was 79.4±1.87 nm, and the entrapment efficiency was 95.54%±0.59%. In vitro studies revealed that liposomes prepared using an NH4EDTA gradient possessed long-term stability and delayed drug release. The in vivo studies also showed the superiority of the new doxorubicin formulation. Compared with an equivalent drug dose (5 mg/kg) prepared by (NH4)2SO4 gradient, NH4EDTA gradient liposomes showed no significant differences in tumor inhibition ratio, but cardiotoxicity and liposome-related immune organ damage were lower, and no drug-related deaths were observed. These results show that use of the NH4EDTA gradient method to load doxorubicin into liposomes could significantly reduce drug toxicity without influencing antitumor activity. PMID:25120359

Song, Yanzhi; Huang, Zhenjun; Song, Yang; Tian, Qingjing; Liu, Xinrong; She, Zhennan; Jiao, Jiao; Lu, Eliza; Deng, Yihui

2014-01-01

236

Formulation and development of a self-nanoemulsifying drug delivery system of irbesartan  

PubMed Central

Irbesartan (IRB) is an angiotensin II receptor blocker antihypertensive agent. The aim of the present investigation was to develop a self-nanoemulsifying drug delivery system (SNEDDS) to enhance the oral bioavailability of poorly water-soluble IRB. The solubility of IRB in various oils was determined to identify the oil phase of SNEDDS. Various surfactants and co-surfactants were screened for their ability to emulsify the selected oil. Pseudoternary phase diagrams were constructed to identify the efficient self-emulsifying region. The optimized SNEDDS formulation contained IRB (75 mg), Cremophor® EL (43.33%), Carbitol® (21.67%) and Capryol® 90 (32%). SNEDDS was further evaluated for its percentage transmittance, emulsification time, drug content, phase separation, dilution, droplet size and zeta potential. The optimized formulation of IRB-loaded SNEDDS exhibited complete in vitro drug release in 15 min as compared with the plain drug, which had a limited dissolution rate. It was also compared with the pure drug solution by oral administration in male Wister rats. The in vivo study exhibited a 7.5-fold increase in the oral bioavailability of IRB from SNEDDS compared with the pure drug solution. These results suggest the potential use of SNEDDS to improve dissolution and oral bioavailability of poorly water-soluble IRB. PMID:22171286

Patel, Jaydeep; Patel, Anjali; Raval, Mihir; Sheth, Navin

2011-01-01

237

Recent advances in ceramic implants as drug delivery systems for biomedical applications  

PubMed Central

Research in the development of new bioceramics with local drug delivery capability for bone regeneration technologies is receiving great interest by the scientific biomedical community. Among bioceramics, silica-based ordered mesoporous materials are excellent candidates as bone implants due to two main reasons: first, the bioactive behavior of such materials in contact with simulated body fluids, ie, a carbonate hydroxyapatite similar to the mineral phase of bone is formed onto the materials surfaces. Second, their capability of acting as delivery systems of a large variety of biologically active molecules, including drugs to treat bone infection, inflammation or diseases, and molecules that promote bone tissue regeneration, such as peptides, proteins, growth factors, and other osteogenic agents. The recent chemical and technological advances in the nanometer scale has allowed the design of mesoporous silicas with tailored structural and textural properties aimed at achieving a better control over molecule loading and release kinetics. Moreover organic modification of mesoporous silica walls has been revealed as a key strategy to modulate molecule adsorption and delivery rates. PMID:19337409

Colilla, Montserrat; Manzano, Miguel; Vallet-Regi, Maria

2008-01-01

238

Nanoparticles for Targeted Drug Delivery  

E-print Network

Nanoparticles were synthesized and modified for target drug delivery. The research involved the aqueous synthesis of near infrared (NIR) sensitive Au-Au2S nanoparticles. An anti-cancer drug (cis-platin) ...

Chow, Gan-Moog

239

Preparation and characterization of 6-mercaptopurine-coated magnetite nanoparticles as a drug delivery system  

PubMed Central

Background Iron oxide nanoparticles are of considerable interest because of their use in magnetic recording tape, ferrofluid, magnetic resonance imaging, drug delivery, and treatment of cancer. The specific morphology of nanoparticles confers an ability to load, carry, and release different types of drugs. Methods and results We synthesized superparamagnetic nanoparticles containing pure iron oxide with a cubic inverse spinal structure. Fourier transform infrared spectra confirmed that these Fe3O4 nanoparticles could be successfully coated with active drug, and thermogravimetric and differential thermogravimetric analyses showed that the thermal stability of iron oxide nanoparticles coated with chitosan and 6-mercaptopurine (FCMP) was markedly enhanced. The synthesized Fe3O4 nanoparticles and the FCMP nanocomposite were generally spherical, with an average diameter of 9 nm and 19 nm, respectively. The release of 6-mercaptopurine from the FCMP nanocomposite was found to be sustained and governed by pseudo-second order kinetics. In order to improve drug loading and release behavior, we prepared a novel nanocomposite (FCMP-D), ie, Fe3O4 nanoparticles containing the same amounts of chitosan and 6-mercaptopurine but using a different solvent for the drug. The results for FCMP-D did not demonstrate “burst release” and the maximum percentage release of 6-mercaptopurine from the FCMP-D nanocomposite reached about 97.7% and 55.4% within approximately 2,500 and 6,300 minutes when exposed to pH 4.8 and pH 7.4 solutions, respectively. By MTT assay, the FCMP nanocomposite was shown not to be toxic to a normal mouse fibroblast cell line. Conclusion Iron oxide coated with chitosan containing 6-mercaptopurine prepared using a coprecipitation method has the potential to be used as a controlled-release formulation. These nanoparticles may serve as an alternative drug delivery system for the treatment of cancer, with the added advantage of sparing healthy surrounding cells and tissue. PMID:24106420

Dorniani, Dena; Hussein, Mohd Zobir bin; Kura, Aminu Umar; Fakurazi, Sharida; Shaari, Abdul Halim; Ahmad, Zalinah

2013-01-01

240

Effect of radiotherapy and hyperthermia on the tumor accumulation of HPMA copolymer-based drug delivery systems  

Microsoft Academic Search

Copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) are prototypic and well-characterized polymeric drug carriers that have been broadly implemented in the delivery of anticancer therapeutics. In an attempt to improve the tumor accumulation of HPMA copolymer-based drug delivery systems, their in vivo application was combined with radiotherapy and hyperthermia. As the effects of radiotherapy and hyperthermia were considered to depend significantly on the

Twan Lammers; Peter Peschke; Rainer Kühnlein; Vladimir Subr; Karel Ulbrich; Jürgen Debus; Peter Huber; Wim Hennink; Gert Storm

2007-01-01

241

Colloidal microgels in drug delivery applications  

PubMed Central

Colloidal microgels have recently received attention as environmentally responsive systems and now are increasingly used in applications as carriers for therapeutic drugs and diagnostic agents. Synthetic microgels consist of a crosslinked polymer network that provides a depot for loaded drugs, protection against environmental hazards and template for post-synthetic modification or vectorization of the drug carriers. The aim of this manuscript is to review recent attempts to develop new microgel formulations for oral drug delivery, to design metal-containing microgels for diagnostic and therapeutic applications, and to advance approaches including the systemic administration of microgels. Novel nanogel drug delivery systems developed in the authors’ laboratory are discussed in details including aspects of their synthesis, vectorization and recent applications for encapsulation of low molecular weight drugs or formulation of biological macromolecules. The findings reviewed here are encouraging for further development of the nanogels as intelligent drug carriers with such features as targeted delivery and triggered drug release. PMID:17168773

Vinogradov, Serguei V.

2005-01-01

242

Floating controlled drug delivery system of famotidine loaded hollow microspheres (microballoons) in the stomach.  

PubMed

Most of the floating systems have an inherent drawback of high variability in the GI transit time, invariably affecting the bioavailability of drug. An attempt has been made to develop floating drug delivery system for improving the drug bioavailability by prolongation of gastric residence time of famotidine in stomach. The floating microballoons were prepared using polymer Eudragit L-100 by solvent evaporation and diffusion technique. The prepared famotidine loaded microspheres were characterised for drug loading, entrapment, encapsulation efficiency, particle size distribution, surface morphology, differential scanning calorimetry, test for buoyancy, in-vitro release and in-vivo antiulcer studies. The results showed an increased drug loading, encapsulation and entrapment efficiency. The thermogram of the DSC showed that the drug was encapsulated in amorphous form and SEM studies revealed the discrete, spherical shaped spheres with rough surface and presence of holes on floating microspheres due high entrapment of PEG which are responsible for drug release and floating ability. The sizes of spheres were found between 20-120 microm which exhibited prolonged release (In-vitro > 8 h) and remained buoyant for > 10 h. The mean particle size increased and the drug release rate decreased at higher Eudragit L-100 polymer concentration. The in-vivo results showed significant antiulcer property of famotidine loaded microspheres when compared to control and standard group of rats by using pyloric ligation method. The mean volume of gastric secretion, mean pH and mean total acid for formulation treated group was calculated as 3.45+/-0.88 ml, 5.65+/-0.74, and 114.15+/-1.80 mEq/L respectively. PMID:20044907

Ramachandran, S; Shaheedha, S M; Thirumurugan, G; Dhanaraju, M D

2010-01-01

243

Pure and Strontium Doped Nano Hydroxyapatite: New Approach for Bone Implant and Drug Delivery System  

NASA Astrophysics Data System (ADS)

Hydroxyapatite, (Ca10(PO4)6(OH)2-Hap), an excellent inorganic biomaterial, find various applications. The chemical composition of Hap is similar to that of the inorganic matrix of human bone and dental enamel. It is also used in drug delivery system and coating of bone implant. In the present study, pure nano Hap and Strontium doped nano-Hap (Sr-Hap) with different concentrations were synthesized by surfactant mediated approach. The samples were characterized by EDAX, XRD and TEM. The hemolytic properties were also studied and it proved that all the samples were non-hemolytic.

Tank, Kashmira P.; Vasant, Sonal R.; Chudasama, Kiran S.; Thaker, Vrinda S.; Joshi, Mihir J.

2011-07-01

244

Multifunctional hybrid nanocarrier: magnetic CNTs ensheathed with mesoporous silica for drug delivery and imaging system.  

PubMed

Here we communicate the development of a novel multifunctional hybrid nanomaterial, magnetic carbon nanotubes (CNTs) ensheathed with mesoporous silica, for the simultaneous applications of drug delivery and imaging. Magnetic nanoparticles (MNPs) were first decorated onto the multiwalled CNTs, which was then layered with mesoporous silica (mSiO2) to facilitate the loading of bioactive molecules to a large quantity while exerting magnetic properties. The hybrid nanomaterial showed a high mesoporosity due to the surface-layered mSiO2, and excellent magnetic properties, including magnetic resonance imaging in vitro and in vivo. The mesoporous and magnetic hybrid nanocarriers showed high loading capacity for therapeutic molecules including drug gentamicin and protein cytochrome C. In particular, genetic molecule siRNA was effectively loaded and then released over a period of days to a week. Furthermore, the hybrid nanocarriers exhibited a high cell uptake rate through magnetism, while eliciting favorable biological efficacy within the cells. This novel hybrid multifunctional nanocarrier may be potentially applicable as drug delivery and imaging systems. PMID:24476195

Singh, Rajendra K; Patel, Kapil D; Kim, Jung-Ju; Kim, Tae-Hyun; Kim, Joong-Hyun; Shin, Ueon Sang; Lee, Eun-Jung; Knowles, Jonathan C; Kim, Hae-Won

2014-02-26

245

Investigations into Thermally Mediated Drug Delivery Using a Preclinical System for MRI-Guided Focused Ultrasound  

NASA Astrophysics Data System (ADS)

The objective of this research was to investigate the use of a preclinical system for MRI-guided focused ultrasound to achieve MRI-controlled hyperthermia and thermally-mediated drug delivery in vivo. Here we report results from ten rabbits, where a focused ultrasound (FUS) beam was scanned in a circular trajectory to heat 10-15 mm diameter regions in normal thigh to 43 °C for 20-30 minutes. MRI thermometry was used for closed-loop feedback control to achieve temporally and spatially uniform heating. Lyso-thermosensitive pegylated liposomal doxorubicin (ThermoDox®, Celsion Corporation, Columbia, MD) was infused intravenously during hyperthermia, and the tissue doxorubicin concentration was measured by the fluorescence intensity of homogenized tissue samples from heated and unheated thigh, obtained 2 hours after heating. Closed-loop control of FUS hyperthermia using MRI thermometry achieved temperature distributions with mean, T90 and T10 of 42.9 °C, 41.0 °C and 44.8 °C across the 10 mm diameter target, varying ±0.9 °C (SD) over 20 min. Drug concentrations in heated regions were, on average 15.3±8.1 (SD) times higher than in the unheated contralateral thigh. The results show the feasibility of using MRI-controlled FUS hyperthermia for preclinical studies of thermally mediated drug delivery with temperature-sensitive liposomes.

Staruch, Robert; Chopra, Rajiv; Hynynen, Kullervo

2011-09-01

246

In vivo real-time monitoring system of electroporation mediated control of transdermal and topical drug delivery  

E-print Network

online 7 October 2013 Keywords: Electroporation Transdermal drug delivery Topical drug delivery Multi of transdermal and topical drug delivery, EP at different amplitudes of electric pulses was evaluated. A new, for the quantification of transdermal and topical drug delivery. EP of the mouse skin was performed with new non

Ljubljana, University of

247

Microneedles for transdermal drug delivery  

Microsoft Academic Search

The success of transdermal drug delivery has been severely limited by the inability of most drugs to enter the skin at therapeutically useful rates. Recently, the use of micron-scale needles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery, especially for macromolecules. Using the tools of the microelectronics industry, microneedles have been fabricated with a

Mark R Prausnitz

2004-01-01

248

Transdermal drug delivery: Microfabrication insights  

Microsoft Academic Search

The paper presented an enhancement solution for transdermal drug delivery using microneedles array with biodegradable tips. The microneedles array was fabricated by using deep reactive ion etching (DRIE) and the biodegradable tips were made to be porous by electrochemical etching process. The porous silicon microneedle tips can greatly enhance the transdermal drug delivery in a minimum invasion, painless, and convenient

Ciprian Iliescu; Bangtao Chen; Jiashen Wei; Zhilian Yue

2009-01-01

249

A hematoporphyrin-based delivery system for drug resistance reversal and tumor ablation.  

PubMed

Nanotechnology-based drug delivery systems have been intensively investigated, while only a few of them can be used for clinic application. Hematoporphyrin (HP), a major molecule in erythrocyte, has been widely used in photodynamic therapy (PDT). In the present study, polyethylene glycol (PEG) modified hematoporphyrin (HPP)-based nanoparticle system was designed to load doxorubicin (HPPD), in achieving a synergistic effect of chemotherapy and PDT. Herein we presented that HPPD formed narrowly dispersed nanoparticles at 35 ± 2 nm, yielding an enhanced drug release at pH5.8 along with laser radiation. This combined treatment with HPPD and radiation facilitated drug penetration to the nucleus thereby reducing 12-fold decrease in IC50 value and promoting apoptosis in drug-resistant breast cancer cells. Notably, little toxicity was detected with HPP at the cellular level and in animal models. Live animal imaging revealed that HPPD performed ultra high tumor uptake in both mice and marmoset models. Strikingly, intravenous administration of HPPD and radiation on the tumor achieved efficient tumor ablation, without inducing myocardial injury. We report here the development of a biomolecule, HP-based nanoparticle system, which can synergistically yield chemotherapy and PDT. PMID:24373420

Ren, Yu; Wang, Ruirui; Liu, Yang; Guo, Hua; Zhou, Xuan; Yuan, Xubo; Liu, Chaoyong; Tian, Jianguo; Yin, Haifang; Wang, Yinsong; Zhang, Ning

2014-03-01

250

Emerging integrated nanohybrid drug delivery systems to facilitate the intravenous-to-oral switch in cancer chemotherapy.  

PubMed

Nanohybrid drug delivery systems have presented lots of characteristic advantages as an efficient strategy to facilitate oral drug delivery. Nonetheless, oral administration of chemotherapy agents by nanoparticulate delivery technology still faces great challenges owing to the multiple biobarriers ranging from poorly physicochemical properties of drugs, to complex gastrointestinal disposition and to presystemic metabolism. This review briefly analyzes a series of biobarriers hindering oral absorption and describes the multiple aspects for facilitating the intravenous-to-oral switch in cancer therapy. Moreover, the developed nanoparticulate drug delivery strategies to overcome the above obstacles are provided, including metabolic enzyme inhibition, enteric-coated nanocarriers, bioadhesive and mucus-penetrating strategies, P-gp inhibition and active targeting. On these foundations, the emerging trends of integrated hybrid nanosystems in response to the present low-efficiency drug delivery of any single approach are summarized, such as mixed polymeric micelles and nanocomposite particulate systems. Finally, the recent advances of high-efficiency hybrid nanoparticles in oral chemotherapy are highlighted, with special attention on integrated approach to design drug delivery nanosystems. PMID:24389337

Luo, Cong; Sun, Jin; Du, Yuqian; He, Zhonggui

2014-02-28

251

An anticancer drug delivery system based on surfactant-templated mesoporous silica nanoparticles.  

PubMed

Three types of surfactant-templated mesoporous silica nanoparticles (Surf@MSNs) of 150-660 nm in diameter were developed as anticancer drug delivery systems. The Surf@MSNs exhibit the high drug (surfactant) loading capacities, the sustained drug (surfactant) release profiles and the high and long-term anticancer efficacy. The effects of the Surf@MSNs concentration, the type of the contained surfactants and the incubation time on the cytotoxicity and proliferative activity of MCF-7 cells were evaluated. A common anticancer drug CPT-11 was also loaded into surfactant-free MSNs (CPT@MSNs) and used as a reference for estimating the anticancer efficacies of Surf@MSNs. Surfactant-extracted MSNs exhibited neglectable cytotoxicity to MCF-7 cell, and free surfactants exhibited higher cytotoxicity than free CPT-11 at the same concentration. The endocytosis enhanced the drug uptake by MCF-7 cells and the anticancer efficacies of Surf@MSNs and CPT@MSNs, and more surfactants would be released in a longer term, which led to the more significant enhancement of the cytotoxicity, than CPT-11 with the process of incubation. Among the investigated Surf@MSNs, CTAB-contained MSNs (CTAB@MSNs) show remarkably higher long-term anticancer efficacy than CPT-11-loaded surfactant-free MSNs (CPT@MSNs), even at very low concentrations of 2-15 microg mL(-1). PMID:20106517

He, Qianjun; Shi, Jianlin; Chen, Feng; Zhu, Min; Zhang, Lingxia

2010-04-01

252

Design of controlled drug delivery system based on disulfide cleavage trigger.  

PubMed

The disulfide bond has drawn increasing attention for the application on controlled drug delivery systems (CDDSs) due to its high redox sensibility, which is derived from the fact that the concentration of glutathione (GSH), a disulfide-bond-breaking agent, in the tumor tissue is 1000-fold higher than that in the blood plasma and the normal tissue. Thus, a disulfide is an ideal candidate for serving as the drug release trigger of CDDSs, which would be stable in the blood circulation and be broken when it reached the tumor tissue. However, improvements are still required in designing the structure of CDDSs and the drug loading patterns for CDDSs, which are important to the performance of CDDSs. This Feature Article briefly summarizes our recent research progress on the design and construction of CDDSs based on disulfide cleavage triggers, with different drug loading strategies (covalent and noncovalent) and carriers (copolymer and mesoporous silica nanoparticle). The controlled drug release mechanism and behaviors of these CDDSs are also discussed. PMID:25320865

Yang, Dong; Chen, Wulian; Hu, Jianhua

2014-10-30

253

Novel sustained release, swellable and bioadhesive gastroretentive drug delivery system for ofloxacin.  

PubMed

Oral sustained release gastroretentive dosage forms offer many advantages for drugs having absorption from upper gastrointestinal tract and improve the bioavailability of medications that are characterized by a narrow absorption window. A new gastroretentive sustained release delivery system was developed with floating, swellable and bioadhesive properties. All these properties were optimized and evaluated. Various release retarding polymers like psyllium husk, HPMC K100M and a swelling agent, crosspovidone in combinations were tried and optimized to get the release profile for 24 h. Formulations were evaluated for in vitro drug release profile, swelling characteristics and in vitro bioadhesion property. The in vitro drug release followed Higuchi kinetics and the drug release mechanism was found to be of anomalous or non-Fickian type. For the developed formulation, the value of n was found to be 0.5766 while for the marketed formulation the value was 0.5718 indicating the anomalous transport. The high water uptake leading to higher swelling of the tablet supported the anomalous release mechanism of ofloxacin. The similarity factor f2 was found to be 91.12 for the developed formulation indicating the release was similar to that of the marketed formulation (Zanocin OD). The swelling properties were increased with increasing crosspovidone concentration and contributed significantly in drug release from the tablet matrix. The bioadhesive property of the developed formulation was found to be significant (P < 0.005) in combination as compared to HPMC K100M and psyllium husk alone. PMID:16567072

Chavanpatil, Mahesh D; Jain, Paras; Chaudhari, Sachin; Shear, Rajesh; Vavia, Pradeep R

2006-06-19

254

Pulsed Laser Processing of Functionalized Polysaccharides for Controlled Release Drug Delivery Systems  

NASA Astrophysics Data System (ADS)

We report on the deposition of triacetate-pullulan polysaccharide thin films on drug pellets (diclofenac sodium) by matrix assisted pulsed laser evaporation method. The radiation generated by a pulsed excimer KrF* laser source (? = 248 nm, ? = 20 ns) operated at 2 Hz repetition rate was used for ice targets evaporation. The timed - controlled drug delivery was proved by spectroscopic in vitro studies and in vivo anti-inflammatory investigations on rabbits. We showed that the coating of drug pellets with triacetate-pullulan thin films resulted in the delayed delivery of the drug for up to 30 min.

Cristescu, R.; Popescu, C.; Popescu, A. C.; Socol, G.; Mihailescu, I.; Caraene, G.; Albulescu, R.; Buruiana, T.; Chrisey, D.

255

IMPLANTABLE MEMS DRUG DELIVERY SYSTEMS FOR ADMINISTRATION OF UNALTERED THERAPEUTIC AGENTS  

E-print Network

therapy intervention plays a major role in the management of many ocular diseases. However, precise delivery vehicle for treating difficult-to-reach diseases affecting the posterior segment of the eye. Drug delivery of pharmaceutical solutions to a specified target within the body is an ongoing challenge in many

Meng, Ellis

256

Orally dissolving strips: A new approach to oral drug delivery system.  

PubMed

Recently, fast dissolving films are gaining interest as an alternative of fast dissolving tablets. The films are designed to dissolve upon contact with a wet surface, such as the tongue, within a few seconds, meaning the consumer can take the product without need for additional liquid. This convenience provides both a marketing advantage and increased patient compliance. As the drug is directly absorbed into systemic circulation, degradation in gastrointestinal tract and first pass effect can be avoided. These points make this formulation most popular and acceptable among pediatric and geriatric patients and patients with fear of choking. Over-the-counter films for pain management and motion sickness are commercialized in the US markets. Many companies are utilizing transdermal drug delivery technology to develop thin film formats. In the present review, recent advancements regarding fast dissolving buccal film formulation and their evaluation parameters are compiled. PMID:24015378

Bala, Rajni; Pawar, Pravin; Khanna, Sushil; Arora, Sandeep

2013-04-01

257

Expansile Nanoparticles: Synthesis, Characterization, and in Vivo Efficacy of an Acid-Responsive Polymeric Drug Delivery System  

E-print Network

. For example, micro- or nanoparticles composed of poly(lactic-glycolic acid), PLGA, are well studied for drugExpansile Nanoparticles: Synthesis, Characterization, and in Vivo Efficacy of an Acid-Responsive Polymeric Drug Delivery System Aaron P. Griset, Joseph Walpole, Rong Liu, Ann Gaffey, Yolonda L. Colson

258

Highly deformable and highly fluid vesicles as potential drug delivery systems: theoretical and practical considerations  

PubMed Central

Vesicles that are specifically designed to overcome the stratum corneum barrier in intact skin provide an efficient transdermal (systemic or local) drug delivery system. They can be classified into two main groups according to the mechanisms underlying their skin interaction. The first group comprises those possessing highly deformable bilayers, achieved by incorporating edge activators to the bilayers or by mixing with certain hydrophilic solutes. The vesicles of this group act as drug carriers that penetrate across hydrophilic pathways of the intact skin. The second group comprises those possessing highly fluid bilayers, owing to the presence of permeation enhancers. The vesicles of this group can act as carriers of drugs that permeate the skin after the barrier of the stratum corneum is altered because of synergistic action with the permeation enhancers contained in the vesicle structure. We have included a detailed overview of the different mechanisms of skin interaction and discussed the most promising preclinical applications of the last five years of Transfersomes® (IDEA AG, Munich, Germany), ethosomes, and invasomes as carriers of antitumoral and anti-inflammatory drugs applied by the topical route. PMID:23986634

Romero, Eder Lilia; Morilla, Maria Jose

2013-01-01

259

Inner ear drug delivery via a reciprocating perfusion system in the guinea pig  

PubMed Central

Rapid progress in understanding the molecular mechanisms associated with cochlear and auditory nerve degenerative processes offers hope for the development of gene-transfer and molecular approaches to treat these diseases in patients. For therapies based on these discoveries to become clinically useful, it will be necessary to develop safe and reliable mechanisms for the delivery of drugs into the inner ear, bypassing the blood–labyrinthine barrier. Toward the goal of developing an inner ear perfusion device for human use, a reciprocating microfluidic system that allows perfusion of drugs into the cochlear perilymph through a single inlet hole in scala tympani of the basal turn was developed. The performance of a prototype, extracorporeal reciprocating perfusion system in guinea pigs is described. Analysis of the cochlear distribution of compounds after perfusion took advantage of the place-dependent generation of responses to tones along the length of the cochlea. Perfusion with a control artificial perilymph solution had no effect. Two drugs with well-characterized effects on cochlear physiology, salicylate (5 mM) and DNQX (6,7-Dinitroquinoxaline-2,3-dione; 100 and 300 ?M), reversibly altered responses. The magnitude of drug effect decreased with distance from the perfusion pipette for up to 10 mm, and increased with dose and length of application. PMID:16274830

Chen, Zhiqiang; Kujawa, Sharon G.; McKenna, Michael J.; Fiering, Jason O.; Mescher, Mark J.; Borenstein, Jeffrey T.; Leary Swan, Erin E.; Sewell, William F.

2007-01-01

260

Emerging Intra-Articular Drug Delivery Systems for the Temporomandibular Joint  

PubMed Central

Temporomandibular joint (TMJ) disorders are a heterogeneous group of diseases that cause progressive joint degeneration leading to chronic pain and reduced quality of life. Both effective pain reduction and restoration of TMJ function remain unmet challenges. Intra-articular injections of corticosteroids and hyaluronic acid are currently used to treat chronic pain, but these methods require multiple injections that increase the risk of iatrogenic joint damage and other complications. The small and emerging field of TMJ tissue engineering aims to reduce pain and disability through novel strategies that induce joint tissue regeneration. Development of methods for sustained, intra-articular release of growth factors and other pro-regenerative signals will be critical for the success of TMJ tissue engineering strategies. This review discusses methods of intra-articular drug delivery to the TMJ, as well as emerging injectable controlled release systems with potential to improve TMJ drug delivery, to encourage further research in the development of sustained release systems for both long-term pain management and to enhance tissue engineering strategies for TMJ regeneration. PMID:18835358

Mountziaris, Paschalia M.; Kramer, Phillip R.; Mikos, Antonios G.

2009-01-01

261

Biodegradable polymeric nanoparticles as drug delivery devices  

Microsoft Academic Search

This review presents the most outstanding contributions in the field of biodegradable polymeric nanoparticles used as drug delivery systems. Methods of preparation, drug loading and drug release are covered. The most important findings on surface modification methods as well as surface characterization are covered from 1990 through mid-2000.

Kumaresh S Soppimath; Tejraj M Aminabhavi; Anandrao R Kulkarni; Walter E Rudzinski

2001-01-01

262

The development and in vivo evaluation of a colon drug delivery system using human volunteers.  

PubMed

The aim of this study was to develop a multiple-unit dosage system that released model drug into the colon, and also to evaluate the efficiency of the dosage form in human volunteers. The developed system combines pH-, time- and biodegradable polymer-based mechanisms for drug targeting to the colon. Pellet cores containing caffeine as model drug and chitosan and microcrystalline cellulose as excipients were prepared by the extrusion/spheronization method. The prepared pellets were film coated with a pH-dependent polymer, Eudragit FS 30 D. The coating total weight gain was 28.83% (w/w). Thanks to the application of an outer enteric film and the multiple unit design of the dosage form, the variability in gastric emptying was overcome, and a colon-specific targeting relied on the reproducibility of a small intestinal transit time, which was reported to be 3 ± 1 hours. A biodegradable polymer in the pellet core, chitosan, ensured the site-specific release of the model drug due to its solubility at the lower pH of the colonic region and by its biodegradability from the bacteria present. The efficiency of the system was confirmed by the in vivo testing of human saliva. The time of the first appearance of caffeine into the saliva, T(lag), was used as a parameter to estimate the disintegration time of the pellets into the gastrointestinal tract. The caffeine appeared in the saliva within 6.95 ± 1.12 hours (T(lag)) in 9 volunteers. A comparison of the reported colon arrival times indicates that the developed system is applicable to colonic drug delivery. PMID:22211714

Zimová, Lucie; Vetchý, David; Muselík, Jan; Štembírek, Jan

2012-02-01

263

Facile fabrication of redox-responsive thiol-containing drug delivery system via RAFT polymerization.  

PubMed

A novel kind of redox-responsive polymeric drug delivery system has been designed and prepared successfully through the coupling of the multithiol branched polymers and thiol-containing drugs. The branched poly((S-(4-vinyl) benzyl S'-propyltrithiocarbonate)-co-(poly(ethylene glycol) methacrylate)) (poly(VBPT-co-PEGMA)) was synthesized by one-pot reaction via reversible addition-fragmentation chain transfer (RAFT) copolymerization. Subsequently, the hydrophobic thiol-containing anticancer drug 6-mercaptopurine (MP) was conjugated to poly(VBPT-co-PEGMA) by thiol-disulfide exchange reaction, resulting in the formation of poly(VBPT-co-PEGMA)-S-S-MP conjugate. Due to its amphiphilicity, poly(VBPT-co-PEGMA)-S-S-MP conjugate self-assembled into amphiphilic micelles in aqueous solution. Under a reductive environment, the disassembly of polymeric micelles resulted in the MP release. Flow cytometry and confocal laser scanning microscopy (CLSM) measurements demonstrated that the poly(VBPT-co-PEGMA)-S-S-MP micelles could be taken up by Raji cells (a Burkitt lymphoma cell line). The viability of the Raji cells incubated with the glutathione (GSH) mediated poly(VBPT-co-PEGMA)-S-S-MP micelles was investigated by Cell Counting Kit-8 (CCK-8) assay. The experimental results showed that the viability of the glutathione monoester (GSH-OEt) pretreated cells was lower than that without pretreatment, while the viability of the buthionine sulfoximine (BSO) pretreated cells was higher than that without pretreatment. The poly(VBPT-co-PEGMA)-S-S-MP micelles could induce the apoptosis of Raji cells, and the apoptosis behavior was dose-dependent. This redox-responsive polymer-drug conjugate provides a promising platform for the delivery of thiol-containing biological molecules. PMID:24598057

Zhuang, Yuanyuan; Su, Yue; Peng, Yu; Wang, Dali; Deng, Hongping; Xi, Xiaodong; Zhu, Xinyuan; Lu, Yunfeng

2014-04-14

264

A novel pulsed drug-delivery system: polyelectrolyte layer-by-layer coating of chitosan–alginate microgels  

PubMed Central

Purpose The aim of this report was to introduce a novel “core-membrane” microgel drug-delivery device for spontaneously pulsed release without any external trigger. Methods The microgel core was prepared with alginate and chitosan. The semipermeable membrane outside the microgel was made of polyelectrolytes including polycation poly(allylamine hydrochloride) and sodium polystyrene sulfonate. The drug release of this novel system was governed by the swelling pressure of the core and the rupture of the outer membrane. Results The size of the core-membrane microgel drug-delivery device was 452.90 ± 2.71 ?m. The surface charge depended on the layer-by-layer coating of polyelectrolytes, with zeta potential of 38.6 ± 1.4 mV. The confocal microscope exhibited the layer-by-layer outer membrane and inner core. The in vitro release profile showed that the content release remained low during the first 2.67 hours. After this lag time, the cumulative release increased to 80% in the next 0.95 hours, which suggested a pulsed drug release. The in vivo drug release in mice showed that the outer membrane was ruptured at approximately 3 to 4 hours, as drug was explosively released. Conclusion These data suggest that the encapsulated substance in the core-membrane microgel delivery device can achieve a massive drug release after outer membrane rupture. This device was an effective system for pulsed drug delivery. PMID:23486565

Zhou, Guichen; Lu, Ying; Zhang, He; Chen, Yan; Yu, Yuan; Gao, Jing; Sun, Duxin; Zhang, Guoqing; Zou, Hao; Zhong, Yanqiang

2013-01-01

265

Microparticle-loaded neonatal porcine Sertoli cells for cell-based therapeutic and drug delivery system.  

PubMed

Neonatal porcine Sertoli cells (NPSC) are immune privileged cells showing innate phagocytic and antibacterial activities. NPSC have been shown capable of immunoaltering the body's response and possess lung homing capacity. These properties encourage investigation of NPSC as functional components of cell-based therapeutic protocols to treat lung infections and related complications. In this work, for the first time, NPSC were tailored to carry an antibiotic drug loaded into poly(d,l lactic) acid microparticles (MP). A loading protocol was developed, which afforded 30% drug uptake and high stability over time, with little or no effects on NPSC viability, morphology, reactive oxygen species production and DNA integrity. FSH receptor integrity, and TGF? (transforming growth factor ?) and AMH (anti-Müllerian hormone) expressions were unchanged after 1month of cryopreservation. Protein tyrosine kinase activation due to phagocytosis may have had resulted in changes in inhibin B expression. The activity of MP-loaded or NPSC alone against Pseudomonas aeruginosa was maintained throughout 1month of storage. NPSC couple an innate antibacterial activity with the capacity to embody drug loaded MP. We showed for the first time that engineered NPSC can be cryopreserved with no loss of their basic properties, thereby possibly representing a novel approach for cell-based therapeutic and drug delivery system. PMID:25111130

Giovagnoli, S; Mancuso, F; Vannini, S; Calvitti, M; Piroddi, M; Pietrella, D; Arato, I; Falabella, G; Galli, F; Moretti, M; Neri, L M; Bodo, M; Capitani, S; Cameron, D F; Ricci, M; Luca, G; Calafiore, R

2014-10-28

266

Nanocarriers as pulmonary drug delivery systems to treat and to diagnose respiratory and non respiratory diseases  

PubMed Central

The purpose of this review is to discuss the impact of nanocarriers administered by pulmonary route to treat and to diagnose respiratory and non respiratory diseases. Indeed, during the past 10 years, the removal of chlorofluorocarbon propellants from industrial and household products intended for the pulmonary route has lead to the developments of new alternative products. Amongst these ones, on one hand, a lot of attention has been focused to improve the bioavailability of marketed drugs intended for respiratory diseases and to develop new concepts for pulmonary administration of drugs and, on the other hand, to use the pulmonary route to administer drugs for systemic diseases. This has led to some marketed products through the last decade. Although the introduction of nanotechnology permitted to step over numerous problems and to improve the bioavailability of drugs, there are, however, unresolved delivery problems to be still addressed. These scientific and industrial innovations and challenges are discussed along this review together with an analysis of the current situation concerning the industrial developments. PMID:18488412

Smola, Malgorzata; Vandamme, Thierry; Sokolowski, Adam

2008-01-01

267

A thermal microjet system with tapered micronozzles fabricated by inclined UV lithography for transdermal drug delivery  

NASA Astrophysics Data System (ADS)

Transdermal drug delivery can be enabled by various methods that increase the permeability of the skin's outer barrier of stratum corneum, including skin exposure to heat and chemical enhancers, such as ethanol. Combining these approaches for the first time, in this study we designed a microdevice consisting of an array of microchambers filled with ethanol that is vaporized using an integrated microheater and ejected through a micronozzle contacting the skin surface. In this way, we hypothesize that the hot ethanol vapor can increase skin permeability upon contacting the skin surface. The tapered micronozzle and the microchamber designed for this application were realized using proximity-mode inclined rotational ultraviolet lithography, which facilitates easy fabrication of complex three-dimensional structures, convenient integration with other functional layers, low fabrication cost, and mass production. The resulting device had a micronozzle with an orifice inner and outer diameter of 220 and 320 µm, respectively, and an extruded height of 250 µm. When the microchamber was filled with an ethanol gel and activated, the resulting ethanol vapor jet increased the permeability of human cadaver epidermis to a model compound, calcein, by approximately 17 times, which is attributed to thermal and chemical disruption of stratum corneum structure. This thermal microjet system can serve as a tool not only for transdermal drug delivery, but also for a variety of biomedical applications.

Yoon, Yong-Kyu; Park, Jung-Hwan; Lee, Jeong-Woo; Prausnitz, Mark R.; Allen, Mark G.

2011-02-01

268

Application of monochromatic keV X-ray source to X-ray drug delivery system  

Microsoft Academic Search

X-ray Drug Delivery System (DDS) enhances accumulation of anti-cancer drug or contrast agent by surrounding it with polymer and Enhanced Penetration and Retention (EPR) effect. DDS uses advanced nano-scaled polymers that contain and deliver drug or contrast agent to cancers without side effects. Several X-ray DDSs pose high-Z atoms such as gold to absorb X-rays effectively and used as contrast

Mitsuru Uesaka; Hiroki Taguchi; Azusa Mori; Noritaka Yusa; Takamitsu Kato; Ryuichi Okayasu

2009-01-01

269

Design and In Vitro Characterization of Buccoadhesive Drug Delivery System of Insulin  

PubMed Central

A buccoadhesive drug delivery system of Insulin was prepared by solvent casting technique and characterized in vitro by surface pH, bioadhesive strength, drug release and skin permeation studies. Sodium carboxymethylcellulose-DVP was chosen as the controlled release matrix polymer. The optimized formulation J4 contained Sodium carboxy methyl cellulose-DVP 2% (w/v), insulin (50 IU/film), propylene glycol (0.25 ml) and Isopropyl alcohol: water (1:4) as solvent system. Bioadhesive strength of the prepared patches was measured on a modified physical balance using bovine cheek pouch as the model membrane. In vitro release studies were carried out at 37 ± 2° using phosphate buffer pH 6.6, in a modified dissolution apparatus fabricated for the purpose. Cumulative amount of drug released from the optimized formulation J4 was 91.64% in 6 hours. In vitro permeation studies were carried out on J4 at 37 ± 2° using Franz diffusion cell. Cumulative amount of drug permeated from J4 was 6.63% in 6 hours. In order to enhance the permeation of protein drug, different permeation enhancers were evaluated. The results suggested that sodium deoxycholate 5% (w/v) was the best permeation enhancer among those evaluated. It enhanced the permeation of insulin from 6.63% to 10.38% over a period of 6 hours. The optimized patches were also satisfactory in terms of surface pH and bioadhesive strength. It can also be easily concluded that the system is a success as compared to the conventional formulations with respect to invasiveness, requirement of trained persons for administration and most importantly, the first pass metabolism. PMID:20390082

Sahni, J.; Raj, S.; Ahmad, F. J.; Khar, R. K.

2008-01-01

270

In vivo real-time monitoring system of electroporation mediated control of transdermal and topical drug delivery.  

PubMed

Electroporation (EP) is a physical method for the delivery of molecules into cells and tissues, including the skin. In this study, in order to control the degree of transdermal and topical drug delivery, EP at different amplitudes of electric pulses was evaluated. A new in vivo real-time monitoring system based on fluorescently labeled molecules was developed, for the quantification of transdermal and topical drug delivery. EP of the mouse skin was performed with new non-invasive multi-array electrodes, delivering different amplitudes of electric pulses ranging from 70 to 570 V, between the electrode pin pairs. Patches, soaked with 4 kDa fluorescein-isothiocyanate labeled dextran (FD), doxorubicin (DOX) or fentanyl (FEN), were applied to the skin before and after EP. The new monitoring system was developed based on the delivery of FD to and through the skin. FD relative quantity was determined with fluorescence microscopy imaging, in the treated region of the skin for topical delivery and in a segment of the mouse tail for transdermal delivery. The application of electric pulses for FD delivery resulted in enhanced transdermal delivery. Depending on the amplitude of electric pulses, it increased up to the amplitude of 360 V, and decreased at higher amplitudes (460 and 570 V). Topical delivery steadily enhanced with increasing the amplitude of the delivered electric pulses, being even higher than after tape stripping used as a positive control. The non-invasive monitoring of the delivery of DOX, a fluorescent chemotherapeutic drug, qualitatively and quantitatively confirmed the effects of EP at 360 and 570 V pulse amplitudes on topical and transdermal drug delivery. Delivery of FEN at 360 and 570 V pulse amplitudes verified the observed effects as obtained with FD and DOX, by the measured physiological responses of the mice as well as FEN plasma concentration. This study demonstrates that with the newly developed non-invasive multi-array electrodes and with the varying electric pulse amplitude, the amount of topical and transdermal drug delivery to the skin can be controlled. Furthermore, the newly developed monitoring system provides a tool for rapid real-time determination of both, transdermal and topical delivery, when the delivered molecule is fluorescent. PMID:24113487

Blagus, Tanja; Markelc, Bostjan; Cemazar, Maja; Kosjek, Tina; Preat, Veronique; Miklavcic, Damijan; Sersa, Gregor

2013-12-28

271

Controlled release of oral tetrahydrocurcumin from a novel self-emulsifying floating drug delivery system (SEFDDS).  

PubMed

The objectives of this study were to develop and evaluate a novel self-emulsifying floating drug delivery system (SEFDDS) that resulted in improved solubility, dissolution, and controlled release of the poorly water-soluble tetrahydrocurcumin (THC). The formulations of liquid self-emulsifying drug delivery system (SEDDS; mixtures of Labrasol, Cremophor EL, Capryol 90, Labrafac PG) were optimized by solubility assay and pseudo-ternary phase diagram analysis. The liquid SEDDS was mixed with adsorbent (silicon dioxide), glyceryl behenate, pregelatinized starch, sodium starch glycolate, and microcrystalline cellulose and transformed into pellets by the extrusion/spheronization technique. The resulting pellets with 22% liquid SEDDS had a uniform size and good self-emulsification property. The microemulsions in aqueous media of different self-emulsifying floating pellet formulations were in a particle size range of 25.9-32.5 nm. Use of different weight proportions of glyceryl behenate and sodium starch glycolate in pellet formulations had different effects on the floating abilities and in vitro drug release. The optimum formulation (F2) had a floating efficiency of 93% at 6 h and provided a controlled release of THC over an 8-h period. The release rate and extent of release of THC liquid SEDDS (80% within 2 h) and self-emulsifying floating pellet formulation (80% within 8 h) were significantly higher than that of unformulated THC (only 30% within 8 h). The pellet formulation was stable under intermediate and accelerated storage conditions for up to 6 months. Controlled release from this novel SEFDDS can be a useful alternative for the strategic development of oral solid lipid-based formulations. PMID:21181511

Setthacheewakul, Saipin; Kedjinda, Wichan; Maneenuan, Duangkhae; Wiwattanapatapee, Ruedeekorn

2011-03-01

272

Semi-solid Sucrose Stearate-Based Emulsions as Dermal Drug Delivery Systems  

PubMed Central

Mild non-ionic sucrose ester surfactants can be employed to produce lipid-based drug delivery systems for dermal application. Moreover, sucrose esters of intermediate lipophilicity such as sucrose stearate S-970 possess a peculiar rheological behavior which can be employed to create highly viscous semi-solid formulations without any further additives. Interestingly, it was possible to develop both viscous macroemulsions and fluid nanoemulsions with the same chemical composition merely by slight alteration of the production process. Optical light microscopy and cryo transmission electron microscopy (TEM) revealed that the sucrose ester led to the formation of an astonishing hydrophilic network at a concentration of only 5% w/w in the macroemulsion system. A small number of more finely structured aggregates composed of surplus surfactant were likewise detected in the nanoemulsions. These discoveries offer interesting possibilities to adapt the low viscosity of fluid O/W nanoemulsions for a more convenient application. Moreover, a simple and rapid production method for skin-friendly creamy O/W emulsions with excellent visual long-term stability is presented. It could be shown by franz-cell diffusion studies and in vitro tape stripping that the microviscosity within the semi-solid formulations was apparently not influenced by their increased macroviscosity: the release of three model drugs was not impaired by the complex network-like internal structure of the macroemulsions. These results indicate that the developed semi-solid emulsions with advantageous application properties are highly suitable for the unhindered delivery of lipophilic drugs despite their comparatively large particle size and high viscosity. PMID:24310496

Klang, Victoria; Schwarz, Julia C.; Matsko, Nadejda; Rezvani, Elham; El-Hagin, Nivine; Wirth, Michael; Valenta, Claudia

2011-01-01

273

Transdermal drug delivery systems of a beta blocker: design, in vitro, and in vivo characterization.  

PubMed

The matrix type transdermal drug delivery systems (TDDS) of metoprolol were prepared by film casting technique using a fabricated stainless steel film casting apparatus and characterized in vitro by drug release, skin permeation, skin irritation, and in vivo pharmacodynamic and stability studies. Four formulations were prepared that differed in the ratio of matrix forming polymers. Formulations M-1, M-2, M-3, and M-4 were composed of Eudragit RL-100 and polyvinyl acetate with the following ratios: 2:8, 4:6, 6:4, and 8:2, respectively. All the four formulations carried 10% (w/w) of metoprolol tartrate, 5% (w/w) of dibutylphthalate, and 5% (w/w) of (+/-) menthol in dichloromethane:isopropyl alcohol (80:20 v/v). Cumulative amount of drug released in 48 hr from the four formulations was 79.16%, 81.17%, 85.98%, and 95.04%. The corresponding values for cumulative amount of drug permeated for the said formulations were 59.72%, 66.52%, 77.36%, and 90.38%. On the basis of in vitro drug release and skin permeation performance, formulation M-4 was found to be better than the other three formulations and it was selected as the optimized formulation. The formulation appeared to be stable when stored at 40 degrees C and 75% RH with negligible degradation of the drug. The TDDS was found to be free of any skin irritation as suggested by skin irritation score of 1.16 (<2.00) under Draize score test. Statistically significant reduction in mean blood pressure (p < .01) was achieved in methyl prednisolone-induced hypertensive rats on treatment with the TDDS. PMID:15168788

Aqil, M; Sultana, Yasmin; Ali, Asgar; Dubey, Kiran; Najmi, A K; Pillai, K K

2004-01-01

274

Novel Platforms for Oral Drug Delivery  

Microsoft Academic Search

The aim of this review is to provide the reader general and inspiring prospects on recent and promising fields of innovation\\u000a in oral drug delivery. Nowadays, inventive drug delivery systems vary from geometrically modified and modular matrices, more\\u000a close to “classic” pharmaceutical manufacturing processes, to futuristic bio micro-electro-mechanical systems (bioMEMS), based\\u000a on manufacturing techniques borrowed from electronics and other fields.

P. Colombo; F. Sonvico; G. Colombo; R. Bettini

2009-01-01

275

A review on proniosomal drug delivery system for targeted drug action  

PubMed Central

Proniosomes are dry formulation of water soluble carrier particles that are coated with surfactant. They are rehydrated to form niosomal dispersion immediately before use on agitation in hot aqueous media within minutes. Proniosomes are physically stable during the storage and transport. Drug encapsulated in the vesicular structure of proniosomes prolong the existence of drug in the systematic circulation and enhances the penetration into target tissue and reduce toxicity. From a technical point of view, niosomes are promising drug carriers as they possess greater chemical stability and lack of many disadvantages associated with liposomes, such as high- cost and variable purity problems of phospholipids. The present review emphasizes on overall methods of preparation characterization and applicability of proniosomes in targeted drug action. PMID:24808669

Radha, G. V.; Rani, T. Sudha; Sarvani, B.

2013-01-01

276

A novel hybrid delivery system: polymer-oil nanostructured carrier for controlled delivery of highly lipophilic drug all-trans-retinoic acid (ATRA).  

PubMed

Many recently developed drugs encounter delivery issues due to their high lipophilicity and poor aqueous solubility. This study reports the development of a novel hybrid nanocarrier known as polymer-oil nanostructured carrier (PONC), in which highly lipophilic drugs such as all-trans-retinoic acid (ATRA) and indomethacin pre-solubilized in oil phase were dispersed in a polymeric matrix of poly(D,L-lactic-co-glycolic acid) (PLGA). In comparison to the standard PLGA only nanoparticles, PONC substantially increased the encapsulation efficiency of ATRA and indomethacin by up to 259% and 124%, respectively. Differential scanning calorimetry analysis revealed that the inclusion of oil introduced nanostructure into the polymeric matrix of the carrier. This feature facilitated more uniform distribution of the drug molecules which subsequently led to improved drug release kinetics with significantly reduced burst release effects (p<0.05). PONC was lyophilizable, remained physically stable when stored at low temperatures, and demonstrated low non-specific carrier toxicity. Delivery of ATRA by PONC also significantly improved its anticancer activity over the standard PLGA only nanoparticles (p<0.05). Our findings have therefore validated a promising delivery system that integrates the advantages of lipid-based (e.g. efficient encapsulation of highly lipophilic drugs) and polymeric colloidal carriers (e.g. uniform size, good stability), plus potential therapeutic benefits for delivery of poorly water-soluble anticancer drugs like ATRA. PMID:22850294

Narvekar, Mayuri; Xue, Hui Yi; Wong, Ho Lun

2012-10-15

277

Inner Ear Drug Delivery for Auditory Applications  

PubMed Central

Many inner ear disorders cannot be adequately treated by systemic drug delivery. A blood-cochlear barrier exists, similar physiologically to the blood-brain barrier, which limits the concentration and size of molecules able to leave the circulation and gain access to the cells of the inner ear. However, research in novel therapeutics and delivery systems has led to significant progress in the development of local methods of drug delivery to the inner ear. Intratympanic approaches, which deliver therapeutics to the middle ear, rely on permeation through tissue for access to the structures of the inner ear, whereas intracochlear methods are able to directly insert drugs into the inner ear. Innovative drug delivery systems to treat various inner ear ailments such as ototoxicity, sudden sensorineural hearing loss, autoimmune inner ear disease, and for preserving neurons and regenerating sensory cells are being explored. PMID:18848590

Swan, Erin E. Leary; Mescher, Mark J.; Sewell, William F.; Tao, Sarah L.; Borenstein, Jeffrey T.

2008-01-01

278

Stereomicroscopic imaging technique for the quantification of cold flow in drug-in-adhesive type of transdermal drug delivery systems.  

PubMed

Cold flow is a phenomenon occurring in drug-in-adhesive type of transdermal drug delivery systems (DIA-TDDS) because of the migration of DIA coat beyond the edge. Excessive cold flow can affect their therapeutic effectiveness, make removal of DIA-TDDS difficult from the pouch, and potentially decrease available dose if any drug remains adhered to pouch. There are no compendial or noncompendial methods available for quantification of this critical quality attribute. The objective was to develop a method for quantification of cold flow using stereomicroscopic imaging technique. Cold flow was induced by applying 1 kg force on punched-out samples of marketed estradiol DIA-TDDS (model product) stored at 25°C, 32°C, and 40°C/60% relative humidity (RH) for 1, 2, or 3 days. At the end of testing period, dimensional change in the area of DIA-TDDS samples was measured using image analysis software, and expressed as percent of cold flow. The percent of cold flow significantly decreased (p < 0.001) with increase in size of punched-out DIA-TDDS samples and increased (p < 0.001) with increase in cold flow induction temperature and time. This first ever report suggests that dimensional change in the area of punched-out samples stored at 32°C/60%RH for 2 days applied with 1 kg force could be used for quantification of cold flow in DIA-TDDS. PMID:24585397

Krishnaiah, Yellela S R; Katragadda, Usha; Khan, Mansoor A

2014-05-01

279

Microneedle delivery for improved efficacy of antiretroviral and antibiotic drugs  

E-print Network

Two classes of drugs, antiretrovirals and antibiotics, could benefit greatly from delivery through microneedles. Microneedles (MN) offer an increase in efficacy for these drugs by providing delivery to the lymphatic system ...

Stauber, Zachary Jason

2012-01-01

280

Self-emulsifying drug delivery systems for improving oral absorption of ginkgo biloba extracts.  

PubMed

Self-emulsifying drug delivery systems (SEDDS) are mixtures of oils, surfactants, and cosurfactants, which are emulsified in aqueous media under conditions of gentle stirring and digestive motility that would be encountered in the gastrointestinal tract. We found that SEDDS could efficiently improve oral absorption of the sparingly soluble drugs by rapid self-emulsification and subsequently dispersion in the absorption sites. Ginkgo biloba extract (GBE) has become a widely used herbal remedy for increasing cognitive function in elderly people. The main purpose of our work is to prepare SEDDS for improving oral absorption of GBE. Pseudoternary phase diagrams were constructed to identify the efficient self-emulsification region, and particle size distributions of resultant emulsions were determined. The optimized formulation for bioavailability assessment consisted of 45% Tween 80-Cremophor EL35 (1:1, w/w), 10% 1, 2-propanediol, and 45% ethyl oleate. The mean droplet size distribution of the optimized SEDDS was approximately 100 nm when diluted with 500-fold volume of the distilled water. The in vitro dissolution rates of the active components of GBE SEDDS form were significantly faster than those of the GBE tablets. After single oral administration of 800 mg GBE as SEDDS or tablets to fasted dogs, the relative bioavailability of SEDDS for bilabolide and ginkgolide A and B was 162.1, 154.6, and 155.8% compared with the reference tablets, respectively. Our results suggested the potential and promising use of SEDDS for the efficient delivery of the sparingly soluble drugs or traditional Chinese medicines, such as GBE by oral administration. PMID:18720135

Tang, Jingling; Sun, Jin; Cui, Fude; Zhang, Tianhong; Liu, Xiaohong; He, Zhonggui

2008-11-01

281

Cost comparison of oral, nasogastric, and intramuscular cimetidine drug delivery systems.  

PubMed

Under diagnosis-related group prospective payment, the role of the hospital pharmacy department is to develop and promote cost effective and rational drug therapy. This study, conducted in a simulated fashion, evaluated the cost effectiveness of various cimetidine drug delivery systems: oral, nasogastric, and intramuscular. The evaluation was also extended to compare time efficacy between different dosage forms for each route of administration with the exception of the intramuscular route. Each of four nurses and four pharmacy technicians conducted 10 trials for each system to detect a statistical significance difference in pharmacy preparation and nursing administration time with at least 80% statistical power. The results showed no statistically significant difference (P > 0.1) between the total oral administration time of a unit-dose tablet or liquid. A significant difference was detected among the pharmacy-prepared liquids, and unit-dose liquid administered nasogastrically (P < 0.01). The most cost-effective system is the orally administered unit-dose tablet and the most expensive system is the unit-dose liquid administered nasogastrically. PMID:10122039

Lau, N C; Caldwell, R D; Arford, P H

1992-11-01

282

Natural gums as sustained release carriers: development of gastroretentive drug delivery system of ziprasidone HCl  

PubMed Central

Background Objective of this study is to show the potential use of natural gums in the development of drug delivery systems. Therefore in this work gastro retentive tablet formulations of ziprasidone HCl were developed using simplex lattice design considering concentration of okra gum, locust bean gum and HPMC K4M as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on hardness, flag time, floating time and drug release for 1 h, 2 h, and 8 h and for 24 h. A checkpoint batch was also prepared by considering the constraints and desirability of optimized formulation to improve its in vitro performance. Significance of result was analyzed using ANOVA and p < 0.05 was considered statistically significant. Results Formulation chiefly contains locust bean gum found to be favorable for hardness and floatability but combined effect of three variables was responsible for the sustained release of drug. The in vitro drug release data of check point batch (F8) was found to be sustained well compared to the most satisfactory formulation (F7) of 7 runs. The ‘n’ value was found to be between 0.5 and 1 suggesting that release of drug follows anomalous (non-fickian) diffusion mechanism indicating both diffusion and erosion mechanism from these natural gums. Predicted results were almost similar to the observed experimental values indicating the accuracy of the design. In vivo floatability test indicated non adherence to the gastric mucosa and tablets remain buoyant for more than 24 h. Conclusions Study showed these eco-friendly natural gums can be considered as promising SR polymers. PMID:23352292

2012-01-01

283

Nanospheres-incorporated implantable hydrogel as a trans-tissue drug delivery system.  

PubMed

The objective of this study is to investigate the anticancer efficacy of a drug delivery system comprised of gelatin hydrogel (jelly) containing cisplatin (CDDP)-loaded gelatin/poly(acrylic acid) nanoparticles by peritumoral implantation and to compare the treatment response between the implantation administration of the jelly and intravenous (i.v.) administration of the nanoparticles. It is found that the implantation of the jelly containing CDDP-loaded nanoparticles on tumor tissue exhibited significantly superior efficacy in impeding tumor growth and prolonging the lifetime of mice than that of i.v. injection of CDDP-loaded nanoparticles in a murine hepatoma H(22) cancer model. An in vivo biodistribution assay performed on tumor-bearing mice demonstrated that the jelly implant caused much higher concentration and retention of CDDP in tumor and lower CDDP accumulation in nontarget organs than that of i.v. injected nanoparticles. Immunohistochemical analysis demonstrated that the nanoparticles from the jelly can be distributed in tumor tissue not only by their diffusion but also by the vasculature in the implantation region into tumor interior, enabling CDDP to efficiently reach more viable cells of tumor compared with i.v. injected nanoparticles. Thus, nanoparticles for peritumoral chemotherapy are promising for higher treatment efficacy due to increased tumor-to-normal organ drug uptake ratios and improved drug penetration in tumors. PMID:21428432

Ding, Dan; Zhu, Zhenshu; Li, Rutian; Li, Xiaolin; Wu, Wei; Jiang, Xiqun; Liu, Baorui

2011-04-26

284

Biodegradable nanoparticles mimicking platelet binding as a targeted and controlled drug delivery system.  

PubMed

This research aims to develop targeted nanoparticles as drug carriers to the injured arterial wall under fluid shear stress by mimicking the natural binding ability of platelets via interactions of glycoprotein Ib-alpha (GPIb?) of platelets with P-selectin of damaged endothelial cells (ECs) and/or with von Willebrand factor (vWF) of the subendothelium. Drug-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles were formulated using a standard emulsion method and conjugated with glycocalicin, the external fraction of platelet GPIb?, via carbodiimide chemistry. Surface-coated and cellular uptake studies in ECs showed that conjugation of PLGA nanoparticles, with GPIb, significantly increased nanoparticle adhesion to P-selectin- and vWF-coated surfaces as well as nanoparticle uptake by activated ECs under fluid shear stresses. In addition, effects of nanoparticle size and shear stress on adhesion efficiency were characterized through parallel flow chamber studies. The observed decrease in bound nanoparticle density with increased particle sizes and shear stresses is also explained through a computational model. Our results demonstrate that the GPIb-conjugated PLGA nanoparticles can be used as a targeted and controlled drug delivery system under flow conditions at the site of vascular injury. PMID:22172292

Kona, Soujanya; Dong, Jing-Fei; Liu, Yaling; Tan, Jifu; Nguyen, Kytai T

2012-02-28

285

Systematic Development of Self-Emulsifying Drug Delivery Systems of Atorvastatin with Improved Bioavailability Potential  

PubMed Central

The aim of this study was to prepare and characterize a self-emulsifying drug delivery system (SEDDS) with a high drug load of poorly water-soluble atorvastatin for the enhancement of dissolution and oral bioavailability. Solubility of atorvastatin in oil, surfactant, and cosurfactant was determined. Pseudo-ternary phase diagrams were constructed by the aqueous titration method, and formulations were developed based on the optimum excipient combinations. A high drug load (10% w/w) was achieved with a combination of oleic acid, Tween 80, and polyethylene glycol 400, ensuring the maximum dissolution property (in the case of SES6). Effects of lipids and surfactants on physical properties of SEDDS such as in vitro emulsification efficiency in terms of self-emulsification time, emulsion droplet size, and percent transmittance were measured. Multiple regression analysis revealed that a higher amount of surfactants significantly increased dissolution of ATV while decreasing emulsion droplet size and emulsification time. About a four-fold increase in dissolution was achieved by SEDDS compared to pure ATV powder. Overall, this study suggests that dissolution and oral bioavailability of ATV could be improved by SEDDS technology. PMID:23264948

Khan, Fariba; Islam, Md. Saiful; Roni, Monzurul Amin; Jalil, Reza-Ul

2012-01-01

286

Modulation of a pulsatile release drug delivery system using different swellable/rupturable materials.  

PubMed

Diclofenac sodium tablets consisting of core coated with two layers of swelling and rupturable coatings were prepared and evaluated as a pulsatile drug delivery system. Cores containing the drug were prepared by direct compression using microcrystalline cellulose and Ludipress as hydrophilic excipients with the ratio of 1:1. Cores were then coated sequentially with an inner swelling layer of different swellable materials; either Explotab, Croscarmellose sodium, or Starch RX 1500, and an outer rupturable layer of different levels of ethylcellulose. The effect of the nature of the swelling layer and the level of the rupturable coating on the lag time and the water uptake were investigated. Drug release rate studies were performed using USP paddle method. Results showed the dependence of the lag time and water uptake prior to tablet rupture on the nature of the swelling layer and the coating levels. Explotab showed a significant decrease in the lag time, followed by Croscarmellose sodium and finally by Starch RX 1500. Increasing the level of ethylcellulose coating retarded the diffusion of the release medium to the swelling layer and the rupture of the coat, thus prolonging the lag time. PMID:18027184

El-Maradny, Hoda A

2007-11-01

287

Fast Disintegrating Quercetin-Loaded Drug Delivery Systems Fabricated Using Coaxial Electrospinning  

PubMed Central

The objective of this study is to develop a structural nanocomposite of multiple components in the form of core-sheath nanofibres using coaxial electrospinning for the fast dissolving of a poorly water-soluble drug quercetin. Under the selected conditions, core-sheath nanofibres with quercetin and sodium dodecyl sulphate (SDS) distributed in the core and sheath part of nanofibres, respectively, were successfully generated, and the drug content in the nanofibres was able to be controlled simply through manipulating the core fluid flow rates. Field emission scanning electron microscope (FESEM) images demonstrated that the nanofibres prepared from the single sheath fluid and double core/sheath fluids (with core-to-sheath flow rate ratios of 0.4 and 0.7) have linear morphology with a uniform structure and smooth surface. The TEM images clearly demonstrated the core-sheath structures of the produced nanocomposites. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results verified that quercetin and SDS were well distributed in the polyvinylpyrrolidone (PVP) matrix in an amorphous state, due to the favourite second-order interactions. In vitro dissolution studies showed that the core-sheath composite nanofibre mats could disintegrate rapidly to release quercetin within 1 min. The study reported here provides an example of the systematic design, preparation, characterization and application of a new type of structural nanocomposite as a fast-disintegrating drug delivery system. PMID:24185912

Li, Xiao-Yan; Li, Yan-Chun; Yu, Deng-Guang; Liao, Yao-Zu; Wang, Xia

2013-01-01

288

Development and in vitro characterization of floating sustained-release drug delivery systems of polyphenols.  

PubMed

The aim of this study was to develop and characterize floating stomach-retentive matrix tablets that will deliver polyphenols in a controlled release manner. The tablets were prepared by direct compression. A number of polymers were examined and egg albumin was chosen in light of a better performance in terms of floating behavior and decomposition time. Dissolution studies for three representative polyphenols loaded into a number of formulations were performed using the "f?" factor in order to compare release profiles of different polyphenols and formulations. The release data showed a good fit into the power law equation and zero-order kinetics has been determined for some of the systems. Erosion and textural analysis studies revealed that higher concentration of egg albumin results in a higher gel strength that is less susceptible to erosion, potentially leading to a prolonged delivery time of drug. The ability of egg albumin-based tablets to resist high mechanical forces was also determined, while comparison to cellulose-derived polymers revealed that the latter have a much lower ability to resist the same forces. The developed delivery system has the potential to increase the efficacy of the therapy for various pathological stomach conditions and to improve patient compliance. PMID:23730744

Rosenzweig, Ohad; Lavy, Eran; Gati, Irith; Kohen, Ron; Friedman, Michael

2013-01-01

289

Tuberculosis therapeutics: Engineering of nanomedicinal systems for local delivery of targeted drug cocktails  

NASA Astrophysics Data System (ADS)

In this thesis, a multifunctional nanocarrier drug delivery system was investigated and optimized to improve tuberculosis therapy by promoting the intracellular delivery of high payloads of antibiotics. To meet the needs of a patient population which continues to grow by close to 10 million people a year, innovative therapeutics must be formulated by robust and scalable processes. We use Flash NanoPrecipitation for the continuous precipitation of nanocarriers by block copolymer directed assembly, which enables the development of nanocarriers with tunable properties. Stable nanocarriers of Rifampicin and a hydrophobic Rifampicin prodrug have efficacy against tuberculosis in vitro that is equivalent to the soluble Rifampicin. To overcome poor in vivo efficacy of the recently discovered antitubercular drug SQ641, we co-encapsulate SQ641 and Cyclosporine A in a stable aqueous nanocarrier suspension, which enables drug administration and also enhances intracellular accumulation and antitubercular efficacy relative to SQ641 in solution. Since the mannose receptor is involved in the phagocytosis of tuberculosis bacilli, we modify the surface of nanocarriers with mannoside residues to target specific intracellular accumulation in macrophages. The surface density of mannoside terminated polyethylene glycol chains was controlled between 0 and 75% and in vitro cellular association reveals a 9% surface density is optimal for internalization mediated by the mannose receptor. We explore the preparation of large, porous aerosol carrier particles of with tunable deposition characteristics by spray freeze drying with ultrasonic atomization for direct dosing to the lungs. Nanocarriers are loaded at 3 - 50 wt% in mannitol particles with constant size, limited nanocarrier aggregation, and 63% dose delivered to the lungs, as determined by in vitro cascade impaction. There has been a lag in the development of new technologies to facilitate development and commercialization of therapeutic nanocarrier formulations. We present three translational technologies. (1) The intrinsic dissolution rates of drug nanocarriers are determined using a novel assay, based on high surface area lipid sink particles and magnetic separations, to improve in vitro/in vivo correlations. (2) The nanocarrier interaction with whole serum and the polymer surface conformation are correlated to in vivo clearance and general rules are proposed for the design of nanocarriers produced by Flash NanoPrecipitation with extended circulation times for targeted delivery. (3) In Hydrogen Bonding Coacervate Precipitation, polyethylene glycol coated nanocarriers are controllably flocculated with the addition of polyacids to enable rapid filtration and drying. In summary, this research outlines approaches to the customization of nanocarrier drug delivery systems to specifically improve outcomes in tuberculosis therapy. New assays and processing techniques for transitioning formulations from bench research to the clinic are developed. The methods are flexible and can be applied to target various diseases, coupled with rational design of nanocarrier payloads, surface functionality, and dosing route.

D'Addio, Suzanne M.

290

A Novel Osmotic Pump Tablet Using Core of Drug-resin Complexes for Time-controlled Delivery System  

Microsoft Academic Search

A novel elementary osmotic pump tablet was developed. The system uses the core of drug-resin complexes (DRCs) loaded with propranolol hydrochloride (PNH) for time-controlled delivery. In traditional osmotic pump tablets (OPTs), the lag time was always minimized. However, in the DRCs osmotic pump tablet (DRCOPT) ,t he lag time was increased to achieve the time-controlled delivery. The quantity of osmotic

Chao WANG; Fei CHEN; Ji-zhong LI; Hai TANG; Xiang LI; Ke-shu YAN; Guan-hao YE; Wei-san PAN

2008-01-01

291

Therapeutic Trials Based on Combination of Drug Delivery System and Ultrasound  

NASA Astrophysics Data System (ADS)

The objective of this study is to show how therapeutically effective a combination of a drug delivery system (DDS) and ultrasound (US) is by introducing data from two related experiments. Fullerene (C60) was chemically modified by polyethylene glycol (PEG) for water-solubilization and tumour targeting. When the PEG-modified C60 was injected intravenously into tumour bearing mice, followed by US irradiation to the tumour site, a synergistic anti-tumour effect was observed. Following the intravenous injection of interferon (IFN) conjugated with pullulan which has an inherent affinity for the liver, and subsequent US irradiation to the liver, the activity level of an IFN-specific enzyme was significantly enhanced compared with that of the conjugate injection alone.

Tabata, Yasuhiko

2005-03-01

292

Gene and drug delivery system and potential treatment into inner ear for protection and regeneration  

PubMed Central

The most common type of hearing loss results from damage to the cochlea including lost hair cells (HCs) and spiral ganglion neurons (SGNs). In mammals, cochlear HC loss causes irreversible hearing impairment because this type of sensory cell cannot regenerate. The protection from SGN from degeneration has implications for cochlear implant to patients with severe deafness. This review summarizes the several treatments for HC regeneration based on experiments. We discuss how transgene expression of the neurotrophic factor can protect SGN from degeneration and describe potential new therapeutic interventions to reduce hearing loss. We also summarized viral vectors and introduced the gene and drug delivery system for regeneration and protection of cochlear HCs. Finally, we introduce the novel endoscopy we developed for local injection into cochlea. PMID:25339903

Kanzaki, Sho

2014-01-01

293

Fullerene C60 as a multifunctional system for drug and gene delivery  

NASA Astrophysics Data System (ADS)

The fullerene family, and especially C60, has delighted the scientific community during the last 25 years with perspective applications in a wide variety of fields, including the biological and the biomedical domains. Several biomedical uses have been explored using water-soluble C60-derivatives. However, the employment of fullerenes for drug delivery is still at an early stage of development. The design and synthesis of multifunctionalized and multimodal C60 systems able to cross the cell membranes and efficiently deliver active molecules is an attracting challenge that involves multidisciplinary strategies. Promising results have emerged in the last years, bringing fullerenes again to the front of interest. Herein, the state of the art of this emerging field is presented and illustrated with some of the most representative examples.

Montellano, Alejandro; da Ros, Tatiana; Bianco, Alberto; Prato, Maurizio

2011-10-01

294

Expanding Alternative Delivery Systems.  

ERIC Educational Resources Information Center

Alternative educational delivery systems that might be useful to community colleges are considered. The following categories of delivery systems are covered: broadcast delivery systems; copy delivery systems, print delivery systems, computer delivery systems, telephone delivery systems, and satellites. Among the applications for broadcast…

Baltzer, Jan A.

295

Magnetic Control of Potential Microrobotic Drug Delivery Systems: Nanoparticles, Magnetotactic Bacteria and Self-Propelled Microjets  

PubMed Central

Development of targeted drug delivery systems using magnetic microrobots increases the therapeutic indices of drugs. These systems have to be incorporated with precise motion controllers. We demonstrate closed-loop motion control of microrobots under the influence of controlled magnetic fields. Point-to-point motion control of a cluster of iron oxide nanoparticles (diameter of 250 nm) is achieved by pulling the cluster towards a reference position using magnetic field gradients. Magnetotactic bacterium (MTB) is controlled by orienting the magnetic fields towards a reference position. MTB with membrane length of 5 ?m moves towards the reference position using the propulsion force generated by its flagella. Similarly, self-propelled microjet with length of 50 ?m is controlled by directing the microjet towards a reference position by external magnetic torque. The microjet moves along the field lines using the thrust force generated by the ejecting oxygen bubbles from one of its ends. Our control system positions the cluster of nanoparticles, an MTB and a microjet at an average velocity of 190 ?m/s, 28 ?m/s, 90 ?m/s and within an average region-of-convergence of 132 ?m, 40 ?m, 235 ?m, respectively. PMID:24110932

Khalil, Islam S. M.; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G.; Abelmann, Leon; Misra, Sarthak

2013-01-01

296

Magnetic control of potential microrobotic drug delivery systems: nanoparticles, magnetotactic bacteria and self-propelled microjets.  

PubMed

Development of targeted drug delivery systems using magnetic microrobots increases the therapeutic indices of drugs. These systems have to be incorporated with precise motion controllers. We demonstrate closed-loop motion control of microrobots under the influence of controlled magnetic fields. Point-to-point motion control of a cluster of iron oxide nanoparticles (diameter of 250 nm) is achieved by pulling the cluster towards a reference position using magnetic field gradients. Magnetotactic bacterium (MTB) is controlled by orienting the magnetic fields towards a reference position. MTB with membrane length of 5 µm moves towards the reference position using the propulsion force generated by its flagella. Similarly, self-propelled microjet with length of 50 µm is controlled by directing the microjet towards a reference position by external magnetic torque. The microjet moves along the field lines using the thrust force generated by the ejecting oxygen bubbles from one of its ends. Our control system positions the cluster of nanoparticles, an MTB and a microjet at an average velocity of 190 µm/s, 28 µm/s, 90 µm/s and within an average region-of-convergence of 132 µm, 40 µm, 235 µm, respectively. PMID:24110932

Khalil, Islam S M; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G; Abelmann, Leon; Misra, Sarthak

2013-01-01

297

The Conjunctival Barrier in Ocular Drug Delivery  

Microsoft Academic Search

Within the context of topical and local drug delivery to the eye, the mammalian conjunctiva functions as a unique biological\\u000a barrier. Various model systems as in vitro tools have been refined and validated over the years to assess drug absorption\\u000a across the conjunctiva. Passive and active drug transport as well as endocytic routes of transconjunctival drug permeation\\u000a have been extensively

Hovhannes J. Gukasyan; Kwang-Jin Kim; Vincent H. L. Lee

298

Controlled and continuous release ocular drug delivery systems: pros and cons.  

PubMed

Topical ocular drug administration is the most preferred route for treating conditions affecting the surface of the eye as well as anterior segment diseases; this is mainly due to the rapid and localised drug action and patient acceptability. However, the ocular bioavailability is typically less than 5% from conventional ophthalmic dosage forms such as eye drops. This is mainly due to the unique anatomical and physiological features of the eye. One of the effective pharmaceutical approaches is to provide a controlled and continuous drug release to the surface of the eye to compensate drug loss by nasolacrimal drainage and non-productive absorption of the topically applied drug. This review provides a critical appraisal (advantages and drawbacks) of the different drug delivery strategies that provides controlled and continuous drug supply to the surface of the eye; it covers research conducted over the past three decades. PMID:22640036

Abdelkader, Hamdy; Alany, Raid G

2012-07-01

299

Affinity-based drug delivery systems for tissue repair and regeneration.  

PubMed

Affinity-based release systems use transient interactions to sustain and control the release of a therapeutic from a polymeric matrix. The most common affinity-based systems use heparin-based scaffolds to sustain the release of heparin-binding proteins, such as fibroblast growth factor-2 (FGF2) and vascular endothelial growth factor (VEGF). However, novel affinity-based systems based on, for example, protein-protein or DNA-protein interactions, are emerging to control the release of an expanding repertoire of therapeutics. Mathematical models of affinity-based systems have provided a thorough understanding of which parameters affect release rate from these systems, and how these release rates can be tuned. In this review, recent affinity-based release systems will be described, including an overview of the various types of affinity interactions used to modulate release, the mechanisms by which release from these systems is tuned, and the time scales of sustained release. This advanced drug delivery paradigm provides tunable and predictable release rates and has expanded the scope of deliverable therapeutics for tissue repair and regeneration. PMID:25230248

Vulic, Katarina; Shoichet, Molly S

2014-11-10

300

A self-microemulsifying drug delivery system to overcome intestinal resveratrol toxicity and presystemic metabolism.  

PubMed

A mixed lipid-mixed surfactant self-microemulsifying drug delivery system (SMEDDS) was developed to exploit the health benefits of resveratrol, a Biopharmaceutical Classification System Class 2 natural polyphenol, subject to extensive intestinal presystemic metabolism. SMEDDS with a mixed lipid phase (castor oil/Capmul MCM 1:1) and a mixed surfactant phase (Kolliphor EL/Kolliphor RH 40 1:1) was developed and evaluated for its self-emulsifying properties and in vitro dispersion. The impact of SMEDDS on the permeability properties of resveratrol and its metabolite fluxes through the rat intestine and Caco-2 cells was monitored. The inhibitory effect of selected SMEDDS components on the efflux transporters multidrug resistance-associated protein and P-gp as well as cytotoxicity was assessed on Caco-2 cells. The formulation allowed for high resveratrol loading (122.5 mg/g SMEDDS), excellent self-emulsifying properties, and very rapid release. When formulated in SMEDDS, resveratrol metabolite efflux significantly declined. The formulation (SMEDDS without incorporated resveratrol) and its individual components did not compromise in vitro cell vitality and integrity. Mixed lipid-mixed surfactant SMEDDS is a prospective formulation to improve resveratrol biopharmaceutical, pharmacokinetic, and toxicological properties, leading the way to resveratrol use not only as a supplement but also as a pharmacological drug. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3491-3500, 2014. PMID:25103361

Seljak, Katarina Bolko; Berginc, Katja; Trontelj, Jurij; Zvonar, Alenka; Kristl, Albin; Gašperlin, Mirjana

2014-11-01

301

Synthetic micro/nanomotors in drug delivery  

NASA Astrophysics Data System (ADS)

Nanomachines offer considerable promise for the treatment of diseases. The ability of man-made nanomotors to rapidly deliver therapeutic payloads to their target destination represents a novel nanomedicine approach. Synthetic nanomotors, based on a multitude of propulsion mechanisms, have been developed over the past decade toward diverse biomedical applications. In this review article, we journey from the use of chemically powered drug-delivery nanovehicles to externally actuated (fuel-free) drug-delivery nanomachine platforms, and conclude with future prospects and challenges for such practical propelling drug-delivery systems. As future micro/nanomachines become more powerful and functional, these tiny devices are expected to perform more demanding biomedical tasks and benefit different drug delivery applications.

Gao, Wei; Wang, Joseph

2014-08-01

302

Switchable selectivity for gating ion transport with mixed polyelectrolyte brushes: approaching 'smart' drug delivery systems  

NASA Astrophysics Data System (ADS)

A pH-responsive mixed polyelectrolyte brush from tethered polyacrylic acid (PAA) and poly(2-vinylpyridine) (P2VP) (PAA:P2VP = 69:31 by weight) was prepared and used for selective gating transport of anions and cations across the thin film. An ITO glass electrode was modified with the polymer brush and used to study the switchable permeability of the mixed brush triggered by changes in pH of the aqueous environment in the presence of two soluble redox probes: [Fe(CN)6]4- and [Ru(NH3)6]3+. The responsive behavior of the brush was also investigated using the in situ ellipsometric measurements of the brush swelling, examination of the brush morphology with atomic force microscopy (AFM), and contact angle measurements of the brush samples extracted from aqueous solutions at different pH values. The mixed brush demonstrated a bipolar permselective behavior. At pH<3 the positively charged P2VP chains enabled the electrochemical process for the negatively charged redox probe, [Fe(CN)6]4-, while the redox process for the positively charged redox probe was effectively inhibited. On the contrary, at pH>6 a reversible redox process for the positively charged redox probe, [Ru(NH3)6]3+, was observed, while the redox process for the negatively charged redox species, [Fe(CN)6]4-, was fully inhibited. Stepwise changing the pH value and recording cyclic voltammograms for the intermediate states of the polymer brush allowed electrochemical observation of the brush transition from the positively charged state, permeable for the negatively charged species, to the negatively charged state, permeable for the positively charged species. The data of ellipsometric, AFM and contact angle measurements are in accord with the electrochemical study. The discovered properties of the brush could be used for the development of 'smart' sensors and drug delivery systems, for example, a smart drug delivery capsule which could release negatively charged molecules of drugs in acidic conditions, while positively charged molecules of drugs will be released in neutral conditions.

Motornov, Mikhail; Tam, Tsz Kin; Pita, Marcos; Tokarev, Ihor; Katz, Evgeny; Minko, Sergiy

2009-10-01

303

Two-scale, three-phase theory for swelling drug delivery systems. Part II: flow and transport models.  

PubMed

Darcy's law and Fick's law of Part I are combined with bulk and species conservation of mass equations, respectively, to obtain flow and transport models for swelling drug delivery systems. The model identifies three distinct regimes and makes the appropriate simplifying assumptions for each. The result is a set of highly nonlinear, coupled, integro-partial differential equations. The advantage of this model is that it can be easily modified to account for multiple simplified scenarios and geometries. As an example, boundary conditions are given for a radially symmetric drug delivery device. PMID:18064592

Weinstein, Tessa F; Bennethum, Lynn S; Cushman, John H

2008-05-01

304

Drug delivery systems based on sugar-macromolecule conjugates Benjamin G Davis* & Mark A Robinson  

E-print Network

-2 RME Receptor-mediated endocytosis SAR Structure-activity relationship SOD Superoxide dismutase-tuning of active drug delivery through their great ability to undergo site- specific modification of two ways: (i) exploiting an existing (endogenous) interaction or activity at the desired site; or (ii

Davis, Ben G.

305

Multi-Scale Validation of a Nanodiamond Drug Delivery System and Multi-Scale Engineering Education  

ERIC Educational Resources Information Center

This dissertation has two primary concerns: (i) evaluating the uncertainty and prediction capabilities of a nanodiamond drug delivery model using Bayesian calibration and bias correction, and (ii) determining conceptual difficulties of multi-scale analysis from an engineering education perspective. A Bayesian uncertainty quantification scheme…

Schwalbe, Michelle Kristin

2010-01-01

306

Designing colon-specific delivery systems for anticancer drug-loaded nanoparticles: an evaluation of alginate carriers.  

PubMed

Incorporation of drug-loaded nanoparticles (NPs) in colon-specific delivery systems shows potential for raising local drug concentrations, tumor targeting and improving chemotherapy. Alginate microcapsules (15-80 µm diameter) containing insoluble Eudragit(®) RS NPs as models were characterized precisely in terms of NP loading and release kinetics. High NP loading (22%, w/w of the dried microcapsules) combined with negligible release in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) suggested that high concentrations of NPs could be transported to the colon. However, NP aggregation was confirmed at extremely low concentration (0.0003%, w/v) in alginate solution (0.007%, w/v) and after release from alginate microcapsules. Indomethacin, a model anticolorectal cancer drug, was encapsulated in pH-responsive Eudragit(®) S100 NPs (116 nm, 5%, w/w drug loading) using the nanoprecipitation method. Approximately 90% of the drug load was released from the NPs in SGF and SIF before transfer to simulated colon fluid (SCF). However, incorporation of NPs in 2 mm alginate pellets resulted in a significantly higher fraction of the drug load (around 60%) being available for release in SCF. Delivery of isolated NPs to the colon for interaction with and uptake by cancer cells requires elimination of NP-excipient interactions that promote NP aggregation. NP-loaded alginate carriers, meanwhile, offer a promising strategy for delivery of anticancer drugs to tumor sites in the colon and reducing systemic side effects. PMID:24124007

Ma, Yiming; Coombes, Allan G A

2014-09-01

307

Nanoparticle-based drug delivery to improve the efficacy of antiretroviral therapy in the central nervous system.  

PubMed

Antiretroviral drug therapy plays a cornerstone role in the treatment of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome patients. Despite obvious advances over the past 3 decades, new approaches toward improved management of infected individuals are still required. Drug distribution to the central nervous system (CNS) is required in order to limit and control viral infection, but the presence of natural barrier structures, in particular the blood-brain barrier, strongly limits the perfusion of anti-HIV compounds into this anatomical site. Nanotechnology-based approaches may help providing solutions for antiretroviral drug delivery to the CNS by potentially prolonging systemic drug circulation, increasing the crossing and reducing the efflux of active compounds at the blood-brain barrier, and providing cell/tissue-targeting and intracellular drug delivery. After an initial overview on the basic features of HIV infection of the CNS and barriers to active compound delivery to this anatomical site, this review focuses on recent strategies based on antiretroviral drug-loaded solid nanoparticles and drug nanosuspensions for the potential management of HIV infection of the CNS. PMID:24741312

Gomes, Maria João; Neves, José das; Sarmento, Bruno

2014-01-01

308

Nanoparticle-based drug delivery to improve the efficacy of antiretroviral therapy in the central nervous system  

PubMed Central

Antiretroviral drug therapy plays a cornerstone role in the treatment of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome patients. Despite obvious advances over the past 3 decades, new approaches toward improved management of infected individuals are still required. Drug distribution to the central nervous system (CNS) is required in order to limit and control viral infection, but the presence of natural barrier structures, in particular the blood–brain barrier, strongly limits the perfusion of anti-HIV compounds into this anatomical site. Nanotechnology-based approaches may help providing solutions for antiretroviral drug delivery to the CNS by potentially prolonging systemic drug circulation, increasing the crossing and reducing the efflux of active compounds at the blood–brain barrier, and providing cell/tissue-targeting and intracellular drug delivery. After an initial overview on the basic features of HIV infection of the CNS and barriers to active compound delivery to this anatomical site, this review focuses on recent strategies based on antiretroviral drug-loaded solid nanoparticles and drug nanosuspensions for the potential management of HIV infection of the CNS. PMID:24741312

Gomes, Maria Joao; Neves, Jose das; Sarmento, Bruno

2014-01-01

309

Matrix-type transdermal drug delivery system of trandolapril: in vitro and ex vivo characterization.  

PubMed

The purpose of the investigation was to develop and evaluate matrix-type transdermal drug delivery systems (TDDSs) of trandolapril. Matrix-type TDDSs of trandolapril were prepared by solvent evaporation technique. Eight formulations (composed of Eudragit RL 100 and Hydroxypropyl methyl cellulose 15 cps at a ratios of 2:8, 4:6, 6:4, 8:2 in formulations A1, A2, A3, A4; and Eudragit RS 100 and Hydroxypropyl methyl cellulose 15 cps in the same ratios in formulations B1, B2, B3, B4, respectively) were prepared. All formulations contained 5% w/w menthol as penetration enhancer and 15% w/w propylene glycol as plasticizer in ethanol as solvent. The prepared TDDSs were evaluated for physicochemical characteristics, in vitro release and ex vivo permeation. The physicochemical interactions between trandolapril and polymers were investigated by Fourier transform infrared spectroscopy. The results suggested that there is no physicochemical interaction between drug and polymers. The maximum drug release in 24 h for A series formulations was 95.45% (A1), 95.82% (A2), and it was 95.26% (B1), 95.69% (B2) for B series formulations, which are significantly (P < 0.05) different than the lowest values 78.79% (A3), 66.9% (A4) and 82.64% (B3), 71.67% (B4). The formulations A1 (flux 25.03 ± 0.98 ?g/cm(2)/h) and B1 (flux 24.62 ± 0.63 ?g/cm(2)/h) showed maximum skin permeation in the respective series. The flux obtained with formulations A1 and B1 meets the required flux (37.04 ?g/h/cm(2)) with a minimum patch area (3.9 cm(2)). Matrix-type transdermal therapeutic systems of trandolapril could be prepared with the required flux using menthol as penetration enhancer. PMID:21502003

Tirunagari, Mamatha; Rao Jangala, Venkateswara; Khagga, Mukkanti; Gannu, Ramesh

2010-01-01

310

Numerical simulations of crystal growth in a transdermal drug delivery system  

NASA Astrophysics Data System (ADS)

Grain growth by precipitation and Ostwald ripening in an unstressed matrix of a dissolved crystallizable component was simulated using a kinetic Monte Carlo model. This model was used previously to study Ostwald ripening in the high crystallizable component regime and was shown to correctly simulate solution, diffusion and precipitation. In this study, the same model with modifications was applied to the low crystallizable regime of interest to the transdermal drug delivery system (TDS) community. We demonstrate the model's utility by simulating precipitation and grain growth during isothermal storage at different supersaturation conditions. The simulation results provide a first approximation for the crystallization occurring in TDS. It has been reported that for relatively higher temperature growth of drug crystals in TDS occurs only in the middle third of the polymer layer. The results from the simulations support these findings that crystal growth is limited to the middle third of the region, where the availability of crystallizable components is the highest, for cluster growth at relatively high temperature.

Zeng, Jianming; Jacob, Karl I.; Tikare, Veena

2004-02-01

311

Drug delivery system based on cyclodextrin-naproxen inclusion complex incorporated in electrospun polycaprolactone nanofibers.  

PubMed

In this study, we select naproxen (NAP) as a reference drug and electrospun poly (?-caprolactone) (PCL) nanofibers as a fibrous matrix for our drug-delivery system. NAP was complexed with beta-cyclodextrin (?CD) to form inclusion complex (NAP-?CD-IC) and then NAP-?CD-IC was incorporated into PCL nanofibers via electrospinning. The incorporation of NAP without CD-IC into electrospun PCL was also carried out for a comparative study. Our aim is to analyze the release profiles of NAP from PCL/NAP and PCL/NAP-?CD-IC nanofibers and we investigate the effect of CD-IC on the release behavior of NAP from the nanofibrous PCL matrix. The characterization of NAP-?CD-IC and the presence of CD-IC in PCL/NAP-?CD-IC nanofibers were studied by FTIR, XRD, TGA, NMR and SEM. The SEM imaging of the electrospun PCL/NAP and PCL/NAP-?CD-IC nanofibers reveal that the average fiber diameter of these nanofibers is around 300nm, in addition, the aggregates of CD-IC in PCL/NAP-?CD-IC nanofibers is observed. The release study of NAP in buffer solution elucidate that the PCL/NAP-?CD-IC nanofibers have higher release amount of NAP than the PCL/NAP nanofibers due to the solubility enhancement of NAP by CD-IC. PMID:24316584

Canbolat, M Fatih; Celebioglu, Asli; Uyar, Tamer

2014-03-01

312

Ultrasound-Mediated Gene and Drug Delivery Using a Microbubble-Liposome Particle System  

PubMed Central

Theranostic agents present a promising clinical approach for cancer detection and treatment. We herein introduce a microbubble and liposome complex (MB-Lipo) developed for ultrasound (US) imaging and activation. The MB-Lipo particles have a hybrid structure consisting of a MB complexed with multiple Lipos. The MB components are used to generate high echo signals in US imaging, while the Lipos serve as a versatile carrier of therapeutic materials. MB-Lipo allows high contrast US imaging of tumor sites. More importantly, the application of high acoustic pressure bursts MBs, which releases therapeutic Lipos and further enhances their intracellular delivery through sonoporation effect. Both imaging and drug release could thus be achieved by a single US modality, enabling in situ treatment guided by real-time imaging. The MB-Lipo system was applied to specifically deliver anti-cancer drug and genes to tumor cells, which showed enhanced therapeutic effect. We also demonstrate the clinical potential of MB-Lipo by imaging and treating tumor in vivo. PMID:25250094

Yoon, Young Il; Kwon, Yong-Su; Cho, Hee-Sang; Heo, Sun-Hee; Park, Kyeong Soon; Park, Sang Gyu; Lee, Soo-Hong; Hwang, Seung Il; Kim, Young Il; Jae, Hwan Jun; Ahn, Gook-Jun; Cho, Young-Seok; Lee, Hakho; Lee, Hak Jong; Yoon, Tae-Jong

2014-01-01

313

The Use of Multi-Walled Carbon Nanotubes as Possible Carrier in Drug Delivery System for Aspirin  

Microsoft Academic Search

Carbon nanotubes (CNTs) have raised great interest in a number of applications, including field emission, energy storage, molecular electronics, sensors, biochips and drug delivery systems. This is due to their remarkable mechanical properties, chemical stability and biofunctionalizability. This nanomaterial is low in weight, has high strength and a high aspect ratio (long length compared to a small diameter). This paper

Alias Mohd. Yusof; Nor Aziah Buang; Lee Sze Yean; Mohd. Lokman Ibrahim

2009-01-01

314

Protein-Based Nanomedicine Platforms for Drug Delivery  

SciTech Connect

Drug delivery systems have been developed for many years, however some limitations still hurdle the pace of going to clinical phase, for example, poor biodistribution, drug molecule cytotoxicity, tissue damage, quick clearance from the circulation system, solubility and stability of drug molecules. To overcome the limitations of drug delivery, biomaterials have to be developed and applied to drug delivery to protect the drug molecules and to enhance the drug’s efficacy. Protein-based nanomedicine platforms for drug delivery are platforms comprised of naturally self-assembled protein subunits of the same protein or a combination of proteins making up a complete system. They are ideal for drug delivery platforms due to their biocompatibility and biodegradability coupled with low toxicity. A variety of proteins have been used and characterized for drug delivery systems including the ferritin/apoferritin protein cage, plant derived viral capsids, the small Heat shock protein (sHsp) cage, albumin, soy and whey protein, collagen, and gelatin. There are many different types and shapes that have been prepared to deliver drug molecules using protein-based platforms including the various protein cages, microspheres, nanoparticles, hydrogels, films, minirods and minipellets. There are over 30 therapeutic compounds that have been investigated with protein-based drug delivery platforms for the potential treatment of various cancers, infectious diseases, chronic diseases, autoimmune diseases. In protein-based drug delivery platforms, protein cage is the most newly developed biomaterials for drug delivery and therapeutic applications. Their uniform sizes, multifunctions, and biodegradability push them to the frontier for drug delivery. In this review, the recent strategic development of drug delivery has been discussed with a special emphasis upon the polymer based, especially protein-based nanomedicine platforms for drug delivery. The advantages and disadvantages are also discussed for each type of protein based drug delivery system.

Ma Ham, Aihui; Tang, Zhiwen; Wu, Hong; Wang, Jun; Lin, Yuehe

2009-08-03

315

Magnetic Nanoparticles as Intraocular Drug Delivery System to Target Retinal Pigmented Epithelium (RPE)  

PubMed Central

One of the most challenging efforts in drug delivery is the targeting of the eye. The eye structure and barriers render this organ poorly permeable to drugs. Quite recently the entrance of nanoscience in ocular drug delivery has improved the penetration and half-life of drugs, especially in the anterior eye chamber, while targeting the posterior chamber is still an open issue. The retina and the retinal pigment epithelium/choroid tissues, located in the posterior eye chamber, are responsible for the majority of blindness both in childhood and adulthood. In the present study, we used magnetic nanoparticles (MNPs) as a nanotool for ocular drug delivery that is capable of specific localization in the retinal pigmented epithelium (RPE) layer. We demonstrate that, following intraocular injection in Xenopus embryos, MNPs localize specifically in RPE where they are retained for several days. The specificity of the localization did not depend on particle size and surface properties of the MNPs used in this work. Moreover, through similar experiments in zebrafish, we demonstrated that the targeting of RPE by the nanoparticles is not specific for the Xenopus species. PMID:24451140

Giannaccini, Martina; Giannini, Marianna; Calatayud, M. Pilar; Goya, Gerardo F.; Cuschieri, Alfred; Dente, Luciana; Raffa, Vittoria

2014-01-01

316

Magnetic nanoparticles as intraocular drug delivery system to target retinal pigmented epithelium (RPE).  

PubMed

One of the most challenging efforts in drug delivery is the targeting of the eye. The eye structure and barriers render this organ poorly permeable to drugs. Quite recently the entrance of nanoscience in ocular drug delivery has improved the penetration and half-life of drugs, especially in the anterior eye chamber, while targeting the posterior chamber is still an open issue. The retina and the retinal pigment epithelium/choroid tissues, located in the posterior eye chamber, are responsible for the majority of blindness both in childhood and adulthood. In the present study, we used magnetic nanoparticles (MNPs) as a nanotool for ocular drug delivery that is capable of specific localization in the retinal pigmented epithelium (RPE) layer. We demonstrate that, following intraocular injection in Xenopus embryos, MNPs localize specifically in RPE where they are retained for several days. The specificity of the localization did not depend on particle size and surface properties of the MNPs used in this work. Moreover, through similar experiments in zebrafish, we demonstrated that the targeting of RPE by the nanoparticles is not specific for the Xenopus species. PMID:24451140

Giannaccini, Martina; Giannini, Marianna; Calatayud, M Pilar; Goya, Gerardo F; Cuschieri, Alfred; Dente, Luciana; Raffa, Vittoria

2014-01-01

317

Targeted liposomal drug delivery systems for the treatment of B cell malignancies.  

PubMed

Nanoparticulate systems have demonstrated significant potential for overcoming the limitations of non-specific adverse effects related to chemotherapy. The treatment of blood malignancies employing targeted particulate drug delivery systems presents unique challenges and considerable research has been focused towards the development of targeted liposomal formulations for B cell malignancies. These formulations are aimed at achieving selectivity towards the malignant cells by targeting several cell surface markers which are over-expressed in that specific malignancy. CD19, CD20, CD22 and CD74 are few of such markers of which CD19, CD22 and CD74 are internalizing and CD20 is non-internalizing. Systems which have been developed to target both types of these cell surface markers are discussed. Specifically, the efficacy and development of targeted liposomes is considered. A number of studies have demonstrated the advantages of targeted liposomal systems encapsulating doxorubicin or vincristine. However, liposomal encapsulation of newer anti-neoplastic agents such as AD 198 which are superior to doxorubicin should be considered. PMID:24433007

Mittal, Nivesh K; Bhattacharjee, Himanshu; Mandal, Bivash; Balabathula, Pavan; Thoma, Laura A; Wood, George C

2014-06-01

318

Targeted Drug Delivery Systems Mediated by a Novel Peptide in Breast Cancer Therapy and Imaging  

PubMed Central

Targeted delivery of drugs to tumors represents a significant advance in cancer diagnosis and therapy. Therefore, development of novel tumor-specific ligands or pharmaceutical nanocarriers is highly desirable. In this study, we utilized phage display to identify a new targeting peptide, SP90, which specifically binds to breast cancer cells, and recognizes tumor tissues from breast cancer patients. We used confocal and electron microscopy to reveal that conjugation of SP90 with liposomes enables efficient delivery of drugs into cancer cells through endocytosis. Furthermore, in vivo fluorescent imaging demonstrated that SP90-conjugated quantum dots possess tumor-targeting properties. In tumor xenograft and orthotopic models, SP90-conjugated liposomal doxorubicin was found to improve the therapeutic index of the chemotherapeutic drug by selectively increasing its accumulation in tumors. We conclude that the targeting peptide SP90 has significant potential in improving the clinical benefits of chemotherapy in the treatment and the diagnosis of breast cancer. PMID:23776619

Chiu, Chien-Yu; Lin, Wei-Chuan; Yan, Shin-Long; Wang, Yi-Ping; Kuo, Yuan-Sung; Yeh, Chen-Yun; Lo, Albert; Wu, Han-Chung

2013-01-01

319

Supplementary Data Drug delivery  

E-print Network

to polymerize and dry at room temperature for 12 to 36 hours depending on the ambient humidity. 2. "Yeast paste temperature for 12 to 36 hours depending on the ambient humidity. 3. "On food" delivery: Appropriate volumes then allowed to dry at room temperature for 12 to 36 hours depending on the ambient humidity. Fly Cultures

Seroude, Laurent

320

Macromolecules in drug delivery Macromolecular targeting agents, carriers, and drugs  

E-print Network

Macromolecules in drug delivery Macromolecular targeting agents, carriers, and drugs 1gauthier@emt.inrs.ca #12;Why macromolecules in drug delivery? 2gauthier@emt.inrs.ca Classic chemotherapy Drug delivery? Targeting A carrier for small drugs A release mechanism (if necessary) Protection of drug cargo #12;How? 3

Barthelat, Francois

321

Ultrasound-mediated blood-brain barrier disruption for targeted drug delivery in the central nervous system.  

PubMed

The physiology of the vasculature in the central nervous system (CNS), which includes the blood-brain barrier (BBB) and other factors, complicates the delivery of most drugs to the brain. Different methods have been used to bypass the BBB, but they have limitations such as being invasive, non-targeted or requiring the formulation of new drugs. Focused ultrasound (FUS), when combined with circulating microbubbles, is a noninvasive method to locally and transiently disrupt the BBB at discrete targets. This review provides insight on the current status of this unique drug delivery technique, experience in preclinical models, and potential for clinical translation. If translated to humans, this method would offer a flexible means to target therapeutics to desired points or volumes in the brain, and enable the whole arsenal of drugs in the CNS that are currently prevented by the BBB. PMID:24462453

Aryal, Muna; Arvanitis, Costas D; Alexander, Phillip M; McDannold, Nathan

2014-06-01

322

Anticancer drug delivery with nanoparticles.  

PubMed

Nanotechnology provides a variety of nanoscale tools for medicine. Among them nanoparticles are revolutionizing the field of drug delivery. These drug nanocarriers have the potential to enhance the therapeutic efficacy of a drug, since they can be engineered to modulate the release and the stability and to prolong the circulation time of a drug, protecting it from elimination by phagocytic cells or premature degradation. Moreover, nanoscale carriers can be tailored to accumulate in tumour cells and tissues, due to enhanced permeability and a retention effect or by active targeting using ligands designed to recognize tumour-associated antigens. Could these nanomedicine tools mark an end to the necessity for loco-regional drug delivery? PMID:17203748

Conti, Matteo; Tazzari, Valeria; Baccini, Cesare; Pertici, Gianni; Serino, Lorenzo Pio; De Giorgi, Ugo

2006-01-01

323

Preparation and In Vitro Evaluation of a Stomach Specific Drug Delivery System based on Superporous Hydrogel Composite  

PubMed Central

This study discusses efforts made to design drug-delivery system based on superporous hydrogel composite for sustained delivery of ranitidine hydrochloride. The characterization studies involve measurement of apparent density, porosity, swelling studies, mechanical strength studies, and scanning electron microscopy. Scanning electron microscopic images clearly showed the formation of interconnected pores, capillary channels, and the cross-linked sodium carboxymethylcellulose molecules around the peripheries of pores. The prepared system floated and delivered the ranitidine hydrochloride for about 17 h. The release profile of ranitidine hydrochloride was studies by changing the retardant polymer in the system. To ascertain the drug release kinetics, the dissolution profiles were fitted to different mathematical models that include zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, Weibull, and Hopfenberg models. The in vitro dissolution from system was explained by Korsmeyer-Peppas model. The diffusion exponent values in Korsmeyer-Peppas model range between 0.48±0.01 and 0.70±0.01, which appears to indicate an anomalous non-Fickian transport. It is concluded that the proposed mechanically stable floating drug-delivery system based on superporous hydrogel composite containing sodium carboxymethylcellulose as a composite material is promising for stomach specific delivery of ranitidine hydrochloride. PMID:22131619

Chavda, H. V.; Patel, C. N.

2011-01-01

324

Nanotechnology-based drug delivery systems and herbal medicines: a review  

PubMed Central

Herbal medicines have been widely used around the world since ancient times. The advancement of phytochemical and phytopharmacological sciences has enabled elucidation of the composition and biological activities of several medicinal plant products. The effectiveness of many species of medicinal plants depends on the supply of active compounds. Most of the biologically active constituents of extracts, such as flavonoids, tannins, and terpenoids, are highly soluble in water, but have low absorption, because they are unable to cross the lipid membranes of the cells, have excessively high molecular size, or are poorly absorbed, resulting in loss of bioavailability and efficacy. Some extracts are not used clinically because of these obstacles. It has been widely proposed to combine herbal medicine with nanotechnology, because nanostructured systems might be able to potentiate the action of plant extracts, reducing the required dose and side effects, and improving activity. Nanosystems can deliver the active constituent at a sufficient concentration during the entire treatment period, directing it to the desired site of action. Conventional treatments do not meet these requirements. The purpose of this study is to review nanotechnology-based drug delivery systems and herbal medicines. PMID:24363556

Bonifacio, Bruna Vidal; da Silva, Patricia Bento; Ramos, Matheus Aparecido dos Santos; Negri, Kamila Maria Silveira; Bauab, Tais Maria; Chorilli, Marlus

2014-01-01

325

Novel gene delivery systems  

PubMed Central

Gene therapy is an emerging field in medical and pharmaceutical sciences because of its potential in treating chronic diseases like cancer, viral infections, myocardial infarctions, and genetic disorders. Application of gene therapy is limited because of lack of suitable methods for proper introduction of genes into cells and therefore, this is an area of interest for most of the researchers. To achieve successful gene therapy, development of proper gene delivery systems could be one of the most important factors. Several nonviral and viral gene transfer methods have been developed. Even though the viral agents have a high transferring efficiency, they are difficult to handle due to their toxicity. To overcome the safety problems of the viral counterpart, several nonviral in vitro and in vivo gene delivery systems are developed. Out of these, the most promising and latest systems include polymer-based nonviral gene carriers, dendrimers, and physical means like electroporation, microinjection, etc., Shunning of possible immunogenicity and toxicity, and the feasibility of repeated administration are some of the merits of nonviral gene delivery systems over viral gene delivery. An ideal nonviral gene carrying system should possess all these merits without any compromise to its gene transferring efficiency. The viral gene delivery systems include lytic and nonlytic vectors for drug delivery. Inspite of its toxicity they are still preferred because of their long term expression, stability, and integrity. This review explores the recent developments and relevancy of the novel gene delivery systems in gene therapy. PMID:23799200

Manjila, Steffy B; Baby, Jomon N; Bijin, Elambilan N; Constantine, Icey; Pramod, Kannissery; Valsalakumari, Janardhanan

2013-01-01

326

A magnetic mesoporous silica nanoparticle-based drug delivery system for photosensitive cooperative treatment of cancer with a mesopore-capping agent and mesopore-loaded drug  

NASA Astrophysics Data System (ADS)

Lately, there has been a growing interest in anticancer therapy with a combination of different drugs that work by different mechanisms of action, which decreases the possibility that resistant cancer cells will develop. Herein we report on the development of a drug delivery system for photosensitive delivery of a known anticancer drug camptothecin along with cytotoxic cadmium sulfide nanoparticles from a magnetic drug nanocarrier. Core-shell nanoparticles consisting of magnetic iron-oxide-cores and mesoporous silica shells are synthesized with a high surface area (859 m2 g-1) and hexagonal packing of mesopores, which are 2.6 nm in diameter. The mesopores are loaded with anticancer drug camptothecin while entrances of the mesopores are blocked with 2-nitro-5-mercaptobenzyl alcohol functionalized CdS nanoparticles through a photocleavable carbamate linkage. Camptothecin release from this magnetic drug delivery system is successfully triggered upon irradiation with UV light, as measured by fluorescence spectroscopy. Photosensitive anticancer activity of the drug delivery system is monitored by viability studies on Chinese hamster ovarian cells. The treatment of cancer cells with drug loaded magnetic material leads to a decrease in viability of the cells due to the activity of capping CdS nanoparticles. Upon exposure to low power UV light (365 nm) the loaded camptothecin is released which induces additional decrease in viability of CHO cells. Hence, the capping CdS nanoparticles and loaded camptothecin exert a cooperative anticancer activity. Responsiveness to light irradiation and magnetic activity of the nanocarrier enable its potential application for selective targeted treatment of cancer.

Kneževi?, Nikola Ž.; Lin, Victor S.-Y.

2013-01-01

327

Microfabrication Technologies for Oral Drug Delivery  

PubMed Central

Micro-/nanoscale technologies such as lithographic techniques and microfluidics offer promising avenues to revolutionalize the fields of tissue engineering, drug discovery, diagnostics and personalized medicine. Microfabrication techniques are being explored for drug delivery applications due to their ability to combine several features such as precise shape and size into a single drug delivery vehicle. They also offer to create unique asymmetrical features incorporated into single or multiple reservoir systems maximizing contact area with the intestinal lining. Combined with intelligent materials, such microfabricated platforms can be designed to be bioadhesive and stimuli-responsive. Apart from drug delivery devices, microfabrication technologies offer exciting opportunities to create biomimetic gastrointestinal tract models incorporating physiological cell types, flow patterns and brush-border like structures. Here we review the recent developments in this field with a focus on the applications of microfabrication in the development of oral drug delivery devices and biomimetic gastrointestinal tract models that can be used to evaluate the drug delivery efficacy. PMID:22166590

Sant, Shilpa; Tao, Sarah L.; Fisher, Omar; Xu, Qiaobing; Peppas, Nicholas A.; Khademhosseini, Ali

2012-01-01

328

Compact, power-efficient architectures using microvalves and microsensors, for intrathecal, insulin, and other drug delivery systems.  

PubMed

This paper describes a valve-regulated architecture, for intrathecal, insulin and other drug delivery systems, that offers high performance and volume efficiency through the use of micromachined components. Multi-drug protocols can be accommodated by using a valve manifold to modulate and mix drug flows from individual reservoirs. A piezoelectrically-actuated silicon microvalve with embedded pressure sensors is used to regulate dosing by throttling flow from a mechanically-pressurized reservoir. A preliminary prototype system is demonstrated with two reservoirs, pressure sensors, and a control circuit board within a 130cm(3) metal casing. Different control modes of the programmable system have been evaluated to mimic clinical applications. Bolus and continuous flow deliveries have been demonstrated. A wide range of delivery rates can be achieved by adjusting the parameters of the manifold valves or reservoir springs. The capability to compensate for changes in delivery pressure has been experimentally verified. The pressure profiles can also be used to detect catheter occlusions and disconnects. The benefits of this architecture compared with alternative options are reviewed. PMID:22580183

Li, Tao; Evans, Allan T; Chiravuri, Srinivas; Gianchandani, Roma Y; Gianchandani, Yogesh B

2012-11-01

329

Development of Chitosan Nanoparticles as a Stable Drug Delivery System for Protein/siRNA  

PubMed Central

Chitosan nanoparticles (CS NPs) exhibit good physicochemical properties as drug delivery systems. The aim of this study is to determine the modulation of preparative parameters on the physical characteristics and colloidal stability of CS NPs. CS NPs were fabricated by ionic interaction with dextran sulphate (DS) prior to determination of their storage stability. The smallest CS NPs of 353 ± 23?nm with a surface charge of +56.2 ± 1.5?mV were produced when CS and DS were mixed at pH 4 and with a DS?:?CS mass ratio of 0.5?:?1. An entrapment efficiency of 98% was achieved when BSA/siRNA was loaded into the nanoparticles. The results also showed that particle size and surface charge of CS NPs were slightly changed up to 2 weeks when stored at 4°C. Greater particle size and surface charge were obtained with increasing the concentration of DS. In conclusion, NPs were sufficiently stable when kept at 4°C and able to carry and protect protein. PMID:24194759

Katas, Haliza; Raja, Maria Abdul Ghafoor; Lam, Kai Leong

2013-01-01

330

Hybrid drug delivery system for oropharyngeal, cervical and colorectal cancer - in vitro and in vivo evaluation  

PubMed Central

The present investigation was designed with the intention to formulate a versatile 5-fluorouracil(5-FU) matrix tablet surpassing issues associated with current conventional chemotherapeutic drug delivery systems. The novel 5-FU matrix tablet fulfills therapeutic needs by engineering matrix tablets utilizing chitosan–sodium alginate interpolyelectrolyte complex (IPEC). IPEC was characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The matrix tablets were formulated utilizing IPEC alone and in combination with chitosan, sodium alginate and sodium deoxycholate as permeation enhancer. Pharmaceutical properties, swelling studies, in vitro dissolution and diffusion studies, mucoadhesive studies and in vivo studies were performed for formulated 5-FU. The selected chitosan–sodium alginate IPEC offers pH independent 5-FU release in comparison to alone or physical mixture of chitosan and sodium alginate. Furthermore, novel matrix tablets demonstrated significantly higher bioadhesive properties with controlled 5-FU release without the initial burst effect and also demonstrated a higher permeation of 5-FU. To conclude, the developed novel 5-FU matrix tablets pave way as an excellent alternative for cancer treatment which could potentially minimize the dose dependent side effects and provide better patient compliance. PMID:23960833

Pendekal, Mohamed S.; Tegginamat, Pramod K.

2012-01-01

331

Deep penetration of nanoparticulate drug delivery systems into tumors: challenges and solutions.  

PubMed

In recent decades, nanoparticulate drug delivery systems have attracted extensive attention in cancer therapy for such appealing properties as small particle size, huge surface area, narrow size distribution and prolonged circulation time. Although several nanomedicines have successfully reached the clinical, evidences have proved that therapeutic efficacy isn't improved significantly, except for better toleration and less side effects. Given that the physiological abnormalities in tumors, multiple biobarriers need to be overcome before nanomedicines are delivered to the target site. Passive targeting nanoparticles ensure nanomedicines' extensive extravasation from tumor vessels via enhanced permeation and retention effect, but the diffusion distance is limited to 2-3 cell layer thicknesses. Active targeting nanoparticles tend to bind the peripheral cells of the tumor mass, hindering nanoparticles further penetration into the tumor core region. Therefore, how to improve the deep penetration of nanomedicines into tumors is a formidable task for achieving the desired anticancer therapeutic efficacy. This review demonstrates the penetration obstacles existing in tumor region for nanoparticles, summarizes the important properties of nanomedicines affecting tumor deep penetration and highlights the solutions to improve tumor deep penetration of nanoparticles. PMID:23651305

Li, L; Sun, J; He, Z

2013-01-01

332

Critical attributes of transdermal drug delivery system (TDDS) - a generic product development review.  

PubMed

Abstract Bioequivalence testing of transdermal drug delivery systems (TDDS) has always been a subject of high concern for generic companies due to the formulation complexity and the fact that they are subtle to even minor manufacturing differences and hence should be clearly qualified in terms of quality, safety and efficacy. In recent times bioequivalence testing of transdermal patches has gained a global attention and many regulatory authorities worldwide have issued recommendations to set specific framework for demonstrating equivalence between two products. These current regulatory procedures demand a complete characterization of the generic formulation in terms of its physicochemical sameness, pharmacokinetics disposition, residual content and/or skin irritation/sensitization testing with respect to the reference formulation. This paper intends to highlight critical in vitro tests in assessing the therapeutic equivalence of products and also outlines their valuable applications in generic product success. Understanding these critical in vitro parameters can probably help to decode the complex bioequivalence outcomes, directing the generic companies to optimize the formulation design in reduced time intervals. It is difficult to summarize a common platform which covers all possible transdermal products; hence few case studies based on this approach has been presented in this review. PMID:24467407

Ruby, P K; Pathak, Shriram M; Aggarwal, Deepika

2014-11-01

333

Gastroretentive microparticles for drug delivery applications.  

PubMed

Many strategies have been proposed to explore the possibility of exploiting gastroretention for drug delivery. Such systems would be useful for local delivery, for drugs that are poorly soluble at higher pH or primarily absorbed from the proximal small intestine. Generally, the requirements of such strategies are that the vehicle maintains controlled drug release and exhibits prolonged residence time in the stomach. Despite widespread reporting of technologies, many have an inherent drawback of variability in transit times. Microparticulate systems, capable of distributing widely through the gastrointestinal tract, can potentially minimise this variation. While being retained in the stomach, the drug content is released slowly at a desired rate, resulting in reduced fluctuations in drug levels. This review summarises the promising role of microencapsulation in this field, exploring both floating and mucoadhesive microparticles and their application in the treatment of Helicobacter pylori, highlighting the clinical potential of eradication of this widespread infection. PMID:21726124

Adebisi, Adeola; Conway, Barbara R

2011-01-01

334

Nanocarriers and Drug Delivery  

Microsoft Academic Search

Nanoparticles may serve, among other techniques, as a useful tool for achieving the main objective of regional cancer therapy:\\u000a they can deliver a higher concentration of the agent to the tumor and expose the tumor to active drug for longer periods than\\u000a safely possible with conventional formulations. These carriers combine many advantages, such as a potential for selective\\u000a targeting and

Svetlana Gelperina

335

Application of hot-melt coating process for designing a lipid based controlled release drug delivery system for highly aqueous soluble drugs.  

PubMed

Hot-melt coating process (HMCP) was applied to develop a lipid based oral controlled release matrix system (tablet) to deliver highly aqueous soluble drugs using paracetamol as a model drug. Granules prepared from paracetamol and particular filler were coated with different levels of lipid and then compressed into tablets to get controlled/sustained delivery of the drug over an optimum period. Process parameters were optimized with particular focus on fluidization pattern during HMCP proposing a 'design space' with 'Quality by Design' (QbD) concept in mind. The results demonstrated that the granule composition influenced the drug release pattern, and the rate of release could be manipulated by varying the amount of lipid in the formulation. The in vitro release profile of the drug was pH-independent and the most promising release profile was obtained from tablets prepared from granules with the water-soluble filler, lactose, and coated at 9% (w/w) level with a lipid, glyceryl behanate. In vivo plasma profiles of the drug were predicted from the in vitro release profile data by convolution analysis which confirmed that the lactose based formulation with 9% (w/w) lipid coating on the granules would be suitable for controlled delivery of the drug over a period of 12 h making the formulation suitable for highly water soluble drug candidates like paracetamol with twice daily dose regimen. Moreover, the dissolution data adequately fitted into Higuchi model suggesting that the drug release occurred predominantly by diffusion. PMID:19420776

Knezevic, Zdravka; Gosak, Darko; Hraste, Marin; Rausl, Dragica; Khan, M Zahirul I

2009-05-01

336

Current perspectives on intrathecal drug delivery  

PubMed Central

Advances in intrathecal analgesia and intrathecal drug delivery systems have allowed for a range of medications to be used in the control of pain and spasticity. This technique allows for reduced medication doses that can decrease the side effects typically associated with oral or parenteral drug delivery. Recent expert panel consensus guidelines have provided care paths in the treatment of nociceptive, neuropathic, and mixed pain syndromes. While the data for pain relief, adverse effect reduction, and cost-effectiveness with cancer pain control are compelling, the evidence is less clear for noncancer pain, other than spasticity. Physicians should be aware of mechanical, pharmacological, surgical, and patient-specific complications, including possible granuloma formation. Newer intrathecal drug delivery systems may allow for better safety and quality of life outcomes.

Bottros, Michael M; Christo, Paul J

2014-01-01

337

pH-responsive drug delivery system based on hollow silicon dioxide micropillars coated with polyelectrolyte multilayers.  

PubMed

We report on the fabrication of polyelectrolyte multilayer-coated hollow silicon dioxide micropillars as pH-responsive drug delivery systems. Silicon dioxide micropillars are based on macroporous silicon formed by electrochemical etching. Due to their hollow core capable of being loaded with chemically active agents, silicon dioxide micropillars provide additional function such as drug delivery system. The polyelectrolyte multilayer was assembled by the layer-by-layer technique based on the alternative deposition of cationic and anionic polyelectrolytes. The polyelectrolyte pair poly(allylamine hydrochloride) and sodium poly(styrene sulfonate) exhibited pH-responsive properties for the loading and release of a positively charged drug doxorubicin. The drug release rate was observed to be higher at pH 5.2 compared to that at pH 7.4. Furthermore, we assessed the effect of the number of polyelectrolyte bilayers on the drug release loading and release rate. Thus, this hybrid composite could be potentially applicable as a pH-controlled system for localized drug release. PMID:25221455

Alba, María; Formentín, Pilar; Ferré-Borrull, Josep; Pallarès, Josep; Marsal, Lluís F

2014-01-01

338

pH-responsive drug delivery system based on hollow silicon dioxide micropillars coated with polyelectrolyte multilayers  

PubMed Central

We report on the fabrication of polyelectrolyte multilayer-coated hollow silicon dioxide micropillars as pH-responsive drug delivery systems. Silicon dioxide micropillars are based on macroporous silicon formed by electrochemical etching. Due to their hollow core capable of being loaded with chemically active agents, silicon dioxide micropillars provide additional function such as drug delivery system. The polyelectrolyte multilayer was assembled by the layer-by-layer technique based on the alternative deposition of cationic and anionic polyelectrolytes. The polyelectrolyte pair poly(allylamine hydrochloride) and sodium poly(styrene sulfonate) exhibited pH-responsive properties for the loading and release of a positively charged drug doxorubicin. The drug release rate was observed to be higher at pH 5.2 compared to that at pH 7.4. Furthermore, we assessed the effect of the number of polyelectrolyte bilayers on the drug release loading and release rate. Thus, this hybrid composite could be potentially applicable as a pH-controlled system for localized drug release. PMID:25221455

2014-01-01

339

pH-responsive drug delivery system based on hollow silicon dioxide micropillars coated with polyelectrolyte multilayers  

NASA Astrophysics Data System (ADS)

We report on the fabrication of polyelectrolyte multilayer-coated hollow silicon dioxide micropillars as pH-responsive drug delivery systems. Silicon dioxide micropillars are based on macroporous silicon formed by electrochemical etching. Due to their hollow core capable of being loaded with chemically active agents, silicon dioxide micropillars provide additional function such as drug delivery system. The polyelectrolyte multilayer was assembled by the layer-by-layer technique based on the alternative deposition of cationic and anionic polyelectrolytes. The polyelectrolyte pair poly(allylamine hydrochloride) and sodium poly(styrene sulfonate) exhibited pH-responsive properties for the loading and release of a positively charged drug doxorubicin. The drug release rate was observed to be higher at pH 5.2 compared to that at pH 7.4. Furthermore, we assessed the effect of the number of polyelectrolyte bilayers on the drug release loading and release rate. Thus, this hybrid composite could be potentially applicable as a pH-controlled system for localized drug release.

Alba, María; Formentín, Pilar; Ferré-Borrull, Josep; Pallarès, Josep; Marsal, Lluís F.

2014-08-01

340

Gelatin-based nanoparticles as drug and gene delivery systems: reviewing three decades of research.  

PubMed

Gelatin is one of the most versatile natural biopolymers widely used in pharmaceutical industries due to its biocompatibility, biodegradability, low cost and numerous available active groups for attaching targeting molecules. These advantages led to its application in the synthesis of nanoparticles for drug and gene delivery during the last thirty years. The current article entails a general review of the different preparation techniques of gelatin nanoparticles (GNPs): desolvation, coacervation-phase separation, emulsification-solvent evaporation, reverse phase microemulsion, nanoprecipitation, self-assembly and layer-by-layer coating, from the point of view of the methodological and mechanistic aspects involved. Various crosslinkers used to improve the physicochemical properties of GNPs includintg aldehydes, genipin, carbodiimide/N-hydroxysuccinimide, and transglutaminase are reported. An analysis is given of the physicochemical behavior of GNPs including drug loading, release, particle size, zeta-potential, cytotoxicity, cellular uptake and stability. This review also attempts to provide an overview of the major applications of GNPs in drug delivery and gene therapy and their in vivo pharmacological performances, as well as site-specific drug targeting using various ligands modifying the surface of GNPs. Finally, nanocomplexes of gelatin with polymers, lipids or inorganic materials are also discussed. PMID:24096021

Elzoghby, Ahmed O

2013-12-28

341

Microemulsions containing medium-chain glycerides as transdermal delivery systems for hydrophilic and hydrophobic drugs.  

PubMed

We evaluated the ability of microemulsions containing medium-chain glycerides as penetration enhancers to increase the transdermal delivery of lipophilic (progesterone) and hydrophilic (adenosine) model drugs as well as the effects of an increase in surfactant blend concentration on drug transdermal delivery. Microemulsions composed of polysorbate 80, medium-chain glycerides, and propylene glycol (1:1:1, w/w/w) as surfactant blend, myvacet oil as the oily phase, and water were developed. Two microemulsions containing different concentrations of surfactant blend but similar water/oil ratios were chosen; ME-lo contained a smaller concentration of surfactant than ME-hi (47:20:33 and 63:14:23 surfactant/oil/water, w/w/w). Although in vitro progesterone and adenosine release from ME-lo and ME-hi was similar, their transdermal delivery was differently affected. ME-lo significantly increased the flux of progesterone and adenosine delivered across porcine ear skin (4-fold or higher, p < 0.05) compared to progesterone solution in oil (0.05 +/- 0.01 microg/cm(2)/h) or adenosine in water (no drug was detected in the receptor phase). The transdermal flux of adenosine, but not of progesterone, was further increased (2-fold) by ME-hi, suggesting that increases in surfactant concentration represent an interesting strategy to enhance transdermal delivery of hydrophilic, but not of lipophilic, compounds. The relative safety of the microemulsions was assessed in cultured fibroblasts. The cytotoxicity of ME-lo and ME-hi was significantly smaller than sodium lauryl sulfate (considered moderate-to-severe irritant) at same concentrations (up to 50 microg/mL), but similar to propylene glycol (regarded as safe), suggesting the safety of these formulations. PMID:19440842

Hosmer, Jaclyn; Reed, Rachel; Bentley, M Vitória L B; Nornoo, Adwoa; Lopes, Luciana B

2009-01-01

342

Pectin-coated chitosan-LDH bionanocomposite beads as potential systems for colon-targeted drug delivery.  

PubMed

This work introduces results on a new drug delivery system (DDS) based on the use of chitosan/layered double hydroxide (LDH) biohybrid beads coated with pectin for controlled release in the treatment of colon diseases. Thus, the 5-aminosalicylic acid (5ASA), the most used non-steroid-anti-inflammatory drug (NSAID) in the treatment of ulcerative colitis and Crohn's disease, was chosen as model drug aiming to a controlled and selective delivery in the colon. The pure 5ASA drug and the hybrid material prepared by intercalation in a layered double hydroxide of Mg2Al using the co-precipitation method, were incorporated in a chitosan matrix in order to profit from its mucoadhesiveness. These compounds processed as beads were further treated with the polysaccharide pectin to create a protective coating that ensures the stability of both chitosan and layered double hydroxide at the acid pH of the gastric fluid. The resulting composite beads presenting the pectin coating are stable to water swelling and procure a controlled release of the drug along their passage through the simulated gastrointestinal tract in in vitro experiments, due to their resistance to pH changes. Based on these results, the pectin@chitosan/LDH-5ASA bionanocomposite beads could be proposed as promising candidates for the colon-targeted delivery of 5ASA, with the aim of acting only in the focus of the disease and minimizing side effects. PMID:24374607

Ribeiro, Lígia N M; Alcântara, Ana C S; Darder, Margarita; Aranda, Pilar; Araújo-Moreira, Fernando M; Ruiz-Hitzky, Eduardo

2014-03-10

343

CCMR: Drug Delivery Using Nanoparticles  

NSDL National Science Digital Library

Safe and nontoxic drug delivery is an ongoing area of research. Some current methods of drug delivery include the use of nanoparticles, hydrogels, dendrimers, and micelles. Nanoparticles can be used as vehicles in which to transport certain drugs to cancerous cells. A certain class of nanoparticles called clays is especially useful in synthesizing these drug delivery vehicles. Layered Double Hydroxides (LDHs) are a type of hydrotalcite clay with a structure similar to smectite clays. They have a general structure that consists of layers of metal hydroxides connected to a layer of another metal hydroxide by hydrogen bonding. LDHs are made up of layers of a trivalent and a divalently charged cation coordinated by six oxygen atoms. The resulting structure consists of two-dimensional sheets with positively charged faces and negatively charged edges that are stacked together via hydrogen bonding between hydroxyl groups on adjacent sheets. These sheets generally have a very high aspect ratio, resulting in a large surface area. The positively charged layers are balanced by the presence of anions between them. A wide variety of LDHs can be synthesized depending on the various cations and interlayer anions used. Characterization of the LDHs themselves as well as LDHs intercalated with the drugs was performed using X-ray diffraction and TEM and SEM microscopy.

Lin, Joyce

2005-08-17

344

Bioadhesive drug delivery systems. I. Characterisation of mucoadhesive properties of systems based on glyceryl mono-oleate and glyceryl monolinoleate.  

PubMed

A group of fatty acid esters capable of forming liquid crystals has been identified as a new class of potential bioadhesive substances. The liquid crystals may act as a controlled release system. The experimental work was focused on the monoglycerides, glyceryl mono-oleate (GMO) and glyceryl monolinoleate (GML). The mucoadhesive properties of GMO and GML were demonstrated in vitro by a 'flushing' bioadhesion test system and a tensiometric method. The flushing system was validated with GMO. Mucoadhesion is influenced by the drug and excipient added, their concentrations, and the ability to form especially the cubic phase. It has been shown that the cubic phase is mucoadhesive when formed on wet mucosa, such as rabbit jejunum, and that drug added to the precursor formulation is incorporated in the cubic phase formed. Tensiometric measurements have shown that the unswollen monoglycerides have the greatest mucoadhesion, followed by the partly swollen lamellar phase and the fully swollen cubic phase. The values found for the work of adhesion were in the range 0.007-0.048 mJcm-2. The mechanism of mucoadhesion is unspecific and probably involves dehydration of the mucosa. The cubic phase of GMO and GML may be an interesting candidate for a bioadhesive drug delivery system. PMID:9795071

Nielsen, L S; Schubert, L; Hansen, J

1998-07-01

345

Design and evaluation of a dry coated drug delivery system with an impermeable cup, swellable top layer and pulsatile release.  

PubMed

In this investigation a novel oral pulsatile drug delivery system based on a core-in-cup dry coated tablet, where the core tablet surrounded on the bottom and circumference wall with inactive material, is proposed. The system consists of three different parts, a core tablet, containing the active ingredient, an impermeable outer shell and a top cover layer-barrier of a soluble polymer. The core contained either diclofenac sodium or ketoprofen as model drugs. The impermeable coating cup consisted of cellulose acetate propionate and the top cover layer of hydrophilic swellable materials, such as polyethylene oxide, sodium alginate or sodium carboxymethyl cellulose. The effect of the core, the polymer characteristics and quantity at the top cover layer, on the lag time and drug release was investigated. The results show that the system release of the drug after a certain lag time generally due to the erosion of the top cover layer. The quantity of the material, its characteristics (viscosity, swelling, gel layer thickness) and the drug solubility was found to modify lag time and drug release. The lag time increased when the quantity of top layer increased, whereas drug release decreased. The use of sodium carboxymethyl cellulose resulted in the greatest swelling, gel thickness and lag time, but the lowest drug release from the system. Polyethylene oxide showed an intermediate behaviour while, the sodium alginate exhibited the smallest swelling, gel thickness and the shortest lag time, but the fastest release. These findings suggest that drug delivery can be controlled by manipulation of these formulations. PMID:16436321

Efentakis, M; Koligliati, S; Vlachou, M

2006-03-27

346

Gelatin Used for Drug Delivery  

NSDL National Science Digital Library

In this activity, learners discover how gelatin can be used as a medium for drug delivery. Learners create colored gelatin and then cut out pieces of the gelatin to simulate medicine (pills). Learners then put their simulated pills in a pan of hot water. Since gelatin is a thermoreversible or cold-setting polymer, gelatin will convert back to a liquid if put in a hot environment. As the gelatin returns to its liquid form, it releases its embedded dye. The dye eventually diffuses completely out of the gelatin which simulates the slow release of a drug from a pill. From this activity, learners learn more about diffusion and drug delivery. Adult supervision recommended.

Mississippi, University O.

2003-01-01

347

Nanoliposomal minocycline for ocular drug delivery  

PubMed Central

Nanoliposomal technology is a promising drug delivery system that could be employed to improve the pharmacokinetic properties of clearance and distribution in ocular drug delivery to the retina. We developed a nanoscale version of an anionic, cholesterol-fusing liposome that can encapsulate therapeutic levels of minocycline capable of drug delivery. We demonstrate that size extrusion followed by size-exclusion chromatography can form a stable 80-nm liposome that encapsulates minocycline at a concentration of 450 ± 30 ?M, which is 2% to 3% of loading material. More importantly, these nontoxic nanoliposomes can then deliver 40% of encapsulated minocycline to the retina after a subconjunctival injection in the STZ model of diabetes. Efficacy of therapeutic drug delivery was assessed via transcriptomic and proteomic biomarker panels. For both the free minocycline and encapsulated minocycline treatments, proinflammatory markers of diabetes were downregulated at both the messenger RNA and protein levels, validating the utility of biomarker panels for the assessment of ocular drug delivery vehicles. PMID:22465498

Kaiser, James M.; Imai, Hisanori; Haakenson, Jeremy K.; Brucklacher, Robert M.; Fox, Todd E.; Shanmugavelandy, Sriram S.; Unrath, Kellee A.; Pedersen, Michelle M.; Dai, Pingqi; Freeman, Willard M.; Bronson, Sarah K.; Gardner, Thomas W.; Kester, Mark

2012-01-01

348

Functional Cyclodextrin Polyrotaxanes for Drug Delivery  

NASA Astrophysics Data System (ADS)

The mobility of cyclodextrins (CDs) threaded onto a linear polymeric chain and the dethreading of the CDs from the chain are the most fascinating features seen in polyrotaxanes. These structural characteristics are very promising for their possible applications in drug delivery. Enhanced multivalent interaction between ligand-receptor systems by using ligand-conjugated polyrotaxanes would be just one of the excellent properties related to the CD mobility. Gene delivery using cytocleavable polyrotaxanes is a more practical but highly crucial issue in drug delivery. Complexation of the polyrotaxanes with DNA and its intracellular DNA release ingeniously utilizes both CD mobility and polyrotaxane dissociation to achieve effective gene delivery. Such a supramolecular approach using CD-containing polyrotaxanes is expected to exploit a new paradigm of biomaterials.

Yui, Nobuhiko; Katoono, Ryo; Yamashita, Atsushi

349

Preparation and pharmaceutical evaluation of nano-fiber matrix supported drug delivery system using the solvent-based electrospinning method.  

PubMed

In this study, utilizing the solvent-based electrospinning (ES) method, which is mainly employed in the textile industry, we prepared nanofiber-based capsules including drugs for controlled-release delivery systems using methacrylic acid copolymer (EUDRAGIT(®) S100, MAC) as a polymer, and evaluated their in vitro drug dissolution profiles and in vivo pharmacokinetics in rats. As the model drugs, uranine (UN) was used as a water-soluble drug and nifedipine (NP) as a water-insoluble drug. The mean diameters of drug free nano-fiber and nano-fiber including NP or UN were 751.5 ± 67.2, 703.3 ± 71.2 and 2477.8 ± 206.1 nm, respectively. X-ray diffraction for the nano-fibrotic sheet showed that UN and/or NP were packed in nano-fiber in an amorphous form. The in vitro release of UN or NP from the nano-fiber packed capsules (NFPC) and milled-powder of nano-fiber packed capsules (MPPC) showed controlled release of UN or NP as compared to capsules of a physical mixture of MAC and each drug. An in vivo pharmacokinetic study in rats after intraduodenal administration of NFPC or MPPC including UN and/or NP clearly demonstrated that application of nano-fibrotic technique as a drug delivery system offers drastic changes in pharmacokinetic profiles for both water-soluble and water-insoluble drugs. The ES method is a useful technique to prepare a nano-fiber like solid dispersion for polar or nonpolar drugs, and has wide potential pharmaceutical applications. PMID:24440839

Hamori, Mami; Yoshimatsu, Shiori; Hukuchi, Yuki; Shimizu, Yuki; Fukushima, Keizo; Sugioka, Nobuyuki; Nishimura, Asako; Shibata, Nobuhito

2014-04-10

350

Development and characterization of polymeric nanoparticulate delivery system for hydrophillic drug: Gemcitabine  

NASA Astrophysics Data System (ADS)

Gemcitabine is a nucleoside analogue, used in various carcinomas such as non small cell lung cancer, pancreatic cancer, ovarian cancer and breast cancer. The major setbacks to the conventional therapy with gemcitabine include its short half-life and highly hydrophilic nature. The objectives of this investigation were to develop and evaluate the physiochemical properties, drug loading and entrapment efficiency, in vitro release, cytotoxicity, and cellular uptake of polymeric nano-particulate formulations containing gemcitabine hydrochloride. The study also entailed development and validation of a high performance liquid chromatography (HPLC) method for the analysis of gemcitabine hydrochloride. A reverse phase HPLC method using a C18 Luna column was developed and validated. Alginate and Poly lactide co glycolide/Poly-epsilon-caprolactone (PLGA:PCL 80:20) nanoparticles were prepared by multiple emulsion-solvent evaporation methodology. An aqueous solution of low viscosity alginate containing gemcitabine was emulsified into 10% solution of dioctyl-sulfosuccinate in dichloro methane (DCM) by sonication. The primary emulsion was then emulsified in 0.5% (w/v) aqueous solution of polyvinyl alcohol (PVA). Calcium chloride solution (60% w/v) was used to cause cross linking of the polymer. For PLGA:PCL system, the polymer mix was dissolved in dichloromethane (DCM) and an aqueous gemcitabine (with and without sodium chloride) was emulsified under ultrasonic conditions (12-watts; 1-min). This primary emulsion was further emulsified in 2% (w/v) PVA under ultrasonic conditions (24-watts; 3-min) to prepare a multiple-emulsion (w/o/w). In both cases DCM, the organic solvent was evaporated (20- hours, magnetic-stirrer) prior to ultracentrifugation (10000-rpm for PLGA:PCL; 25000-rpm for alginate). The pellet obtained was washed thrice with de-ionized water to remove PVA and any free drug and re-centrifuged. The particles were re-suspended in de-ionized water and then lyophilized to obtain the dried powdered delivery formulation. Particle size and surface charge of the nano-particles were measured using zeta-sizer. The surface morphology and microstructure were evaluated by scanning electron microscopy The drug loading and entrapment efficiencies were evaluated by a HPLC method (Luna C18 column (4.6 X 250 mm), 95/5 (v/v) 0.04M ammonium acetate/acetonitrile mobile phase (pH 5.5), 1.0 ml/min flow rate and 268 nm UV detection). Differential scanning calorimetry (DSC) was used to determine the physical state of gemcitabine in the nanoparticles. The cytotoxicity in pancreatic cancer cells (BxPC-3) was evaluated by MTT assay. The cellular uptake of gemcitabine solution and gemcitabine loaded alginate nano-particle suspension in BxPC-3 cells was determined for 15, 30 and 60 minutes. The particle-size and surface-charge was 564.7+/-56.5nm and -25.65+/-1.94mV for PLGA:PCL and 210.6+/-6.90nm and -33.21+/-1.63mV for alginate. Both the nano-particles were distinctly spherical and non-porous. The drug load was 5.14% for PLGA:PCL and 6.87% for alginate-particles, and the practical entrapment efficiency was found to be 54.1 % and 22.4% respectively. However, in case of PLGA:PCL particles, a two-fold increase in the entrapment efficiency was observed with the addition of sodium-chloride. The absence of endothermic melting peak of the drug in the DSC thermogram was an indication of the non-crystalline state of gemcitabine in the nanoparticles. In addition, there was no cytotoxicity associated with nanoparticle concentrations at-or-below 5 mg/mL. The uptake of nano-particles was around 4 times higher than the solution with treatment for 15 minutes and increased to almost 7 times following treatment for 60 minutes. Gemcitabine hydrochloride could be successfully formulated into a sustained release nano-particulate formulation using calcium cross-linked alginate and dioctyl sulfo succinate system. The nano-particulate delivery system exhibited better cytotoxic activity and also significantly enhanced the accumulation of the drug in BxPC-3 cell monolayers.

Khurana, Jatin

351

Development of a polylactic acid (PLA) polymer with an acid-sensitive N-ethoxybenzylimidazole (NEBI) crosslinker as a drug delivery system  

E-print Network

and tuned systems capable of variable release. Grafting2.17), the release of the drug delivery system can still besystem exhibited many desirable properties including increased payload, acid-promoted release and

Hang, Leibniz Fangtinq

2012-01-01

352

Combination of Polymer Technology and Carbon Nanotube Array for the Development of an Effective Drug Delivery System at Cellular Level  

NASA Astrophysics Data System (ADS)

In this article, a carbon nanotube (CNT) array-based system combined with a polymer thin film is proposed as an effective drug release device directly at cellular level. The polymeric film embedded in the CNT array is described and characterized in terms of release kinetics, while in vitro assays on PC12 cell line have been performed in order to assess the efficiency and functionality of the entrapped agent (neural growth factor, NGF). PC12 cell differentiation, following incubation on the CNT array embedding the alginate delivery film, demonstrated the effectiveness of the proposed solution. The achieved results indicate that polymeric technology could be efficiently embedded in CNT array acting as drug delivery system at cellular level. The implication of this study opens several perspectives in particular in the field of neurointerfaces, combining several functions into a single platform.

Riggio, Cristina; Ciofani, Gianni; Raffa, Vittoria; Cuschieri, Alfred; Micera, Silvestro

2009-07-01

353

Combination of Polymer Technology and Carbon Nanotube Array for the Development of an Effective Drug Delivery System at Cellular Level  

PubMed Central

In this article, a carbon nanotube (CNT) array-based system combined with a polymer thin film is proposed as an effective drug release device directly at cellular level. The polymeric film embedded in the CNT array is described and characterized in terms of release kinetics, while in vitro assays on PC12 cell line have been performed in order to assess the efficiency and functionality of the entrapped agent (neural growth factor, NGF). PC12 cell differentiation, following incubation on the CNT array embedding the alginate delivery film, demonstrated the effectiveness of the proposed solution. The achieved results indicate that polymeric technology could be efficiently embedded in CNT array acting as drug delivery system at cellular level. The implication of this study opens several perspectives in particular in the field of neurointerfaces, combining several functions into a single platform. PMID:20596464

2009-01-01

354

Amphiphilic linear-dendritic block copolymers for drug delivery  

E-print Network

Polymeric drug delivery systems have been widely used in the pharmaceutical industry. Such systems can solubilize and sequester hydrophobic drugs from degradation, thereby increasing circulation half-life and efficacy. ...

Nguyen, Phuong, Ph. D. Massachusetts Institute of Technology

2007-01-01

355

Ethosomes-based topical delivery system of antihistaminic drug for treatment of skin allergies.  

PubMed

Abstract Cetirizine is indicated for the treatment of allergic conditions such as insect bites and stings, atopic and contact dermatitis, eczema, urticaria. This investigation deals with development of a novel ethosome-based topical formulation of cetirizine dihydrochloride for effective delivery. The optimised formulation consisting of drug, phospholipon 90 G™ and ethanol was characterised for drug content, entrapment efficiency, pH, vesicular size, spreadability and rheological behaviour. The ex vivo permeation studies through mice skin showed highest permeation flux (16.300?±?0.300?µg/h/cm(2)) and skin retention (20.686?±?0.517?µg/cm(2)) for cetirizine-loaded ethosomal vesicles as compared to conventional formulations. The in vivo pharmacodynamic evaluation of optimised formulation was assessed against oxazolone-induced atopic dermatitis (AD) in mice. The parameters evaluated were reduction in scratching score, erythema score, skin hyperplasia and dermal eosinophil count. Our results suggest that ethosomes are effective carriers for dermal delivery of antihistaminic drug, cetirizine, for the treatment of AD. PMID:24963956

Goindi, Shishu; Dhatt, Bhavnita; Kaur, Amanpreet

2014-01-01

356

Design, Development, and Optimization of Polymeric Based-Colonic Drug Delivery System of Naproxen  

PubMed Central

The aim of present investigation deals with the development of time-dependent and pH sensitive press-coated tablets for colon specific drug delivery of naproxen. The core tablets were prepared by wet granulation method then press coated with hydroxypropyl cellulose (HPC) or Eudragit RSPO?:?RLPO mixture and further coated with Eudragit S-100 by dip immerse method. The in vitro drug release study was conducted in different dissolution media such as pH 1.2, 6.8, and 7.4 with or without rat caecal content to simulate GIT conditions. Surface morphology and cross-sectional view of the tablets were visualized by scanning electron microscopy (SEM). All prepared batches were in compliance with the pharmacopoeial standards. The tablets which are compression coated with HPC followed by Eudragit S-100 coated showed highest in vitro drug release of 98.10% in presence of rat caecal content. The SEM of tablets suggested that the number of pores got increased in pH 7.4 medium followed by dissolution of coating layer. The tablets coat erosion study suggested that the lag time depends upon the coating concentrations of polymers. A time-dependent hydrophilic polymer and pH sensitive polymer based press-coated tablets of naproxen were promising delivery for colon targeting. PMID:24198725

Sharma, Pooja; Chawla, Anuj; Pawar, Pravin

2013-01-01

357

Design, development, and optimization of polymeric based-colonic drug delivery system of naproxen.  

PubMed

The aim of present investigation deals with the development of time-dependent and pH sensitive press-coated tablets for colon specific drug delivery of naproxen. The core tablets were prepared by wet granulation method then press coated with hydroxypropyl cellulose (HPC) or Eudragit RSPO?:?RLPO mixture and further coated with Eudragit S-100 by dip immerse method. The in vitro drug release study was conducted in different dissolution media such as pH 1.2, 6.8, and 7.4 with or without rat caecal content to simulate GIT conditions. Surface morphology and cross-sectional view of the tablets were visualized by scanning electron microscopy (SEM). All prepared batches were in compliance with the pharmacopoeial standards. The tablets which are compression coated with HPC followed by Eudragit S-100 coated showed highest in vitro drug release of 98.10% in presence of rat caecal content. The SEM of tablets suggested that the number of pores got increased in pH 7.4 medium followed by dissolution of coating layer. The tablets coat erosion study suggested that the lag time depends upon the coating concentrations of polymers. A time-dependent hydrophilic polymer and pH sensitive polymer based press-coated tablets of naproxen were promising delivery for colon targeting. PMID:24198725

Sharma, Pooja; Chawla, Anuj; Pawar, Pravin

2013-01-01

358

Lipoidal Soft Hybrid Biocarriers of Supramolecular Construction for Drug Delivery  

PubMed Central

Lipid-based innovations have achieved new heights during the last few years as an essential component of drug development. The current challenge of drug delivery is liberation of drug agents at the right time in a safe and reproducible manner to a specific target site. A number of novel drug delivery systems has emerged encompassing various routes of administration, to achieve controlled and targeted drug delivery. Microparticulate lipoidal vesicular system represents a unique technology platform suitable for the oral and systemic administration of a wide variety of molecules with important therapeutic biological activities, including drugs, genes, and vaccine antigens. The success of liposomes as drug carriers has been reflected in a number of liposome-based formulations, which are commercially available or are currently undergoing clinical trials. Also, novel lipid carrier-mediated vesicular systems are originated. This paper has focused on the lipid-based supramolecular vesicular carriers that are used in various drug delivery and drug targeting systems. PMID:22888455

Kumar, Dinesh; Sharma, Deepak; Singh, Gurmeet; Singh, Mankaran; Rathore, Mahendra Singh

2012-01-01

359

Novel chitosan-functionalized spherical nanosilica matrix as an oral sustained drug delivery system for poorly water-soluble drug carvedilol.  

PubMed

A novel spherical nanosilica matrix (SNM) together with chitosan (CTS) encapsulated SNM (CTS-SNM) was developed in order to investigate the feasibility of using chitosan to regulate drug release rate from porous silica and obtain an oral sustained drug delivery system. To achieve this goal, we synthesized a spherical nanosilica matrix (SNM) and incorporated chitosan chains on the SNM surface. Solvent evaporation method was adopted to load the model drug carvedilol into SNM and CTS-SNM. The physicochemical properties of the drug carriers and drug-loaded composites were systematically studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The structural changes in CTS-SNM in simulated gastrointestinal fluid as well as the relationships between swelling effect of chitosan and in vitro drug release behaviors were investigated. Pharmacokinetic and bioavailability aspects were also discussed. The results showed that the powerful dispersing effect of SNM and the blocking action due to the swelling of chitosan were the two main factors contributing to the sustained drug release behavior. The swelling effect of chitosan in an acidic environment together with the shrinking effect in a relatively alkaline environment allowed regulation of drug release behavior in simulated gastrointestinal fluid. An in vivo study showed that the bioavailability of CAR was improved 182% compared with that of the commercial capsule when SNM was used as the drug carrier. As for CAR-CTS-SNM, the T(max) of CAR was delayed by about 3.4 h and the bioavailability was slightly increased in comparison with the commercial capsule. We believe that SNM and CTS-SNM developed in this study will help increase the use of polymers and inorganic materials in pharmaceutical applications and stimulate the design of oral drug delivery systems for immediate or sustained release of poorly water-soluble drugs. PMID:23237208

Sun, Lizhang; Wang, Yanzhu; Jiang, Tongying; Zheng, Xin; Zhang, Jinghai; Sun, Jin; Sun, Changshan; Wang, Siling

2013-01-01

360

Combination of iCVD and porous silicon for the development of a controlled drug delivery system.  

PubMed

We describe a pH responsive drug delivery system which was fabricated using a novel approach to functionalize biodegradeable porous silicon (pSi) by initiated chemical vapor deposition (iCVD). The assembly involved first loading a model drug (camptothecin, CPT) into the pores of the pSi matrix followed by capping the pores with a thin pH responsive copolymer film of poly(methacrylic acid-co-ethylene dimethacrylate) (p(MAA-co-EDMA)) via iCVD. Release of CPT from uncoated pSi was identical in two buffers at pH 1.8 and pH 7.4. In contrast, the linear release rate of CPT from the pSi matrix with the p(MAA-co-EDMA) coating was dependent on the pH; release of CPT was more than four times faster at pH 7.4 (13.1 nmol/(cm(2) h)) than at pH 1.8 (3.0 nmol/(cm(2) h)). The key advantage of this drug delivery approach over existing ones based on pSi is that the iCVD coating can be applied to the pSi matrix after drug loading without degradation of the drug because the process does not expose the drug to harmful solvents or high temperatures and is independent of the surface chemistry and pore size of the nanoporous matrix. PMID:22720638

McInnes, Steven J P; Szili, Endre J; Al-Bataineh, Sameer A; Xu, Jingjing; Alf, Mahriah E; Gleason, Karen K; Short, Robert D; Voelcker, Nicolas H

2012-07-25

361

Drug delivery and nanoparticles: Applications and hazards  

PubMed Central

The use of nanotechnology in medicine and more specifically drug delivery is set to spread rapidly. Currently many substances are under investigation for drug delivery and more specifically for cancer therapy. Interestingly pharmaceutical sciences are using nanoparticles to reduce toxicity and side effects of drugs and up to recently did not realize that carrier systems themselves may impose risks to the patient. The kind of hazards that are introduced by using nanoparticles for drug delivery are beyond that posed by conventional hazards imposed by chemicals in classical delivery matrices. For nanoparticles the knowledge on particle toxicity as obtained in inhalation toxicity shows the way how to investigate the potential hazards of nanoparticles. The toxicology of particulate matter differs from toxicology of substances as the composing chemical(s) may or may not be soluble in biological matrices, thus influencing greatly the potential exposure of various internal organs. This may vary from a rather high local exposure in the lungs and a low or neglectable exposure for other organ systems after inhalation. However, absorbed species may also influence the potential toxicity of the inhaled particles. For nanoparticles the situation is different as their size opens the potential for crossing the various biological barriers within the body. From a positive viewpoint, especially the potential to cross the blood brain barrier may open new ways for drug delivery into the brain. In addition, the nanosize also allows for access into the cell and various cellular compartments including the nucleus. A multitude of substances are currently under investigation for the preparation of nanoparticles for drug delivery, varying from biological substances like albumin, gelatine and phospholipids for liposomes, and more substances of a chemical nature like various polymers and solid metal containing nanoparticles. It is obvious that the potential interaction with tissues and cells, and the potential toxicity, greatly depends on the actual composition of the nanoparticle formulation. This paper provides an overview on some of the currently used systems for drug delivery. Besides the potential beneficial use also attention is drawn to the questions how we should proceed with the safety evaluation of the nanoparticle formulations for drug delivery. For such testing the lessons learned from particle toxicity as applied in inhalation toxicology may be of use. Although for pharmaceutical use the current requirements seem to be adequate to detect most of the adverse effects of nanoparticle formulations, it can not be expected that all aspects of nanoparticle toxicology will be detected. So, probably additional more specific testing would be needed. PMID:18686775

De Jong, Wim H; Borm, Paul JA

2008-01-01

362

Drug delivery Preparation of Monodisperse Biodegradable Polymer  

E-print Network

Drug delivery Preparation of Monodisperse Biodegradable Polymer Microparticles Using a Microfluidic Flow-Focusing Device for Controlled Drug Delivery Qiaobing Xu, Michinao Hashimoto, Tram T. Dang, Todd microparticles have broad utility as vehicles for drug delivery and form the basis of several therapies approved

Prentiss, Mara

363

Emergency delivery of Vasopressin from an implantable MEMS rapid drug delivery device  

E-print Network

An implantable rapid drug delivery device based on micro-electro-mechanical systems (MEMS) technology was designed, fabricated and validated for the in vivo rapid delivery of vasopressin in a rabbit model. In vitro ...

Ho Duc, Hong Linh, 1978-

2009-01-01

364

Tuberculosis chemotherapy: current drug delivery approaches  

PubMed Central

Tuberculosis is a leading killer of young adults worldwide and the global scourge of multi-drug resistant tuberculosis is reaching epidemic proportions. It is endemic in most developing countries and resurgent in developed and developing countries with high rates of human immunodeficiency virus infection. This article reviews the current situation in terms of drug delivery approaches for tuberculosis chemotherapy. A number of novel implant-, microparticulate-, and various other carrier-based drug delivery systems incorporating the principal anti-tuberculosis agents have been fabricated that either target the site of tuberculosis infection or reduce the dosing frequency with the aim of improving patient outcomes. These developments in drug delivery represent attractive options with significant merit, however, there is a requisite to manufacture an oral system, which directly addresses issues of unacceptable rifampicin bioavailability in fixed-dose combinations. This is fostered by the need to deliver medications to patients more efficiently and with fewer side effects, especially in developing countries. The fabrication of a polymeric once-daily oral multiparticulate fixed-dose combination of the principal anti-tuberculosis drugs, which attains segregated delivery of rifampicin and isoniazid for improved rifampicin bioavailability, could be a step in the right direction in addressing issues of treatment failure due to patient non-compliance. PMID:16984627

du Toit, Lisa Claire; Pillay, Viness; Danckwerts, Michael Paul

2006-01-01

365

Evaluation of drug load and polymer by using a 96-well plate vacuum dry system for amorphous solid dispersion drug delivery.  

PubMed

It is well recognized that poor dissolution rate and solubility of drug candidates are key limiting factors for oral bioavailability. While numerous technologies have been developed to enhance solubility of the drug candidates, poor water solubility continuously remains a challenge for drug delivery. Among those technologies, amorphous solid dispersions (SD) have been successfully employed to enhance both dissolution rate and solubility of poorly water-soluble drugs. This research reports a high-throughput screening technology developed by utilizing a 96-well plate system to identify optimal drug load and polymer using a solvent casting approach. A minimal amount of drug was required to evaluate optimal drug load in three different polymers with respect to solubility improvement and solid-state stability of the amorphous drug-polymer system. Validation of this method was demonstrated with three marketed drugs as well as with one internal compound. Scale up of the internal compound SD by spray drying further confirmed the validity of this method, and its quality was comparable to a larger scale process. Here, we demonstrate that our system is highly efficient, cost-effective, and robust to evaluate the feasibility of spray drying technology to produce amorphous solid dispersions. PMID:22562615

Chiang, Po-Chang; Ran, Yingqing; Chou, Kang-Jye; Cui, Yong; Sambrone, Amy; Chan, Connie; Hart, Ryan

2012-06-01

366

Nanotech approaches to drug delivery and imaging  

Microsoft Academic Search

Nanotechnology, a multidisciplinary scientific undertaking, involves creation and utilization of materials, devices or systems on the nanometer scale. The field of nanotechnology is currently undergoing explosive development on many fronts. The technology is expected to create innovations and play a critical role in various biomedical applications, not only in drug delivery, but also in molecular imaging, biomarkers and biosensors. Target-specific

Sanjeeb K. Sahoo; Vinod Labhasetwar

2003-01-01

367

REVIEW NANOPARTICLES IN DELIVERY OF CARDIOVASCULAR DRUGS  

Microsoft Academic Search

Everything in nature is built upward from the atomic level to define limits and structures to everything. Nanomedicines marked the field of medicine from nanobiotechnology, biological micro-electromechanical systems, microfluidics, biosensors, drug delivery, microarrays to tissue microengineering. Since then nanoparticles has overcome many challenges from blood brain barrier to targeting tumors. Where solid biodegradable nanoparticles were a step up liposome, targeting

M. SAEED ARAYNE; NAJMA SULTANA; FAIZA QURESHI

368

Multiple unit gastroretentive drug delivery systems: a new preparation method for low density microparticles.  

PubMed

The aim of this study was to develop a new preparation method for low density foam-based, floating microparticles and to demonstrate the systems' performance in vitro. Major advantages of the novel preparation technique include: (i) short processing times, (ii) no exposure of the ingredients to high temperatures, (iii) the possibility to avoid toxic organic solvents, and (iv) high encapsulation efficiencies close to 100%. Floating microparticles consisting of polypropylene foam powder, model drug [chlorpheniramine maleate (CPM), diltiazem HCl, theophylline or verapamil HCl] and polymer [Eudragit RS or polymethyl methacrylate (PMMA)] were prepared by soaking the microporous foam carrier with an organic solution of drug and polymer and subsequent drying. The effects of various formulation and processing parameters on the resulting in vitro floating behaviour, internal and external particle morphology, drug loading, in vitro drug release and physical state of the incorporated drug were studied. Good in vitro floating behaviour was observed in most cases and a broad variety of drug release patterns could be achieved by varying the drug loading and type of polymer. Interestingly, PMMA-based microparticles showed incomplete drug release with verapamil HCl. This restriction could be overcome by forming the free base of the drug prior to microparticle preparation. In contrast to the salt, the free base acted as a plasticizer for PMMA, resulting in sufficiently high diffusion coefficients and, consequently, complete drug release. The low density microparticles were compressed into rapidly disintegrating tablets in order to provide an administrable oral dosage form. PMID:12881114

Streubel, A; Siepmann, J; Bodmeier, R

2003-01-01

369

Development of drug delivery systems based on nanostructured porous silicon loaded with the anti-tumoral drug emodin adsorbed on silver nanoparticles  

NASA Astrophysics Data System (ADS)

A study of the fluorescence and Raman spectra of a new and complex drug delivery system formed by emodin adsorbed on silver nanoparticles embedded into a matrix of porous silicon is here reported. Several experimental methods of inclusion of the drug-silver set inside the pores, without previous functionalization of porous silicon, have been tested in order to optimize the conditions for the fluorescence detection of emodin. In this sense, we have also added bovine serum albumin to the system, finding that the presence of the protein enhances the fluores-cence signal from emodin.

Hernández, Margarita; Recio, Gonzalo; Sevilla, Paz; Torres-Costa, Vicente; García-Ramos, José V.; Domingo, Concepción; Martín-Palma, Raúl J. J.

2012-10-01

370

[Skin permeation and transdermal delivery systems of drugs: history to overcome barrier function in the stratum corneum].  

PubMed

Transdermal Drug Delivery Systems (TDDS), where active drugs must be absorbed into the systemic circulation after penetrating the skin barrier, were first launched in 1979, and about 10 TDDS containing different kinds of drugs were developed during the initial decade. Interestingly, a developmental rush has come again in the present century. Various penetration-enhancing approaches to improve drug permeation of the skin (stratum corneum) have been attempted. These approaches are of two types: chemical and physical. Examples of the chemical approach are enhancers such as alcohol, monoterpenes and fatty acid esters, as well as chemical modification of prodrugs. In contrast, physical approaches include the use of electrical-, thermal- and mechanical-energy, as well as microneedles, needle-free injectors or electroporation to completely or partially evade the barrier function in the stratum corneum. The chemical approaches are mainly effective in increasing the skin permeation of low-molecular chemicals, whereas physical means are effective for these chemicals but also high-molecules like peptides, proteins and nucleotides (DNA or RNA). Marked development has been observed in these physical means in the past decade. In addition, recent developments in tissue engineering technologies enables the use of cultured skin containing keratinocytes and fibroblasts as a TDDS. An effective "cell delivery system" may be a reality in the near future. This paper will look back on the 30-year history of TDDS and evaluate the feasibility of a new generation of these systems. PMID:19952520

Sugino, Masahiro; Todo, Hiroaki; Sugibayashi, Kenji

2009-12-01

371

Design and in vitro evaluation of effervescent gastric floating drug delivery systems of propanolol HCl.  

PubMed

Abstract. The purpose of this research was to develop and evaluate effervescent gastric floating tablets of propranolol HCl. The oral delivery of antihypertensive propranolol HCl was facilitated by preparing an effervescent floating dosage form which could increase its absorption in the stomach by increasing the drug's gastric residence time. In the present work, effervescent floating tablets were prepared with a hydrophilic carrier such as polyethylene oxide (PEO WSR N 60K and PEO WSR 303) as a release retarding agent and sodium bicarbonate as a gas generating agent. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, drug release and rate order kinetics. From the results, P9 was selected as an optimized formulation based on their 12 h drug release, minimal floating lag time and maximum total floating time. The optimized formulation followed first order rate kinetics with erosion mechanism. The optimized formulation was characterized with FTIR studies and no interaction between the drug and the polymers were observed. PMID:22524109

Meka, Venkata Srikanth; Songa, Ambedkar Sunil; Nali, Sreenivasa Rao; Battu, Janaki Ram; Kolapalli, Venkata Ramana Murthy

2012-03-01

372

The effect of micro and nanotopography on endocytosis in drug and gene delivery systems.  

PubMed

Endocytosis is a fundamental biological process and is also the key mechanism for drug and non-viral gene delivery. The importance of topographical cues in modulating cell behaviors has become increasingly evident, but the influence of topography on endocytosis has however only been sparsely studied. We hypothesize that topography can enhance cellular endocytosis, and in turn the non-viral transfection efficiency. Nano- to microtopographical patterns were fabricated using nano-imprinting lithography (NIL). We first investigated if the substrate topographies could modulate endocytosis and in turn the cellular transfectability. Our results showed increased internalization of fluorescently labeled dextran by human mesenchymal stem cells (hMSCs) and monkey kidney fibroblasts (COS7) when they were cultured on micro- and nanopillars. When the hMSCs were introduced to green-fluorescent protein (GFP) encoding plasmid with Lipofectamine, highest transfection efficiency was observed in cells on nanopillars. Tunable detachable substrate topographies were also fabricated using NIL to promote endocytosis in different cell types, and our results show hMSCs phagocytosis of these polymeric structures. Besides being important in understanding the fundamental process of endocytosis, the current research results may also lead to applications utilizing nanotopography to enhance drug and gene delivery. PMID:21924770

Teo, Benjamin K K; Goh, Seok-Hong; Kustandi, Tanu S; Loh, Wei Wei; Low, Hong Yee; Yim, Evelyn K F

2011-12-01

373

Modification of chitosan by using samarium for potential use in drug delivery system.  

PubMed

In the presence of hydroxyl and amine groups, chitosan is highly reactive; therefore, it could be used as a carrier in drug delivery. For this study, chitosan-Sm complexes with different concentrations of samarium from 2.5 to 25 wt.% have been successfully synthesized by the impregnation method. Chitosan combined with Sm3+ ions produced a drug carrier material with fluorescence properties; thus, it could also be used as an indicator of drug release with ibuprofen (IBU) as a model drug. We evaluated the spectroscopic and interaction properties of chitosan and Sm3+ ions, the interaction of chitosan-Sm matrices with IBU as a model drug, and the effect of Sm3+ ions addition on the chitosan ability to adsorb the drug. The result showed that the hypersensitive fluorescence intensity of chitosan-Sm (2.5 wt.%) is higher than the others, even though the adsorption efficiency of chitosan-Sm 2.5wt.% is lower (29.75%) than that of chitosan-Sm 25 wt.% (33.04%). Chitosan-Sm 25 wt.% showed the highest efficiency of adsorption of ibuprofen (33.04%). In the release process of ibuprofen from the chitosan-Sm-IBU matrix, the intensity of orange fluorescent properties in the hypersensitive peak of 4G5/2?6H7/2 transition at 590 nm was observed. Fluorescent intensity increased with the cumulative amount of IBU released; therefore, the release of IBU from the Sm-modified chitosan complex can be monitored by the changes in fluorescent intensity. PMID:24177873

Kusrini, Eny; Arbianti, Rita; Sofyan, Nofrijon; Abdullah, Mohd Aidil A; Andriani, Fika

2014-01-01

374

A New Brain Drug Delivery Strategy: Focused Ultrasound-Enhanced Intranasal Drug Delivery  

PubMed Central

Central nervous system (CNS) diseases are difficult to treat because of the blood-brain barrier (BBB), which prevents most drugs from entering into the brain. Intranasal (IN) administration is a promising approach for drug delivery to the brain, bypassing the BBB; however, its application has been restricted to particularly potent substances and it does not offer localized delivery to specific brain sites. Focused ultrasound (FUS) in combination with microbubbles can deliver drugs to the brain at targeted locations. The present study proposed to combine these two different platform techniques (FUS+IN) for enhancing the delivery efficiency of intranasally administered drugs at a targeted location. After IN administration of 40 kDa fluorescently-labeled dextran as the model drug, FUS targeted at one region within the caudate putamen of mouse brains was applied in the presence of systemically administered microbubbles. To compare with the conventional FUS technique, in which intravenous (IV) drug injection is employed, FUS was also applied after IV injection of the same amount of dextran in another group of mice. Dextran delivery outcomes were evaluated using fluorescence imaging of brain slices. The results showed that FUS+IN enhanced drug delivery within the targeted region compared with that achieved by IN only. Despite the fact that the IN route has limited drug absorption across the nasal mucosa, the delivery efficiency of FUS+IN was not significantly different from that of FUS+IV. As a new drug delivery platform, the FUS+IN technique is potentially useful for treating CNS diseases. PMID:25279463

Chen, Hong; Chen, Cherry C.; Acosta, Camilo; Wu, Shih-Ying; Sun, Tao; Konofagou, Elisa E.

2014-01-01

375

Surface functionalized gold nanoparticles for drug delivery.  

PubMed

Gold nanoparticles have been widely explored as cancer therapeutics and diagnostic agents in recent years. With their unique subcellular size and good biocompatibility, gold nanoparticles are a promising drug delivery vehicle. In this study, folic acid-coated gold nanoparticles conjugated with fluorophore FITC through amine terminated poly(ethylene glycol) were prepared and confocal microscopy together with bright-field differential interference contrast imaging data showed that folic acid-coated gold nanoparticles accumulated mainly in cytoplasm of primary human fibroblasts, without causing any observable cytotoxicity upon exposure for 48 hours. Through the further development of a drug delivery system that conjugates doxorubicin onto the surface of gold nanoparticles with a poly(ethylene glycol) spacer via an SMCC linker, we demonstrated that multidrug resistance in cancer cells can be significantly overcome by a combination of highly efficient cellular entry and enhanced cytotoxicity of Au-SMCC-DOX nanoconjugates, as revealed both by confocal microscopy imaging and cytotoxicity assay. The prepared Au-SMCC-DOX nanoconjugates demonstrated enhanced drug accumulation and retention in multidrug resistant hepG2-R cancer cells when it was compared with free doxorubicin, with a cytoplasm accumulation profile. The results indicated that gold nanoparticles are a kind of promising drug delivery vehicle with good biocompatibility and suitable for further applications in drug delivery for improved chemotherapy, especially for overcoming multidrug resistance. PMID:23926802

Cheng, Jinping; Gu, Yan-Juan; Cheng, Shuk Han; Wong, Wing-Tak

2013-08-01

376

Microencapsulation: A promising technique for controlled drug delivery  

PubMed Central

Microparticles offer various significant advantages as drug delivery systems, including: (i) an effective protection of the encapsulated active agent against (e.g. enzymatic) degradation, (ii) the possibility to accurately control the release rate of the incorporated drug over periods of hours to months, (iii) an easy administration (compared to alternative parenteral controlled release dosage forms, such as macro-sized implants), and (iv) Desired, pre-programmed drug release profiles can be provided which match the therapeutic needs of the patient. This article gives an overview on the general aspects and recent advances in drug-loaded microparticles to improve the efficiency of various medical treatments. An appropriately designed controlled release drug delivery system can be a foot ahead towards solving problems concerning to the targeting of drug to a specific organ or tissue, and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed. PMID:21589795

Singh, M.N.; Hemant, K.S.Y.; Ram, M.; Shivakumar, H.G.

2010-01-01

377

Intracellular antioxidants dissolve man-made antioxidant nanoparticles: using redox vulnerability of nanoceria to develop a responsive drug delivery system.  

PubMed

Regeneratable antioxidant property of nanoceria has widely been explored to minimize the deleterious influences of reactive oxygen species. Limited information is, however, available regarding the biological interactions and subsequent fate of nanoceria in body fluids. This study demonstrates a surprising dissolution of stable and ultrasmall (4 nm) cerium oxide nanoparticles (CeO2 NPs) in response to biologically prevalent antioxidant molecules (glutathione, vitamin C). Such a redox sensitive behavior of CeO2 NPs is subsequently exploited to design a redox responsive drug delivery system for transporting anticancer drug (camptothecin). Upon exposing the CeO2 capped and drug loaded nanoconstruct to vitamin c or glutathione, dissolution-accompanied aggregation of CeO2 nanolids unleashes the drug molecules from porous silica to achieve a significant anticancer activity. Besides stimuli responsive drug delivery, immobilization of nanoceria onto the surface of mesoporous silica also facilitates us to gain a basic insight into the biotransformation of CeO2 in physiological mediums. PMID:25312332

Muhammad, Faheem; Wang, Aifei; Qi, Wenxiu; Zhang, Shixing; Zhu, Guangshan

2014-11-12

378

Nanoparticle drug delivery enhances the cytotoxicity of hydrophobichydrophilic drug conjugates  

E-print Network

Nanoparticle drug delivery enhances the cytotoxicity of hydrophobic­hydrophilic drug conjugates, Accepted 4th October 2011 DOI: 10.1039/c1jm13834k We report a drug conjugation approach to concurrently load both hydrophobic and hydrophilic drugs into the same drug delivery nanocarrier in a precisely

Zhang, Liangfang

379