The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Sanjay Garg - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of osmotically controlled Oral Drug Delivery system of glipizide
European Journal of Pharmaceutics and Biopharmaceutics, 2004Co-Authors: Rajan K Verma, Sanjay GargAbstract:Extended release formulation of glipizide based on osmotic technology was developed and evaluated. The effect of different formulation variables, namely, level of solubility modifier in the core, membrane weight gain, and level of pore former in the membrane, were studied. Drug release was found to be affected by the level of solubility modifier in the core formulation. Glipizide release was inversely proportional to the membrane weight but directly related to the initial level of pore former (PVP) in the membrane. Burst strength of the exhausted shells increased with the weight gain of the membrane. On the other hand, burst strength decreased with an increase in the level of pore former in the membrane. Drug release from the developed formulations was independent of pH and agitational intensity, but dependent on the osmotic pressure of the release media. Results of SEM studies showed the formation of pores in the membrane from where the Drug release occurred. The numbers of pores were directly proportional to the initial level of pore former in the membrane. The manufacturing procedure was found to be reproducible and formulations were stable after 3 months of accelerated stability studies.
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formulation aspects in the development of osmotically controlled Oral Drug Delivery systems
Journal of Controlled Release, 2002Co-Authors: Rajan K Verma, Divi Murali Krishna, Sanjay GargAbstract:Osmotically controlled Oral Drug Delivery systems utilize osmotic pressure for controlled Delivery of active agent(s). Drug Delivery from these systems, to a large extent, is independent of the physiological factors of the gastrointestinal tract and these systems can be utilized for systemic as well as targeted Delivery of Drugs. The release of Drug(s) from osmotic systems is governed by various formulation factors such as solubility and osmotic pressure of the core component(s), size of the Delivery orifice, and nature of the rate-controlling membrane. By optimizing formulation and processing factors, it is possible to develop osmotic systems to deliver Drugs of diverse nature at a pre-programmed rate. In the present review, different types of Oral osmotic systems, various aspects governing Drug release from these systems, and critical formulation factors are discussed.
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osmotically controlled Oral Drug Delivery
Drug Development and Industrial Pharmacy, 2000Co-Authors: Rajan K Verma, B Mishra, Sanjay GargAbstract:It is advantageous to deliver some Drugs with short half-life, and which are to be given frequently for chronic ailments, in the form of controlled-release (CR) formulations. The Orally administered Drugs, in the form of conventional matrix or reservoir type formulations, pose problems of bioavailability fluctuations due to gastric pH variations. Moreover, the release of Drug(s) from these systems is affected by the hydrodynamic conditions of the body. Osmotically controlled Drug Delivery systems utilize the principles of osmotic pressure for the controlled Delivery of active agent(s). The release rate of Drug(s) from these systems is independent of the physiological factors of the gastrointestinal (GI) tract to a large extent. In the present review, theory underlying the Delivery of Drugs from osmotic systems is presented. Different types of Oral osmotic systems, their advantages over conventional matrix and reservoir types of systems, and their applications are also discussed. Finally, some of the limit...
Rajan K Verma - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of osmotically controlled Oral Drug Delivery system of glipizide
European Journal of Pharmaceutics and Biopharmaceutics, 2004Co-Authors: Rajan K Verma, Sanjay GargAbstract:Extended release formulation of glipizide based on osmotic technology was developed and evaluated. The effect of different formulation variables, namely, level of solubility modifier in the core, membrane weight gain, and level of pore former in the membrane, were studied. Drug release was found to be affected by the level of solubility modifier in the core formulation. Glipizide release was inversely proportional to the membrane weight but directly related to the initial level of pore former (PVP) in the membrane. Burst strength of the exhausted shells increased with the weight gain of the membrane. On the other hand, burst strength decreased with an increase in the level of pore former in the membrane. Drug release from the developed formulations was independent of pH and agitational intensity, but dependent on the osmotic pressure of the release media. Results of SEM studies showed the formation of pores in the membrane from where the Drug release occurred. The numbers of pores were directly proportional to the initial level of pore former in the membrane. The manufacturing procedure was found to be reproducible and formulations were stable after 3 months of accelerated stability studies.
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formulation aspects in the development of osmotically controlled Oral Drug Delivery systems
Journal of Controlled Release, 2002Co-Authors: Rajan K Verma, Divi Murali Krishna, Sanjay GargAbstract:Osmotically controlled Oral Drug Delivery systems utilize osmotic pressure for controlled Delivery of active agent(s). Drug Delivery from these systems, to a large extent, is independent of the physiological factors of the gastrointestinal tract and these systems can be utilized for systemic as well as targeted Delivery of Drugs. The release of Drug(s) from osmotic systems is governed by various formulation factors such as solubility and osmotic pressure of the core component(s), size of the Delivery orifice, and nature of the rate-controlling membrane. By optimizing formulation and processing factors, it is possible to develop osmotic systems to deliver Drugs of diverse nature at a pre-programmed rate. In the present review, different types of Oral osmotic systems, various aspects governing Drug release from these systems, and critical formulation factors are discussed.
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osmotically controlled Oral Drug Delivery
Drug Development and Industrial Pharmacy, 2000Co-Authors: Rajan K Verma, B Mishra, Sanjay GargAbstract:It is advantageous to deliver some Drugs with short half-life, and which are to be given frequently for chronic ailments, in the form of controlled-release (CR) formulations. The Orally administered Drugs, in the form of conventional matrix or reservoir type formulations, pose problems of bioavailability fluctuations due to gastric pH variations. Moreover, the release of Drug(s) from these systems is affected by the hydrodynamic conditions of the body. Osmotically controlled Drug Delivery systems utilize the principles of osmotic pressure for the controlled Delivery of active agent(s). The release rate of Drug(s) from these systems is independent of the physiological factors of the gastrointestinal (GI) tract to a large extent. In the present review, theory underlying the Delivery of Drugs from osmotic systems is presented. Different types of Oral osmotic systems, their advantages over conventional matrix and reservoir types of systems, and their applications are also discussed. Finally, some of the limit...
N. Kurjakovic - One of the best experts on this subject based on the ideXlab platform.
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A pH-Dependent Colon-Targeted Oral Drug Delivery System Using Methacrylic Acid Copolymers. II. Manipulation of Drug Release Using Eudragit® L100 and Eudragit S100 Combinations
Drug development and industrial pharmacy, 2000Co-Authors: M. Z. I. Khan, H. P. Stedul, N. KurjakovicAbstract:Tablets containing mesalazine as a model Drug were coated using various combinations of two methacrylic acid copolymers, (Eudragit® L100 and Eudragit S100) by spraying from aqueous systems. The Eudragit L100–Eudragit S100 (w/w) combinations studied were 1:0, 4:1, 3:2, 1:1, 2:3, 1:4, 1:5, and 0:1. The coated tablets were tested in vitro for their suitability for pH-dependent colon-targeted Oral Drug Delivery. The dissolution profiles of the Drug obtained from the studied tablets demonstrate that the release of the Drug could be manipulated by changing the Eudragit L100–Eudragit S100 ratios in the combinations within the pH range between 6.0 and 7.0 in which the individual polymers are soluble, and a coating formulation consisting of a combination of the two polymers can overcome the issue of high gastrointestinal (GI) pH variability among individuals. The results also demonstrate the feasibility of using aqueous dispersions of Eudragit L100–Eudragit S100 combinations for coating tablets for colon-targeted ...
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a ph dependent colon targeted Oral Drug Delivery system using methacrylic acid copolymers i manipulation of Drug release using eudragit l100 55 and eudragit s100 combinations
Journal of Controlled Release, 1999Co-Authors: Zahirul M I Khan, željko Prebeg, N. KurjakovicAbstract:Abstract Lactose-based placebo tablets were coated using various combinations of two methacrylic acid copolymers, Eudragit® L100-55 and Eudragit® S100, by spraying from aqueous systems. The Eudragit® L100-55–Eudragit® S100 combinations (w/w) studied were 1:0, 4:1, 3:2, 1:1, 2:3, 1:4, 1:5 and 0:1. The coated tablets were tested in vitro for their suitability for pH dependent colon targeted Oral Drug Delivery. The same coating formulations were then applied on tablets containing mesalazine as a model Drug and evaluated for in vitro dissolution rates under various conditions. The disintegration data obtained from the placebo tablets demonstrate that disintegration rate of the studied tablets is dependent on: (i) the polymers combination used to coat the tablets, (ii) pH of the disintegration media, and (iii) the coating level of the tablets. Dissolution studies performed on the mesalazine tablets further confirmed that the release profiles of the Drug could be manipulated by changing the Eudragit® L100-55 and Eudragit® S100 ratios within the pH range of 5.5 to 7.0 in which the individual polymers are soluble respectively, and a coating formulation consisting of a combination of the two copolymers can overcome the issue of high gastrointestinal (GI) pH variability among individuals. The results also demonstrated that a combination of Eudragit® L100-55 and Eudragit® S100 can be successfully used from aqueous system to coat tablets for colon targeted Delivery of Drugs and the formulation can be adjusted to deliver Drug at any other desirable site of the intestinal region of the GI tract on the basis of pH variability. For colon targeted Delivery of Drugs the proposed combination system is superior to tablets coated with either Eudragit® L100-55 or Eudragit® S100 alone.
Tejal A Desai - One of the best experts on this subject based on the ideXlab platform.
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fabrication of sealed nanostraw microdevices for Oral Drug Delivery
ACS Nano, 2016Co-Authors: Cade B. Fox, Hariharasudhan D. Chirra, Yuhong Cao, Nicholas A. Melosh, Cameron L Nemeth, Rachel W Chevalier, Tejal A DesaiAbstract:The Oral route is preferred for systemic Drug administration and provides direct access to diseased tissue of the gastrointestinal (GI) tract. However, many Drugs have poor absorption upon Oral administration due to damaging enzymatic and pH conditions, mucus and cellular permeation barriers, and limited time for Drug dissolution. To overcome these limitations and enhance Oral Drug absorption, micron-scale devices with planar, asymmetric geometries, termed microdevices, have been designed to adhere to the lining of the GI tract and release Drug at high concentrations directly toward GI epithelium. Here we seal microdevices with nanostraw membranes—porous nanostructured biomolecule Delivery substrates—to enhance the properties of these devices. We demonstrate that the nanostraws facilitate facile Drug loading and tunable Drug release, limit the influx of external molecules into the sealed Drug reservoir, and increase the adhesion of devices to epithelial tissue. These findings highlight the potential of na...
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microfabricated devices for enhanced bioadhesive Drug Delivery attachment to and small molecule release through a cell monolayer under flow
Small, 2009Co-Authors: Kristy M Ainslie, Rachel D Lowe, Tristan T Beaudette, Lamar Petty, Eric M Bachelder, Tejal A DesaiAbstract:The development of a novel microfabricated device for Oral Drug Delivery that overcomes many of the common barriers present in the gastrointestinal tract is reported. Specifically, the attachment of targeting ligands, subsequent device binding, and small molecule release from the microdevices in flow are investigated. A diffusion chamber that permits the simultaneous study of particle binding and small-molecule release under physiologically relevant shear conditions is developed. It is observed that once the particles bind to the cell surface, they remain attached. A small fraction of the devices detach in flow; however, most of these devices readily reattach to the cell layer in a new location. This steady-state density of microdevices is most likely the result of larger order microdevice clusters releasing their loose interactions with nearby microdevices, shifting slightly downstream, and subsequently reattaching to the cell monolayer. The release of a model small molecule from microdevices over time is roughly linear and approximately ten times greater than that observed with the small molecule alone. Overall, the preparation and characterization of an Oral Drug-Delivery microdevice system capable of both targeting and asymmetric release in flow is reported.
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bioadhesive microdevices with multiple reservoirs a new platform for Oral Drug Delivery
Journal of Controlled Release, 2002Co-Authors: Aamer Ahmed, Tejal A Desai, Chris BonnerAbstract:A variety of Delivery systems have been devised, in recent years, to improve the Oral bioavailability of Drugs including enterically coated tablets, capsules, particles, and liposomes. Microfabrication technology may offer some potential advantages over conventional Drug Delivery technologies. This technology, combined with appropriate surface chemistry, may permit the highly localized and unidirectional release of Drugs, permeation enhancers, and/or promoters. In this study, we demonstrate the fabrication of prototype reservoir-containing microdevices and a surface chemistry protocol that can be used to bind lectin via avidin-biotin interactions to these micromachined Drug Delivery vehicles. The use of microfabrication allows one to tailor the size, shape, reservoir volume, and surface characteristics of the Drug Delivery vehicle. In vitro studies show enhanced bioadhesion of these lectin conjugated silicon microdevices. This approach may be used to improve the absorption of pharmacologically active biopolymers such as peptides, proteins and oligonucleotides into circulation at targeted sites in the GI system via the creation of a robust hybrid organic/inorganic Delivery system. This paper describes one of the first applications of microfabrication to Oral Drug Delivery.
Jouni Hirvonen - One of the best experts on this subject based on the ideXlab platform.
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multifunctional nanotube mucoadhesive poly methyl vinyl ether co maleic acid hydroxypropyl methylcellulose acetate succinate composite for site specific Oral Drug Delivery
Advanced Healthcare Materials, 2017Co-Authors: Nattha Kerdsakundee, Joao Pedro Martins, Zehua Liu, Feng Zhang, Marianna Kemell, Alexandra Correia, Yaping Ding, Mikko Airavaara, Jouni HirvonenAbstract:An advanced Oral Drug Delivery system that can effectively deliver Drugs with poor Oral bioavailability is strongly desirable. Herein, a multifunctional nano-in-micro structured composite is developed by encapsulation of the mucoadhesive poly(methyl vinyl ether-co-maleic acid) modified halloysite nanotubes (HNTs) with the pH-responsive hydroxypropyl methylcellulose acetate succinate by the microfluidics to control the Drug release, increase cell–particle interaction, and improve Drug absorption. The microparticles show spherical shape, homogeneous particle size distribution (58 ± 1 µm), and pH-responsive dissolution behavior at pH > 6, and they prevent the premature release of curcumin in simulated pH conditions of the stomach and immediately release the curcumin in simulated pH conditions of the small intestine. The surface modification of HNT with mucoadhesive poly(methyl vinyl ether-co-maleic acid) significantly enhances its interactions with the intestinal Caco-2/HT29-MTX cells and the mouse small intestines, and increases the permeability of curcumin across the co-cultured Caco-2/HT29-MTX cell monolayers by about 13 times compared to the free curcumin. Therefore, the developed multifunctional nanotube–mucoadhesive poly(methyl vinyl ether-co-maleic acid)@hydroxypropyl methylcellulose acetate succinate composite is a promising Oral Drug Delivery system for Drugs with poor Oral bioavailability.
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the mucoadhesive and gastroretentive properties of hydrophobin coated porous silicon nanoparticle Oral Drug Delivery systems
Biomaterials, 2012Co-Authors: Mirkka Sarparanta, Ermei Makila, Jarno Salonen, Luis M Bimbo, Paivi Laaksonen, A Kerttuli M Helariutta, Markus Linder, Jouni Hirvonen, Timo Laaksonen, Helder A SantosAbstract:Impediments to intestinal absorption, such as poor solubility and instability in the variable conditions of the gastrointestinal (GI) tract plague many of the current Drugs restricting their Oral bioavailability. Particulate Drug Delivery systems hold great promise in solving these problems, but their effectiveness might be limited by their often rapid transit through the GI tract. Here we describe a bioadhesive Oral Drug Delivery system based on thermally-hydrocarbonized porous silicon (THCPSi) functionalized with a self-assembled amphiphilic protein coating consisting of a class II hydrophobin (HFBII) from Trichoderma reesei. The HFBII-THCPSi nanoparticles were found to be non-cytotoxic and mucoadhesive in AGS cells, prompting their use in a biodistribution study in rats after Oral administration. The passage of HFBII-THCPSi nanoparticles in the rat GI tract was significantly slower than that of uncoated THCPSi, and the nanoparticles were retained in stomach by gastric mucoadhesion up to 3 h after administration. Upon entry to the small intestine, the mucoadhesive properties were lost, resulting in the rapid transit of the nanoparticles through the remainder of the GI tract. The gastroretentive Drug Delivery system with a dual function presented here is a viable alternative for improving Drug bioavailability in the Oral route.