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Progress in Controlled Gastroretentive Delivery Systems
R Garg, GD Gupta
Tropical Journal of Pharmaceutical Research , 2008,
Abstract: Controlled release (CR) dosage forms have been extensively used to improve therapy with several important drugs. However, the development processes are faced with several physiological difficulties such as the inability to restrain and localize the system within the desired region of the gastrointestinal tract and the highly variable nature of the gastric emptying process. This variability may lead to unpredictable bioavailability and times to achieve peak plasma levels. On the other hand, incorporation of the drug in a controlled release gastroretentive dosage forms (CR-GRDF) which can remain in the gastric region for several hours would significantly prolong the gastric residence time of drugs and improve bioavailability, reduce drug waste, and enhance the solubility of drugs that are less soluble in high pH environment. Gastroretention would also facilitate local drug delivery to the stomach and proximal small intestine. Thus, gastroretention could help to provide greater availability of new products and consequently improved therapeutic activity and substantial benefits to patients. Controlled gastric retention of solid dosage form may be achieved by the mechanisms of floatation, mucoadhesion, sedimentation, expansion or by a modified shaped system. The purpose of this paper is to review the recent literature and current technology used in the development of gastroretentive dosage forms.
Design and Evaluation of Polyox and Pluronic Controlled Gastroretentive Delivery of Troxipide  [PDF]
Swati C. Jagdale,Shraddha B. Kamble,Bhanudas S. Kuchekar,Aniruddha R. Chabukswar
Journal of Drug Delivery , 2014, DOI: 10.1155/2014/804616
Abstract: Objective. Objective of the present work was to develop site-specific gastroretentive drug delivery of Troxipide using polymers Pluronic F127 and Polyox 205?WSR. Troxipide is a novel gastroprotective agent with antiulcer, anti-inflammatory, and mucus secreting properties with elimination half-life of 7.4?hrs. Troxipide inhibits H. pylori-derived urease. It is mainly absorbed from stomach. Methods. 32 factorial design was applied to study the effect of independent variable. Effects of concentration of polymer on dependant variables as swelling index, hardness, and % drug release were studied. Pluronic F127 and Polyox 205?WSR were used as rate controlled polymer. Sodium bicarbonate and citric acid were used as effervescent-generating agent. Results. From the factorial batches, it was observed that formulation F5 (19% Pluronic F127 and 80% Polyox 205?WSR) showed optimum controlled drug release (98.60%?±?1.82) for 10?hrs with ability to float >12?hrs. Optimized formulation characterized by FTIR and DSC studies confirmed no chemical interactions between drug and polymer. Gastroretention for 6?hrs for optimized formulations was confirmed by in vivo X-ray placebo study. Conclusion. Results demonstrated feasibility of Troxipide in the development of gastroretentive site-specific drug delivery. 1. Introduction Oral controlled release dosage forms have been developed over the past three decades due to their considerable therapeutic advantages such as ease of administration, patient compliance, and flexibility in formulation. Gastroretentive dosage form can remain in the gastric region for several hours and hence significantly prolong the gastric residence time of drugs. Prolonged gastric retention improves bioavailability, reduces drug wastage, and improves solubility of drugs that are less soluble in a high pH environment. It is also suitable for local drug delivery to stomach and proximal small intestine. Several approaches have been attempted in the preparation of gastroretentive drug delivery system as floating, swellable and expandable, high density, bioadhesive, altered shape, gel forming solution or suspension system and sachet systems [1–3]. In case of certain drug candidate, greater therapeutic value is achieved by increasing the gastric retention time. Some examples include drugs absorbed from the proximal part of the gastrointestinal tract, for example, diltiazem; drugs that get degraded in intestinal alkaline pH, for example, bromocriptine; drugs that are absorbed primarily in the stomach, for example, albuterol; and drugs that degrade in the colon,
Mucoadhesive: As Oral Controlled Gastroretentive Drug Delivery System  [PDF]
Nikalje Anna Pratima,Shailee Tiwari,Smrutigandha Kamble
International Journal of Research in Pharmacy and Science , 2012,
Abstract: Mucoadhesion is a field of current interest in the design of drug delivery systems. Mucoadhesive drugdelivery system prolong the residence time of the dosage form at the site of application or absorptionand facilitate an intimate contact of the dosage form with the underline absorption surface and thuscontribute to improved and / or better therapeutic performance of the drug. In recent years many suchmucoadhesive drug delivery systems have been developed for oral, buccal, nasal, rectal and vaginalroutes for both systemic and local effects. In this paper main prominence on gastrointestinal dosageforms along with concepts, mechanism of mucoadhesion, factors affecting mucoadhesion, permeationenhancers and evaluation methods and also some review regarding research work already been carried.An overview of the last decade’s discoveries on mucoadhesion and applications of mucoadhesive asdrug carriers is given. Mucoadhesive drug delivery systems with its various advantages have a lot ofpotential in formulating dosage forms for various chronic diseases.
Makwana Ami,Sameja Krunal,Parekh Hejal,Pandya Yogi
Journal of Drug Delivery and Therapeutics , 2012,
Abstract: Oral delivery of the drug is by far the most preferable route of drug delivery due to the ease of administration, patient compliance and flexibility in the formulations but has a drawback of non-site specificity and short gastric resident time. In order to overcome the drawbacks of conventional oral drug delivery systems, several technical advancements have led to the development of gastro retentive drug delivery system that could revolutionize method of medication and provide a number of therapeutic benefits. In order to understand various physiological difficulties to achieve gastric retention, we have summarized important factors controlling gastric retention. Afterwards, we have reviewed various gastroretentive approaches designed and developed until now, i.e. floating drug delivery system(FDDS), bio- or mucoadhesive system, expandable, unfoldable system, high density system, raft forming system, super porous hydrogel system and magnetic systems. Among these systems, FDDS have been most commonly used. Finally, advantages, disadvantages, evaluation, marketed preparation and future potential of gastro retentive drug delivery systems were covered.
Shiva Kumar Yellanki
International Journal of Pharmaceutical Research and Development , 2010,
Abstract: The aim of the current study was to design a porous osmotic pump-based drug delivery system for controlled release of Metoprolol Tartrate. Based on the principles of an elementary osmotic pump (OP), OP tablets were designed and evaluated with the aim to deliver Metoprolol Tartrate (MT) in a controlled manner. The tablets were prepared by direct compression method. Effects of coating thickness, surface porosity and viscolyzing polymer were studied. Optimization results indicated that MT release was inversely proportional to the membrane thickness and viscolyzing polymer; however directly proportional to the surface porosity of the membrane, respectively. It was concluded that the osmotic pump tablets could provide more prolonged and controlled MT release that may result in an improved therapeutic efficacy and patient compliance
Stomach Specific Mucoadhesive Tablets As Controlled Drug Delivery System – A Review Work
G.C.Rajput,Dr. F.D.Majmudar,Dr.J.K.Patel,K.N.Patel
International Journal of Pharmaceutical and Biological Research , 2010,
Abstract: Stomach-specific mucoadhesive tablets as a controlled drug delivery system have been developed to increase gastric retention time of the dosage forms. This article presents the polymers use for mucoadhesive tablets, factor affecting the mucoadhesion, and developments in the techniques for in vitro and in vivo evaluation of mucoadhesive tablets have also been discussed.
Bhalla.Neetika,Deep Arsh,Goswami Manish
International Research Journal of Pharmacy , 2012,
Abstract: In recent years scientific and technological advancements have been made in the research and development of oral drug delivery system. Oral sustained drug delivery system is complicated by limited gastric residence times (GRTs). In order to understand various physiological difficulties to achieve gastric retention, we have summarized important factors controlling gastric retention. To overcome these limitations, various approaches have been proposed to increase gastric residence of drug delivery systems in the upper part of the gastrointestinal tract includes floating drug dosage systems (FDDS), swelling or expanding systems , mucoadhesive systems , magnetic systems, modified-shape systems, high density system and other delayed gastric emptying devices.
The Role of Oral Controlled Release Matrix Tablets in Drug Delivery Systems  [cached]
Ali Nokhodchi,Shaista Raja,Pryia Patel,Kofi Asare-Addo
BioImpacts , 2012,
Abstract: Formulations that are able to control the release of drug have become an integral part of the pharmaceutical industry. In particular oral drug delivery has been the focus of pharmaceutical research for many years. This type of drug delivery has been at the centre of research due to its many benefits over conventional dosage. The focus of this review is on matrix tablets due to their widely use and simplicity of the formulation. This includes the discussion of various types of matrix tablets and factors affecting the drug release from these formulations. The mechanism of drug release from HPMC matrices is also discussed.
Design and optimization of levofl oxacin gastroretentive tablets  [cached]
D. Nagendrakumar, S.B. Shirsand, M.S. Para, A.D. Chauhan
RGUHS Journal of Pharmaceutical Sciences , 2012,
Abstract: In the present study, gastroretentive floating tablets of levofl oxacin hemihydrate were designed with objective of retention of tablet in acidic pH to improve bioavailability with reduction in dosing frequency. Hydroxypropyl methyl cellulose of different viscosity grades (K4M and K100LV) was used as polymer and sodium bicarbonate as gas generating agent to reduce floating lag time. Tablets were prepared by direct compression method. The prepared formulations were evaluated for hardness, friability, weight variation, drug content, swelling index, in-vitro drug release, short-term stability, floating lag time and in-vitro buoyancy. A 32 factorial design was applied to systematically optimize the drug release profi le. The proportions of release retardant material HPMC K100LV(X1), sodium bicarbonate (X2) were selected as independent variables and t50% (Y1), and t70% (Y2) were selected as dependent variables. The promising formulation containing levofl oxacin hemihydrate (100 mg), HPMC K100LV (100 mg) and sodium bicarbonate (80 mg) has t50% (5.95 h), t70% (8.52 h), floating lag time was only 10.33 sec and released more than 90% drug in 12 h. This study proved that gastroretentive drug delivery system of levofl oxacin hemihydrate was designed using HPMC K100LV, which provided excellent gastroretentive property, thus improved the bioavailability of drug
Dahiya Amarjeet,Rohilla Ankur,Rohilla Seema,Khan M.U
International Research Journal of Pharmacy , 2011,
Abstract: Gastroretentive drug delivery system has been a significant approach over the past few years that have been noted to prolong gastric residence time, thereby targeting site-specific drug release in the upper gastrointestinal (GI) tract for local or systemic effects. The present study has been investigated to compile the recent as well as past literature with special focus on various gastroretentive approaches that have recently become leading methodologies in the field of site-specific orally administered controlled release drug delivery. Floating systems have been considered as one of the imperative categories of drug delivery systems with gastric retentive behavior. The review article explains the various floating drug delivery systems that are formulated in order to enhance the drug bioavailability. Moreover, various gastroretentive approaches designed and developed such as high density, floating, bioadhesive, super porous hydrogel and magnetic systems have been clearly discussed in the article.
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