Current Issue : January - March Volume : 2012 Issue Number : 1 Articles : 6 Articles
Famotidine is histamine H2-receptor antagonist widely used in the treatment of gastric ulcers. Famotidine is having a short biological half-life of 2.5-3.5 hrs. To overcome the multiple doses at short intervals of time due to short biological half-life and poor bioavailability of famotidine, it was formulated into gastroretentive floating tablets, employing a new floating polymer tamarind kernel gum and known polymers HPMC-K4M and HPMCK15M. Eventhough there are several floating polymers, there is a continuous need to develop new floating polymer for better buoyancy and controlled release of drug. Isolated tamarind kernel gum is off white, free flowing and amorphous in nature which is supported by XRD and micromeritic studies. The formulation employing tamarind kernel gum showed slow release i.e spread over 12hrs and followed first order kinetics with non fickian diffusion of drug release. Isolated tamarind gum is comparable to HPMC K-15M in floating and a drug release characteristics and it was found to be better than HPMC K4M. So it was concluded that tamarind kernel gum could be used as floating and controlled release polymer in the formulation of gastroretentive formulations....
The aim of present investigation is to enhance in vitro dissolution of poorly soluble drug albendazole by preparing solid dispersions using modified gum karaya (MGK). Solid dispersions of drug were prepared by solvent evaporation method using modified gum karaya as carrier. Four batches of solid dispersions (SD1, SD2, SD3 and SD4) and physical mixtures (PM1, PM2, PM3 and PM4) were prepared and characterized by differential scanning colorimetry (DSC), fourier transform infrared (FTIR) spectroscopy, powder x-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. Equilibrium solubility studies were carried out in shaker incubator for 24 h and in vitro drug release was determined using USP Dissolution Apparatus II. Result showed that batch SD2 showed maximum solubility and in vitro dissolution. No significant enhancement of dissolution characteristics were observed in the corresponding physical mixture (PM2). Low viscosity and comparable swelling characteristics of modified gum karaya may lead to improvement in dissolution behavior of solid dispersion batches. Also the conversion of crystalline form of drug to amorphous form may be a responsible factor which was further confirmed by DSC, FTIR studies and X-RD studies. SEM photographs of batch SD2 revealed porous nature of particle surface...
Guar acetate, a hydrophobic derivative of guar gum was synthesized by esterification with acetic anhydride and acetic acid using acid catalysts and evaluated for physicochemical properties. Plasticized and nonplasticized free films prepared by solvent evaporation method were tested for surface morphology, water vapour transmission and mechanical properties (tensile strength, percent elongation and modulus of elasticity). The films showed low tensile strength and high percent elongation values achieving smooth and uniform surface. Guar acetate was further characterized for film coating by evaluating the release of a model drug (diclofenac sodium) from pellets coated with guar acetate as retarding membrane. Drug release was sustained up to 8 h due to 20% w/w coat built up. Increase in coat-built-up further facilitated sustained release from coated forms. Film coating could be achieved without agglomeration of the pellets within a reasonable operating time. The present study proposes novel film forming materials with potential use in sustained drug delivery....
Numerous nanocarriers of various compositions and geometries have been developed for the delivery and release of therapeutic and imaging agents. Due to the high specific surface areas of nanocarriers, different mechanisms such as ion pairing and hydrophobic interaction need to be explored for achieving sustained release. Recently, we developed a three-parameter model that considers reversible drug-carrier interaction and first-order drug release from liposomes. A closed-form analytical solution was obtained. Here, we further explore the ability of the model to capture the release of bioactive molecules such as drugs and growth factors from various nanocarriers. A parameter study demonstrates that the model is capable of resembling major categories of drug release kinetics. We further fit the model to 60 sets of experimental data from various drug release systems, including nanoparticles, hollow particles, fibers, and hollow fibers. Additionally, bootstrapping is used to evaluate the accuracy of parameter determination and validate the model in selected cases. The simplicity and universality of the model and the clear physical meanings of each model parameter render the model useful for the design and development of new drug delivery systems....
A new poly(amidoamine)-cholesterol (PAA-cholesterol) conjugate was synthesized, characterized and used to produce nanoparticles by the electrospraying technique. The electrospraying is a method of liquid atomization that consists in the dispersion of a solution into small charged droplets by an electric field. Tuning the electrospraying process parameters spherical PAA-chol nanoparticles formed. The PAA-cholesterol nanoparticles showed sizes lower than 500?nm and spherical shape. The drug incorporation capacity was investigated using tamoxifen, a lipophilic anticancer drug, as model drug. The incorporation of the tamoxifen did not affect the shape and sizes of nanoparticles showing a drug loading of 40%. Tamoxifen-loaded nanoparticles exhibited a higher dose-dependent cytotoxicity than free tamoxifen, while blank nanoparticles did not show any cytotoxic effect at the same concentrations. The electrospray technique might be proposed to produce tamoxifen-loaded PAA-chol nanoparticle in powder form without any excipient in a single step....
Gastroretentive drug delivery system is an upcoming type of novel drug delivery system. The uniqueness of this technology is that, it remains in the upper part of the small intestine for a long period of time. Polymers play an important role in gastroretentive drug delivery system. Large number of derivatizable groups, wide range of molecular weights, varying chemical composition and gel forming nature of the polymers also provide an exciting opportunities in the fascinating arena of applied polymer science and drug delivery technology. All these characteristics make them suitable candidate for design and fabrication of gastroretentive drug delivery systems. The present article highlights various recent efforts and advanced approaches exploiting several polymers in this technology....
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