Publications (2)0.91 Total impact
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Article: Eudraginated polymer blends: a potential oral controlled drug delivery system for theophylline.
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ABSTRACT: 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.Acta Pharmaceutica 03/2012; 62(1):71-82. · 0.91 Impact Factor -
Article: Preparation and evaluation of colon targeted drug delivery systems for albendazole using kneading, extrusion and compaction technology.
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ABSTRACT: Albendazole is an orally administered broad-spectrum benzimidazole anthelmintic used against helminthiasis, hydatid cyst disease and neurocysticercosis. The objectives of this investigation are to develop a sustained release drug delivery system for albendazole, and to target its delivery to colon. Albendazole matrix tablets containing varying proportions of single and binary blends of four polymers; polyacrylic acid (carbopol 971), ethylcellulose (Etcell), eudragit L100-55 (EUD), and sodium carboxymethyl cellulose (CMC) were prepared by a modified wet granulation technique of kneading, extrusion and compaction. In vitro release profiles of albendazole was sequentially determined in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) without enzymes and in rat caecal content medium (RCCM) at 37 degrees C. The in vitro drug release from matrix tablets containing CMC and Etcell as single polymers showed initial burst effect in the first 2 h (>20% and 50% respectively), followed by a slow release in SIF. However, matrix tablets containing polymer blends showed that no appreciable drug release occurred up to 5 h. Drug release from tablets containing polymer blends in the dissolution medium containing rat caecal material suddenly increased to > or =30% after 5 h (RCCM), and reaching up to 90% in 24 h. Albendazole matrix tablets containing carbopol 971, Etcell, EUD, and CMC as single polymers and as blends were formulated for oral use. Drug release from the tablet matrices containing carbopol alone, binary blends of carbopol/Etcell, and CMC/EUD were found to be very slow and dependent on polymer concentration. Matrix tablets containing blends of these polymers formulated using kneading, extrusion and compaction technique could provide sustained drug release and can be utilized in the colonic delivery of albendazole.Yao xue xue bao = Acta pharmaceutica Sinica 10/2009; 44(10):1152-8.
