Formulation optimization of gastroretentive drug delivery system for allopurinol using experimental design

Abstract

Introduction: The objective of the present investigation was to develop a multiparticulate modified release system of methylphenidate hydrochloride (HCl) generating biphasic release profile from single core. Materials and Methods: Wurster (bottom spray fluid bed coating) process was employed to develop extended release (ER) pellets of methylphenidate HCl. Impact of various formulation variables was assessed using statistical interpretation such as analysis of variance. A 3 2 (two factor, three level) factorial design was employed to study the effect of independent variables (ER polymer [Eudragit RSPO/ Eudragit RLPO/Ethocel] concentration and plasticizer concentration), on dependent variables (drug release at 3 rd and 8 th h). Optimization was done by fitting experimental data to the software program (Design Expert). The design space for formulation variables (ER polymer concentration and plasticizer concentration) and its influence on drug release was developed. Results and Discussion: Fabricated pellets were characterized for various physicochemical parameters. In vitro release data observed from the optimized formulation was fitted into various kinetic equations. The optimized formulation showed desired drug release at both 3 rd and 8 th h as 60.33% ± 0.58% and 93.33% ± 0.58%, respectively. Capsules showed an initial burst release preceding a more gradual ER phase following first order kinetics and Fickian diffusion process. Conclusion: Methylphenidate HCl ER pellets were successfully developed by employing bottom spray fluid bed coating (Wurster) technique. The factorial experimental design facilitated the formulation and optimization of modified drug delivery system of methylphenidate HCl.

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“…However, the effect of the polymer Badam gum was more pronounced than HPMC K4 M on bioadhesion strength since Badam gum has significant sticking property these findings are in agreement with previously reported results by Meka, et al, [23] who found the Badam gum has remarkable swelling and sticking character in gastric pH. [23][24][25][26][27][28][29][30][31][32][33] This developed floating-bioadhesive combination formulation would overcome the drawback of floating and bioadhesive individual system and improving the therapeutic effect of the drug involved.…”

“…Floating lag time and total floating duration (time during which tablet remains buoyant) were recorded. [25] In vitro drug release studies Drug release studies of the prepared floating bioadhesive tablets were performed, in triplicate, in a USP dissolution tester apparatus, type-II (Paddle method) (dissolution tester, electro lab) at 37 ± 0.50°C. The paddles rotated at a speed of 50 rpm.…”

“…From this mucoadhesive strength, the force of adhesion, i.e., the force required for separating the tablet from the tissue surface was calculated using the following formula. [24][25][26][27][28][29][30][31] Force of adhesion N = Bioadhesive strength 9.81…”

Preparation and evaluation of floating tablets of pregabalin

“…Gastro-retentive systems are usually appropriate for drugs having certain properties/limitations like local action, good absorption from stomach, poor aqueous solubility, unstability at alkaline pH and/or narrow absorption window 1,[5][6][7] .…”

“…Drug Dev Ind Pharm, Early Online:[1][2][3][4][5][6][7] Drug Dev Ind Pharm Downloaded from informahealthcare.com by Yale Dermatologic Surgery on 07/08/15For personal use only.…”