FORMULATION AND IN VITRO EVALUATION OF FLOATING TABLET OF HYDROXY PROPYL METHYL CELLULOSE, XANTHAN GUM AND CARBOPOL 934P USING ZIDOVUDINE AS A MODEL DRUG

Aswathy C.* and Ajith Chandran

ABSTRACT

The present study demonstrated successful development of effervescent based floating tablets by employing gel forming polymers and effervescent couple as a promising approach to increase the gastric residence time and drug release up to 24 hrs there by reducing the dosing frequency. Floating tablets are prepared by direct compression method by using different polymers like hydroxyl propyl methyl cellulose, Xanthan gum, and Carbopol 934 P. The sodium bi carbonate and citric acid were used as the gas generating agents. The powder blend was subjected to precompressional parameters. The prepared tablets are evaluated for post compressional parameters such as hardness, friability, weight variation, thickness, drug content, lag time, buoyancy time, in vitro dissolution studies, and swelling index and stability studies as per ICH guidelines at 40±20c/75±5% RH for 3 months. All the pre and post compressional parameters were within the acceptable limits. The values of invitro buoyancy time ranges from 3 hrs. to 24 hrs. whereas floating lag time ranges from 10-40 seconds. The in vitro drug release study reveals that formulation F1-F4 containing different grades of HPMC in which HPMC K100M was able to sustain up to 24 hours without effervescent couple. Formulation F5 containing HPMC K100 M and effervescent couple shows initially burst release indicate insufficient amount of polymer. Formulations F6-F9 contains Carbopol 934P and F10-F13 contains Xanthan gum gives sustained release. The formulation F9 shows maximum drug release at the end of 24 hrs and the release kinetics of F9 follows Korsemeyer peppas model.

Keywords: Floating tablets, controlled release, HPMC K 100M, Carbopol 934 P, Xanthan gum, effervescent couple.