Formulation and Characterization of Gastroretentive Floating Tablets of Atorvastatin Calcium Using Central Composite Design

Abstract

The aim of the study was to develop a gastroretentive floating drug delivery system of atorvastatin calcium by effervescence technique. Design/methodology/approach : The objective behind the study was to investigate the effect of concentration of HPMC K4M (X), concentration of guar gum (X), concentration of sodium bicarbonate (X) on the release of 1 2 3 atorvastatin calcium using central composite design.The floating tablets were formulated using atorvastatin calcium (20% w/w), HPMC K4M (5-15% w/w), guar gum (5-15% w/w), sodium bicarbonate (4-12% w/w), lactose (q.s.), talc (2% w/w) and magnesium stearate (1% w/w). Atorvastatin calcium floating tablets were evaluated for physical characterization viz. hardness, swelling index, floating capacity, weight variation, friability, in vitro drug release and kinetic studies. Findings : All tablets were floated for more than 12 hrs in 0.1 N HCl at 37±0.5°C and the in vitro drug release was found to be vary from 79% to 93%. The percentage cumulative drug released was maximum at low value of HPMC, low value of guar gum and high value of sodium bicarbonate. A mathematical model was developed to formulate floating tablets of atorvastatin calcium. The data fitting to Korsemeyer-Peppas equation revealed that the release mechanism from the dosage form followed the non-fickian transport. Value : The gastroretentive floating tablets of atorvastatin calcium will enhance the patient compliance and play a vital role in improving patient's quality of life.