Development of Carbomer Based Controlled Release Matrix Tablet of Atorvastatin and Evaluation of their Buoyancy and Release Pattern

Atorvastatin Tablet is one of the best selling drugs in the world, but still it suffers inadequate bioavailability problem from oral dosage. An attempt was taken to evaluate the floating drug delivery system for Atorvastatin by incorporating it in different grades of Carbomer matrix. Direct compression technique was selected and different once daily formulations were designed. The tablets were successfully floated over prolonged time and released the drug at a controlled fashion depending on the grade and quantity of Carbomer used. The tablets were evaluated for different physical tests including weight variation, friability, hardness, diameter and thickness. The compatibility between drug and polymers were confirmed by FT-IR spectra. Buoyancy characteristics of the tablets were determined by observing lag time, swelling index and total buoyancy period. The mechanism of drug release from the matrixes was assumed by fitting the release profile with different mathematical equations. Formulation F-5 and F-10 were found to release the drug at most sustaining manner and also had the longest total floating time.