Volume 6

October-December 2014

Formulation and evaluation of sustained release bilayer tablets of ramipril-7.5mg

Kotta Kranthi Kumar, K Kavitha, V Saikishore

Abstract:
The objective of this study was to design Ramipril sustain release bi layer tablets containing immediate release layer and sustain release layer. Tablets were prepared by wet granulation technique using various polymers such as Hydroxy propyl methyl cellulose (HPMC K 100), Sod.CMC, Xanthum gum and Guar gum as release rate retardant and tablets were evaluated for hardness, friability, weight variation, thickness and drug content uniformity. In vitro release studies were performed using USP type II apparatus (paddle method) in 900 mL of pH 6.8 at 50 rpm for 8 hours and compared with USP specification. In vitro release studies revealed that the release rate decreased with increase of polymer loading. The maximum drug release was found to be 98.9% over a period of 8 hours in Xanthum gum based tablets (F11). Drug release was analyzed using zero-order, first order, Higuchi and Korsmeyer-Peppas equations to explore and explain the mechanism of drug release from the bi layer matrix tablets. Mathematical analysis of the release kinetics indicated that release from the matrix tablets followed diffusion. So the bi-layer tablets could be a potential dosage form for delivering Ramipril.

Keywords: Ramipril, Bilayer Tablets, Hydrophilic Polymers, Wet Granulation.