INFLUENCE OF SOME FORMULATION FACTORS ON THE RELEASE OF FELODIPINE FROM EXTENDED RELEASE HYDROPHILIC MATRIX TABLETS

In this paper we have studied the influence of some variables on the release of felodipine from extended release hydrophilic matrix tablets. The employed polymers for the extension of the release were: hydroxypropylmethylcellulose (Methocel E4MCR and Methocel K100M) and polyethylene oxide (Polyox WSR Coagulant). For this purpose a reduced experimental design with 3 variables and 2 levels was used. The studied formulation variables were: the percent of polymers, the type of hydroxypropyl-methylcellulose and the ratio between the polymers in the tablet. From the obtained results it was concluded that the most important variable on the release of felodipine was the percent of polymers in the tablet. From the experimental data, an optimal formulation was developed, which has proved to be similar with the dissolution profile of the chosen reference product.