The objective of this study was to formulate and optimize taste masked rapidly disintegrating tablet of intensely bitter drug tramadol hydrochloride by 32 factorial design. The drug polymer complex was prepared by coacervation method using aminoalkyl methacrylate copolymer (Eudragit EPO) as polymer and sodium hydroxide as precipitant and characterized for molecular properties, drug content, in vitro dissolution and taste evaluation. Drug polymer complex with a ratio of 1:8 was selected based on no release in phosphate buffer pH 6.8 showing successful taste masking of drug. Bitterness score was evaluated by human gustatory sensation test. The bitterness score of drug polymer complex was decreased as compared to tramadol hydrochloride. Optimized drug polymer complex was characterized and used for preparation of rapidly disintegrating tablet using menthol as subliming agent and crospovidone as superdisintegrant by applying 32 factorial design. Rapidly disintegrating tablet were evaluated for disintegration time, weight variation, friability and dissolution studies. Best fit equations for optimization purposes of disintegration time (Y ), % cumulative drug release in 5 min in pH 1.2 (Q min pH 1.2) (Y ) and % cumulative release after 5 min in 1 5 2 phosphate buffer pH 6.8 (Q min pH 6.8) (Y ) were obtained. Findings of this study demonstrated successful masking of taste by DPC. Experimental design study 5 3 revealed that the dependent variables strongly depended (p<0.05) on the independent variables. It is thus concluded that by adopting a systematic formulation approach, an optimum point can be reached in the shortest time with minimum efforts.
Keywords: Tramadol HCl, Eudragit EPO, Drug polymer complex, factorial design, taste masking.