Abstract

FORMULATION DEVELOPMENT OF VALSARTAN TABLETS EMPLOYING ? CD, CROSPOVIDONE AND SLS: OPTIMIZATION BY 23 FACTORIAL DESIGN

Ch. Tarakaramarao and K. P. R. Chowdary*

Abstract

Valsartan, a widely prescribed anti hypertensive drug belongs to class II under BCS classification and exhibit low and variable oral bioavailability due to its poor aqueous solubility. Because of poor aqueous solubility and dissolution rate it poses challenging problems in its tablet formulation development. It needs enhancement in the dissolution rate in its formulation development. Complexation with β- cyclodextrin (βCD) and use of Crospovidone and SLS are tried in the present study for enhancing the dissolution rate of Valsartan in its formulation development. The objective of the present study is optimization of Valsartan tablet formulation with NLT 85% dissolution in 10 min employing βCD, Crospovidone and SLS by 23 factorial design. Eight valsartan tablet formulations employing selected combinations of the three Factors i.e., βCD, Crospovidone, and SLS as per 23 Factorial design were formulated and prepared by direct compression method. All the tablets prepared were evaluated for drug content, hardness, friability, disintegration time and dissolution rate characteristics. The dissolution rate (K1) values were analysed as per ANOVA of 23 Factorial design to find out the significance of the individual and combined effects of the three Factors involved on the dissolution rate of valsartan tablets formulated. The individual and combined effects of βCD, Crospovidone and SLS on the dissolution rate (K1) of valsartan tablets are highly significant (P Fab>Fabc> Fa> Fac> F1>Fc. The polynomial equation describing the relationship between the response i.e. percent drug dissolved in 10 min (Y) and the levels of β CD (X1) , Crospovidone (X2) and SLS (X3 ) based on the observed results is Y = 60.05 + 5.34 (X1) +33.88 (X2) –8.95 (X1 X2 ) -3.18 (X3) -2.38 (X1 X3) + 2.80 (X2 X3) + 1.95 (X1 X2 X3). Based on the above polynomial equation, the optimized valsartan tablet formulation with NLT 85% dissolution in 10 min could be formulated employing βCD at 1:3 ratio of drug: β CD, Crospovidone at 26.31% of drug content, and SLS at 1% of drug content. The optimized valsartan tablet formulation gave 85.86 % dissolution in 10 min fulfilling the target dissolution set. Formulation of valsartan tablets with NLT 85% dissolution in 10 min could be optimized by 23 Factorial design

Keywords: Valsartan tablets, Optimization, ?-cyclodextrin, Crospovidone, SLS, Factorial Design, Formulation development.