Development and Evaluation of Floating Sustained Release Bilayer Tablets Containing Drotaverine HCl

Bilayer floating tablets of Drotaverine HCL were developed by direct compression method. Immediate release layer contains 20 mg of drug and super disintegrant sodium starch glycolate, serves the purpose of loading dose. Sustained release layer contained HPMC K100, natural polymers like xanthan gum, guar gum, karaya gum release the drug for 12 hours’ time. Sodium bicarbonate and citric acid are used to produce effervescence. Floating lag time of optimized tablet is 92 sec, whereas floating duration is more than 12 hours. FTIR results revealed that there was no interaction between drug and HPMC K100 / xanthan gum. The post compression parameters of developed tablets were found to be satisfactory. In this study, it was confirmed that the formulations containing HPMC K100, have shown better floating properties and finally the formulation containing a combination of HPMC K100 and xanthan gum in 3:1 ratio, has exhibited decent sustained drug release properties. The release kinetics of optimized formulation prepared with the combination of HPMC K100 and xanthan gum followed zero order kinetics.