Formulation and evaluation of combined tablet of drotaverine-hcl and piroxicam

Renal colic is a very painful condition in which patient suffers severe flank pain which is caused by obstruction of urinary tract through calculus. The treatment required both analgesic and spasmolytic action in addition to anti inflammatory action. Two drugs were used: drotaverine-HCl (anti spasmodic) and piroxicam in one tablet as fixed dose combination (FDC). Wet granulation method was used to formulate the tablet. The tablets were formed by using two formulations (F1 and F2). The tablet of formulation F1 couldn’t qualify the disintegration test with Dt time of 22 min (U.S.P limit NMT 15 min), because the formulation had contained gelatin as a binder which bounded the tablet so strongly that Dt time of the tablet had increased from the official limits. Formulation F2 passed the Dt test and qualify for further testing. The dissolution rate of F2 tablet for drotaverine-HCl is 92.73% (U.S.P. NLT 75%) and for piroxicam is 92.33%, (U.S.P. NLT 75%). This showed good release pattern of both drugs in (FDC). FTIR spectrophotometry studies had been conducted between drugs and excipients. The monographs of FTIR for drugs showed that they had separate peaks and there was no interaction and incompatibility among active ingredients. Hence the assay of drugs contents was above 90% (U.S.P limit is 90 to 110%). Similarly, the Formulation F2 had acceptable values (U.S.P.) for hardness, friability, weight variation, and drug content.