Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract

A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz^®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml⁻¹ for dipyrone and from 0.5–1.5 mg ml⁻¹ for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).

Keywords:

• Drugs
• partial least squares regression
• spectrophotometric determination

Acknowledgments

The authors would like to thank Prof. Carol H. Collins for her contributions and Jez W. Braga for his important advice in the development of this work. M.G.T was supported by CNPq, process no. 142111/2003‐1.