Simultaneous estimation of metformin and pioglitazone by ultraviolet spectrophotometry

This work deals with the simultaneous estimation of metformin hydrochloride and pioglitazone hydrochloride in a bilayered tablet dosage form, without prior separation by two techniques. The methods employed are derivative spectrophotometery and Q analysis. The absorption maxima at 231 nm and 269 nm were used for the estimation of metformin and pioglitazone, respectively. Both the drugs and their mixture obey Beer-Lamberts law at selected wavelength at given concentration range. The result of analysis has been validated statistically and recovery studies confirmed the accuracy of the proposed method. The proposed procedures are simple, rapid, require no separation steps and can be used for the routine analysis of both drugs.