Determination of pioglitazone hydrochloride in bulk and pharmaceutical formulations by HPLC and MEKC methods

High Performance Liquid Chromatographic (HPLC) and Micellar Electrokinetic Chromatographic (MEKC) methods have been developed for the determination of pioglitazone, a new englycemic antidiabetic agent. Pioglitazone and its unsaturated impurity were separated by MEKC in less than 7 min using a 43 cm x 50 microm i.d. uncoated fused-silica capillary with extended light path for better sensitivity (25 kV at 30 degrees C) and a background electrolyte (BGE) consisting of 20% acetonitrile (v/v) in 20 mM sodium borate buffer pH 9.3 containing 50 mM sodium dodecyl sulphate (SDS). The influence of various parameters on the separation such as pH of the buffer, SDS concentration, buffer concentration, organic modifiers, temperature and voltage were investigated. The MEKC method was compared with HPLC method using a 5 microm symmetry C18 column (250 x 4.6 mm i.d.) eluted with a mobile phase consisting of a mixture of 50% (v/v) acetonitrile and 10 mM potassium dihydrogen phosphate buffer, adjusting the pH to 6.0 with 0.1 M KOH. The HPLC method is capable of detecting all process related compounds, which may be present at trace levels in finished products. Both methods were fully validated and a comparison was made. The results confirm that the methods are highly suitable for its intended purpose.