Application of a Stability-Indicating Densitometric RP-TLC Method for Analysis of Pioglitazone Hydrochloride in the Bulk Material and in Pharmaceutical Formulations

Pioglitazone hydrochloride is an oral anti-hyperglycemic agent used for treatment of type-II diabetes. This paper reports a stability-indicating densitometric RP-TLC method for analysis of pioglitazone hydrochloride in the bulk material and in pharmaceutical formulations. Use of aluminum foil plates coated with silica gel 60 RP-18 F254s and acetone—water—acetic acid 4:1:0.1 (v/v) as mobile phase resulted in a compact band for pioglitazone hydrochloride (RF 0.68 ± 0.02). UV densitometric detection was performed at 225 nm. The method was highly sensitive with good linearity over the concentration range 500–3000 ng per band. The method was validated for accuracy, precision, recovery, and robustness. LOD and LOQ were 46.62 and 141.30 ng, respectively. Pioglitazone hydrochloride was subjected to acid and alkaline hydrolysis, oxidation, and photochemical and thermal degradation. The drug was degraded under all these conditions. Statistical analysis proved the method enabled repeatable, selective, and accurate analysis of the drug. Because the method could effectively separate the drug from its degradation products, it can be regarded as stability-indicating.