Stability-Indicating HPTLC Method of Carteolol in Bulk Drug and in Pharmaceutical Dosage Forms

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatography (HPTLC) method was developed and validated for analysis of carteolol both bulk drug and in formulation. The HPTLC method was chosen in order to generate better resolution and evade the tedious and prolonged sample preparation methods necessarily performed with HPLC methods when analyzing in samples. Carteolol was separated from the formulation on a silica gel 60F254 as the stationary phase. Elution was performed with mobile phase consisted of chloroform and methanol (5:1 v/v). Quantification of carteolol was carried out as per beak area observed from the densitometry at 254 nm absorbance mode. This system was found to give compact spots for carteolol (RF value of 0.31 ± 0.015, for three replicates). The method was validated for linearity, precision, robustness, limit of detection (LOD), limit of quantification (LOQ), specificity accuracy and degradation. Linearity was found to be in the range of 200–1200 ng spot−1 with significantly high value of correlation coefficient r2 = 0.997 ± 0.24. The linear regression analysis data for the calibration plots showed good linear relationship. The LOD and LOQ were 34.19 ± 0.58 ng spot−1 and 103.51 ± 1.34 ng spot−1, respectively. Carteolol was subjected to acid and alkali hydrolysis, oxidation and photo degradation. The degraded products were well resolved from the pure drug with significantly different RF values. Statistical analysis proves that the method is repeatable and specific for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating assay method.