STRESS DEGRADATION STUDIES ON HYDROCHLOROTHIAZIDE AND LISINOPRIL USING VALIDATED STABILITY INDICATING HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC METHOD

A specific stability indicating high-performance thin-layer chromatographic method for analysis of hydrochlorothiazide and lisinopril in formulations was developed and validated. The method employed precoated silica gel 60F254 HPTLC as the stationary phase. The optimized mobile phase system consisted of acetic acid: methanol: toluene (4:3:8, V/V/V), that gave compact spots for lisinopril and hydrochlorothiazide at Rf of 0.29 and 0.68, at 220 nm, respectively. The drugs were subjected to various accelerated conditions. The peaks of degraded products under various accelerated conditions were well resolved from the peak of standard drug with different Rf values and drug was more susceptible to acidic degradation. Linear relationship was found in the range of 800–1800 and 800-2300ng/band for hydrochlorothiazide and lisinopril respectively. Various parameters were validated as per ICH guideline. Moreover, the method could effectively separate the drug from its degradation products; hence it can be employed as a stability indicating method.