Comparative determination of miconazole, nystatin, hydrocortisone and neomycin by HPTLC/HPLC-DAD

Two new validated methods for the quantification of miconazole (MIC), nystatin (NYS), hydrocortisone acetate (HCA) and neomycin (NS) by high performance thin layer chromatography (HPTLC)-densitometry and reverse-phase high-performance liquid chromatography procedure coupled with photodiode array detector (RP-HPLC-DAD) were developed and compared. HPTLC separations were performed using a mobile phase, ethylacetate:methanol:glacial acetic acid (60:40:0.4, v:v:v) for MIC, NYS, HCA and ethylacetate for NS. For HPLC-DAD analysis, using an isocratic elution system, separation of all compounds was achieved. Good resolution and quantization were achieved, accuracy and precision, as well as detection and quantitation limits of the two methods, were evaluated and compared. Excellent linearity was observed for all of the standard calibration curves, and the correlation coefficients were above 0.9997. HPTLC limits of quantitation were 15.37×10-2, 9.8×10-2, 13.32×10-2 and 15.19×10-2 μg/mL for MIC, NYS, HCA and NS respectively, whereas HPLC limits were 6.80×10-2, 6.56×10-2, 1×10-1 and 10.16×10-2 μg/band for MIC, NYS, HCA and NS respectively. In comparison with HPLC, HPTLC is less expensive and faster procedure, requiring 2-3 h to analyse 10-12 samples on a single plate. The developed methods were proved to be specific, robust and accurate for the determination of cited drugs in pharmaceutical preparations.