Quantitation of Ofloxacin, Tinidazole, Terbinafine Hydrochloride, and Clobetasol propionate in topical cream formulation by chromatographic methods

Abstract

A combination of Ofloxacin, Tinidazole, Terbinafine hydrochloride, and Clobetasol propionate is used for treatment, control, prevention, and improvement of bacterial and fungal skin infections. Two chromatographic methods (HPLC and HPTLC) were developed for the quantitative determination of these four drugs in their combined topical formulation. The HPLC method employed a C₁₈ (250 × 4.6 mm, 5 μ) column as a stationary phase and acetonitrile: 0.1% triethylamine (pH 3.5) with gradient elution as mobile phase. The chromatographic separation in HPTLC was carried out on precoated silica 60F₂₅₄ plates using toluene:ethyl acetate:methanol:triethylamine:formic acid (5:4:1:0.3:0.3 v/v/v/v/v) as mobile phase. Both methods used 238 nm as detection wavelength and were able to separate all four drugs with resolved and sharp peaks. Developed methods were validated as per ICH Q2(R1) guidelines. Both methods were found to be linear in selected ranges (r² > 0.998), precise (RSD < 2%), accurate (recovery > 99.5%), sensitive and specific for quantitation of all four drugs. Validated methods were successfully applied for the quantitative determination of four drugs in the cream formulation and assay results were found to be in good agreement with the stated amount of each drug. Assay results were statistically compared (t-test) and no significant difference was observed (p > 0.05) between the results obtained by both methods.

Graphical Abstract

Keywords:

• Clobetasol
• HPLC
• HPTLC
• ofloxacin
• terbinafine
• tinidazole

Acknowledgments

The authors are thankful to Cadila Pharmaceuticals, Ahmedabad, India for providing the gift samples of Ofloxacin, Tinidazole, Terbinafine hydrochloride, and Clobetasol propionate standards to support the present work. The authors also acknowledge Spinco Biotech Pvt. Ltd., Ahmedabad, and AIC-LMCP Foundation, Ahmedabad for providing technical and instrumental support.