Eco-friendly HPTLC method for simultaneous analysis of sofosbuvir and ledipasvir in biological and pharmaceutical samples: Stability indicating study

Recently, many single-pill combinations are used as a promising choice in hepatitis C treatment. However, this trend made a serious challenge to drug analysts due to difficulty of analysis of two or more drugs simultaneously. In this study, sofosbuvir (SF) and ledipasvir (LD) were simultaneously analyzed by developing a simple, inexpensive, rapid and eco-friendly high-performance thin layer chromatographic (HPTLC) method with densitometric detection. Separation was carried out using aluminum HPTLC plates silica gel 60 F254 as the stationary phase developed using the mobile phase ethyl acetate: methanol: water: glacial acetic acid (30: 1.5: 1: 0.2% v/v). Development was done in a twin-trough chamber followed by densitometric detection of SF and LD at 260 and 320 nm, respectively. The calibration curves for standard solutions showed a rectilinear relationship for SF and LD in the range of 2 -12 and 0.45-6.0 mu g band(-1), respectively with correlation coefficients > 0.9995 and limits of detection of 0.6 and 0.1 mu g band(-1) for SF and LD, respectively. While, calibration curves for biological samples showed linear relationships for SF and LD in the range of 1.0-20 and 0.2-6.0 mu g mL(-1), respectively with correlation coefficients > 0.99 and limits of detection of 0.21 and 0.27 mu g mL(-1) for SF in plasma and urine samples, respectively and 0.05 and 0.03 mu g mL(-1) for LD in plasma and urine samples, respectively. Also, it was effectively used in the analysis of the investigated drugs within their pharmaceutical form and biological fluids without any matrix interference with high precision (% RSD < 2%) and good accuracy with % Er value < 2%. Moreover, SF and LD were analyzed along with their degradation products after performing forced degradation studies.