Stability-Indicating Validated HPTLC Method for Simultaneous Estimation of Atazanavir Sulfate and Ritonavir in Pharmaceutical Dosage Form

A high-performance thin layer chromatography (HPTLC) method for Atazanavir Sulfate (ATV) and Ritonavir (RTV) was developed in the present work. The mobile phase selected was Ethyl acetate: Toluene: methanol (7.5: 2: 0.5 v/v/v) with UV detection at 234 nm. The standard solution ranging from 1000-7000ng/band was applied for ATV and standard solution ranging from 500-3500ng/band was applied for RTV. Linearity was observed in this concentration range on precoated silica gel 60 F₂₅₄ TLC plate in the form of bands with 100 μl sample syringe using automatic sample applicator LINOMAT V. After development, plate was immediately dried and was observed under UV chamber. The well resolved bands of drugs were scanned with Camag TLC scanner III densitometer controlled by WINCAT's software version 4. Retention factor for ATV and RTV were found to be 0.76 ± 0.95 and 0.54 ± 1.43 respectively. Drugs were subjected to oxidation, acid hydrolysis, base hydrolysis and sun light to apply stress condition for degradation studies. Results of analysis were validated statistically and by recovery studies.