A Rapid and Sensitive LC Method for Determination of Diastereomeric Purity of Tenofovir Alafenamide

A rapid and sensitive LC method was developed and validated for the determination of diastereomeric purity of tenofovir alafenamide (GS-7340). Baseline separation with resolution >2.8 was achieved within 17 min on a CHIRALPAK AD-3 (250 × 4.6 mm; particle size 3 μm) column using n-hexane:2-propanol (60:40 v/v) as the mobile phase at a flow rate of 1 mL min^?1. The analytes were detected by UV absorbance at 260 nm. The effects of ethanol, 2-propanol, and temperature on diastereomeric selectivity and resolution of diastereomerism were evaluated. The method was extensively validated and proved to be robust. The recoveries were between 98.17 and 102.84 % with <1.93 % relative standard deviation. The limit of detection and limit of quantitation for GS-7339 were 0.77 and 2.56 μg mL^?1 and for GS-7340 were 0.61 and 2.04 μg mL^?1, respectively. This method was extensively proved to be accurate, stable, rapid, and sensitive for the determination of diastereomeric purity of tenofovir alafenamide (GS-7340) in bulk samples.