Development and validation of a novel stability-indicating reverse phase HPLC method for the determination of sacubitril-valsartan premix stereoisomers: Cellulose tris(4-methyl benzoate) stationary phase.

A new stability indicating reverse phase HPLC method has been developed and validated as per International Conference on Harmonization guidelines for the determination of sacubitril-valsartan premix stereoisomers, namely, (2R)-valsartan, (2S,4S)-sacubitril, (2R,4S)-sacubitril, and (2R,4R)-sacubitril. Primarily, stability indicating separation study was done on reverse phase LC conditions; it was described by peak homogeneity of sacubitril-valsartan and its stereoisomers. Cellulose tris(4-methylbenzoate) packing column Chiralcel OJ-RH(150 mm × 4.6 mm), 5 μm provided better resolution than those of amylose based stationary phase's. Resolution between two arbitrary adjacent analyte was found to be more than 2.0 with 0.1% trifluoroacetic acid in water as mobile phase-A and mobile phase-B consisting of acetonitrile, methanol, and trifluoroacetic acid (90:10:0.1, v/v/v). Gradient elution was performed at a flow rate of 1.0 ml/min, column temperature 20°C, injection volume 10 μl, UV detection at 254 nm and run time was 52 min. The detector response linearity of stereoisomers found to be linear (R  ≥ 0.9998), limit of detection (0.290 μg/ml, 0.122 μg/ml, 0.123 μg/ml, and 0.124 μg/ml), and limit of quantification (0.878 μg/ml, 0.370 μg/ml, 0.373 μg/ml, and 0.375 μg/ml), respectively. Percentage recovery was found to be 98-105. Finally, the proposed method is user friendly and can be used in bulk drugs analysis.