Stability-indicating method development and validation for the concurrent determination of darunavir, cobicistat, emtricitabine and tenofovir alafenamide by UPLC in bulk and tablet dosage forms

Future Journal of Pharmaceutical Sciences

Table 4 Precision studies

Parameter	Results
Parameter	TAF	COBI	FTC	DRV
Method precision (for n = 6)
Mean %Assay	99.65	100.00	100.23	100.30
Mean % RSD of assay	0.2	0.8	0.3	0.9
System precision (for n = 6)
Mean of peak area	114,978	375,780	548,633	2,016,744
Mean % RSD of peak area	1.0	0.5	0.6	0.5
Intermediate precision (for n = 12)
Mean peak area	106,219	356,448	530,491	1,912,564
Mean % RSD of peak area	0.8	0.7	0.4	0.2

TAF tenofovir alafenamide, COBI cobicistat, FTC emtricitabine, DRV darunavir, % percentage, RSD relative standard deviation, n no. of determinations