A Validated Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Tenofovir, Emtricitabine, and a Efavirenz and Statistical Approach to Determine the Effect of Variables

Table 3

System suitability and linearity data for the proposed method.

Parameters	FTC	TDF	EFV
Retention time (%RSD)	2.0 (0.38)	5.0 (0.1)	7.7 (0.05)
USP tailing (% RSD)	0.9 (0.01)	1 (0.02)	0.9 (0.01)
USP resolution (% RSD)	—	20.8 (0.27)	22.9 (0.08)
USP plate count (% RSD)	1883.27 (5.84)	34246.96 (0.7)	9878.73 (4.49)
Linearity range (𝜇g mL^−1)	20–300	24.5–367.5	60–900
LOD (𝜇g mL^−1)	0.36	0.26	0.18
LOQ (𝜇g mL^−1)	1.19	0.85	0.61
Slope (±SD)	9162.85; (±27.23)	7941.53; (±25.84)	11530.82 (±128.26)
Intercept (±SD)	4074.06 (±2379.20)	−8620.11 (±2521.86)	248882.17 (±30661.19)
Slope without intercept	9182.91	7906.88	11939.32
Standard error of slope	74.08	71.61	149.85
Standard error of intercept	12265.46	14524.99	74438.21
95% confidence interval; of slope	8957.18–9368.52	7742.71–8140.35	11114.76–11946.88
95% confidence interval; of intercept	−29980.31–; 38128.43	−48947.95–31707.73	42208.56–455555.79
Correlation coefficient (r)	0.9997	0.9996	0.9992
Method precision (RSD%)	0.3	0.33	0.91