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 2

Specificity studies.

Degradation mode	ETC		TDF		EFV
	Purity angle	Purity threshold	Purity angle	Purity threshold	Purity angle	Purity threshold
Acid degradation	0.28	0.92	0.17	0.47	0.49	0.81
Base degradation	0.14	1.06	3.10	8.26	0.46	1.05
Neutral degradation	0.13	1.06	0.43	1.50	1.13	1.35
Oxidation degradation	0.11	0.28	0.33	0.36	6.12	8.46
Thermal degradation	0.09	0.29	0.26	0.31	0.51	2.49
Photo degradation	0.24	0.36	0.24	0.39	1.64	2.60
Accelerated stability	0.09	0.31	0.14	0.43	0.44	1.32
Marketed tablet	0.34	2.67	0.35	0.43	1.79	3.81