Microemulsion Liquid Chromatographic Method for Simultaneous Determination of Simvastatin and Ezetimibe in Their Combined Dosage Forms

Table 1

Effect of different experimental parameters on the retention factors, number of theoretical plates, and resolution.

Parameter	Retention factors (𝐷𝑚)		NETP		𝑅𝑠
	SIM	EZT	SIM	EZT
Concentration of cosurfactant %
5.0	Overlapped peaks
7.5	3.22	4.87	311	587	1.96
10.0	2.64	4.47	488	810	2.57
12.5	2.10	4.14	545	859	3.03
15.0	2.08	4.21	584	882	3.10
Type of cosurfactant
Propanol	2.64	4.47	488	810	2.57
Butanol	Band broadening and retardation especially in case of EZT
THF	3.39	5.15	464	756	2.05
Acetonitrile	Incomplete separation
Type of internal phase
Octanol	2.64	4.47	488	810	2.57
Di-isopropyl ether	2.81	4.68	339	749	2.25
Ethyl acetoacetate	2.90	7.77	310	596	4.92