Quantitative effects of interacting variables on vitamin K,, phylloquinone, entrapment in liposomes

Abstract

Vitamin Kt is poorly absorbed by the oral route in certain diseased conditions. Entrapment of this vitamin in liposomes is expected to improve oral absorption. In this study, vitamin K, has been encapsulated into multilamellar vesicles (MLVs) composed of either egg phosphatidylcholine (egg PC, EPC) or dipalmitoyllecithin (DPPC) by the classical film method involving hydration of lipids by either hand shaking or vigorous vortex mixing. Amounts of vitamin K, ranging from 4.4 to 22.1 uMol were employed to medicate liposome suspensions (26uMm or 1 A 23 factorial design was employed to quantitative the effects of the interaction of certain variables viz: nature of lipid (L), method of agitation (M) and initial drug concentration (C), on encapsulation capacity (EC) of liposomes. The results of this study suggest, in particular, that the concentration of the drug (C) and the nature of the Iipid-drug interactions (L-C) are the most influential variables. This probably infers that any pre-formulation studies with this drug delivery system should start with a consideration of L-C interaction. A negative correlation was found between initial drug concentration and encapsulation capacity of liposomes.