Fresta M, Puglisi G
Dipartimento Di Scienze Farmaceutiche, Università di Catania, Italy.
J Drug Target. 1996;4(2):95-101. doi: 10.3109/10611869609046267.
The potential application of liposomes as dermal delivery systems was investigated, with regard to vesicle composition and size. Liposomes were made up of phospholipids or skin lipids, referred to as phospholipid-based liposomes and stratum corneum lipid-based liposomes, respectively. A stripping procedure from stratum corneum to dermis by means of adhesive tape was carried out to evaluate the extent of accumulation in the superficial layers of the skin. The various liposomes were radiolabelled both in the bilayer structures with [3H]cholesterol, [14C]dipalmitoylphosphatidylcholine and [14C]palmitic acid, depending on vesicle type, and in the aqueous compartments with [14C]inulin. Inulin absorption and elimination was also evaluated. Stratum corneum lipid-based liposomes could permeate the stratum corneum to a greater extent than phospholipid-based liposomes. Stratum corneum lipid-based liposomes could deliver a greater amount of aqueous radiolabelled marker ([14C]inulin) to the deeper skin strata (epidermis and dermis), while avoiding systemic absorption and, hence, organ distribution and renal elimination of [14C]inulin. Another important parameter in determining the extent of absorption is the vesicle size: the greater the mean size of liposomes, the poorer the permeation through stratum corneum layers. When fluid liposomes made up of unsaturated lecithins were used, a percutaneous absorption was obtained instead of dermal delivery. Stratum corneum lipid-based unilamellar liposomes may be suitable devices for dermal delivery.
研究了脂质体作为皮肤给药系统的潜在应用,涉及囊泡组成和大小。脂质体由磷脂或皮肤脂质组成,分别称为基于磷脂的脂质体和基于角质层脂质的脂质体。通过胶带进行从角质层到真皮的剥离程序,以评估在皮肤表层的积累程度。根据囊泡类型,各种脂质体在双层结构中用[3H]胆固醇、[14C]二棕榈酰磷脂酰胆碱和[14C]棕榈酸进行放射性标记,在水相中用[14C]菊粉进行放射性标记。还评估了菊粉的吸收和消除情况。基于角质层脂质的脂质体比基于磷脂的脂质体更能渗透角质层。基于角质层脂质的脂质体可以将更多的水性放射性标记物([14C]菊粉)递送至更深的皮肤层(表皮和真皮),同时避免全身吸收,从而避免[14C]菊粉的器官分布和肾脏消除。决定吸收程度的另一个重要参数是囊泡大小:脂质体的平均大小越大,通过角质层的渗透越差。当使用由不饱和卵磷脂组成的流体脂质体时,获得的是经皮吸收而不是皮肤给药。基于角质层脂质的单层脂质体可能是适合皮肤给药的装置。