Krishna G, Wood G C, Sheth B B
Vion Pharmaceuticals Inc., New Haven, Connecticut, USA.
PDA J Pharm Sci Technol. 1998 Nov-Dec;52(6):331-6.
The objective of this study was to seek improvement in the emulsification efficacy of lecithin by formulation design. A Base Emulsion was developed containing lecithin as the primary emulsifier. The lecithin concentration and method of preparation of the Base Emulsion were optimized to obtain minimum particle size and creaming of the emulsion. Selected hydrophilic and hydrophobic synthetic surfactants were evaluated as secondary emulsifiers for their ability to reduce particle size of the Base Emulsion. The selection of type and concentration of the secondary emulsifier was done by application of the HLB method. The hydrophilic emulsifiers selected were Tween 80, Tween 20, Pluronic F68, and Pluronic F127. The hydrophobic surfactants studied included Span 20, Span 80, Pluronic P103, and Pluronic P123. The median droplet size of the Base Emulsion was 2.7 microns. Addition of the hydrophilic emulsifiers caused an increase in particle size and substantial creaming of the emulsions. Addition of three of four hydrophobic surfactants resulted in particle size reduction, but the emulsions showed substantial creaming. Span 20 was found to be the most effective secondary emulsifier. The median particle size of the emulsion was 1.7 microns. These results suggest that supplementing the hydrophilic attributes of lecithin with an appropriate type and amount of hydrophobic surfactant improves the emulsion properties by applying principles of formulation design.
本研究的目的是通过配方设计提高卵磷脂的乳化效果。开发了一种以卵磷脂为主要乳化剂的基础乳液。对基础乳液中卵磷脂的浓度和制备方法进行了优化，以获得最小的粒径和乳液的分层现象。评估了选定的亲水性和疏水性合成表面活性剂作为辅助乳化剂降低基础乳液粒径的能力。通过应用HLB方法选择辅助乳化剂的类型和浓度。选定的亲水性乳化剂有吐温80、吐温20、普朗尼克F68和普朗尼克F127。研究的疏水性表面活性剂包括司盘20、司盘80、普朗尼克P103和普朗尼克P123。基础乳液的中位液滴尺寸为2.7微米。添加亲水性乳化剂导致乳液粒径增大和大量分层。添加四种疏水性表面活性剂中的三种导致粒径减小，但乳液出现大量分层。发现司盘20是最有效的辅助乳化剂。乳液的中位粒径为1.7微米。这些结果表明，通过应用配方设计原理，用适当类型和数量的疏水性表面活性剂补充卵磷脂的亲水性属性可改善乳液性能。
