Lecithin parenteral preparations

Lecithin-based o/w MEs for parenteral use were formulated using polysorbate 80, IPM (Isopropyl myristate), lecithin, and water at different lecithin-polysorbate 80 weight ratios [115]. The formulated systems were shown to be highly stable and of minimal toxicity when evaluated in vitro. Phospholipid-based ME formulations of all-trans retinoic acid (ATRA) for parenteral administration were prepared and tested in vitro [116]. ATRA is effective against acute promyelocytic leukemia with highly variable oral bioavailability. Parenteral ME of ATRA was prepared using pharmaceutically acceptable ingredients, namely phospholipids and soybean oil. The inhibitory effect of ATRA on two human cancer cell lines (HL-60 and MCF-7) was not affected by incorporation into a ME formulation. 

Cationic surfactants are bactericidal agents and are used as antiseptics and disinfectants in topical and other external preparations and are never used in parenterals. Lecithins and other natural phospholipids, as one of the main constituents... 

Amphoteric surfactants possess both an anionic and a cationic function. In small-scale preparation they are little used but their role may increase in the future. Examples are long chain betains and phospholipids (e.g. lecithin). Phospholipids play an important role as emulsifiers and micelle formers for parenteral emulsions (see Sect. 13.5.7) and micellar solutions and also in liposome technology. 

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