Hydrogenated soybean phosphatidylcholine

Several phospholipid-based excipients are finding increased application as solubilizing agents, emulsifying agents, or as components of liposomal formulation. The phospholipids occur naturally and are biocompatible and biodegradable. Examples include egg phosphatidylcholine, soybean phosphatidylcholine, hydrogenated soybean phosphatidylcholine (HSPC),... 

FIGURE 4.7 Effects of phospholipid/polymer ratio on the cumulative release of leuprolide from lipospheres. Lipospheres were prepared from L-PLA and EPC (1 6, pluses), hydrogenated soybean phosphatidylcholine (1 3, open circles), HSPC (1 6, filled circles), or HSPC (1 10, filled triangles), as described in Figure 4.6. Microspheres release data (filled squares) are presented for comparison. (Adapted from [35] with permission from Elsevier.)... 

Recently, a very extensive and we11-de.signed study was described by Ogi.so et al. (54). They compared gel systems in which /-limonene or lauracapram was present as penetration enhancer and studied the transport of -histine with and without liposomes in these gels. The liposomes were prepared from either egg phosphatidylcholine or hydrogenated soybean phosphatidylcholine. In vivo stud-... 

AmBisome . This is a sterile lyophilised liposomal formulation. Each vial contains 50 mg amphotericin B, 194 mg hydrogenated soybean phosphatidylcholine, 84 mg distearoylphosphatidylglycerol and 52 mg cholesterol. Upon reconstitution with sterile water for injection, small unilamellar liposomes that have a mean diameter of 80-100 nm are formed. Adult dose 1-3 mg/kg daily. Amphocil . This is a sterile lyophilised cofioidal dispersion. Each vial contains 50 or 100 mg amphotericin B and sodium cholesterol sulphate approximately equimolar amount. Upon reconstitution with sterile water for injection it forms a colloidal dispersion. Adult dose 1-4 mg/kg daily. 

Many studies have employed phospholipids as liposomes (vesicles) to transport drugs into and through human skin. However, a few investigations have also employed phospholipids in a nonvesicular form as penetration enhancers. For example, 1% phosphatidylcholine in PG, a concentration at which liposomes would not form, enhanced theophylline penetration through hairless mouse skin [64]. Similarly, indomethacin flux was enhanced through rat skin by the same phospholipid and hydrogenated soybean phospholipids increased diclofenac permeation through rat skin in vivo. 

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