Surfactants in pharmaceuticals

OI Corrigan, AM Healy. Surfactants in pharmaceutical products and systems. In J Swarbrick, JC Boy-lan, eds. Encyclopedia of Pharmaceutical Technology, Vol. 14. New York Marcel Dekker, 1996, pp 295-331. 

The permeability of two peptides, P-gp substrate and non P-gp substrate, across caco-2 cells in the presence or absence of polysorbate 80 and cremophor EL, commonly used surfactants in pharmaceutical formulations, was investigated. The permeability of the P-gp substrate peptide across caco-2 cells was enhanced in the presence of polysorbate 80 and cremophor EL, whereas the non-P-gp substrate peptide was not affected by these surfactants [94]. Another commonly used lipidic excipient that has been shown to inhibit P-gp mediated efflux is D-a-tocopheryl polyethylene glycol 1000 succinate (TPGS) [95]. The insertion of a known CYP3A4 and P-gp inhibitor to the formulation is another approach to elevate bioavailability. 

Pharmaceutical Excipient Testing Regulatory and Preclinical Perspective, p. 2771. Solubilization of Drugs in Aqueous Media, p. 3311. Surfactants in Pharmaceutical Products and Systems, p. 3583. 

Surface-active agents (surfactants) are substances which, at low concentrations, adsorb onto the surfaces or interfaces of a system and alter the surface or interfacial free energy and the surface or interfacial tension. Surface-active agents have a characteristic structure, possessing both polar (hydrophilic) and non-polar (hydrophobic) regions in the same molecule. Thus surfactants are said to be amphipathic in nature. The wide range of uses for surfactants in pharmaceutical products and systems is the subject of this article. 

Tables 1-4 in the article Surfactants in Pharmaceutical Products and Systems in Volume 14 of the first edition of this encyclopedia, together with the references cited therein, give listings of some of the surfactants most commonly used in pharmaceuticals, along with the purpose(s) for which they are usually employed.

Docusate sodium and docusate salts are widely used as anionic surfactants in pharmaceutical formulations. Docusate sodium is mainly used in capsule and direct-compression tablet formulations to assist in wetting and dissolution. Docusate salts are also used in oral formulations as laxatives and fecal softeners see Table I. 

DCS Docusate calcium Uses Surfactant in pharmaceuticals, stool softeners, vitamin formulations, ear wax removal compds. lubricant, emollient in laxative prods. 

The use of the surfactants in pharmaceutical dosage forms is indeed so widespread that a comprehensive and thorough review of each practical and theoretical application is simply beyond the scope of this chapter. We will discuss the utilization of amphiphilic molecules in various pharmaceutical dosage forms, divided according to their route of administration. 

Chapter 18 Applications of Surfactants in Pharmaceutical Dosage Forms.455... 

I 73 Surfactants in Pharmaceutical Formulations c) Polyoxyethylated glycol monoethers... 

---