Medium chain fatty acids, absorption effect

An important issue that has been recognized recently concerns the potential adverse effect of absorption enhancers on the rectal mucosa, as shown in rats after a single application [61,62], Safety evaluation of the applicability of absorption enhancers is imperative. In clinical application, medium-chain fatty acids such as sodium caprate are used only for suppositories containing antibiotics [36],... 

Van Hoogdalem, E.J., et al. 1988. Absorption enhancement of rectally infused cefoxitin sodium by medium-chain fatty acids in conscious rats Concentration-effect relationship. Pharm Res 5 453. 

Strategies to overcome the absorption barrier focus on the other hand on low molecular mass permeation enhancers (Chapter 5) such as medium chain fatty acids, which can still be regarded as a kind of gold standard. As low molecular mass permeation enhancers are per se rapidly uptaken from the gastrointestinal mucosa, however, the macromolecular drug is to a considerable high extent left alone behind in the gastrointestinal tract. In addition, local and systemic toxic side effects of low molecular mass permeation enhancers cannot be excluded. In contrast, polymeric permeation enhancers (Chapter 6) are simply too big to be absorbed from the GI tract. Consequently, systemic toxic side effects can be excluded. More recently various excipients could be identified as potent efflux pump inhibitors which can be subdivided into low molecular mass efflux pump inhibitors and polymeric efflux pump inhibitors (Chapter 7). Certain polymeric... 

Ikeda, I., Tomari, Y., Sugano, M., Watanabe, S., and Nagata, J. 1991. Lymphatic absorption of structured glycerolipids containing medium-chain fatty acids and linoleic acid, and their effect on cholesterol absorption in rats. Lipids 26 369-373. 

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