Medium-chain triglycerides (MCTs) are triglycerides with two or three fatty acids having an aliphatic tail of 6-12 carbon atoms, i.e., medium-chain fatty acids (MCFAs). Rich food sources for commercial extraction of MCTs include palm kernel oil and coconut oil.
Caprylic acid glyceride has good emulsification, oil solubility, elongation and lubricity, high temperature resistance, and the viscosity is almost unchanged after long-term frying, and it is not easy to oxidize.
MCTs can be used in solutions, liquid suspensions and lipid-based drug delivery systems for emulsions, self-emulsifying drug delivery systems, creams, ointments, gels and foams as well as suppositories. MCTs are also suitable for use as solvent and liquid oily lubricant in soft gels. Brand names of pharma-grade MCT include Kollisolv MCT 70.
MCTs passively diffuse from the GI tract to the portal system (longer fatty acids are absorbed into the lymphatic system) without requirement for modification like long-chain fatty acids or very-long-chain fatty acids. In addition, MCTs do not require bile salts for digestion. Patients who have malnutrition, malabsorption or particular fatty-acid metabolism disorders are treated with MCTs because MCTs do not require energy for absorption, use, or storage.
Medium-chain triglycerides are generally considered a good biologically inert source of energy that the human body finds reasonably easy to metabolize. They have potentially beneficial attributes in protein metabolism, but may be contraindicated in some situations due to a reported tendency to induce ketogenesis and metabolic acidosis. However, there is other evidence demonstrating no risk of ketoacidosis or ketonemia with MCTs at levels associated with normal consumption, and that the moderately elevated blood ketones can be an effective treatment for epilepsy.
Due to their ability to be absorbed rapidly by the body, medium-chain triglycerides have found use in the treatment of a variety of malabsorption ailments. MCT supplementation with a low-fat diet has been described as the cornerstone of treatment for Waldmann disease. MCTs are an ingredient in some specialised parenteral nutritional emulsions in some countries. Studies have also shown promising results for epilepsy through the use of ketogenic dieting.