Medium chain glycerides

Van Hoogdalem, E.J., et al. 1989. Rectal absorption enhancement of des-enkephalin-y-endorphin (DeyE) by medium-chain glycerides and EDTA in conscious rats. Pharm Res 6 91. 

The most efficient rectal absorption enhancers, which have been studied, include surfactants, bile acids, sodium salicylate (NaSA), medium-chain glycerides (MCG), NaCIO, enamine derivatives, EDTA, and others [45 17]. Transport from the rectal epithelium primarily involves two routes, i.e., the paracellular route and the transcellular route. The paracellular transport mechanism implies that drugs diffuse through a space between epithelial cells. On the other hand, an uptake mechanism which depends on lipophilicity involves a typical transcellular transport route, and active transport for amino acids, carrier-mediated transport for (3-lactam antibiotics and dipeptides, and endocytosis are also involved in the transcellular transport system, but these transporters are unlikely to express in rectum (Figure 8.7). Table 8.3 summarizes the typical absorption enhancers in rectal routes. 

Sekine, M., et al. 1985. Improvement of bioavailability of poorly absorbed drugs. V. Effect of surfactants on the promoting effect of medium chain glyceride for the rectal absorption of (3-lactam antibiotics in rats and dogs. J Pharmacobiodyn 8 653. 

P. P. Constantinides and J. P. Scalart, Formulation and physical characterisation of water-in-oil microemulsions containing long-versus medium chain glycerides, Int. J. Pharm. 758 57-68 (1997). 

Sekine M, Maeda E, Sasahara K, Okada R, Kimura K, Fukami M, Awazu S (1985) Improvement of bioavailability of poorly absorbed drugs. III. Oral acute toxicity and local irritation of medium chain glyceride. J Pharmacobio-Dyn 8 633-644 Shimazaki T, Tomita M, Sadahiro S, Hayashi M, Awazu S (1998) Absorption-enhancing effects of sodium caprate and palmitoyl carnitine in rat and human colons. Dig Dis Sci 43 641-645... 

Constantinides, P. R, Scalart, J. P., Lancaster, C., Marcello, J., and Smith, P. L., et al. (1994), Formulation and intestinal absorption enhancement evaluation of water-in-oil microemulsions incorporating medium-chain glycerides, Pharm. Res., 11,1385-1390. 

Medium-chain glycerides (mainly Cg-Cio) are known to increase the intestinal absorption of poorly permeable drugs, mono- and diglycerides, especially, improve bioavailability, and it is believed that mainly transcellular permeation is increased. 

Unowsky, J. Behl, C.R. Beskid, G. Sattler, J. Halpem, J. Cleeland, R. Effect of medium chain glycerides on enteral and rectal absorption of beta-lactam and aminoglycoside antibiotics. Chemotherapy 1988, 34, 272-276. 

W/o microemulsions incorporating medium-chain glycerides have been used to deliver calcein intraduodenally and produce significantly higher plasma levels of the dmg compared to an aqueous formulation. ... 

Sek, L., Porter, C.J.H., Kaukonen,A.M.and Charman, W.N. (2002) Evaluation of the in-vitro digestion profiles of long and medium chain glycerides and the phase behaviour of their lipolytic products. The Journal of Pharmacy and Pharmacology, 54, 29. 

Lundin, P., Bojrup, M., Ljusberg-Wahren, H., Westrom, B.R. and Lundin, S. (1997) Enhancing effects of monohexanoin and two other medium-chain glyceride vehicles on intestinal absorption of desmopressin (Ddavp). /. Pharm. Exp. Ther., 282, 585-590. 

Glycerides Natural oils, medium chain glycerides, phospholipids, polyoxyethylene glyceryl esters... 

Octanoic acid Decanoic acid Medium chain glycerides... 

Sekine, M., H. Terashima, K. Sasahara, K. Nishimura, R. Okada, and S. Awazu. 1985. Improvement of bio availability of poorly absorbed II. Effect of medium-chain glyceride base on the intestinal absorption of cefmetazole sodium in rats and dogs. J. Pharmacobio. Dyn. 8 286-295. 

Yeh, P. Y., P. L. Smith, and H. Ellens. 1994. Effect of medium-chain glycerides on physiological properties of rabbit intestinal epithehum in vitro. Pharm. Res. 11 1148-1153. 

Digestion of usual food fats and subsequent absorption of their digestion products (2), the in vitro digestion profiles of long-and medium-chain glycerides, and the phase behavior of their lipolytic products have been reviewed recently (3). In the present review, the stereospecific aspects will be highlighted. 

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