Chitooligosaccharide reconstitutes intestinal mucus layer to improve oral absorption of water-soluble drugs

Intestinal mucus is a complex natural hydrogel barrier with unique physical properties that impede the absorption of various oral drugs. Both washout from the upper water layer and the physical resistance of the mucus layer particularly affect bioavailability of, especially, highly water-soluble molecules. One potential strategy for designing pharmaceutical formulations is to add absorption enhancers (AEs). However, there are few reports of AEs that work on mucus and their underlying mechanisms, leading to imprecise application. In this study, we investigated chitooligosaccharide (COS) as a safe, low-cost, and effective oral drug AE. We revealed the hydrodynamic law of interaction between COS and the intestinal mucus layer, which was associated with absorption benefiting mucus structural reconstruction. Based on this, we designed a translational strategy to improve the bioavailability of a group of soluble oral drugs by drinking COS solution before administration. Moreover, this research is expected to expand its application scenario by reducing drug dosage such as avoiding gastro-intestinal irritation and slowing veterinary antibiotic resistance.

Disposition of a new steroidal anti-inflammatory agent, deflazacort, in rat, dog and man

The physiological disposition of a new steroid anti-inflammatory agent, deflazacort, was examined in rat, dog and man following 5 mg/kg doses to the animals, and 50 mg to humans. The administered radiocarbon [2'-14C]-deflazacort), is rapidly and extensively absorbed into the general circulation in rat and man, whereas the bioavailability in the dog is low. The terminal plasma half-life for radioactivity elimination was, on the average, 11, 15 and 28 hr in rats, dogs and man, respectively. Urinary excretion was the predominant route of 14C elimination in the rat (-54% of the dose) and in man (-68% of the dose), whereas in the dog the majority of the dose was eliminated via the feces (82%). Tissue distribution studies in the rat did not show target organs, with the exception of the blood cells. Studies of binding to plasma proteins of the 21-desacetyl deflazacort, demonstrate in all the species a rather low level of binding of non-saturable type.