Effect on cerebral blood flow of orally administered indomethacin-loaded poly(isobutylcyanoacrylate) and poly(DL-lactide) nanocapsules.

Nanocapsules, containing indomethacin, were prepared either by interfacial polymerization of isobutylcyanoacrylate monomers or by interfacial deposition of a performed (DL-lactide) polymer. In-vitro release of indomethacin from nanocapsules was dependent on the pH of the sink solution and was enhanced by addition of albumin. A decrease in cerebral blood flow was noted 15 min after oral administration to rats of indomethacin nanocapsules (5 mg kg-1) and lasted over 3 h. Empty nanocapsules had no effect. Since release of indomethacin from nanocapsules is unlikely to occur in the lumen of the stomach, due to unsuitable pH conditions, and nanocapsules have been previously shown to be able to cross the intestinal barrier, to reach the villi vessels intact and to protect against the ulcerating effect of the free drug, it is suggested that the rapid onset of the pharmacological effect was sufficiently induced by free indomethacin released in the plasma following absorption of the intact nanocapsules.