ANTIHYPERTENSIVE EFFECT OF ORAL CONTROLLED-RELEASE MICROSPHERES CONTAINING AN ACE-INHIBITOR (DELAPRIL HYDROCHLORIDE) IN RATS

An oral controlled-release drug delivery system based on microspheres of polyglycerol esters of fatty acids (PGEFs), was applied to an anti- hypertensive, delapril hydrochloride. The in-vitro release profile was controlled by selecting a PGEF with an appropriate hydrophilic-lipoph ilic balance value for the matrix. The microspheres from which 80% of the drug was released in 6 h were orally administered to rats. The pla sma concentration of the active metabolite was sustained after adminis tration of the microspheres in comparison with administration of a sol ution. The in-vivo release profile was in good agreement with the invi tro release profile. When the microspheres were administered, the phar macological effect of delapril hydrochloride on the angiotensin I-indu ced presser response was also sustained showing consistency with the p lasma concentration-time curve.