A New Technique to Efficiently Entrap Leuprolide Acetate into Microcapsules of Polylactic Acid or Copoly(Lactic/Glycolic) Acid

• Published in: Chemical & pharmaceutical bulletin Vol. 36; no. 3; pp. 1095 - 1103
• Main Authors: OGAWA, YASUAKI, YAMAMOTO, MASAKI, OKADA, HIROAKI, YASHIKI, TAKATSUKA, SHIMAMOTO, TSUGIO
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 01.03.1988; Maruzen; Japan Science and Technology Agency
• Subjects: Biological and medical sciences; Capsules; Chemistry, Pharmaceutical; entrapment; General pharmacology; Glycolates; Gonadotropin-Releasing Hormone - analogs & derivatives; Gonadotropin-Releasing Hormone - analysis; Lactates; Lactic Acid; Leuprolide; Medical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Polyesters; Polymers; Lactic acid polymer; Pharmaceutical technology; Preparation; Microcapsule; Dosage form; Copolymer; Glycolic acid polymer
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.36.1095

The aim of this work was to develop injectable microcapsules containing leuprolide acetate, that would deliver that drug at a zero-order rate over a period of about one month. A large amount of leuprolide acetate, a hydrophilic drug, was entrapped into polylactic aicd (PLA) and copoly-(lactic/glycolic) acid (PLGA) microcapsules prepared by an in-water dring method using a (w/o)/w emulsion. The basic techniques were designed to increase the viwcosities of the inner water phase and w/o emulsion. Under the conditions used, it was possible for the drug to be completely entrapped by the microcapsules in the range of 10 to 20% on the basis of the polymer. However, the release profiles of the drug in vitro were inadequate for controlled release for one month.