Yasuaki Ogawa

TL;DR: 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, but the release profiles of the drug in vitro were inadequate for controlled release for one month.

TL;DR: In this paper, a microcapsule designed for zero order release of a physiologically active polypeptide over a period of at least two months, which is produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing about 20 to 70% (w/w) of said polypeptic and an oil layer containing a copolymer or homopolymer having a weight-average molecular weight of 7,000 to 30,000, wherein the composition ratio of lactic acid/glycolic acid in the copolymers or

TL;DR: Elevation of the glass transition temperature of the microspheres was observed with an increase in drug loading, suggesting formation of a rigid structure that provides a hydrophobic barrier against diffusion of the hydrophilic peptide, resulting in high trapping efficiency and long-term sustained release dependent on polymer erosion.

TL;DR: A microcapsule produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing water-soluble drug and a drug retaining substance therefor and an oil layer containing a polymer substance, then thickening or solidifying said inner annealing layer to a viscosity of not lower than about 5000 centiposes and finally subjecting the resulting emulsion to in water drying gives prolonged release of water soluble drug.

TL;DR: The release profile of the drug from microcapsules prepared with PLGA of average molecular weight 14000 and a copolymer ratio of 75/25 was ideal for one month's release, but the release rate of leuprolide acetate was still too slow to give the desired drug level over one month.