Patent ID: 6190700
Filing Date: 2001-02-20
Classification: A61K,Y10S

Abstract:
A method of producing a sustained-release preparation for injection having a mean diameter of 10 to 40 .mu.m which comprises1) providing microspheres which are obtained bya) adding a solution containing leuprorelin acetate to a solution containing a polylactic acid having a weight-average molecular weight of about 10,000 to about 20,000 and a degree of dispersion of the polylactic acid is 1.5 to 3.5 to provide a w/o emulsion wherein the ratio of leuprorelin acetate to polylactic acid is about 0.1 to 1% (w/w);b) adding the w/o emulsion to a 0.05 to 10% aqueous solution of polyvinyl alcohol to provide a w/o/w emulsion;2) adding D-mannitol to the microspheres in an amount of about 5 to about 40% (w/w) relative to the microspheres; and3) freeze drying subsequent heating the microspheres at a temperature ranging from the glass transition temperature of the microspheres to a temperature which is about 10.degree. C. higher than the glass transition temperature for about 69 to about 72 hours.