Claims for Patent: 5,741,523

Summary for Patent: 5,741,523

Title:	Stabilized prostaglandin E1
Abstract:	A stable and lyophilized formulation of prostaglandin E-1 made by the process comprising a) dissolving PGE-1 in a solution of lactose and tertiary butyl alcohol wherein said tertiary butyl alcohol is present in an amount of from about 15% to about 33% volume/volume and the ratio of said lactose to PGE-1 is from about 40,000 to 1 to about 10,000 to 1 weight/weight whereby a formulation of PGE-1dispersed in lactose is formed; b) adjusting and maintaining the pH of said formulation from about 3.5 to about 6 with an organic acid buffer; c) freezing said formulation to about -50.degree. C.; and d) drying said formulation to obtain a moisture content of less than 1% by dry weight and a tertiary butyl alcohol content of less than 3% by dry weight. Preferably, step c) includes after freezing said formulation to about -50.degree. C., warming to about -25.degree. C. for about 2 hours then refreezing to about 50.degree. C. Preferably, the prostaglandin is in an amount of about 25 to 100 ppm in lactose and the pH is maintained at about 4 to 5.
Inventor(s):	Teagarden; Dirk L. (Kalamazoo, MI), Petre; William J. (Kalamazoo, MI), Gold; Paul M. (Vicksburg, MI)
Assignee:	Pharmacia & Upjohn Company (Kalamazoo, MI)
Application Number:	08/619,690
Patent Claims:	1. A lyophilized formulation of PGE-1 made by the process consisting of: a) adding PGE-1 to lactose and tertiary butyl alcohol wherein said tertiary butyl alcohol is present in an amount of from about 15% to about 33% volume/volume and the ratio of said lactose to PGE-1 is from about 40,000 to 1 to about 10,000 to 1 weight/weight whereby a formulation of PGE-1 dispersed in lactose is formed; b) adjusting the pH of said formulation from about 4 to about 5 with a citrate or acetate buffer; c) freezing said formulation to about -50.degree. C., warming to about -25.degree. C. for about 2 hours then refreezing to about -50.degree. C.; and d) drying said formulation to obtain a moisture content of less than 1% by dry weight and a tertiary butyl alcohol content of less than 3% by dry weight. 2. The lyophilized formulation of PGE-1 made by the process of claim 1 wherein in said organic acid buffer of step b) is sodium citrate. 3. The lyophilized formulation of PGE-1 made by the process of claim 1 wherein in PGE-1 is in an amount of about 25 to about 100 ppm in lactose.