Patent ID: 8865220

Claim:
A method for controlled release delivery of biologically active polypeptide with activity similar to parathyroid hormone to a subject suffering from osteoarthritis in effective therapeutic concentration comprising: administrating to the subject a controlled release microsphere with mean average size greater than 50 μm, which is produced by preparing a water-in-oil (w/o) emulsion comprising an inner aqueous layer containing the biologically active polypeptide, and an oil layer containing a polymer substance of poly(lactic-co-glycolic acid) (PLGA), then gradually adding the w/o emulsion into aqueous polyvinyl alcohol (PVA) solution to form a water-in-oil-in-water (w/o/w) double emulsion and then desorbing the solvent in the oil layer, whereby the polypeptide is released in the effective therapeutic concentration ranging from about 1×10 −7 M to about 5×10 −9 M for at least 18 days.