Patent Title:
Use of Insulin for the Treatment of Cartilaginous Disorders
Assignee:
Inventors:
Ellen Filvaroff, Franklin Okumu
Patent:
Summary Related to Spray Freeze Dried Microspheres by means of an Ultrasonic Spray Nozzle:
In preparation for insertion into the microspheres, the above HI formulations were first spray-freeze dried. This process was accomplished by atomizing the above formulations through an ultrasonic nozzle into liquid nitrogen, followed by lyophilization. For example, the dried Zn—HI powder (100 mg) was added to 5.8 ml of a 0.17 mg/ml solution of the D,L-PLGA in ethylacetate solvent and homogenized for 2 minutes at 8000 rpm with a shear homogenizer in order to form a uniform suspension of Zn—HI and polymer. The polymer and Zn—HI suspension was sprayed through a sonicating nozzle into a vessel containing 300 ml of frozen ethanol. The vessel was then placed in a −70° C. freezer (to raise the temperature to −70° C.) whereupon the frozen ethanol melted and the micropheres slowly hardened as the ethylacetate solvent was extracted by the ethanol. After 3 days, the hardened microspheres were harvested by filtration through a 20 μm screen then dried under nitrogen gas for 4 days and finally sieved through a 60 μm screen.
