Cylindrical implants for the controlled release of growth hormones

• US 4,786,501 A
• Filed: 07/15/1985
• Issued: 11/22/1988
• Est. Priority Date: 07/15/1985
• Status: Expired due to Term

• Current Assignee: International Minerals & Chemical Corp. (The Mosaic Company)
• Original Assignee: International Minerals & Chemical Corp. (The Mosaic Company)
• Inventors: Yang, Ren-Der, Janski, Alvin M.
• Primary Examiner(s): Schain, Howard E.
• Assistant Examiner(s): Draper, Garnette D.
• Application Number:
  US06/755,093
• Time in Patent Office: 1,226 Days
• Field of Search: 604/891, 604/892, 604/890, 604/896, 424/19, 424/31-33, 424/422-426, 935/60, 935/59, 935/64
• US Class Current: 424/422
• CPC Class Codes: A61K 38/27 Growth hormone [GH], i.e. somatotropin
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00

Abstract

This invention relates to a method for purifying and concentrating biologically active growth hormone to produce growth hormone in a form suitable for incorporation into a controlled release device (or system). A buffered solution of purified recombinant growth hormone is dialyzed against a buffered solution until the salt level is reduced to less than 5% and then lyophilized.

Claims

1. A cylindrical implant for the controlled and continuous administration of growth hormone to a host comprising a compressed composition of an animal growth hormone produced by expression of a gene coding for the hormone in a transformant microorganism, said growth hormone being recovered from said microorganism and processed to produce a growth hormone containing less than 5% salt, and a biocompatible and growth hormone compatible polymer, said composition being surrounded along the length of the cylinder by a microporous polymer film and sealed at its ends by a non-porous polymer film.

2. The implant of claim 1 wherein the growth hormone is selected from bovine growth hormone and porcine growth hormone.

3. The implant of claim 2 wherein the compatible polymer is ethyl cellulose.

4. The implant of claim 2 wherein the compressed compostion contains about 30 weight percent growth hormone, 30 weight percent ethyl cellulose and 40 weight percent sucrose.

5. The implant of claim 2 wherein the microporous polymer is microporous polyethylene and the non-porous polymer is non-porous polyethylene.

6. The implant of claim 1 wherein the compressed composition contains from about 50-90 weight percent growth hormone and from about 10-50 weight percent biocompatible and growth hormone compatible polymer.

7. The implant of claim 6 wherein the biocompatible and growth hormone compatible polymer is ethylcellulose, the microporous polymer is microporous polyethylene and the non-porous polymer is non-porous polyethylene.