Patent · US Expired

Process for microencapsulating cells

US5648099A · kind A · utility

17Cited by
16References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 3, 1994
Grant dateJul 15, 1997
Priority date
Expiry dateFeb 3, 2014

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC12N11/04
  • WIPO fieldPharmaceuticals
  • WIPO sectorChemistry

Abstract

Oxalate-degrading enzymes and bacteria were encapsulated for both enteric and intraperitoneal administration. We have shown that via alginate microencapsulation of Oxalobacter formigenes, enzymatic activity was retained for several months. A new process was developed which strengthened the alginate microcapsules and their tolerance to citrate treatment. Much smaller (30-50 .mu.m) alginate microcapsules were made for injection as means of implantation. For oral administration, multi-encapsulated microspheres of cellulose acetate phthalate in poly-2-vinylpyridine (pKa=3.5) were prepared to protect the enzymes from gastric juices.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.