Method of preparing elongated seamless capsules containing biological material
US5418154A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1992 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Dec 24, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S530/817
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biologically active factor, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through the inner bore and the polymeric casting solution is extruded through the outer bore. The method involves initiating extrusion of the coagulant subsequent to initiating delivery of the casting solution through the respective bores to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.