The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 15, 1992
Filed:
Sep. 16, 1991
Neil B Graham, Glasgow, GB;
National Research Development Corporation, London, GB;
Abstract
An envelope having flexible water-permeable or porous walls contains a quantity of particulate water-insoluble hydrogel. The quantity of hydrogel in the envelope is such that, when the hydrogel is fully swollen at 20.degree. C., its volume is at least 66%, preferably at least 100%, of the maximum non-stretched internal volume of the envelope. Thus, the envelope according to the invention is limp and floppy under dry conditions but in a wet environment the hydrogel absorbs water and swells accordingly causing the envelope to swell and take on a more rigid configuration. The envelope is particularly useful for the administration of sustained release pharmaceutically or veterinarily active ingredients. Thus the limp dry envelope may for example be rolled up for introduction through the throat but will swell up and therefore be retained in the stomach for sustained release of the active ingredient therein.