pH and temperature sensitive terpolymers for oral drug delivery
US5484610A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 2, 1991 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Jan 2, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/916
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Terpolymers which are sensitive to pH and temperature are useful carriers for conducting bioactive agents through the gastric juices of the stomach in protected form. Such terpolymers swell at the higher physiologic pH of the intestinal tract causing release of the bioactive agents into the intestine. The terpolymers are linear and are made up of 35 to 99 wt % of a temperature sensitive component, which imparts to the terpolymer LCST (lower critical solution temperature) properties below body temperatures, 1 to 30 wt % of a pH sensitive component having a pK.sub.a in the range of from 2 to 8 which functions through ionization or deionization of carboxylic acid groups to prevent the bioactive agent from being lost at low pH but allows bioactive agent release at physiological pH of about 7.4 and a hydrophobic component which stabilizes the LCST below body temperatures and compensates for bioactive agent effects on the terpolymers. Such terpolymers provide for safe bioactive agent loading, a simple procedure for dosage form fabrication and the terpolymer functions as a protective carrier in the acidic environment of the stomach and also protects the bioactive agents from digestive enz…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.