Osmotic devices having vapor-permeable coatings
US5827538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1996 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Jan 17, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/164
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
An osmotic device that, following the imbibement of water vapor, provides for the controlled release of a beneficial agent to an aqueous environment. The device comprises a hydrophilic formulation including a beneficial agent, and if needed, an osmagent, surrounded by a wall. The wall is formed at least in part of a semipermeable hydrophobic membrane having an average pore size between about 0.1 .mu.m and 30 .mu.m. The pores are substantially filled with a gas phase. The hydrophobic membrane is permeable to water in the vapor phase and the hydrophobic membrane is impermeable to an aqueous medium at a pressure less than about 100 Pa. The beneficial agent is released, for example, by osmotic pumping or osmotic bursting upon imbibement of sufficient water vapor into the device core. These devices minimize incompatibilities between the beneficial agent and ions (such as hydrogen or hydroxyl) or other dissolved or suspended materials in the aqueous medium, since contact between the beneficial agent and the aqueous medium does not occur until after the beneficial agent is released. This results from the semipermeable membrane's selective permeability for water vapor. In addition, the hig…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.