Osmotic system with laminated wall comprising structurally different semipermeable lamina
US4116241A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1976 |
| Grant date | Sep 26, 1978 |
| Priority date | — |
| Expiry date | Dec 15, 1996 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F9/0017
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
An osmotic system for delivering a beneficial agent to an environment of use is disclosed. The system comprises a laminate surrounding a compartment and has a passageway through the laminate for releasing agent from the compartment. The laminate comprises at least two laminae; one consisting of a semipermeable, polymeric material that is permeable to the passage of an external fluid and maintains its physical and chemical integrity in the environment of use, and one consisting of a semipermeable polymeric material that is permeable to the passage of fluid, substantially impermeable to the passage of agent and maintains its physical and chemical integrity in the presence of agent. The compartment comprises an active agent that is either soluble in the external fluid and exhibits an osmotic pressure gradient across the laminate against the fluid, or the agent has limited solubility in the fluid and it is mixed with an osmotically effective compound that is soluble in the fluid and exhibits an osmotic pressure gradient across the laminate against the fluid. In operation, agent is released from the system by fluid being imbibed through the laminate into the compartment at a rate contro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.