Multiparticulate controlled porosity osmotic
US4851228A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1987 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Jul 15, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K9/0004
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The instant invention is directed to a multiparticulate osmotic pump, for the controlled release of a pharmaceutically active agent to an environment of use, said pump comprising: PA0 (I) a carrier medium which does not maintain its integrity in the environment of use; PA0 (II) a multiple of tiny osmotic pump elements each consisting essentially of: PA1 (A) a core comprises at least one pharmacologically active agent soluble in an external fluid, or a mixture of an agent having a limited solubility in the external fluid with an osmotically effective solute that is soluble in the fluid, which exhibit an osmotic pressure gradient across the wall against the external fluid surrounded by PA1 (B) a rate controlling water insoluble wall, having a fluid permeability of 6.96.times.10.sup.-18 to 6.96.times.10.sup.14 cm.sup.3 sec/g and a reflection coefficient of less than 0.5, prepared from: PA1 (i) a polymer permeable to water but impermeable to solute and PA1 (ii) 0.1 to 60% by weight, based on the total weight of (i) and (ii), of at least one pH insensitive pore forming additive dispersed throughout said wall.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.