Drug delivery systems utilizing liquid crystal structures
US5891845A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Nov 21, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K9/4858
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Vitamin E TPGS/drug compositions and methods are provided which obviate the need for surfactants or non-evaporated co-solvents because the active drug component is dissolved directly into Vitamin E TPGS to form a true molecular solution--not an emulsion or a micro-emulsion. The invention provides a slowly dissolving TPGS/Drug matrix that absorbs gastrointestinal fluid into the matrix at the dosage form/fluid interface, where a gel-like liquid crystal is formed. This gel front forms a liquid crystal boundary where drug dissolution is highest. At this liquid crystal/GI fluid boundary, a synchronization takes place in which the rate of formation of liquid crystals equals the dissolution rate of liquid crystals at the water interface, thereby giving controlled order release of the drug into the GI tract. The rate of dissolution is also controlled by the geometry of the dosage form. The solid Vitamin E TPGS/drug matrices of the invention can be solidified and compressed into tablets or filled into capsules, with other excipients, binders and/or fillers. The solid TPGS/drug solution of the invention also can be made into an immediate release liquid formulation upon addition of water, or …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.