| 摘要 |
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 into a controlled release system solid tablet by the use of impermeable or semi-permeable barriers or coatings surrounding portions of the tablet.
|
