TDDS can be formulated by different ways as follows, Polymer membrane permeation controlled TDDS. Polymer matrix diffusion controlled TDDS. Adhesive Dispersion – Type Systems. Microreservoir dissolution controlled TDDS. Polymer membrane permeation controlled TDDS: A polymeric membrane that controls flow rate is positioned between a backing laminate that is drug-impermeable and a drug reservoir . The drug is evenly distributed throughout the drug reservoir compartment in a solid polymeric matrix (like polyisobutylene) and suspended in a viscous, non-leachable liquid medium (like silicon fluid) to create a paste-like suspension. A polymeric membrane that controls rate can be either microporous or nonporous, such as ethylene-vinyl acetate copolymer . Estraderm (used twice weekly to treat postmenopausal syndrome) and Duragesic (used to manage chronic pain for 72 hours) are two examples of this type of patch. The intrinsic rate of drug release from this type...
A blog about "pharmacy lecture notes".