Topical drug delivery

  Microsponge can be effectively incorporated into topical drug delivery system for retention of dosage form on skin, and also use for oral delivery of drugs using bioerodible polymers, especially for colon specific delivery and controlled release drug delivery system thus improving patient compliance by providing site specific drug delivery system and prolonging dosage intervals. Microsponge drug delivery systems offers entrapment of ingredients and is believed to contribute towards reduced side effects, improved stability, reduces systemic exposure and minimize local cutaneous reactions, increased elegance, and enhanced formulation flexibility. Topical preparations have some disadvantages like unpleasant odour, greasiness and skin irritation and fail to reach the systemic circulation this problem is overcome by microsponge delivery system. Microsponge formulations are stable over range of PH 1 to 11; Microsponge formulations are stable at the temperature up to 1300C; compatible with most vehicles and ingredients.  The present review introduces Microsponge technology along with its synthesis, characterization, programmable parameters and release mechanism of MDS.

  The conventional oral dosage forms has significant drawbacks of low bioavailability due to hepatic first pass metabolism and tendency to produce rapid blood level spikes (Both high and low), leading to a need for frequent dosing, which can be both cost ineffective and inconvenient. To improve such characters transdermal drug delivery system (TDDS) was emerged which will improve the therapeutic efficacy and safety of drugs by more precise (i.e. site specific) placement within the body thereby reducing both the size and number of doses. The TDDS has numerous advantages over the more traditional drug delivery system. These include high bioavailability, absence of first pass hepatic metabolism, maintenance of steady plasma level of the drug, increase therapeutic efficiency. This review article provides an overview of TDDS, its advantages over conventional dosage forms, Limitations, various components of Transdermal patches, types of Transdermal patches, methods of preparation and Ideal requirements for TDDS, regulatory issues over transdermal drug delivery and its physicochemical methods of evaluation. Key words: Transdermal drug delivery systems, Transdermal patches, skin penetration, Topical drug delivery