Microsponge Delivery System (mds): a Unique Technology for Delivery of Active Ingredients

In pharmaceutical industry, various controlled released dosage forms like solid formulation, semi solid formulation and topical preparation have more importance due to efficacy and patient compliance. Topical preparations have some disadvantages like unpleasant odour, greasiness and skin irritation and fail to reach the systemic circulation in sufficient amounts in few cases. This problem is overcome by microsponge delivery system. Microsponges are tiny sponge like spherical and highly porous micro-sized particles with a unique ability for entrapping actives. They offers programmable release active drug into the skin in order to reduce systemic exposure and minimize local cutaneous reactions to active. These MDS’s are closely related to microspheres, and used in the sun screens, creams, ointments, overthe-counter (OTC) skin care preparations, recently used in oral drug as well as biopharmaceuticals (peptides, proteins and DNA-based therapeutics) drug delivery. The present review introduces microsponge technology along with its synthesis, characterization, programmable parameters and release mechanism of MDS. INTRODUCTION: The microsponge technology was developed by Won in 1987 and the original patents were assigned to Advanced Polymer Systems, Inc . Several predictable and reliable systems were developed for systemic delivered through skin under the title of transdermal delivery system (TDS). It has improved the efficacy and safety of many drugs that may be better administered via skin. But transdermal delivery system is unrealistic for delivery of materials whose final target is skin itself . No efficient vehicles have been developed for controlled and localized delivery of drugs into the stratum corneum and underlying skin layers and not beyond the epidermis . Conventional formulations of topical drugs are intended to work on the outer layers of the skin. Typically, such products release their active ingredients upon application, producing a highly concentrated layer of active ingredient that is rapidly absorbed . Furthermore, the significance of topical drugs suffers from various problems like greasiness, stickiness associated with the ointments and so on, that often result in lack of patient compliance. These vehicles necessitate a high concentration of active agents for effective therapy because of their low efficiency of delivery system, resulting into irritation and allergic reactions in significant users. Other drawbacks of topical formulations are uncontrolled evaporation of active ingredient, unpleasant odour. The fundamental appeal of the microsponge technology stems from these difficulties experienced with conventional formulations in releasing active ingredients over an extended period of time.