ENHANCEMENT OF ORAL BIOAVAILABILITY OF LIPOPHILLIC DRUGS FROMSELF-MICROEMULSIFYING DRUG DELIVERY SYSTEM (SMEDDS)

Approximately 40 per cent of new drug candidates have poor water solubility and the oral delivery of such drugs isfrequently associated with implications of low bioavailability, high intra and inter-subject variability, and lack of doseproportionality. Bioavailability problem of lipophillic drugs can be solved by formation of Self-Micro Emulsifying DrugDelivery System (SMEDDS). SMEDDS appears to be a unique and industrially feasible approach to overcome theproblem of low oral bioavailability associated with the lipophillic drugs. Self-micro emulsifying formulations are mixturesof oils and surfactants, ideally isotropic, and sometimes containing co-solvents, which emulsify spontaneously to producefine oil-in-water emulsion when introduced into aqueous phase under conditions of gentle agitation. The digestive motilityof the stomach and intestine provide the agitation necessary for self-emulsification in vivo. This review describesSMEDDS as one of the important approaches to overcome the formulation difficulties of potent lipophillic drugs.