Self micro emulsifying drug delivery systems (smedds): as a promising approach in enhancing bioavailability of poorly aqueous soluble drugs

Pandey Vikas¹, Kohli Seema²*

Dept of Pharmacy, Kalaniketan Polytechnic College

ABSTRACT

Oral delivery of hydrophobic drugs presents a foremost confront because of the low aqueous solubility of such compounds. Number of technologies has been developed till now to overcome poor solubility issues, out of which recently Self micro-emulsifying drug delivery systems (SMEDDS) have gained much attention. (SMEDDS), which are isotropic mixtures of oils, surfactants, solvents and co-solvents/surfactants, can dissolve hydrophobic drugs facilitating them to be rendered as a unit dosage form from oral administration. These can be orally administered in soft or hard gelatin capsules and form fine relatively stable oil-in-water (o/w) emulsions on releasing in GIT lumen with the aid of GI fluid. This leads to in situ solubilization of drugs that can consequently be absorbed by lymphatic pathways. The efficiency of oral absorption of the drug compound from the SMEDDS depends on several formulations related parameters, such as surfactant concentration, oil/surfactant ratio, and polarity of the emulsion, droplet size and charge, all of which in essence determine the self-emulsification ability. The fact that almost 40% of the new drug compounds are hydrophobic in nature implies that studies with SMEDDS will continue, and more drug compounds formulated as SMEDDS will reach the pharmaceutical market in the future. This article includes reports on diverse types of self micro-emulsifying formulations with emphasis on their formulation, characterization and in vitro analysis, with examples of currently marketed preparations.

Keywords: Self emulsifying oil formulations (SEOF), Lipophilic drugs, Oral bioavailability, lipid formulations