Strategies to Overcome the Solubility Issue of Drug

The oral hydrophobic drugs delivery are the biggest challenges due to insolubility in the aqueous vehicle of these components. Self-emulsifying drug delivery system is classified to self-nanoemulsifying drug delivery system (SNEDDS) and self-micro emulsifying drug delivery system (SMEDDS). Self-micro emulsifying drug delivery systems has ability to increase the solubility and bioavailability of low water soluble drugs. The real mechanism of this system is not until now understood, to increase solubility as well as bioavailability of poorly water soluble drugs but it has recommended self- emulsification happens while entropy change favoring dispersion is more than energy necessary to enlarge dispersion surface area. Therefore by decreasing the droplet size increasing the surface area, hence increase the solubility as well as bioavailability of drugs. There are several formulation factors effect on efficacy of oral absorption of lipophilic drugs such as, amount of surfactant, oil, ratio of oil and surfactant, droplet size and charge, polarity of emulsion and some of specific pharmaceutical inactive ingredients. The aim of surfactant used in SMEDDS formulation to reduce the interfacial tensions among both phases (O/W) and improve the flow ability of drugs in GIT environments.