A self-emulsifying drug delivery system is defined as a mixture of isotropic
substances such as oil and surfactant solvents/co-solvents, which is used for the
improvement of the oral drug delivery system. The oral drug delivery system consists
of soft and hard gelatin capsules. They are stable O/W emulsion preparations. There are
several types of parameters used in this process. The utilisation of herbal medicine has
been gaining popularity of late. Herbal drugs are also used in self-emulsion drug
delivery systems due to their isotropic thermodynamic property. The lipophilic nature
of this formulation could solve the problem of poor solubility of drugs. The
bioavailability of poorly soluble drugs is determined by the drug dissolution process.
Prodrug process is used to improve bioavailability.
Keywords: Bioavailability, Herbal drugs, Oral dosage form, SEDDS and SMEDDS.