A Review on Novel vesicular systems for enhanced Oral bioavailability of Lipophilic drugs

Abstract

The poor oral bioavailability of many drugs is mainly due to the poor aqueous solubility, chemical instability and pre-absorptive metabolism. Numerous approaches have been developed for enhancement of oral bioavailability and were currently in the clinical application. Even though, some drugs not meet the required clinical application due to the patient compliance and ineffective therapeutic levels. Vesicular delivery systems are considered as alternative delivery for the enhancement the bioavailability of this category of drugs. The enhanced bioavailability of the liphophilic drugs from the vesicular systems mainly due to the increased effective surface area of the drug in the presence of lipids, surfactants and co surfactants, enhanced lymphatic uptake, altered gastric motility and by virtue of their small particle size. Extensive literature is available for the properties, applications, and preparation and evaluation methods. This review mainly dealt with the reported drug loaded various vesicular systems such as liposomes, niosomes, lipid nanoparticles, self-emulsifying delivery system, nanosuspensions.