Groundnut oil based emulsion gels for passive and iontophoretic delivery of therapeutics

There is a persistent demand for an efficient drug delivery system, suitable for the delivery of both hydrophilic and lipophilic drugs. This study explores groundnut oil-based emulsion gels for the above-mentioned application. On the basis of stability, two representative gels OG5-80 (low oil content) and OG7-45 (high oil content) were studied further. Analysis of microarchitecture by ESEM and confocal microscopy, in conjugation with fluorescence recovery after photobleaching, confirmed the conversion of the dispersion phase from oil-continuous (OG7-45) to bicontinuous (OG5-80) with increasing water proportion. The gels were viscoelastic with unique stress relaxation properties. Passive and active (iontophoretic) release kinetics of the drugs showed differential release patterns. Mathematical modeling elucidated composition-dependent temporal variation in the drug release and stress relaxation patterns. In vitro cell viability study, cell cycle analysis, and immunocytochemistry divulged compatibility of the gels to human skin cells (keratinocytes). Drug-loaded gels were found active against B. subtilis and E. coli. Hence, groundnut oil-based emulsion gels can be an efficient and stable multimodal carrier system for the passive and the active delivery of both hydrophilic and lipophilic drugs.