In vitro comparative evaluation of various nanosystems containing Phyllanthus Emblca fruite extract

Abstract

Phyllanthus emblica (Ma-Kham Pom) fruit extract is a well known antioxidant and skin lightening agent. Various extraction methods could render extracts with different biological activities. Thus, the present study aimed to find the most active extract of P. emblica fruit and to propose the most suitable system for skin delivery. Biological activities and total phenolic content were used to select the most active extract prepared by various extraction methods. The chosen active extract was then incorporated into various nanosystems including conventional liposomes, elastic liposomes, niosomes, microemulsions (ME1, ME2, ME3) and nanoemulsions (NE1, NE2, NE3). Nanosystems were evaluated in terms of appearance, particle size and entrapment efficiency. Their stability, in vitro release and in vitro skin permeation were performed. Results showed that the ethanolic extract of dried P. emblica fruit exhibited high antioxidant activity (IC50 = 1.221 ± 0.005 μg/mL), tyrosinase inhibition activity (IC₅₀ = 0.519 ± 0.007 mg/mL) and total phenolic content (490.756 ± 0.185 mg GAE/g of the extract) with high yield. The extract-loaded nanosystems were physically and biologically stable at 4 ºC (for liposomes) or at room temperature (for niosomes, all microemulsions and nanoemulsions except NE2) for at least 8 weeks. Slow releases were observed in all nanosystems. From in vitro skin permeation study using newborn pig skin, all nanosystems could deliver the extract better than their controls. Nanoemulsions and microemulsions were more effective in skin delivery of the extract than the vesicular systems. Amongst the nanosystems, nanoemulsions was the most suitable system for dermal and transdermal delivery of the P. emblica fruit extract. Therefore, nanoemulsions (NE1), microemulsions (ME3) and elastic liposomes were chosen for further development of cosmetic products.