Standardization and quantitative analysis of Araucaria Heterophylla extract via an UPLC-MS/MS method and its formulation as an antibacterial phytonanoemulsion gel

Abstract

Abstract Skin infections are among the bacterial infections that present significant therapeutic challenges due to antibiotic resistance. Recently, herbal products clutched a significant attention as safe replacements for other medications but their low aqueous solubility and poor bioavailability are considered major challenges which could be circumvented via formulation. As a species of genera Araucaria, Araucaria Heterophylla possesses pharmacological activities such as antioxidant and antibacterial actions, and this study aimed to standardize the extract of the plant against 4ʹʹʹmethoxyamentoflavone (as a main component of the extract) through a validated UPLC-MS/MS method and evaluate its antibacterial activity, which was followed by loading the standardized extract into a nanoemulsion to form a phytonanoemulsion (PNE), where the design analysis and optimization were performed through a simplex lattice design. The optimized PNE (PNE 3) was then loaded into HPMC/Pluronic F-127 gel (in ratio 1:4) to sustain the release of the active constituent. The heightened penetrability of PNE 3 gel was visualized via confocal laser scanning microscopy, and its prolonged effect was proved thru an in vivo study conducted on male Wistar rats. A histopathological study revealed the safety of the formulation when applied topically. Thus, PNE gel could be a potentially broad-spectrum antibacterial drug delivery system.