Qualitative phytochemical profiling, antioxidant activity, and development of a water-in-oil cream containing combined oil and water infusions of frankincense resin (Boswellia spp.): a preliminary in vitro study

Background Frankincense (gum olibanum, Boswellia spp.) is an oleo-gum resin widely used in traditional medicine and cosmetics owing to the presence of volatile oils and pentacyclic triterpenic acids (boswellic acids) with reported anti-inflammatory and antioxidant properties. Objectives The aim of this study was to extract and characterize oil- and water-soluble fractions of frankincense resin, evaluate their antioxidant potential, and incorporate them into a stable water-in-oil ( w/o ) nourishing/antiaging cream. Methods Frankincense resin was ground and macerated separately in sweet almond oil and Madinah rosewater to yield oil and water infusions, respectively. Qualitative phytochemical tests and FT-IR spectroscopy were employed for the characterization of both extracts and final formulations. Antioxidant potential was assessed using the DPPH assay followed by the development of a w/o cream (beeswax:almond oil:rosewater base) using combined infusions, which was evaluated for pH, viscosity, phase separation, spreadability, and thermal stability. Results Phytochemical screening showed presence of triterpenoids and boswellic type functionalities predominantly in the oil infusion, whereas saponins and minor alkaloids were detected in the water infusion. In the DPPH assay, significant free radical scavenging activity was observed as sample 2 showed 71% inhibition at 343.46 ± 34.2 μg/mL. The developed cream formulation showed good physical stability, acceptable pH and shear-thinning rheology. Conclusion A stable, all-natural w/o cream formulation was developed incorporating combined oil- and water-soluble frankincense infusions. Future studies are warranted to perform quantitative chemical analysis, in vitro skin permeation, and formal skin safety testing to ensure uninform active content, good bioavailability and tolerability prior to clinical studies.