Enhancement of skin localization of β-carotene from red fruit (Pandanus conoideus Lam.) using solid dispersion-thermoresponsive gel delivered via polymeric solid microneedles

[Display omitted] •Beta carotene extract from Papuan red fruit were incorporated into solid dispersion.•Solid dispersion-loaded thermoresponsive gel delivered by polymeric solid microneedles.•The combination showed desirable characteristics for enhanced skin localization.•In vitro release exhibits a seven-fold increase compared to plain hydrogel.•The combination enhanced in vivo dermato-pharmakokinetic parameters by 200–400%. Red fruit (Pandanus conoideus Lam.) boasts high β-carotene (BC) content, often consumed orally. However, absorption issues and low bioavailability due to food matrix interaction have led to transdermal delivery exploration. Nevertheless, BC has a short skin retention time. To address these limitations, this study formulates a β-carotene solid dispersion (SD-BC) loaded thermoresponsive gel combined with polymeric solid microneedles (PSM) to enhance in vivo skin bioavailability. Characterization of SD-BC includes saturation solubility, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and in vitro release. Characterization of SD-BC thermoresponsive gel includes gelation temperature, viscosity, rheological behaviour, pH, bio-adhesiveness, spreadability, and extrudability. PSM’s mechanical properties and insertion capability were assessed. Ex vivo and in vivo dermato-pharmacokinetic studies, drug content, hemolysis, and skin irritation assessments were conducted to evaluate overall performance. Results confirm amorphous SD-BC formation, enhancing solubility. Both SD-BC thermoresponsive gel and PSM exhibit favourable characteristics, including rheological properties and mechanical strength. In vitro release studies showed a seven-fold increase in BC release compared to plain hydrogel. SD-BC thermoresponsive gel combined with PSM achieves superior ex vivo permeation (Cmax = 305.43 ± 32.07 µg.mL−1) and enhances in vivo dermato-pharmacokinetic parameters by 200–400 %. Drug content, hemolysis, and skin irritation studies confirmed its safety and non-toxicity.