Objective To prepare osthole nanosuspension thermosensitive gel (Ost-NS-TG), evaluate its quality, and study for its pharmacodynamics in the treatment of atopic dermatitis. Methods A single-factor experiment combined with orthogonal design was used to optimize the prescription of the temperature-sensitive gel using the gelling temperature as the evaluation index; and quality evaluation of the prepared Ost-NS-TG in terms of properties, gelling temperature, gelling time, pH value, viscosity, ζ potential, drug loading capacity, release and skin irritation was carried out. Finally, the pharmacodynamics of Ost-NS-TG for the treatment of atopic dermatitis was evaluated by dorsal skin lesion scoring, scratching behavior observation, histopathological examination, and detection of inflammatory factors in serum and skin lesion tissues of mice. Results The optimal preparation process of Ost-NS-TG was 18% of Poloxamer 407, 4% of Poloxamer 188, and 5% of Ost-NS lyophilized powder. The gelation temperature of Ost-NS-TG was (32.67 ± 0.06) ℃. The gelation time was (60.88 ± 1.62) s; pH value was 6.68 ± 0.03; the ζ potential was (-32.90 ± 0.89) mV. The drug loading of Ost-NS-TG was (6.96 ± 0.01) mg/mL. The cumulative release rates of Ost-TG and Ost-NS-TG at 144 h were 60.67% and 86.54%, respectively, indicating that Ost-NS-TG exhibits better release characteristics.. The results of the quality evaluation showed that Ost-NS-TG had good dermal safety. The results of pharmacodynamic experiments showed that Ost-NS-TG was able to improve the skin lesions in mice and reduce the expression levels of inflammatory factors immunoglobulin E (IgE), interleukin-4 (IL-4), and interferon-γ (IFN-γ) in serum and skin lesion tissues of mice. Conclusion Ost-NS-TG has a simple and stable prescription process, good slow release and transdermal properties, and has a certain therapeutic effect on atopic dermatitis.

osthole  /  nanosuspension  /  thermosensitive gel  /  pharmacodynamics  /  orthogonal design  /  skin safety  /  atopic dermatitis