Optimization and Evaluation of the Quercus infectoria Galls Thermosensitive In Situ Gel for Rectal Delivery

Resveratrol-loaded microemulsion based thermosensitive hydrogel for potential topical treatment of the vaginal inflammation

BACKGROUND

Vaginal inflammation is a prevalent gynecological condition. If left untreated, it can potentially spread to the urinary and reproductive systems.

METHODS

In this study, we propose a resveratrol-loaded microemulsion-based thermosensitive hydrogel (Res-Me-Tsgel) and compare it with a chitosan hydrogel-based Res-Me-Cogel. We characterized the different characters of Res-Me-Tsgel. The safety of Res-Me-Tsgel was also evaluated in vitro and in vivo. Finally, we measured the retention of Res in the vagina after drug administration.

RESULTS

The Res-Me-Tsgel we prepared is a transparent liquid solution at room temperature that rapidly forms a gel at 37oC. Compared to Res solution and Res-Me, both Res-Me-Cogel and Res-Me-Tsgel demonstrate superior sustained release properties. Both in vitro and in vivo studies confirm the excellent biosafety profile of Res-Me-Cogel and Res-Me-Tsgel. Vaginal administration of these formulations in rats results in prolonged retention of resveratrol within the vagina. Notably, due to its improved flow into vaginal folds after administration, the retention of Resveratrol was approximately three times higher for the Res-Me-Tsgel group compared to the Res-Me-Cogel group at 24 h post-administration. Overall, these findings highlight the potential application of Res-Me-Tsgel as an effective means for vaginal inflammation.

CONCLUSIONS

We developed a novel micromulsion based thermosensitive hydrogel for the delivery of Res. The sustained release of Res and favorable vaginal retention from Res-Me-Tsgel make them promise as a potential candidate for local intravaginal therapy.

Curcumin Transferosome-Loaded Thermosensitive Intranasal in situ Gel as Prospective Antiviral Therapy for SARS-Cov-2

Purpose

Immunomodulatory and broad-spectrum antiviral activities have motivated the evaluation of curcumin for Coronavirus infection 2019 (COVID-19) management. Inadequate bioavailability is the main impediment to the therapeutic effects of oral Cur. This study aimed to develop an optimal curcumin transferosome-loaded thermosensitive in situ gel to improve its delivery to the lungs.

Methods

Transferosomes were developed by using 33 screening layouts. The phospholipid concentration as well as the concentration and type of surfactant were considered independent variables. The entrapment efficiency (EE%), size, surface charge, and polydispersity index (PDI) were regarded as dependent factors. A cold technique was employed to develop thermosensitive in-situ gels. Optimized transferosomes were loaded onto the selected gels. The produced gel was assessed based on shape attributes, ex vivo permeability enhancement, and the safety of the nasal mucosa. The in vitro cytotoxicity, antiviral cytopathic effect, and plaque assay (CV/CPE/Plaque activity), and in vivo performance were evaluated after intranasal administration in experimental rabbits.

Results

The optimized preparation displayed a particle size of 664.3 ± 69.3 nm, EE% of 82.8 ± 0.02%, ZP of -11.23 ± 2.5 mV, and PDI of 0.6 ± 0.03. The in vitro curcumin release from the optimized transferosomal gel was markedly improved compared with that of the free drug-loaded gel. An ex vivo permeation study revealed a significant improvement (2.58-fold) in drug permeability across nasal tissues of sheep. Histopathological screening confirmed the safety of these preparations. This formulation showed high antiviral activity against SARS-CoV-2 at reduced concentrations. High relative bioavailability (226.45%) was attained after the formula intranasally administered to rabbits compared to the free drug in-situ gel. The curcumin transferosome gel displayed a relatively high lung accumulation after intranasal administration.

Conclusion

This study provides a promising formulation for the antiviral treatment of COVID-19 patients, which can be evaluated further in preclinical and clinical studies.