Supramolecular polyelectrolyte complexes based on cyclodextrin-grafted chitosan and carrageenan for controlled drug release.

In the present study, supramolecular polyelectrolyte complexes (SPEC) based on a cyclodextrin-grafted chitosan derivative and carrageenan were prepared and evaluated for controlled drug release. Samples were characterized by FTIR, SEM, and ζ-potential measurements, which confirmed the formation of the polymeric complex. The phenolphthalein test confirmed the presence and availability of inclusion sites from the attached ßCD. Silver sulfadiazine was used as the model drug and the association with the SPEC was studied by FTIR and computational molecular modeling, using a semi-empirical method. DRS and TEM analyses have shown that Ag+ ions from the drug were reduced to form metallic silver nanostructures. In vitro tests have shown a clear bacterial activity toward Gram-positive bacteria Staphylococcus aureus and Enterococcus durans/hirae and Gram-negative bacteria Klebsiella pneumoniae and Escherichia coli. Finally, this work shows that ßCD-chitosan/carrageenan supramolecular polyelectrolyte complexes hold an expressive potential to be applied as a polymer-based system for controlled drug release.

Orofacial antinociceptive effect and antioxidant properties of the hydroethanol extract of Hyptis fruticosa salmz ex Benth.

ETHNOPHARMACOLOGICAL RELEVANCE: Hyptis fruticosa is a plant native to Brazil with antinociceptive and antiinflamatory properties. This study evaluated the antinociceptive activity of the hydroethanol extract of the plant leaves (CHEE) against orofacial pain as well as its in vitro effect against lipid peroxidation. MATERIALS AND METHODS: The antinociceptive activity was investigated in mice orally treated with different doses of the CHEE (50, 100, and 200 mg/kg) and morphine (5 mg/kg) using formalin, glutamate, and capsaicin orofacial pain models using. Lipoperoxidation was induced in egg yolk by AAPH and FeSO4 in the absence and presence of the CHEE (5, 50, 100, and 150 µg/mL). RESULTS: CHEE (200 mg/kg) significantly reduced (ρ<0.001) the pain response in the first (69.6%) and second (81.8%) phases of the formalin test, while the nociception caused by capsaicin was significantly (ρ<0.001) reduced by up to 62% at 200 mg/kg of extract. When glutamate was used as algogen, a significant (ρ<0.001) nociception reduction of up to 85% at 200 mg/kg extract was observed. CHEE showed a higher protection against lipoperoxidation caused by FeSO4 (82.3% TBARS inhibition) than AAPH (35.7% TBARS inhibition) at 150 µg/mL. CONCLUSION: Hyptis fruticosa leaf CHEE is of pharmacological interest because it was able to inhibit the peripheral and central transmission of orofacial pain, while reducing the spreading of the inflammatory processes by neutralizing reactive oxygen species, which are by-products in the biosynthesis of pain mediators.