Desenvolvimento de sistemas de liberação modificada à base de cumarinas (escopoletina e cumarina) e ZIF-8

Abstract

Scopoletin (7-hydroxy-6-metoxychromen-2-one, SC) and coumarin (chromen-2-one, CM) are commonly found in several medicinal plants, however, its use in vivo has been a problem due to its low aqueous solubility. Thus, the aim of this work was the development of drug delivery system (DDS) of these coumarins and the Zeolitic Imidazolate Framework-8 (ZIF-8) carrier. Initially, a systematic review of the literature on the pharmacological activities of SC was done. The development of the system SC:ZIF-8 was also done by an in situ method and both SC, ZIF-8 and the system were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), thermogravimetry (TG), differential scanning calorimetry (DSC) and absorption spectroscopy in the Fourier transform infrared region (FTIR). The quantification of SC in the solution was performed by high-performance liquid chromatography with diode-array detection (HPLC-DAD) and the release profile of SC and SC:ZIF-8 was evaluated under non-sink conditions at pHs 4.5 and 6.5. As a basis for the development of CM:ZIF-8, CM was characterized by XRD, SEM, TG, DSC, FTIR techniques, quantified in solution by HPLC-DAD and release profile under non-sink conditions at pHs 2.0, 4.5 and 6.86. SC, SC:ZIF-8 and CM were evaluated for expectorant activity and the antitussive effect, evaluated only for CM. The data showed that SC:ZIF-8 system was obtained with an encapsulation efficiency of 22.5% confirmed from the analytical techniques used. SC also showed expectorant activity at 30 and 100 mg/kg doses. CM was successfully characterized, and its antitussive effect was also observed at the dose of 100 mg/kg. The development of the CM:ZIF-8 system requires optimization since the developed systems had low encapsulation efficiency values or did not obtain adequate release rates.