Desenvolvimento de sistema terapêutico transdérmico híbrido à base de Annona muricata L. com potencial antiinflamatório: caracterização físico-química, avaliações in vitro e in vivo

Abstract

Rheumatoid arthritis is a chronic inflammatory disease that causes tissue destruction and deformities. It is a disabling disease, but with early diagnosis lines of treatment can be implemented to slow the progression of the disease. The available and commonly used drugs are non-steroidal anti-inflammatory drugs, glucocorticoids and anti-rheumatics, however the chronic use of these drugs has limitations due to adverse effects. With this, the search and development of a treatment based on plant active pharmaceutical ingredient (IFAV) and transdermal therapeutic systems (STT) become promising and necessary. The objective of this study was to obtain the extract from the leaves of Annona muricata, to develop and characterize a transdermal therapeutic system containing the extract, as well as to evaluate the anti-inflammatory activity. The IFAV was characterized through granulometric analyses, bulk density, loss on drying, pH and ash content. Then, the quantification of total flavonoids was performed. The extract was characterized by thermogravimetry, and analyzed for cytotoxicity in a human hepatoma cell line (HepG2). The in vivo assays corresponded to the acute toxicity test of the extract and the paw edema test induced by 2% zymosan, at concentrations of 10, 100 and 200 mg/kg. The second part of the research consisted of developing STT, firstly the hybrid materials were synthesized by the sol-gel method. The physical-chemical characterization was performed by atomic force microscopy (AFM), small angle X-ray scattering (SAXS) and thermogravimetry (TG). The in vivo study was performed against the paw edema test. The results regarding the physicochemical characteristics of the plant drug reveal a moderately thick powder, with a density of 0.30 ± 0.01 g/mL, loss on desiccation of 8.82 ± 3.4%, pH 5.54 ± 0 .1, total ash 8.04% ± 0.26 and acid insoluble ash 1.56 ± 0.19. Thermogravimetry showed three events, the first between 31.55 and 200.05 °C with a mass loss (Δm) of 24.34%, the second between 200.05 and 376.38°C, with a Δm of 37.92% and the third with between 376.38 and 499.41 °C, with Δm of 14.08%. The events were associated with the loss of volatile products and degradation of micro and macronutrients. The maceration method, in a 70:30 ethanol/water ratio and 2% concentration of IFAV, resulted in an extract with a higher concentration of total flavonoids. In the in vitro cytotoxicity results, the IC50 of the extract was 8.95 ± 0.21 µg/ml and, in concentrations lower than or equal to 0.20781 µg/ml, they did not show cytotoxicity. The in vivo test of acute toxicity through Hippocratic screening and organ analysis did not reveal any significant change in the signs of animals treated with a dose of 2000 mg/kg during the 14 days of analysis. The model for antiinflammatory activity by paw edema showed a 100% reduction for the group treated with the extract at a concentration of 10mg/kg, sustained for 4 hours. Subsequently, the hybrid system was synthesized and the extract was incorporated in the proportion of 6% m/m. Visual results demonstrate a homogeneous system with a dark green color. AFM revealed pores on the surface of the material in the order of 1.575 μm. SAXS demonstrates that the “silicon knots” have a distance of 2.33 nm and increase to 33 nm after 30 minutes in the nanoscopic swelling test. Thermogravimetry revealed that the extract has greater thermal stability when incorporated into the system. Finally, the in vivo test revealed that the commercial ointment and the system with extract after 30min, 1, 2, 4 and 6hrs showed inhibition of 28.15; 31.06; 75.72; 44.66 and 37.86% and 23.30; 94.17; 118.44; 84.46 and 43.68%, respectively, demonstrating that the developed system has better anti-inflammatory activity.