Desenvolvimento e avaliação farmacológica de nanocápsulas de cinamato de metila : potencial anti-inflamatório

Abstract

ABSTRACT DEVELOPMENT AND PHARMACOLOGICAL EVALUATION OF METHY L CINNAMATE NANOCAPSULES: ANTI-INFLAMMATORY POTENTIAL . Elizama Shirley Silveira. Advisor: Profª. Drª. Luzia Kalyne Almeida Moreira Leal. Master degree. Program of Post-Graduate in Pharmaceutical Sciences . Department of Pharmacy. Federal University of Ceará, 2013. The methyl cinnamate (MC) is a monoterpene found in the essential oil of medicinal plants of various species, which have antimicrobial and analg esic and activities. In addition, studies have shown that the MC itself has anti-spamodic and anti-inflammatory action. However, the considerable volatility of the MC, poor stability ( stable freshly prepared solution) and lipophilic character is a challenge for further stu dies for the development of pharmaceutical formulations from that monoterpene. In this context , the encapsulation of MC in nanocarriers can be an alternative to overcome or reduce these c hallenges without compromising or even improving the pharmacological characteristics of th e product. Given the above, the objective of this work was the development and characterizati on of nanocapsules of MC (NCMC) through analytical method validation, and to evalua te the possible cytotoxicity and investigate the anti-inflammatory potential of the MC and the N CMC using in vitro assays. To that end, we developed and validated analytical method for id entification and quantification of the MC by UV spectrophotometry, as recommended in Resoluti on RE No. 899 (BRAZIL, 2003). Nanocapsules MC (NCMC) or nanocapsule-white NCW (wi thout MC) were prepared by Eudragit® RS100 polymer interfacial deposition of t he preformed polymer and characterized as the diameter (D), polydispersity index (PDI), ze ta potential (PZ), pH and content; and investigated the stability of the product for 60 da ys at ambient temperature. he in vitro toxicity was evaluated in the NCMC neutrophils or h uman keratinocytes by lactate dehydrogenase activity, and the MTT (Bromide 3 [4,5 -dimethylthiazol-2-yl] -2,5- diphenyltetrazolium bromide) test, while the anti-i nflammatory potential of MC and NCMC was assessed by neutrophil degranulation model indu ced by PMA (phorbol 12- myristate 13- acetate) , (0,1 μ M). For purposes of characterizati on and NCMC stability studies, the spectrophotometric method (270 nm) was validated, b eing specific, linear, precise, accurate and robust. In developing NCCM, among produced form ulations (NCMC1-3), the NCMC3 was selected for the large active content (88.50%) compared with other formulations (NCMC1: 42.48%; NCMC2: 81.60 %); and a diameter (D) average 136.1 ± 1.71 nm and low PDI (0.127 ± 0.01). The NCMC3 presented also an enc apsulation efficiency of 87.03 ± 0.21%. The results obtained with formulations white (NCW1-3) showed that MC does not influence the characteristics. The cytotoxicity of NCMC3 in human neutrophils (LDH) was proportional to the concentration (> 50 μ g/ml) and incubation time ( ≥ 30 min). In the MTT assay in human keratinocytes or neutrophils NCMC3 w as not cytotoxic, and quenched toxicity of free MC. Both the MC (1-100 mg / mL) an d the NCMC (1-100 μ g/mL) showed anti-inflammatory activity by significantly reducin g the degranulation of human neutrophils. In addition, the encapsulation of MC promoted an in crease in this activity in relation to the free MC, with similar magnitude to indomethacin. Th e MC encapsulation nanoscale allowed an increased in the time of stability of terpene an d reduced its cytotoxicity and increase their anti-inflammatory action in human.