Interações da trancinolona com ciclodextrinas em sistemas multicomponentes

Triamcinolone is a relevant anti-inflammatory costicosteroid drug, used mainly by injectable suspensions due its poor water solubility. The association of triamcinolone with cyclodextrins and co-solvents (triethanolamine TEA and N-methylpirrolidone NMP) was held to solubilize the drug and explain the involved interactions. Phase-solubility diagrams showed that triamcinolone was solubilized forming incredible stable complexes with cyclodextrins, in which bests results were observed applying randomyl-methylated-beta-cyclodextrin (RMβCD) (161 fold on increased solubility). The co-solvents TEA and NMP also enhanced drug solubility 1.4 and 6.7 fold, respectively. The association of both co-solvents with CDs seems decreased complexation stability, but enables higher amount of uncomplexed drug. Experimental magnetic resonance 2D-ROESY and theoretical molecular modeling studies demonstrated TRI-CDs interactions and elucidated the structure of formed complex, which occurred due to the inclusion of ring A of TRI on CDs cavity. Physicochemical aspects of solid binary and ternary complexes prepared by spray drying were assessed by using FTIR, X-ray diffraction and SEM photographs. Dissolution studies showed that binary and ternary associations presented higher dissolution efficacy in detrimental to pure drug system. In addition, the ternary complex containing TEA and RMβCD allowed drug dissolution faster than binary complex with RMβCD. Therefore, given the higher solubility and drug dissolution rate, binary and ternary complexes are new raw materials with great potential for pharmaceuticals containing triamcinolone.