Ilza Maria Oliveira Souza

Docosahexaenoic acid ethyl esther (DHAEE) microcapsule production by spray-drying: optimization by experimental design

O acido docoso-hexaenoico e um acido graxo poli-insaturado essencial que desempenha importantes acoes metabolicas. Entretanto, por possuir duplas ligacoes conjugadas torna-se suscetivel a decomposicao. Uma das formas de minimizar esta possivel decomposicao e o emprego da tecnica de atomizacao para microencapsulacao. Porem, esta tecnica envolve uma serie de parâmetros de processo, que podem vir a alterar a qualidade do produto final. Assim, o objetivo deste trabalho foi microencapsular oleo de peixe enriquecido no ester etilico do acido docoso-hexaenoico (DHAEE-85%), variando condicoes operacionais e avaliar o rendimento pela analise por cromatografia gasosa, apos extracao das microcapsulas. Para tanto, foi utilizado o processo de microencapsulacao por atomizacao e o agente encapsulante foi a goma arabica. A avaliacao cromatografica de varios experimentos delineados pelo software Statistica, mostrou que os pontos otimos para obtencao das microcapsulas de DHAEE foram: temperatura de entrada 188 °C, porcentagem de recheio 30%, vazao de nitrogenio 55 mm N2 e vazao da bomba de 12,5 mL/minuto. Estas condicoes de processo foram testadas experimentalmente, resultando no teor de 66% m/m de DHAEE no oleo extraido, valor correspondente a 19,8% m/m de DHAEE encapsulado, valor considerado satisfatorio uma vez que 30% das microcapsulas correspondiam teoricamente ao material de parede.

Semi-synthetic derivative of Artemisia annua-loaded transdermal bioadhesive for the treatment of uncomplicated Malaria in children caused by Plasmodium falciparum

According to the most recent World Health Organization statistics, malaria infected approximately 219 million people in 2017, with an estimate of 435,000 deaths (World Health Organization, 2018). Communities isolated from cities are the most deprived of access to the necessary hospital facilities. Herein we report the development of a transdermal bioadhesive containing artemether (ART), an alternative, potentially lifesaving, treatment regimen for malaria in low-resource settings. Bioadhesives were prepared from an aqueous blend of hydroxyethylcellulose (4.5% w/w), ART, propoxylated-ethoxylated-cetyl-alcohol, polysorbate 80, propyleneglycol, glycerine, mineral oil, and oleic acid. In this study, the average pore size of bioadhesive 5.5b was 52.6 ± 15.31 μm. Differential scanning calorimetry and thermogravimetric analyses confirm the thermal stability of ART bioadhesives at room temperature. Tensile tests indicated good mechanical properties for bioadhesive 5.5b, when compared to 5.5a, where 5.5b showed elastic modulus 0.19 MPa, elongation at break 204%, tensile stress 0.31 MPa, tensile strength at break 0.23 MPa. Bioadhesion assays suggested that formulations containing surfactants had higher detachment forces. Permeation studies demonstrated that the best outcome was achieved with a bioadhesive containing 25 mg ART (5.5b) that after 24 h released 6971 ± 125 μg, which represents approximately 28% of drug permeation. Data reported presents a promising candidate for a new antimalarial transdermal formulation.