ABSTRACT
Formulating low-solubility or low-permeability drugs is a challenge, particularly with the low administration volumes required in intranasal drug delivery. Nanoemulsions (NE) can solve both issues, but their production and physical stability can be challenging, particularly when a high proportion of lipids is necessary. Hence, the aim of the present work was to develop a NE with good solubilization capacity for lipophilic drugs like simvastatin and able to promote the absorption of drugs with low permeability like fosphenytoin. Compositions with high proportion of two lipids were screened and characterized. Surprisingly, one of the compositions did not require high energy methods for high droplet size homogeneity. To better understand formulation factors important for this feature, several related compositions were evaluated, and their relative cytotoxicity was screened. Optimized compositions contained a high proportion of propylene glycol monocaprylate NF, formed very homogenous NE using a low-energy phase inversion method, solubilized simvastatin at high drug strength, and promoted a faster intranasal absorption of the hydrophilic prodrug fosphenytoin. Hence, a new highly homogeneous NE obtained by a simple low-energy method was successfully developed, which is a potential alternative for industrial application for the solubilization and protection of lipophilic actives, as well as (co-)administration of hydrophilic molecules.
ABSTRACT
Objetivou-se avaliar a atividade antibacteriana in vitro da própolis marrom, por meio da determinação da Concentração Inibitória Mínima (CIM). O extrato alcoólico de própolis foi obtido de 35 g de própolis bruta macerada em 65 mL de álcool de cereais. As concentrações do extrato de própolis usadas foram: 75mg/mL; 56,4mg/mL; 37,5mg/mL; 18,9mg/mL; 9,3mg/mL; 4,5mg/mL e 2,25mg/mL. Foram utilizados 32 isolados de bactérias Gram-positivas: Rhodococcus equi, Staphylococcus aureus, Staphylococcus hyicus, Staphylococcus spp. e Streptococcus spp., e 32 isolados de bactérias Gram-negativas: Enterobacter agglomerans, Escherichia coli, Klebsiella pneumoniae, Klebsiella sp., Pseudomonas aeruginosa, Pseudomonas spp., Salmonella spp. e Serratia rubidaea, provenientes de processos clínicos infecciosos de animais domésticos, obtidas e armazenadas no Laboratório de Bacteriologia da FAMEZ/UFMS. O extrato de própolis marrom apresentou atividade antimicrobiana com CIM variando de 2,25 a 18,9mg/mL para as bactérias Gram-positivas e 4,5 a 18,9mg/mL para as bactérias Gram-negativas, sendo as bactérias provenientes de bovinos e caninos as mais resistentes. Conclui-se que a própolis marrom tem ação bactericida, em função da espécie da bactéria e da procedência animal.
The aim of this study was to evaluate the in vitro antibacterial activity of brown propolis, by determining the minimum inhibitory concentration (MIC). The alcoholic extract of propolis was obtained from 35g of crude propolis macerated in 65mL of cereals alcohol. Dilutions of propolis extracts used were: 75mg/mL; 56.4mg/mL; 37.5mg/mL; 18.9mg/mL; 9.3mg/mL; 4.5mg/mL, and 2.25mg/mL. Thirty-two Gram-positive bacteria isolates were used: Rhodococcus equi, Staphylococcus aureus, Staphylococcus hyicus, Staphylococcus spp. and Streptococcus spp.; and the thirty-two Gram-negative bacteria isolated were: Enterobacter agglomerans, Escherichia coli, Klebsiella pneumoniae, Klebsiella sp., Pseudomonas aeruginosa, Pseudomonas sp., Salmonella sp., and Serratia rubidaea, obtained from infectious clinical processes of domestic animals, and stored in the Laboratory of Bacteriology of FAMEZ/UFMS. The brown propolis extract showed antibacterial activity with MIC ranging from 2.25 to 18.9mg/ml for Gram-positive bacteria and 4.5 to 18.9mg/ml for Gram-negative bacteria, and bacteria from cattle and dogs were more resistant. It was concluded that brown propolis has antibacterial action, but the effect depends on the species of the bacterium and its origin.
