IQUIR   05412
INSTITUTO DE QUIMICA ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Evaluation of the Efficacy of ABZ Solid Formulations on Trichinellosis Chronic Stage. Studies in Male and Female CBi Mice with Different Susceptibility to the Infection
Autor/es:
CODINA, A.V.; VASCONI, M.D.; PRIOTTI, J.; LEONARDI, D.; HINRICHSEN, L.I.; SALOMÓN, C.J.; LAMAS, M.C.
Lugar:
San Diego
Reunión:
Congreso; AAPS Annual Meeting and Exposition; 2017; 2017
Resumen:
Purpose: Albendazole (ABZ) is a broad-spectrum anthelmintic agent, substantially effective for oral treatment of trichinellosis. This infection iscaused by Trichinella spiralis and the definitive host becomes infected by eating raw or poorly cooked pork meat containing infective L1 stage larvae encysted in muscle fibres. ABZ is poorly soluble in water, and this is the major obstacle to overcome to development of highly efficient pharmaceutical systems. Recently many micro and nanonization approaches have emerged to increase the surface areas and change crystalline forms. Nano and microcrystals prepared by bottom-up technology is one of the formulation strategies to prepare ABZ solid formulations. Nanocrystals/microcrystals obtained by bottom-up technology may be produced by controlled precipitation and solvent evaporation through spray drying process. Polymers and/or surfactants should be used for crystalstabilization. The aim of this study was to evaluate efficacy of ABZ microcrystals against two lines of female and male mice (CBi/L resistant genotype and CBi+ susceptible genotype) with different behaviour to the infection.MethodsABZ microcrystals were prepared as follows: ABZ was dissolved in acetic acid/ethanol 1:1.5 (ABZ concentration 40 mg/mL). Hydroxyethylcellulose was dissolved in bi-distilled water while chitosan was dissolved in acetic acid 1% v/v (polymer concentration 0.5% w/v). The ABZ solution was added into the polymeric solution, stirred at 1000 rpm. After that, the suspension was dried in a Mini Büchi Spray Dryer B-290 (conditions: temperature 130°C, air flow 35 m3/h, feed rate 5 mL/min, and aspirator set 100%). In order to assay in vivo efficacy, adult mice of the resistant line CBi/L and susceptible line CBi+ were orally infected with 2 L1 larvae/g body weight. Mice were randomly divided, n=4 per treatment group, per line and per sex. Treatment groups were four: control (C), treated with raw ABZ (ABZ), treated with ABZ microcrystals based on hydroxyethylcellulose (M1) or ABZ microcrystals based on chitosan (M2). Doses of 30 mg ABZ/kg body weight were administered orally three days (27, 28 and 29) post-infection, and were sacrificed seven days after last dose. L1 were recovered by artificial digestion of tongues, number of L1 larvae and dead larvae were identified with the methylene blue supravital staining method. The tongue was chosen because it is a preferred site of encystment in mice. Relative larval loads (rLLs) were calculated as number of L1 larvae/g tissue weight and percentages of dead larvae were calculated as (number of dead larvae/number of total larvae) x 100%. Ordinary one-way ANOVA followed by the Bonferroni´s multiple comparison test was used to compare rLL among groups. Differences in percentages of dead larvae were assessed by the nonparametric Kruskall-Wallis test, using Dunn´s test for comparison of groups. In all tests, differences were considered significant if P < 0.05.ResultsTotal rLLs were higher in male mice than in female, in both lines of mice and for all treatment groups. Statistically significant differences were found in M2 in CBi/L line (p=0.0095). Percentages of dead larvae in each group are expressed as median and range:CBi/L male: C 20 (8-29); ABZ 28 (0-37); M1 29 (14-37); M2 64 (18-88).CBi/L female: C 9 (0-25); ABZ 37 (0-68); M1 33 (0-96); M2 50 (6-100).CBi+ male: C 24 (14-33); ABZ 30 (15-60); M1 38 (7-93); M2 54 (13-74).CBi+ female: C 7 (4-14); ABZ 7 (5-21); M1 13 (6-20); M2 12 (5-22).Males and females showed significant differences within CBi+ line (p=0.0348). On the other hand, it can be observed that M2 is the most effective in both lines, except in CBi+ female mice since M1 and M2 had similar efficacy. With respect to the lines, percentages of dead larvae in CBi+ females were lower than in CBi/L females, but this was not observed in males.ConclusionMicrocrystals based on chitosan could be an effective way to improve therapeutic activity of trichinellosis chronic stage. Sex provedto be an important factor in treatment response.