Difusión de cotrimoxazol a través de un expansor tisular: Estudio in vitro

introduction: infection associated with tissue expansion is one of the main complications and force to take away the tissue expander. an alternative to avoid this action is to dilute antibiotics inside it. the aim of this experiment was to quantify the concentration of cotrimoxazole diffused through a tissue expander at different expansion and pressure volumes. material and methods: a test was performed with 12 tissue expanders immersed in a closed system. these were divided in 4 sets according to the introduced expansion rate. three independent variables were considered: percentage of lumen volume introduced into the expander, pressure inside the expander, and experiment duration. the concentration of the drug diffused through the expander was taken as dependent variable. the solution in which the expander was immersed was continuously sampled and drug concentration was determined by high performance liquid chromatography (hplc). anova was used to determine differences between concentrations measured of every variable applied. results: only trimethoprim (tmx) diffused. no lineal correlation was observed between expansion rate and pressure inside the expander. the difference with respect to time and concentration of the drug outside the expander was statistically significant among the 4 sets of expanders (p = 0.0000). conclusion: sulfametoxazole (smx) did not diffuse and crystallized inside the expander because of the different pk of the two drugs (smx-tmx) respect to ph of dilution which was similar to pk of trimethoprim. the expansion rate had a proportional effect on tmx concentration outside the expander: an over-expansion of the system greater than 200% increases diffusion highly.