In vitro study of the dynamics in elution of antibacterial drugs impregnated into matrices based on polymer hydrogel

The objective was to explore the dynamics and duration of antibiotic elution in samples based on polymer hydrogel and PMMA. Material and methods The samples impregnated with vancomycin, rifampicin and cefazolin at various concentrations were placed in phosphate-buffered saline and incubated at 37 °C. The medium was completely replaced at 1, 3, 7, 14, 21 and 28 days. Spectrophotometry was used to measure concentration of drugs in solution and the release profiles. The median and 95 % CI were employed to statistically describe data obtained from 5 parallel studies. Results Concentrations of the antibiotics eluted from the polymer hydrogel were 7 times greater than those released from PMMA on day 1; 15 times greater on days 2 and 3; 6.6 times greater on day 7 and 3 times or more in the following days of observation. The rate of antibiotic release from hydrogel volumes also differed markedly. Discussion The drug release was more than 70% of the total amount for all hydrogel samples in contrast to PMMA with elution not exceeding 10 %. Despite the fact that a burst release was observed with 80 % of the antibiotic released in the first 5 days as seen in the case of bone cement, the concentration of the drug eluted from hydrogels was several times higher and exceeded the MIC throughout the observation period. The release of the antimicrobial agent from hydrogels was caused by diffusion of the particles from the entire volume of the matrix demonstrating an important advantage over PMMA with the potential being limited by surface depletion. Conclusion At this point, we have shown the possibility of creating potential depot systems based on unsaturated PVA derivatives with controlled release of antibiotics and characteristics being superior to PMMA.