Quantitative study on Vancomycin release from cement in 3 different formulations: preliminary results and antimicrobial activity

The purpose of this study is to investigate the best preparation method of the cement powder mixture, solvent and antibiotic in order to obtain the greatest amount of antibiotic in the joint for the longest time as possible. At time T0 the three samples, packed in a sterile environment in different formulations, were placed in sterile tubes, adding to each one 5 ml of saline phosphate buffer solution (PBS) and put in a stove at 37°C for 24 h. A sample of PBS without cement (T control) was also created. Qualitative and quantitative assessment of the incubated liquid with cement was performed along with biochemical analysis with High Performance Liquid Chromatography (HPLC). The analysis of the raw data demonstrated that at T1 there was a prevalence of antibiotic release from sample , compared to sample 2 and 3. This difference was maintained until the T20; from T21 the antibiotic release gradually leveled in 3 samples. The elution of the antibiotic remained detectable up to T60. Our work shows that the sample preparation is decisive on the quantity of released antibiotic. These results are confirmed by microbiological tests. It is useful to know the actual kinetics of antibiotics in articulation. Further studies are necessary to determine the effectiveness of antibiotic against micro-organisms and how long it acts.