The in vitro elution characteristics of vancomycin combined with imipenem-cilastatin in acrylic bone-cements -: A pharmacokinetic study

The aim of this in vitro study was to compare the elution characteristics of vancomycin alone and in combination with imipenem-cilastatin from 3 acrylic bone-cements (CMWI [DePuy International, Blackpool, UK], Palacos R [Schering-Plough, Wehrheim, Germany], and Simplex P [Howmedica International, London, UK]). Six groups of 3 antibiotic-loaded cement disks were prepared, incorporating 2 g of vancomycin (3 groups) and 2 g of vancomycin plus 2 g of imipenem-cilastatin (3 groups). The disks were placed in saline baths for 5 weeks, with the baths being sampled periodically and the elution rates calculated. The total amount of vancomycin released by the cements treated with vancomycin alone was 7.98 mg for CMW1, 7.74 mg for Palacos R, and 6.76 mg for Simplex P; with the addition of imipenem-cilastatin, the total amount of vancomycin released by the 3 cements increased by 30.58%, 50.52%, and 50.15%. CMW1 had better elution characteristics than the other cements when treated with vancomycin alone; the elution of Palacos R and Simplex P was better than that of CMW1 when vancomycin was combined with imipenem-cilastatin.