<p>Antibiotics released locally through a carrier is a commonly used technique to prevent infection in orthopaedic procedures. Antibiotic-impregnated bone chips are an interesting carrier in bone reconstructive surgery. Cefazolin is a potentially interesting antibiotic given its proven efficiency in preventing surgical site infection when administered systemically. Preliminary in vitro studies with fresh frozen or processed bone chips impregnated with cefazolin solution showed rapid complete release within a few hours, questioning its potential for local infection prophylaxis. On the other hand, commercially available bone chips impregnated after purification using supercritical CO₂ have been shown to be an efficient carrier for the antibiotics vancomycin or tobramycin. With this in vitro study we wanted to investigate whether this specific type of processing protocol would improve the release pattern of cefazolin. In addition we investigated the impact of the timing of impregnation during the different steps of the processing protocol on the release of cefazolin.</p>