Amikacin sulfate

Eight antibiotics frequently used in clinical practice were evaluated in this study: amikacin sulfate (014‐24941, Wako, Osaka, Japan; AMK), cefazolin sodium salt (CEZ; 038‐22981; Wako, Osaka, Japan), cefotiam hydrochloride (CTM; 029‐22911; Wako), daptomycin (DPT; 103060‐53‐3; Wako), minocycline hydrochloride (MINO; PAA105932; Pfizer, NY), piperacillin (PIPC; P3462; LKT Laboratories, MN), teicoplanin (TEIC; 1756‐100; Wako), and vancomycin hydrochloride (VCM; 226‐01301; Wako). The concentration of the antibiotic solution in porous HAp/Col for each animal experiment was generally decided assuming a systemic daily dose per 5 cm³ of porous HAp/Col and considering the solubility in saline (Table 1). The volume percentage of antibiotic solution that infiltrated into porous HAp/Col was 60%.

The minimum inhibitory concentrations (MIC) of several antibiotics were determined by the agar dilution method using Muller-Hinton agar II (Difco, Franklin Lake, NJ, USA) according to the method recommended by the Japanese Society of Chemotherapy. The antibiotics used were chloramphenicol 8–1024 µg/mL (Wako, Japan), ciprofloxacin 0.0625–32 µg/mL (LKT Laboratories, St Paul, MN, USA), tetracycline hydrochloride 0.5–128 µg/mL (Wako, Japan), amikacin sulfate 0.25–128 µg/mL (Wako, Osaka, Japan), aztreonam 0.25–32 µg/mL (MP Biomedicals, USA), imipenem 0.125–32 µg/mL (MSD K.K., Tokyo, Japan), rifampicin 2–512 µg/mL (Tokyo Chemical Industry, Tokyo, Japan), and minocycline hydrochloride 1–256 µg/mL (Tokyo Chemical Industry, Tokyo, Japan). The standard laboratory strain, PAO1S, and representative clinical isolated strain, 8380 strain, were used as control. All experiments were performed in triplicate.