Shinto Y, Uchida A, Korkusuz F, Araki N, Ono K
Department of Orthopaedic Surgery, Osaka University Medical School, Japan.
J Bone Joint Surg Br. 1992 Jul;74(4):600-4. doi: 10.1302/0301-620X.74B4.1320622.
Porous blocks of calcium hydroxyapatite ceramic were evaluated as delivery systems for the sustained release of antibiotics. We tested gentamicin sulphate, cefoperazone sodium, and flomoxef sodium in powder form placed in a cylindrical cavity in calcium hydroxyapatite blocks, using in vitro studies of elution and in vivo studies in rats. Gentamicin sulphate gave a maximum concentration within the first week, which gradually decreased but was still effective at 12 weeks, when 70% of the antibiotic had been released. Even at this stage the antibiotic concentration from a 75 mg dose was five times the minimum inhibitory concentration for staphylococci. In the in vivo studies the release of gentamicin sulphate into the normal bone of rats was at similar rates and levels. The bacteriocidal activity of the drugs was not affected by packing into calcium hydroxyapatite ceramic and the blocks were completely biocompatible on histology. This new system overcomes the disadvantages of other drug delivery systems, avoiding thermal damage to the antibiotics and a second operation for the removal of the carrier. Some mechanical strength is provided by the ceramic and healing may be accelerated by bone ingrowth into its micropores.
羟基磷灰石陶瓷多孔块被评估为抗生素缓释的给药系统。我们将硫酸庆大霉素、头孢哌酮钠和氟氧头孢钠制成粉末状，置于羟基磷灰石块的圆柱形腔体内，进行了体外洗脱研究和大鼠体内研究。硫酸庆大霉素在第一周内达到最高浓度，随后逐渐下降，但在12周时仍有效果，此时70%的抗生素已释放。即使在这个阶段，75毫克剂量的抗生素浓度仍是葡萄球菌最低抑菌浓度的五倍。在体内研究中，硫酸庆大霉素向大鼠正常骨中的释放速率和水平相似。药物的杀菌活性不受装入羟基磷灰石陶瓷的影响，并且这些块在组织学上完全具有生物相容性。这种新系统克服了其他给药系统的缺点，避免了对抗生素的热损伤以及去除载体的二次手术。陶瓷提供了一定的机械强度，骨长入其微孔可能会加速愈合。
