Ciprofloxacin-impregnated poly-l-lactic acid drug carrier

Summary

Resorbable poly-l-lactic acid (PLLA) cylinders (3.5 mm diameter, 5 mm in length) carrying 6% of weight ciprofloxacin (Ciprobay, Bayer AG, Leverkusen, FRG) were investigated in vitro to explore their properties as a slow-release antibiotic deposit. Forty bioactive cylinders stored in test tubes were covered with phosphate buffer (pH 7.4 at 37°C) and 40 with fresh human blood plasma and tested under various conditions. For comparison a gentamicin-polymethylmethacrylate (PMMA) chain (Septopal, E. Merck, Darmstadt, FRG) was exposed to similar test conditions. The quantities of ciprofloxacin and gentamicin released were analysed by a microbiological method (bioassay). The concentrations of ciprofloxacin released were analysed by a microbiological method (bioassay). The concentrations of ciprofloxacin released from 40 cyclinder were initially very high (up to 180 mg/1) but they decreased rapidly within the first 5 days (4.2–22.5 mg/l). Early release of gentamicin reached up to 227.5 mg/l but dropped to of 22 mg/l on the 14th day. Complete degradation of the PLLA-cylinders was not seen in the observed period of 92 days. The mean loss of mass was 8.4%, The recovery of incorporated ciprofloxacin was 6.5% on average.