ISSN:
1435-2451
Keywords:
Osteomyelitis
;
Local treatment
;
Bioabsorbable cylinders
;
Antibiotic deposit
;
Antibiotic release
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Description / Table of Contents:
Zusammenfassung Als resorbierbare Antibiotikumträger mit prolongierter Freisetzung des Chemotherapeutikums Ciprofloxacin (Ciprobay®, Bayer-Leverkusen) wurden aus Polyglykolsäure (PGS) and Poly-L-Laktid (PLLA) hergestellte Zylinder mit unterschiedlichen Wirkstoffkonzentrationen (0,5–5 mg/Zylinder) in vitro getestet. Die Höhe der Freisetzung des Wirkstoffs wurde im Eluat (Phosphatpuffer oder Plasma) mittels HPLC oder Bioassay bestimmt and mit der aus Gentamicin-PMMA-Kugeln verglichen (gleiche Versuchsbedingungen). Die besten, his zum 155. Tag verfolgten Varianten ergaben Ciprofloxacinkonzentrationen deutlich über der MHK osteitisrelevanter Keime. Im Beobachtungszeitraum konnte ein Zerfall der PLLA-Träger nicht beobachtet werden (Massenabnahme durchschnittlich 8,4%). Aufgrund des frühzeitigeren Zerfalls und der besseren Freisetzungskinetik werden die PGS-Wirkstoffträger für in-vivo-Versuche ausgewählt.
Notes:
Summary Resorbable polyglycolic acid (PGA)- and poly-L-lactic acid (PLLA) cylinders were investigated in vitro to explore their properties as an antibiotic deposit (Ciprobay®, Bayer Leverkusen) with prolonged release. PGA cylinders sized 3.2 × 5 mm, 4.5 × 5 mm and 4.5 × 7 mm respectively were shaped in monofil and polyfil technique. The Ciprofloxacin concentration varied from 0.5 mg to 5.0 mg of each cylinder. The cylinders were eluated in phosphate buffer, pH-value of 7.4, at 37°C. The daily antibiotic release was measured by high performance liquid chromatography. Best combinations we could find demonstrated an initial delivery of Ciprofloxacin in vitro of 67 mg/l. The average daily release was about 16 mg/l during the first 36 days. After complete hydrolysis of the PGA carriers the recovery of Ciprofloxacin reached up to 6.5% and 11.6% respectively. For 40 bioactive cylinders (size ϕ 3.5 mm x 5 mm, containing 4 mg Ciprofloxacin) were eluated with phosphate buffer (pH 7.4 at 37°C) respectively fresh human blood plasma and tested under various conditions. A gentamicin-polymethylmetacrylate (PMMA) chain (Septopal®, E. Merck, Darmstadt) was exposed to equal test conditions for comparison. The quantities of released Ciprofloxacin and Gentamicin were analysed by a microbiological method (bioassay). Initially released rates of Ciprofloxacin were measured very high (up to 180 mg/l) but decreased rapidly within the first 5 days (4.2–22.5 mg/l). The release of Gentamicin produces an initial sharp decrease in concentration during the first 3 days (from 227.5 mg/l to 77.5 mg/l); this is then followed by an almost constant release over a long period of time (about 20 mg/l). Within the observed period of 92 days we could not find an obvious degradation of the cylinders. The loss of mass in relation to initial weight came to 8.4% in average. The recovery of incorporated Ciprofloxacin was 6.5% in average.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00184346
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