Ciprofloxacin-impregnated poly-L-lactic acid drug carrier. New aspects of a resorbable drug delivery system in local antimicrobial treatment of bone infections.

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 degrees 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 cylinder were initially very high (up to 180 mg/l) 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.

[Resorbable antibiotic delivery systems in local treatment of chronic osteitis--polyglycolic acid/poly-L-lactide as drug carrier. Experimental studies in vitro]. / Resorbierbare Antibiotikumträger zur lokalen Behandlung der chronischen Osteitis--Polyglykolsäure/Poly-L-Laktid als Träger. Experimentelle Untersuchungen in vitro.

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 x 5 mm, 4.5 x 5 mm and 4.5 x 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 degrees 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 phi 3.5 mm x 5 mm, containing 4 mg Ciprofloxacin) were eluated with phosphate buffer (pH 7.4 at 37 degrees 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).(ABSTRACT TRUNCATED AT 250 WORDS)

Endosseous dental implantology from the periodontist's viewpoint.

Oral implantology has been a controversial dental therapeutic procedure for many years. Periodontics, as a specialty, did not really get involved until the word, osseointegration, was placed in the implant nomenclature by Dr. Per-Ingvar Branemark and the attendant success rate for osseointegrated prostheses was presented in a fully documented format. In March 1985, the definition of the scope of periodontics was provisionally changed by the Executive Council of the American Academy of Periodontology to include the discipline of oral implantology. Requirements for Advanced Specialty Education Programs in Periodontics with an effective date of January 1, 1986, include a statement as to the desirability of including implantology in some form in the postdoctoral curriculum. Many implant materials and designs are presently being used in endosseous dental implantology; studies are in progress to evaluate the short- and long-term response of hard and soft tissues to these materials. Continuing, nonbiased research is needed to fully understand and use this promising modality.