[The effect of age on pharmacokinetic parameters of oxytetracycline and rolitetracycline in rabbits]. / Vplyv veku králikov na niektoré farmakokinetické parametre oxytetracyklínu a rolitetracyklínu.

The effect of rabbit age in the Californian White breed was investigated on oxytetracycline and rolitetracycline concentrations in the blood serum and soft tissues, and on the biological half-life of the given antibiotics. The animals were at the age shortly before sexual maturity or they had reached sexual maturity. Oxytetracycline was administered in form of the preparation Oxymykoin inj. a. u. v. Spofa and roliteracycline nitrate in form of the preparation Rolitetracycline inj. Spofa. These tetracyclines were administered intramuscularly at a single dose of 20 mg per kg liveweight. In comparison with adult animals, in young rabbits the starting concentrations of the two tetracyclines in the blood (first hour) were statistically insignificantly higher; they were resorbed in the systemic circulation in a shorter time and were excreted faster from the blood (mainly oxytetracycline). The significantly lower serum concentrations were recorded in the 6th, 12th and 24th hour after oxytetracycline administration, and in the 12th and 24th hour after rolitetracycline administration. At the same time a decrease was observed in the concentrations of the two oxytetracyclines in the organs and muscles of young animals.

[Penetration of antibiotics into the intervertebral disk]. / Penetrace antibiotika do intervertebrálního disku.

The role of antibiotics in the treatment and prevention of postoperative spondylodiscitis is still controversial. In a group of 15 patients operated on account of lumbar discopathy, the authors investigated the penetration of antibiotics into the intervertebral disc, in correlation to serum levels, when antibiotics were administered during operation. Despite high serum levels rolitetracycline was not detected in extirpated material of the disc, gentamycin reached 2-6% serum levels. The authors give an account of views on the role of antibiotics in the prophylaxis of postoperative spondylodiscitis and recommend their administration in particular in risk groups. They recommend antibiotics in case of early diagnosis of postoperative spondylodiscitis, in the later stages of the disease the role of antibiotics is controversial.

Species specific pharmacokinetics of rolitetracycline.

Comparative studies on some selected pharmacokinetic parameters of rolitetracycline (effective antimicrobial activity levels) in sheep, pigs, rabbits, chickens and pigeons were carried out after intravenous administration of the drug at a dose of 5 mg/kg. The results revealed that a two-compartment open model was usually optimal. Interspecies differences in the rate (alpha) and the volume of distribution (Vda), the area under the serum concentration time curve (AUC) and the total body clearance (ClB) were small. The values of the elimination half-life (t1/2 beta) found in sheep, pigs, rabbits, chickens and pigeons were 1.51, 3.06, 2.18, 4.33 and 2.51 h respectively. These results and data in mice, rabbits and man taken from literature were analysed to determine any correlation to body mass (W). The log of the elimination half-life values (log t1/2 beta) of rolitetetracycline revealed a significant correlation with log values of (W) between animal species. This relationship was described by the equation t1/2 beta = 1.27.W0.29 (r = 0.93, P < 0.01, n = 5) for mammal species and t1/2 beta = 1.81.W0.24 (r = 0.78, P < 0.05, n = 7) for mammal and bird species.

Membranas de colágeno como suporte de liberaçäo controlada de antibióticos / Collagen membranes as support the controlled release of antibiotics

Este trabalho estudou a liberação controlada dos antibióticos rolitetraciclina e ciprofloxacina suportados em membranas de colágeno. No caso de membranas com ciprofloxacina, ocorreu liberação total em 10 min, enquanto que a liberação da rolitetraciclina ocorreu durante um período de 90 min, com valores de k e n de respectivamente 0,10 e 0,48, por meio de um processo de difusão comum. Estes resultados sugerem que a rolitetraciclina suportada pode ser utilizada em periodontia e em implantes dentários.

Abstract: This work studied the controlled release of rolitetracycline and ciprofloxacine supported by collagen membranes. While ciprofloxacine was totally released within a time interval of 1 O min, rolitetracycline was released to only 73% after 90 min, with values for k and n of respectively O, 1 O and 0,48, suggesting a normal diffusion release mechanism. These results suggest that supported rolitetracyclines may be useful with periodontal and dental implant surgery

Estudos de liberaçäo de rolitetraciclina suportada em gel injetável de colágeno aniônico: ramsana / Delivery studies of supported rolitetracycline in injectable gel of anion collagen: ramsana

Um Gel injetável de colágeno: ramasana (75:1) foi estudado como suporte para liberação de antibióticos para o tratamento de doenças periodontais. Os resultados mostraram que nas condições estudadas e na presença do antibiótico rolitetraciclina, a liberação ocorreu por meio de um processo difusional normal, com um valor de n igual a 0,47 + 0,02. A liberação sustentada se manteve por um período de 10 dias, com uma taxa de liberação de cerca de 90 por cento nesse período, tempo compatível para o controle da flora bacteriana junto ao periodonto.