• Journal of Pharmaceutical Investigation
• /
• v.35 no.5
• /
• pp.333-336
• /
• 2005

The objective of this study was to investigate the stability of tetracycline HCl on encapsulation into and inside reverse micelles. To do so, tetracycline HCl was first mixed with cetyltrimethylammonium bromide, water and ethyl formate to make reverse micelles. The degradation kinetics of tetracycline HCl inside the reverse micelles was then assessed by scrutinizing its stability data. Under our experimental conditions, the reverse micelles formed spontaneously in absence of any mixing devices. During the preparation of the reverse micelles, however, considerable portions of tetracycline HCl underwent a chemical reaction (e.g., epimerization). For instance, $51.4{\pm}0.6%$ of an initial concentration of tetracycline HCl was transformed into a degradation product. Once dissolved inside the reverse micelles, the degradation of tetracycline HCl followed an exponential decay pattern. The plot of log{the degradation rate of tetracycline HCl} versus log{tetracycline HCl concentration} made it possible to determine the order of degradation reaction and rate constant. It was proven that the degradation of tetracycline HCl inside the reverse micelles followed a first order kinetics with a rate constant of 0.0027 $hour^{-1}$. Meriting further investigation might be formulation studies to stabilize tetracycline HCl on encapsulation into and inside the reverse micelles.

• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.1
• /
• pp.27-37
• /
• 2021

Tetracycline is one of the most commonly used as antibiotics for the livestock industry and it is still widely used nowadays. Tetracycline and its metabolites are excreted with excrement, which is difficult to completely removed with conventional sewage treatment, therefore it is apprehended that the tetracycline-resistant bacteria occurs. In this study, the oxidant named ferrate(VI) was used to degrade the tetracycline and investigate the reaction between ferrate(VI) and tetracycline under various aqueous conditions. The highest degradation efficiency of tetracycline occurred in basic condition (pH 10.1 ± 0.1) because of the pKa values of tetracycline and ferrate(VI). The results also showed the effect of water temperature on the degradation of tetracycline was not significant. In addition, the dosage of ferrate(VI) was higher, the degradation of tetracycline and the self-degradation of ferrate(VI) also higher, finally the efficiency of ferrate(VI) was lower. The results said that the various mechanisms effects the reaction of ferrate(VI) oxidation, it required the consideration of the characteristics of the target compound for optimal degradation efficiency. Additionally, intermediate products were detected with LC/MS/MS and three degradation pathways were proposed.

• Journal of Korean Society on Water Environment
• /
• v.22 no.3
• /
• pp.527-533
• /
• 2006

Tetracycline is one of the mostly used antibiotics around the world. The purpose of this study was to evaluate the fate of two different types of tetracycline resistant bacteria in biological wastewater treatment plants. Tetracycline resistant enterics and heterotrophic bacteria were monitored under two different lab-scale experimental conditions. Tetracycline resistant enteric bacteria showed the lower percentages of total enteric bacteria and net specific growth rate in the monitored activated sludge system as compared to tetracycline resistant heterotrophic bacteria. Therefore, total enterics, potentially E.coli, might not be the best indicator microorganism for evaluating the antibiotic resistant bacteria in biological wastewater treatment plant.

• Journal of Life Science
• /
• v.16 no.5
• /
• pp.799-805
• /
• 2006

The in vitro activities of quinolones were determined with 36 strains of tetracycline- resistant, 39 strains of erythromycin-resistant, 21 strains of both resistant to tetracycline and erythromycin, and 27 strains of both susceptible to tetracycline and erythromycin of the M. pneumoniae isolates which have been isolated and classified in previous studies. The $MIC_{90}$ of moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, amikacin, and clarithromycin against 36 strains of tetracycline-resistant M. pneumoniae isolates were 0.125, 0.39, 0.125, 1.0, 1.0, 15.6, and $1.56\;{\mu}g/ml$, respectively. The $MIC_{90}$ against 39 strains of eryhtromycin-resistant M. pneumoniae isolates were 0.06, 0.39, 0.125, 1.0, 1.0, 15.6, and $25.0\;{\mu}g/ml$, respectively. The $MIC_{90}$ against 21 strains of both resistant to tetracycline and eryhtromycin of M. pneumoniae isolates were 0.125, 0.39, 0.125, 1.0, 1.0, 3.9, and $1.56\;{\mu}g/ml$, respectively. The $MIC_{90}$ against 27 strains of both susceptible to tetracycline and eryhtromycin of M. pneumoniae isolates were 0.125, 0.39, 0.125, 1.0, 1.0, 7.8, and $0.09\;{\mu}g/ml$, respectively. These result suggest that moxifloxacin, levofloxacin, and sparfloxacin of the quinolones might be promising antimicrobial agents for the treatment of tetracycline- and erythromycin-resistant M. pneumoniae infection. However, selection of ofloxacin, ciprofloxacin, and clarithromycin for the treatment of M. pneumoniae infection should be cautious decision with antimycoplasmal susceptibility test.

• Journal of Periodontal and Implant Science
• /
• v.27 no.1
• /
• pp.79-90
• /
• 1997

The purpose of this study was to evaluate the substantivity of experimentally developed gel type tetracycline HCl and a mixture of tetracycline-citric acid gel, and compare to those of solution type tetracycline HCl. 11 extracted anterior teeth were subjected to this study. After scaling and root planing teeth were randomly divided into 3 treatments groups : group 1; 3 teeth were irrigated with tetracycline HCl(50mg/ml) solution , group 2; tetracycline gel (5%) was inserted in the periodontal pockets of 3 teeth, group 3; a mixture of tetracycline and citric acid gel was inserted in the pockets of 3 teeth. And 2 teeth treated in 0.9 % sterile saline served as controls. After 5-minute exposure, each tooth immediately extracted and incubated at room temperature for 22 days in tris-buffered saline as a desorption media. The total volume of TBS was removed and replaced with fresh TBS, at 24-h intervals. Removed desorption media transferred to a sterile vial and stored at -70 oC. This procedure was repeated every 24 h throughout the 22-day desorption period. Using Porphyromonas gingivalis as an indicator organism, a microtiter assay was used to evaluate antimicrobial activity desorbed from the teeth. 1. 50mg/ml tetracycline HCl solution exhibited the longest antimicrobial activity. Compared to saline treated group, it showed significant difference on the day 1 and day 2 desorption period. 2. The ODs of 5% tetracycline gel and a mixture of tetracycline-citric acid gel were significantly different during the first 24 hour only. 3. There was no statistically significant difference after the day 3 between the groups.(p<0.05). Despite our expectation a mixture of tetracycline-citric acid gel did not show longer antimicrobial activities than those of tetracycline gel, and the solution type exhibited the longest activities. Because the gel type agents may stay in the subgingival environment longer than the solution, if the teeth were not extracted immediately after the delivery of the agent, the result could be different. hus this result suggests the possibilities of practical use of these kind of gel type agents.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.1
• /
• pp.95-99
• /
• 1987

When tetracycline resistancy were cured by ethidium bromide treatment, some of the cured strains lost the tetracycline resistance plasmid while other strains kept the plasmids. Both strains of lost and remained plasmids were digested with restriction endonuclease Hind III and these cleaved plasmids were compared with that of parent strains, two plasmid remained strains showed same cleavage patterns between parent and cured strains, however, one plasmid lost strain showed dissimilarity with parent strain, but in the other one strain, among 4 plasmid lost colonies, 2 showed same but other 2 showed different patterns compared to parent strain. Tetracycline was transfered by conjugation in on set(Staphylococcus aureus donor versus Staphylococcus epidermidis, recipient) with relative high frequency but the other 2 sets showed a low degree of frequency and the other 2 sets exhibited no transfer.

• The korean journal of orthodontics
• /
• v.5 no.1
• /
• pp.33-41
• /
• 1975

To study the effect of the tetracycline-HCl on the growth of the rats, the author made a daily injection of tetracycline-HCl in the amount of 40mg/kg of body weight to the lactating mother and weanling rats for 7 days. Lactating and weanling young rats were killed at a week intervals and removed tibia and mandible from soft tissues. The effect of the tetracycline on the growth of rats were analysed from the weight, the length of tibia and the size of mandible. The results were as follows: 1. Tetracycline inhibited the growth of young rats. 2. Inhibitory effects were greater ill the weanling group than the lactating group. 3. The inhibitory effect was marked just after the injection of tetracycline-HCl in body weight and after a week in mandible and tibia. 4. The inhibitory effect of growth nab continued for 2-3 weeks in body weight and 3-4 weeks in tibia and mandible. 5. In growth of mandible, the antero-posterior growth was more inhibited than the vertical.

• Journal of Periodontal and Implant Science
• /
• v.27 no.4
• /
• pp.751-765
• /
• 1997

Periodontal disease is a bacterially causal by disease, To remove plaque and bacteria, it has been necessary to prescribe chemical drug to patient to subjugate therapeutic unvalue by mechanical scaling. As a patient on a high dosage of the antibiotics to maintain the effective concentration may produce unfavorable side effects, this decase demands the Slow-release local drug delivery system. The object of the experiment is to study on the slow-release local drug delivery effects of calcium sulfate compounded with tetracycline that mainly used in periodontal disease. Experimental groups were divided into four classes as follow: Group 1 10% tetracycline compounded modified calcium sulfate paste. Group 2 : compounded and hardened 10% tetracycline and calcium sulfate. Group 3 : compounded 10% tetracycline and calcium sulfate, used Just before hardened. Group 4 : tetracycline-ethylene vinyl acetate fiber. In the four groups, release concentration, it's durability and the period of absorption by times are observed and concluded as follow: 1. An effective concentration($4{\mu}g/ml$) remained until 5 weeks in group 1, 9 days in group 2, 7 days in group 3, 15 days in group 4. 2. It was fully fused at 11.8 days average in group 2 and 14.8 days average in group 3. . There were no statistically significant results in tetracycline concentration until a week in group 2 and 3(p<0.05) These results suggest that tetracycline loaded calcium sulfate release sufficient tetracycline and fused in $11{\sim}14$ days, so calcium sulfate is useful carrier as slow release local drug delivery system.

• Journal of Environmental Science International
• /
• v.23 no.3
• /
• pp.379-386
• /
• 2014

Adsorption and biodegradation performance of tetracycline antibiotic compounds such as ttetracycline (TC), oxytetracycline (OTC), minocycline (MNC), chlortetracycline (CTC), doxycycline (DXC), meclocycline (MCC), demeclocycline (DMC) on granular activated carbon (GAC) and anthracite-biofilter were evaluated in this study. Removal efficiency of seven tetracycline antibiotic compounds showed 54%~97% by GAC adsorption process (EBCT: 5~30 min). The orders of removal efficiency by GAC adsorption were tetracycline, demeclocycline, oxytetracycline, chlortetracycline, doxytetracycline, meclocycline and minocycline. Removal efficiencies of seven tetracycline antibiotic compounds showed 1%~61% by anthracite biofiltration process (EBCT: 5~30 min). The highest biodegradable tetracycline antibiotic compound was minocycline, and the worst biodegradable tetracycline antibiotic compounds were oxytetracycline and demeclocycline.

• Journal of Periodontal and Implant Science
• /
• v.25 no.1
• /
• pp.76-88
• /
• 1995

The purpose of this was to evaluate the in vitro effects of different application modes of tetracycline HCI on dentin root surfaces. The study group was comprised of 30 teeth with advanced periodontal disease extracted before the start of periodontal therapy. The diseased root surface was vigorously root planed to expose dentin. The teeth were sectioned and cotton pellets. soaked in a saturated solution of tetracycline HCI, were either "placed" or "burnished" on the prepared root surface for 3, 5 min. respectively. Control surfaces were similarly treated with root planing only. Following the various treatments, teeth were fixed. dehydrated, critical point dried, and coated for scanning electron microscopic(SEM) evaluation. The surfaces of tetracycline HCI treated specimens considerably differed from specimens treated with root planing only. Results demonstrated that root-planed, no-tetracycline HCI specimens had amorphous, irregular surface which corresponded to a smear layer. Tetracycline HCI specimens exhibited collagen fibers and dentinal tubules exposed by the removal of the smear layer. Although some differences were seen in surface structures among some specimens. "burnished" application causes more extensive change than "placed" application, and application time of the tetracycline HCl did not seem to have any major impact on the surface morphology.