Drug Deliv. 2000 Oct-Dec;7(4):237-43.
Positively charged gelatin microspheres as gastric mucoadhesive drug delivery system for eradication of H. pylori.

Wang J, Tauchi Y, Deguchi Y, Morimoto K, Tabata Y, Ikada Y.

Department of Pharmaceutics, Hokkaido College of Pharmacy, Otaru-city, Japan.

Gastric mucoadhesive drug delivery systems are very promising for eradication of Helicobacter pylori (H. pylori), a spiral bacterium that resides in the gastric mucus layer and at the mucus-epithelial cell interface. New positively charged biodegradable microspheres were prepared using aminated gelatin by surfactant-free emulsification in olive oil, followed by a cross-linking reaction with glutaraldehyde. The amino group contents of the modified gelatin and the microspheres were determined using a 2,4,6-trinitrobenzenesulfonic acid method. With the increase of glutaraldehyde concentration, the amino group content of the microspheres decreased accordingly. The influence of glutaraldehyde concentration, cross-linking reaction time, drug-loading patterns, and type of release media on the in vitro release characteristics of amoxicillin from the microspheres was investigated. Amoxicillin release rate from the modified gelatin microspheres was significantly reduced compared with that from gelatin microspheres. Furthermore, the release was decreased with the increase of glutaraldehyde concentration and/or cross-linking time. On the other hand, a faster release was observed in a lower pH release medium and/or using a lower pH solution for amoxicillin loading. The gastric mucoadhesive properties of the microspheres were evaluated using RITC-labeled microspheres in an isolated rat stomach. The gastric mucoadhesion of the modified gelatin microspheres was markedly improved compared with that of gelatin microspheres. The modified gelatin microsphere proves to be a possible candidate delivery system for the effective eradication of H. pylori.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11195431&dopt=Abstract antibiotic amoxicillin




Med Sci Monit. 2000 Mar-Apr;6(2):300-4.
Antibiotic-sensitivity of Moraxella catarrhalis isolated from clinical materials in 1997-1998.

Mikucka A, Janicka G, Krawiecka D, Kochanowska J.

Department of Microbiology, Medical University, ul. M. Sklodowskiej-Curie 9, 85-094 Bydgoszcz, Poland.

Moraxella catarrhalis (M. catarrhalis) may normally be found in the upper respiratory tract. This bacterium, however, may cause infections such as acute otitis media, sinusitis, conjunctivitis, bronchitis chronica, pneumonia, endocarditis, septicaemia and meningitis. Haemophilus influenzae, Streptococcus pneumoniae and M. catarrhalis were the main causative agents responsible for respiratory tract infections. The major resistance problems associated with these species are those which cause resistance to beta-lactams. beta-lactamase was produced by > 80% M. catarrhalis strains. The susceptibility to ampicillin, amoxicillin/clavulanic acid, cefuroxime, erythromycin, ciprofloxacin was tested in 137 M. catarrhalis strains. All the strains resistant to ampicillin produced beta-lactamase and were sensitive to amoxicillin/clavulanic acid. For M. catarrhalis, the most active antimicrobials included cefuroxime (99%), ciprofloxacin (99%) and erythromycin (93%).

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11208326&dopt=Abstract antibiotic amoxicillin



J Hazard Mater. 2005 Jul 15;122(3):243-50.
Antibiotic removal from wastewaters: The ozonation of amoxicillin.

Andreozzi R, Canterino M, Marotta R, Paxeus N.

Dipartimento di Ingegneria Chimica, Facolta di Ingegneria, Universita di Napoli "Federico II", p.le V. Tecchio 80, 80125 Napoli, Italy.

The presence of amoxicillin, a widely used antibiotic, has been documented in Sewage Treatment Plant (STP) effluents. As for other pharmaceuticals, ozonation is proposed as a process for its abatement from these effluents. The results of ozonation experiments on amoxicillin-containing aqueous solutions indicate that ozone attack is mainly directed towards the phenolic ring of the studied molecule leading to the formation of hydroxyderivative intermediates. No direct evidences of attack on sulfur atom with sulfoxide formation are found. A kinetic investigation is carried out allowing the assessment of the kinetics of direct ozone attack and that of OH radicals to amoxicillin.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15967280&dopt=Abstract antibiotic amoxicillin




agu.edu.bh

OBJECTIVE: The aim of this study was to evaluate the prevalence of resistance among 83 Helicobacter pylori isolates cultured from biopsies taken during routine endoscopies in 1998-1999. METHODS: Minimum Inhibitory Concentration of amoxicillin, tetracycline, clarithromycin and metronidazole were determined by Epsilometer test. RESULTS: Forty-seven strains (57%) were resistant to metronidazole, and 27 (32.5%) were resistant to clarithromycin. Twenty of the 27 strains resistant to clarithromycin were also resistant to metronidazole. None of the strains were resistant to amoxicillin or tetracycline. CONCLUSION: A high percentage of patients from Bahrain were infected with resistant strains of Helicobacter pylori. Antibiotic resistance monitoring is very important and unified national treatment policies are needed.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11255612&dopt=Abstract antibiotic amoxicillin




An Esp Pediatr. 2000 Feb;52(2):157-63.
[Antibiotic prescribing patterns in primary health care. Do pediatricians use antibiotics rationally?]

[Article in Spanish]

Calvo Rey C, Albanil Ballesteros R, Sanchez Mendez MY, Olivas Dominguez A.

Hospital Severo Ochoa, Leganes, Area 9, Madrid.

OBJECTIVES: To determine antibiotic prescribing patterns in the pediatric (infants and children) population attended to at a primary health care centre in the community of Madrid. We also wanted to determine the necessity or otherwise of antibiotic therapy and whether the selected antibiotic drug was appropriate for the pathology diagnosed. METHODS: Retrospective study of all infectious or respiratory processes diagnosed during 1 year and of the respective antibiotic cycles prescribed in all patients under the age of 4 years. The prescribing physician and the appropriateness of all therapeutic decisions, including those where the decision was not to treat with antibiotic drugs, were analyzed. RESULTS: We evaluated 910 children under the age of 4 years with a total of 3, 847 processes (mean of 4.55 +/-3.6 processes per child per year). Sixty-three percent of the children received at least one cycle of antibiotic drugs per year (mean 1.63+/-1.69 cycles of treatment per child per year). Of all therapeutic decisions, 85.2% were considered appropriate. In 36% of the processes antibiotics were prescribed (1,386 cycles), 46% of which were considered inappropriate either because no antibiotic therapy should have been given (71.6%) or because the chosen drug was not appropriate for the pathology (28.4%). There were significant differences among the evaluated physicians. The most correct decisions were taken by the pediatrician in the outpatient clinic, especially when compared with physicians in the emergency ward (p<0.0001). The most frequently prescribed antibiotic drugs were amoxicillin (41.2%) and amoxicillin combined with clavulanic acid (33%). Cephalosporin accounted only for 6.9% of the prescriptions. CONCLUSIONS: Antibiotic therapy is overprescribed in children, a situation that should be corrected.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11003882&dopt=Abstract antibiotic amoxicillin