Mise au point et developpment des systemes lipidiques emulsionnes contenant la Benzathine Penicilline G /
Abstract:Acute rheumatic fever (ARF) or rheumatic fever (RF), a systemic illness that may occur following Group A beta-haemolytic streptococcal (GABHS) pharyngitis in children, is a major problem in countries with limited resources. It affects the cardiac valves and muscles, joints, skin and central...
Na minha lista:
| Principais autores: | , , , |
|---|---|
| Formato: | Tese |
| Publicado em: |
|
| Assuntos: | |
| Endereço do item: | https://app.bczm.ufrn.br/home/#/item/161703 |
| Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
| Resumo: | Abstract:Acute rheumatic fever (ARF) or rheumatic fever (RF), a systemic illness that may occur following Group A beta-haemolytic streptococcal (GABHS) pharyngitis in children, is a major problem in countries with limited resources. It affects the cardiac valves and muscles, joints, skin and central nervous system. Preventive and prophylactic therapy is indicated to avoid further valve damage. Primary prophylaxis (an initial course of antibiotics administered to eradicate the streptococcal infection) also serves as the first course of secondary prophylaxis: an injection of Benzathine Penicillin G (BPG) suspension every 3 or 4 weeks. Despite its excellent in vitro efficacy, the inability of penicillin to eradicate GABHS is frequently reported. Over the past 50 years, the rate of penicillin failure has consistently increased from about 7% in 1950 to almost 40% in 2000. Nevertheless, penicillin is still used for treatment of ARF, despite its high failure rate, mainly because of its long track record and low cost. The aim of this work was to study the possible causes of failure, as well as the inconvenience of the current prophylactic treatment of ARF and suggest a new pharmacotherapeutic system that could replace the current one. The poor penetration into the tonsilar tissues is one of the major reasons for the failure of penicillin. Other explanations relate to (i) the bacterial interactions between GABHS and other members of the pharyngo¬ tonsillar bacterial flora; (ii) resistance or tolerance to the antibiotic used; (iii) inappropriate dose ar drug delivery, (iv) duration of therapy, and (v) poor compliance, among others. Further pharmacokinetic studies reported that intramuscular injection of benzathine Penicillin G did nat, in a significant proportion of patients, produce serum values above the minimal inhibitory concentration by week 3. Hence, this apparent failure of a month long schedule is not sufficient to successfully prevent ARF. Nanocarrier-based systems are able to confer stability, improved absorption, controlled and quantitative release on the encapsulated malecule and therefore, improve its pharmacodynamic activity. Site-specific delivery is designed to minimise undesired effects caused by conventional therapy Microemulsions have been shown to labile drug, control drug release, increase bioavailability and reduce the variability of patiente outcomes. Theadvantages for drug delive offered by microemulsions include improved drug solubilization and protection against enzymatic hydrolysis, as well as the potencial for enhanced absorption provided by surfactant-induced membrane fluidity leading to permeability changes. Microemulsions have great potential vehicle for penicillin in the treatment of ARF because they may be used to obtain prolonged release formulations. These systems can alo modifi the pharmacokinetics of the encapsulated drug, and that it significantly increase the half-life, the area under curve and the mean residence time. Therefore the delivery of penicillin G in nanocarrier-based system, particularly a microemulsion, could be a plausible and innovative to the current treatment. |
|---|