Banca de QUALIFICAÇÃO: KATTYA GYSELLE DE HOLANDA E SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.

DISCENTE: KATTYA GYSELLE DE HOLANDA E SILVA

DATA: 20/09/2010

HORA: 14:30

LOCAL: AUDITORIO

TÍTULO:

MISE AU POINT ET DÉVELOPPMENT DES SYSTÈMES LIPIDIQUES ÉMULSIONNÉS CONTENANT LA BENZATHINE PENICILLINE G.

PALAVRAS-CHAVES:

Penicillin G, Rheumatic Fever, Nanotechnology

PÁGINAS: 126

GRANDE ÁREA: Ciências da Saúde

ÁREA: Farmácia

RESUMO:

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 pharyngotonsillar
bacterial flora; (ii) resistance or tolerance to the antibiotic used; (iii) inappropriate
dose or drug delivery, (iv) duration of therapy, and (v) poor compliance, among others.
Further pharmacokinetic studies reported that intramuscular injection of benzathine Penicillin
G did not, 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
molecule 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 patient outcomes. The advantages for drug delivery offered by microemulsions
include improved drug solubilization and protection against enzymatic hydrolysis, as well as
the potential for enhanced absorption provided by surfactant-induced membrane fluidity
leading to permeability changes. Microemulsions have great potential as a parenteral vehicle
for Penicillin in the treatment of ARF because they may be used for intravenous,
subcutaneous or intramuscular administration. Furthermore, they can be used to obtain
prolonged release formulations. These systems can also modify 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 a nanocarrier-based
system, particularly a microemulsion, could be a plausible and innovative alternative to the
current treatment.

MEMBROS DA BANCA:
Presidente - 1178187 - ERYVALDO SOCRATES TABOSA DO EGITO
Externo à Instituição - HATTEM FESSI - NENHUMA