Proposed reduction of the in vivo pyrogen test by the in vitro LAL assay for the quality control of anticrotallic, antiscorpion, antirabies and antitetanus sera.

The rationale for a formal study of the LAL (kinetic chromogenic method) assay for anticrotallic (SAC), antirabies (SAR), antitetanus (SAT) and antiscorpion (SAE) sera involved the determination of parameters required by the Brazilian National Health Surveillance Agency (ANVISA), the USA Food and Drug Administration (FDA), USP (United States Pharmacopeia, 39) and ICH (International Conference on Harmonization). The curve correlation coefficients obtained with the standard endotoxin control ranged from -0.980 to -1.000 in all experiments. Endotoxin recovery added to the SAC, SAR, SAT and SAE samples, at the working dilutions (1:10, 1:10, 1:10 and 1, 100 respectively), met the criteria required by the FDA, USP and Brazilian ANVISA for the Inhibition-Potentiation test. The applied methodology for the four analyzed sera fulfilled the required criteria for all performance parameters. Thus, the present study demonstrated that the in vivo pyrogen test can be potentially replaced by the LAL assay for all assessed sera samples displaying higher sensitivity and following the 3 Rs principle, in addition to maintaining quality control in Sanitary Surveillance.

Membrane adsorber for endotoxin removal

ABSTRACT The surface of flat-sheet nylon membranes was modified using bisoxirane as the spacer and polyvinyl alcohol as the coating polymer. The amino acid histidine was explored as a ligand for endotoxins, aiming at its application for endotoxin removal from aqueous solutions. Characterization of the membrane adsorber, analysis of the depyrogenation procedures and the evaluation of endotoxin removal efficiency in static mode are discussed. Ligand density of the membranes was around 7 mg/g dry membrane, allowing removal of up to 65% of the endotoxins. The performance of the membrane adsorber prepared using nylon coated with polyvinyl alcohol and containing histidine as the ligand proved superior to other membrane adsorbers reported in the literature. The lack of endotoxin adsorption on nylon membranes without histidine confirmed that endotoxin removal was due to the presence of the ligand at the membrane surface. Modified membranes were highly stable, exhibiting a lifespan of approximately thirty months.

RESUMO A superfície de membranas planas de nylon foi modificada utilizando-se bisoxirano como espaçador e poli(álcool vinílico) para recobrimento das membranas. O aminoácido histidina foi utilizado como ligante para endotoxinas, visando à sua aplicação na remoção de endotoxinas a partir de soluções aquosas. São discutidas as etapas de caracterização do adsorvedor com membranas, análise do procedimento de despirogenização e avaliação da eficiência de remoção em modo estático. A densidade de ligantes nas membranas foi em torno de 7 mg/g membrana (massa seca), permitindo uma remoção de endotoxinas de até 65%. O desempenho das membranas preparadas com nylon e recobertas com poli(álcool vinílico) contendo histidina como ligante foi superior ao de outros adsorvedores com membranas descritos na literatura. A ausência de adsorção de endotoxinas em membranas sem histidina confirma que a remoção das endotoxinas deve-se exclusivamente à presença do ligante na superfície da membrana. As membranas modificadas mostraram-se bastante estáveis, exibindo um tempo de vida superior a 30 dias.

Hepatitis B monovalent vaccines produced by different manufacturers: comparative study on the quality of vaccine in period before and after the shelf life / Vacinas de Hepatite B monovalente produzidas por diferentes fabricantes: estudo comparativo da qualidade das vacinas no período pré e após o prazo de validade

For over 20 years, the hepatitis B (HB) vaccine has been produced by the expression of the viral gene encoding the hepatitis B surface antigen (HBsAg) in yeast. According to the data from WHO, the hepatitis B vaccines are generally stable for up to three years when stored at 2 ºC to 8 ºC. The purpose of this study was to evaluate whether the hepatitis B vaccine, at the time of their release, the quality criteria of this product were maintained seven years after the expiration date. Vaccine vials in multi-dose (10 and 05 doses) and three lots from each manufacturer (A, B and C) were analyzed. All batches were assayed for visual appearance, potency, bacterial endotoxin, thiomersal amount, aluminum hidroxyde contents and pH by means of validated tests. The nine lots evaluated seven years after the expiration date showed similar concentrations when compared to those demonstrated at the time of batches release by the National Institute for Quality Control in Health (INCQS). No significant change in the quality of the hepatitis B vaccine after the expiration date was confirmed. These data might be useful to subsidize a future evaluation for reviewing an extension of the vaccines shelf life.

As vacinas contra a hepatite B são produzidas pela expressão do gene viral codificado para o antígeno de superfície do vírus da hepatite B (HBsAg) em levedura, há mais de 20 anos. De acordo com os dados da OMS, a vacina de hepatite B tem até três anos de estabilidade quando armazenada entre 2 ºC e 8 ºC. O objetivo deste estudo foi de avaliar se, no momento da liberação, os critérios de qualidade da vacina de hepatite B foram mantidos após sete anos da data de validade. Foram analisados frascos de vacinas multi-dose (10 e 5 doses), sendo três lotes de cada produtor (A, B e C). Todos os lotes foram avaliados quanto às características de aparência visual, potência, endotoxina bacteriana, presença de timerosal, conteúdo de hidróxido de alumínio e pH por meio de testes validados. Os nove lotes avaliados sete anos após a data de expiração tiveram resultados similares quando comparados às concentrações na época de liberação dos lotes, realizada pelo Instituto Nacional de Controle de Qualidade em Saúde (INCQS). Os estudos confirmaram a manutenção da qualidade da vacina após o período de expiração. Estes dados podem subsidiar uma futura avaliação para extensão do prazo de validade das vacinas.

Intralaboratory validation of kinetic chromogenic Limulus amebocyte lysate assay for bacterial endotoxin determination in anti-bothropic serum.

Over the years, substituting in vitro biological methods for in vivo tests has posed an ever increasing challenge for researchers, including those who study the applications for snake antivenom. In the quality control of antivenons, the only official test recommended by pharmacopoeias for detecting pyrogenicity is the rabbit pyrogen test. In the present study, we propose intralaboratory validation of a method to replace the rabbit pyrogen test: in vitro determination of bacterial endotoxin in anti-bothropic serum (ABS) with quantitative kinetic chromogenic limulus amebocyte lysate (LAL) assay. The kinetic chromogenic LAL assay is specific to the detection of gram-negative bacterial endotoxin. The validation of the test involved the determination of performance parameters required by the Agência Nacional de Vigilância Sanitária Brasileira (ANVISA, the Brazilian National Health Surveillance Agency), the United States Food and Drug Administration (FDA) and the United States Pharmacopeia (USP) 35. In all experiments, the correlation coefficient of the curve obtained with the control standard endotoxin (CSE; Escherichia coli 055:B5 strain, range, 0.005-50 EU/mL) was between -0.998 and -1.000; and the recovery of endotoxin added to the sample of ABS (0.5 EU/mL) at the working dilution (1:10) followed the recuperation criteria (i.e., 50-200%). We performed six determinations, in each of which the coefficient of variation for the intermediate precision was between 5.6% and 13.8% (below the 15% threshold) and the accuracy was between 90.7% and 114.3% (within the acceptable range of 80-120%). The endotoxin concentration limit for the ABS was determined to be ≤ 2.9 EU/mL. The intralaboratory validation of the methodology was considered to have been successful because it met the criteria for all of the performance parameters.