Abstract This study aimed to develop and evaluate the stability of sulfadiazine sugar-free extemporaneous oral suspensions, focusing on treating congenital toxoplasmosis. The excipients were carefully chosen to obtain safe products for the pediatric population. Sulfadiazine suspensions (100 mg/ mL) were prepared from the raw material or tablets, stored in amber glass bottles at 5±3ºC, and evaluated at 0, 14, and 30 days. An ultra-performance liquid chromatographic method was developed and validated to assay the drug. The particle size ranged from 29.3 to 50.6 µm, with some variation over the study; pH values around 7.0 and non-Newtonian behavior were observed without modification in the period. Formulations showed a fast dissolution rate (>80% in 15 minutes) without variation over the study. The drug assay was about 100% of the label claimed throughout the study, demonstrating the chemical stability and the preparations’ dose homogeneity. The microbiological investigation indicated that both preparations met the requirements for the microbial count and absence of pathogens. In conclusion, the developed formulations can be used for 30 days when stored under refrigeration. The oral suspensions produced are easy to prepare and contain safe components, providing an alternative for congenital toxoplasmosis treatment in children.

The first method by micellar electrokinetic chromatography (MEKC) for the determination of empagliflozin in tablets was developed and validated following the ICH guidelines. The separation was achieved in a fused silica capillary with 50 µm x 40 cm (inner diameter x effective length) at 28 ºC, +28 kV voltage, hydrodynamic injection 4s (50 mBar), detection at 225 nm and paracetamol was the internal standard. The running electrolyte was a mixture of 20 mM tris(hydroxymethyl)aminomethane (pH 10) and 100 mM sodium dodecyl sulphate (1:1). Specificity was evaluated by the stress testing and the method was specific, with no interference of the degradation product. Linearity was observed in the range of 50 to 150 μg/mL (r=0.9999). The method showed adequate accuracy (recovery value=100.60±0.60%), precision (RSD values <2%) and robustness, which was evaluated by a full factorial design 23. Drug degradation kinetics was evaluated in alkaline and acidic conditions and first-order kinetic was observed in both conditions. The cytotoxicity of sample solutions degraded by UVA and UVC radiation, alkaline and acid media were studied as well. A similar cellular viability profile was observed with a slight decrease only in samples degraded by UVC radiation and basic medium

resumo A daptomicina (DPT) é o primeiro lipopeptídeo cíclico disponível para comercialização. Possui atividade frente a bactérias gram-positivas, incluindo cepas resistentes. O objetivo deste trabalho foi desenvolver e validar um ensaio microbiológico turbidimétrico para quantificar a daptomicina na forma injetável. Empregou-se delineamento 3x3, nas concentrações de 1,0; 2,0 e 4,0 µg/mL. Como micro-organismo teste foi usado Staphylococcus aureus ATCC 6538p, e Meio para Antibióticos nº 3 foi empregado como meio de cultura. A validação do método demonstrou que o ensaio foi linear (r=0,9995), preciso (RSD=2,55%), exato (recuperação de 100,48 ± 2,11%) e robusto. A cinética de degradação em meio alcalino foi avaliada, indicando que a daptomicina segue cinética de primeira ordem nessa condição. A análise das soluções degradadas mostrou que os produtos de degradação da daptomicina não possuem atividade antimicrobiana. O bioensaio foi comparado com o método por CLAE previamente desenvolvido e não houve diferença significativa entre ambos (p<0,05). O método mostrou-se apropriado para o controle de qualidade da daptomicina injetável.

abstract Daptomycin (DPT) was the first lipopeptide antibiotic available for commercialization. It is active against gram-positive bacteria, including resistant strains. This work aimed to develop and validate a turbidimetric microbiologic assay to determine daptomycin in an injectable form. A 3x3 design was employed, at concentrations of 1, 2 and 4.0 µg/mL. The microorganism test used was Staphylococcus aureus ATCC 6538p, and Antibiotic Medium 3 was used as the culture medium. Method validation demonstrated that the bioassay was linear (r=0.9995), precise (RSD=2.58%), accurate (recovery 100.48± 2.11%), and robust. Degradation kinetics was also performed in an alkaline medium, indicating that daptomycin degradation follows first order kinetics under these conditions. The analyses of degraded solutions showed that daptomycin degradation products do not possess bactericidal activity. The bioassay was compared to HPLC method that was previously developed and no significant difference was found between them (p>0.05). The method proved to be appropriate for daptomycin injection quality control.

<p>A saxagliptina é uma inibidora potente e seletiva da enzima dipeptidil peptidase 4. É efetiva no tratamento do Diabete <italic>mellitus</italic> tipo 2, pois estimula a produção de insulina pelo pâncreas. No presente estudo, desenvolveu-se e validou-se método por cromatografia líquida de alta eficiência para quantificar o fármaco em comprimidos. O método foi baseado em eluição isocrática, utilizando fase móvel constituída por ácido fosfórico 0,1% pH 3,0-metanol (70 : 30, v/v), fluxo de 1,0 mL.min^-1, com detecção UV em 225 nm. A separação cromatográfica foi alcançada em 8 minutos em coluna Waters XBridge C18 (250 mm x 4,6 mm, 5 µm) mantida à temperatura ambiente. O método proposto mostrou-se específico e robusto para o controle de qualidade de saxagliptina em comprimidos, sendo linear na faixa de concentração de 15,0-100,0 µg.mL^-1 (r>0,999), preciso (RSD<1,49%) e exato, com resultados entre 99,42 e 101,59%. O método mostrou-se indicativo de estabilidade e foi aplicado com sucesso no controle de qualidade de saxagliptina em comprimidos.</p>

<p>Saxagliptin is a potent and selective inhibitor of the enzyme dipeptidyl peptidase 4. It is effective in the treatment of type 2 diabetes mellitus because it stimulates the pancreas to produce insulin. In the present study, a liquid chromatography method was developed and validated to quantify the drug in tablets. This method was based on the isocratic elution of saxagliptin, using a mobile phase consisting of 0.1% phosphoric acid at pH 3.0 - methanol (70: 30, v/v) at a flow rate of 1 mL.min^-1 with UV detection at 225 nm. The chromatographic separation was achieved in 8 minutes on a Waters XBridge C18 column (250 mm x 4.6 mm, 5µm) maintained at ambient temperature. The proposed method proved to be specific and robust for the quality control of saxagliptin in pharmaceutical dosage forms, showing good linearity in the range of 15.0 - 100.0 µg.mL^-1 (r>0.999), precision (RSD<1.49%) and accuracy values between 99.42 and 101.59%. The method was found to be stability indicating and was successfully applied for the analysis of saxagliptin in tablets in a routine quality control laboratory.</p>