Josélia Larger Manfio

Development and validation of a UPLC-ESI-MS/MS method for the determination of N-butylscopolamine in human plasma: Application to a bioequivalence study

A sensitive and fast ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method for measurements of N-butylscopolamine in plasma was developed and validated. A single protein precipitation was proposed for the clean up of the plasma and N-methylhomatropine was added as internal standard (IS). The analyses were carried out using a C(18) column and mobile phase of acetonitrile: 5 mM ammonium acetate + 0.1% formic acid (90:10, v/v). The triple quadrupole mass spectrometer equipped with an electrospray source in positive mode, was set up in selective reaction monitoring, to detect precursor → product ion 360.0 → 194.0 m/z and 290.3 → 138.0 m/z transitions, for N-butylscopolamine and IS, respectively. The method was linear in 0.03 (lower limit of quantitation; LLOQ) - 10.00 ng/ml range for N-butylscopolamine. Satisfactory selectivity, linearity, precision, accuracy, and robustness were obtained for the UPLC-ESI-MS/MS method. The proposed method was successfully applied to a pharmacokinetic study of healthy human volunteers; the results showed that the two scopolamine butylbromide formulations tested are not bioequivalent in rate and extent of absorption.

Pharmacokinetic Assessment of Sufentanil in Cardiac Surgery

Plasma monitoring and pharmacokinetic assessment are important tools used in therapeutic control. Sufentanil is responsible for the hemodynamic stabilization of patients, providing better suppression of the neuroendocrine response compared to its analogue fentanyl. This study aims to use the plasma monitoring of sufentanil in patients undergoing cardiac surgery with extracorporeal circulation (ECC, group 1) or without ECC (group 2) to assess the pharmacokinetics of the compound.The 42 patients in this study received 0.5 μg/kg of sufentanil through bolus injection followed by a maintenance infusion of 0.5 μg/kg.h. Serial blood samples were collected during the post induction intraoperative period and during the postoperative period until 36 h after sufentanil administration. The plasma concentrations were determined by a validated method utilizing liquid chromatography coupled to mass spectrometry. The pharmacokinetic modeling was performed using a 3-compartment model fit.The surgical patients included in the protocol were adults of both genders, with 30 patients in the ECC group and 12 in the group without ECC. The plasma concentrations obtained were significantly different between the 2 groups. During the extracorporeal circulation procedure, intense fluctuations were observed in the sufentanil plasma concentrations. Compared with the results of group 2, the ECC procedure reduced the terminal or gamma half-life from 36.35 ± 6.37 h to 23.25 ± 2.75 h in group 1. In addition, the ECC procedure promoted higher fluctuations in the sufentanil plasma concentrations without causing alterations in the area under the curve, distribution volume, clearance or the distributional (alpha) and rapid elimination (beta) half-lives (t1/2α and t1/2β, respectively).

Bioavailability of two oral formulas of secnidazole in healthy volunteers

Secnidazole is an antimicrobial agent used primarily in the treatment of amoebiasis. For this bioequivalence study of secnidazole, twenty-eight healthy female volunteers were enrolled in a randomized crossover study. Each volunteer was given a single oral dose of secnidazole test preparation and then the reference preparation, or vice versa, with a wash out interval of two weeks. The plasma concentrations of secnidazole were determined by HPLC, and the samples were extracted with tert-butyl-methyl-ether: dicloromethane (60:40, v/v). Secnidazole and its parent compound metronidazole were separated on a C18 column with water:acetonitrile (85:15, v/v) as the mobile phase, and monitored at 310 nm. The ratio of mean Cmax, AUC0-t and AUC0-∞ values for the test and reference products were within the predetermined range established by ANVISA, demonstrating that the two formulations are bioequivalent in rate and extent of absorption.

Determinação do prazo de validade do medicamento carbocisteína xarope através do método de Arrhenius

A carbocisteina e um agente mucolitico utilizado como adjuvante no tratamento de infeccoes do trato respiratorio. A qualidade, seguranca e eficacia do medicamento durante o seu prazo de validade sao responsabilidades da industria farmaceutica. A validade pode ser determinada atraves de estudos de estabilidade acelerados, nos quais fatores extrinsecos provocam a degradacao do produto. De acordo com Arrhenius, existe uma relacao entre temperatura e cinetica quimica. Desta forma, amostras do produto foram expostas a condicoes drasticas: 40, 50, 60 e 70 oC. O metodo de doseamento do xarope de carbocisteina foi validado podendo ser aplicado nas avaliacoes de rotina do controle de qualidade e no estudo de estabilidade deste produto. O prazo de validade proposto para o xarope de carbocisteina, calculado atraves da equacao de Arrhenius, para a temperatura de 25 oC foi de 240,9 dias. No entanto, foi observada diferenca entre o prazo proposto e a validade usualmente praticada para este produto. Este estudo, ainda, demonstrou a presenca de picos endogenos, que precisam ser melhor estudados a fim de se confirmar a presenca de produtos de degradacao.

Bioequivalence study of two formulations of 100 mg capsule of itraconazole. Quantification by tandem mass spectrometry.

The purpose of this study is to compare the bioavailability of two itraconazole (CAS 84625-61-6) capsule formulations. An open, randomized, two-period crossover study with a 7-day washout interval was conduced in 32 healthy volunteers. The plasma samples were obtained up to 96 h after drug administration. A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of itraconazole in human plasma. Itraconazole and ketoconazole (internal standard) were extracted from the plasma by liquid-liquid extraction using diethylether : dichloromethane (70 : 30) as extraction solvent and separated on a C8 analytical column (150 mm x 4.6 mm I.D.) maintained at 40 degrees C. The elution was performed by a constant flow rate of 1.2 mL/min and the mobile phase consisted of acetonitrile and acetic acid 0.1% (85 :15 v/v). The mass spectrometer equipped with an electrospray source in positive mode, was set up in multiple reaction monitoring, to detect parent --> production 705.0 392.0 (itraconazole) and 531.0 --> 81.70 (ketoconazole). The chromatographic separation was obtained within 3.5 min and was linear in the concentration range of 5 to 600 ng/mL. Bioequivalence between the products was determined by calculating 90% confidence intervals for the ratio of C(max) (95.02%-109.48%), AUC(0-t) (81.41%-107.77%) and AUC(0-inf) (80.85%-106.86%). These values for the test and reference products are within the 80-125% interval, proposed by FDA and EMEA. It was concluded that the proposed method was successfully applied to a pharmacokinetic study in healthy human volunteers, and results showed that the two itraconazole formulations are bioequivalent in their rate and extent of absorption.

DESAFIOS DO DESENVOLVIMENTO DOS DOSSIÊS DE REGISTRO DE MEDICAMENTOS FITOTERÁPICOS

Os beneficios da utilizacao de plantas medicinais sao amplamente discutidos no âmbito academico atraves de pesquisa basica e pela populacao em geral, baseado no ainda presente uso tradicional. Porem, e evidente a baixa demanda por registro no orgao sanitario competente (ANVISA) de produtos considerados medicamentos fitoterapicos ou produto tradicional fitoterapico. A ANVISA tem implementado requisitos visando garantir a qualidade, seguranca e eficacia destes produtos, a luz do que se exige aos medicamentos classificados como sinteticos. Nesta revisao, aspectos relacionados a pesquisa e desenvolvimento, em linhas gerais, de um medicamento fitoterapico sao relacionados com o arcabouco regulatorio que normatiza o registro de tais produtos. Cada etapa de desenvolvimento relaciona-se a uma normativa em especifico, de tal forma, que a execucao de qualquer experimento de forma diversa da preconizada, impossibilita sua utilizacao na documentacao de registro do produto. Este link e essencial para que se obtenha resultados satisfatorios no sentido de viabilizar-se o registro e futura comercializacao dos produtos desenvolvidos. O aproveitamento dos estudos realizados, a qualidade da documentacao gerada e a aderencia aos requisitos regulatorios, permitem a submissao de dossies de registro, que uma vez analisados, serao aprovados pelo orgao competente. A aplicabilidade das politicas de atencao basica a saude que preconizam a utilizacao de fitoterapicos, depende do correto desenvolvimento destes produtos, aprovacao do orgao regulador para que somente entao a populacao possa ter acesso.