Electroanalysis Applied to Compatibility and Stability Assays of Drugs: Carvedilol Study Case.

Carvedilol (CRV) is a non-selective blocker of α and ß adrenergic receptors, which has been extensively used for the treatment of hypertension and congestive heart failure. Owing to its poor biopharmaceutical properties, CRV has been incorporated into different types of drug delivery systems and this necessitates the importance of investigating their compatibility and stability. In this sense, we have investigated the applicability of several electroanalytical tools to assess CRV compatibility with lipid excipients. Voltammetric and electrochemical impedance spectroscopy techniques were used to evaluate the redox behavior of CRV and lipid excipients. Results showed that Plurol® isostearic, liquid excipient, and stearic acid presented the greatest anode peak potential variation, and these were considered suitable excipients for CRV formulation. CRV showed the highest stability at room temperature and at 50 °C when mixed with stearic acid (7% w/w). The results also provided evidence that electrochemical methods might be feasible to complement standard stability/compatibility studies related to redox reactions.

Electrochemical Characterization of Central Action Tricyclic Drugs by Voltammetric Techniques and Density Functional Theory Calculations.

This work details the study of the redox behavior of the drugs cyclobenzaprine (CBP), amitriptyline (AMP) and nortriptyline (NOR) through voltammetric methods and computational chemistry. Results obtained in this study show that the amine moiety of each compound is more likely to undergo oxidation at 1a at Ep1a ≈ 0.69, 0.79, 0.93 V (vs. Ag/AgCl/KClsat) for CBP, AMP and NOR, respectively. Moreover, CBP presented a second peak, 2a at Ep2a ≈ 0.98 V (vs. Ag/AgCl/KClsat) at pH 7.0. Furthermore, the electronic structure calculation results corroborate the electrochemical assays regarding the HOMO energies of the lowest energy conformers of each molecule. The mechanism for each anodic process is proposed according to electroanalytical and computational chemistry findings, which show evidence that the methods herein employed may be a valuable alternative to study the redox behavior of structurally similar drugs.

Evaluation of the antiproliferative activity of the leaves from Arctium lappa by a bioassay-guided fractionation.

Arctium lappa L. (Asteraceae) is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetate, and n-butanol. The ethyl-acetate fraction (EAF) showed antiproliferative activity. This fraction was subjected to sequential column chromatography over silica gel to afford onopordopicrin (1), mixtures of 1 with dehydromelitensin-8-(4'-hydroxymethacrylate) (2), a mixture of 2 with dehydromelitensin (3), mixture of 1 with melitensin (4), dehydrovomifoliol (5), and loliolide (6). The compounds were identified by spectroscopic methods (NMR, MS) and comparison with literature data. This is the first description of compounds 2-5 from this species. The compounds tested in Caco-2 cells showed the following CC(50) (µg/mL) values: 1: 19.7 ± 3.4, 1 with 2: 24.6 ± 1.5, 2 with 3: 27 ± 11.7, 1 with 4: 42 ± 13.1, 6 30 ± 6.2; compound 5 showed no activity.

Determinação dos antipsicóticos prescritos no Hospital Municipal de Maringá / Determination of the antipsychotics prescribed in Maringá Municipal Hospital

A classe terapêutica dos antipsicóticos faz parte dos medicamentos mais utilizados para o tratamento da esquizofrenia, e eles são divididos em típicos e atípicos. A esquizofrenia é causadora de um severo transtorno do funcionamento cerebral e leva à incapacitação ou desvio de personalidade do indivíduo, comprometendo seu lado profissional e suas relações interpessoais. O estudo realizado teve como objetivo quantificar a prescrição dos antipsicóticos típicos e atípicos no Hospital Municipal de Maringá “Dra Thelma Villanova Kasprowicz”, no ano de 2005. A busca de informações para embasamento teórico foi realizada por meio do banco de dados CAPES, Pubmed, Scielo e artigos obtidos do serviço COMUT, bem como livros textos. Pode-se observar que a classe dos antipsicóticos mais utilizada foi a dos típicos, no entanto, estes dados já eram esperados por se tratar de um Hospital público, no qual as considerações econômicas são um fator adicional para a escolha do medicamento. Outro fator importante sobre os medicamentos atípicos pesquisados, é que a risperidona, é o único padronizado na instituição; os outros só foram utilizados por meio de amostras grátis deixadas aos médicos pelos laboratórios farmacêuticos. A faixa etária mais acometida com o transtorno da psicose está entre 22 e 50 anos, com predominância do sexo feminino.

The therapeutic class of antipsychotic is among the most used medicines for the treatment of schizophrenia and may be divided in typical and atypical. Schizophrenia causes a severe disruption of the brain along with an impairment of the individual’s capacity for work or interpersonal relationships. This present study meant to quantifying the prescription of typical and atypical antipsychotics in Maringá Municipal Hospital Dra. Thelma Villanova Kasprowicz in the year of 2005. The information for theoretical foundation was obtained from databases such as CAPES, Pubmed, Scielo, and from textbooks and articles from the COMUT service. It was verified that the most used class of the antipsychotics was the typical ones. This result was already expected because it refers to a public hospital where economical considerations are a matter of choice. Another important factor about the atypical medicines under this research was the fact that the risperidone drug is the only standardized medication in the institution; the others are only used through free samples that doctors are given by the pharmaceutical laboratories. Most people, predominately female, who suffer from the disruption of psychosis, are between 22 and 50 years old.