Academic literature on the topic 'Diethylcarbamazine'

Objective: The present work describes the development and subsequent validation of a simple, precise and stability–indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of diethylcarbamazine citrate, guaiphenesin and chlorpheniramine maleate in tablet dosage forms.Methods: A simple, accurate, precise and robust RP-HPLC method was developed and validated for the estimation of diethylcarbamazine citrate, guaiphenesin and chlorpheniramine maleate. The chromatographic separation of all the three active components was achieved by using luna phenyl-hexyl column (250 mmx4.6 mm, dp=5 µm) with a mobile phase consisting of isocratic method with 0.1% triethylamine as buffer along with orthophosphoric acid adjusted to PH 2.5: acetonitrile (50:50v/v) at a flow rate 1.0 ml/min and ultraviolet detection at 210 nm.Results: The retention time of chlorpheniramine maleate, guaiphenesin and diethylcarbamazine citrate were 2.86, 4.89 and 7.76 min respectively. Validation of the proposed method was carried out according to an international conference on harmonization (ICH) guidelines. The established method was linear in the range of 1-15, 0.6-9, 0.02-0.3 µg/ml and correlation coefficient was 0.999, 0.9991, and 0.993 for diethylcarbamazine citrate, guaiphenesin and chlorpheniramine maleate respectively.Conclusion: The proposed method can be used for the quantitative analysis of diethylcarbamazine citrate, guaiphenesin and chlorpheniramine maleate.

A caracterização no estado sólido de insumos farmacêuticos constitui uma parte muito importante no entendimento de suas propriedades físicas, químicas e farmacológicas. A partir da análise estrutural por difração de raios X em monocristal, pode-se identificar a conformação no estado sólido do fármaco, assim como sua densidade eletrônica. Estes estudos podem ser complementados com dados provenientes da Modelagem Molecular, que compreende um número de ferramentas e métodos computacionais e teóricos que têm como objetivos compreender e prever o comportamento de sistemas reais. Nesse contexto, visando compreender melhor as propriedades de estado sólido apresentadas pelo fármaco anti-filariose dietilcarbamazina (DEC), foi obtido um novo sal, o maleato de dietilcarbamazina (DEC maleato), cujas propriedades foram comparadas com as das estruturas já reportadas, DEC citrato e DEC pura. A DEC maleato foi caracterizada por difração de raios X em monocristal, espectroscopias Raman e Infravermelho e análise térmica. A DEC maleato cristaliza no grupo espacial triclínico PI com dois confôrmeros da molécula de DEC na unidade assimétrica, ambos exibindo caudas etílicas na conformação syn em relação ao anel piperazina, diferentemente do que ocorre na DEC citrato e na DEC pura, nas quais esses fragmentos moleculares apresentam uma conformação anti. A principal interação intermolecular entre o fármaco e o ácido maleico é do tipo N-H•••O, que caracteriza a formação do sal e, consequentemente, do par iônico (DEC)+(maleato)-. Além disso, uma rede complexa de interações intermoleculares não-clássicas do tipo C-H•••O estão presentes entre as moléculas de DEC, DEC-maleato e maleato-maleato, levando a um empacotamento cristalino na forma de um sanduíche, onde os confôrmeros da DEC acomodam-se em colunas intercaladas por bicamadas de íons maleato. Não foram observadas transições de fase estruturais em função da temperatura entre 100 K e temperatura ambiente. No entanto, devido à variação conformacional observada entre as moléculas de DEC, cálculos quânticos foram realizados na fase gasosa, otimizando as conformações moleculares tanto da molécula de DEC neutra quanto da carregada a fim de determinar as características de sua estrutura eletrônica utilizando o método da Teoria do Funcional de Densidade, com o funcional híbrido B3LYP e o conjunto de função de base 6-31++G. Através dos cálculos teóricos foram obtidas quatro novas conformações, uma para DEC neutra e três da carregada, para as quais analisou-se as energias de conformação, os espectros vibracionais simulados e por fim os mapas de potencial eletrostático e os orbitais de fronteira.
The solid state characterization of active pharmaceutical ingredients (API) constitutes an important part in understanding their physical, chemical and pharmacological properties. From the structural analysis by single crystal X-ray diffraction, the API conformation in the solid form, as well as its electronic density, can be identified. These studies can be supplemented with data from the Molecular Modeling, which includes a number of theoretical and computational tools used to understand and to predict the behavior in real systems. In this context, aiming to better comprehend the solid state properties exhibited by the anti-filarial drug diethylcarbamazine (DEC), a new salt was obtained, the diethylcarbamazine maleate (DEC maleate), and its properties were compared with the ones of the reported structures, DEC citrate and pure DEC. The DEC maleate was characterized by single crystal X-ray diffraction, infrared and Raman spectroscopy and thermal analysis. DEC maleate was found to crystallize in the triclinic space group PI with two very similar conformers of the DEC molecule in the asymmetric unit, both exhibiting the ethylic chains in conformation syn in relation to the piperazine ring, unlike what happens to DEC citrate and pure DEC, where these chains are anti related. The main intermolecular interaction between the API and the maleic acid is of the type NH•••O, characterizing the salt formation, and thus, the ionic pair (DEC)+(maleate)-. Moreover, a complex network of no-classical intermolecular interactions of the type CH•••O occur between DEC-DEC, DEC-maleate, and maleate-maleate molecules, leading to a sandwich like crystal packing, where DEC conformers are accommodated in columns intercalated by maleates bilayers. No phase transitions were observed for the molecule structure in function of temperature between 100 K and room temperature. However, due conformational variations observed among DEC molecules of the three structures, quantum calculations were performed in the gas phase, optimizing the molecular conformations of both, the neutral and the charged DEC molecules to determine the characteristics of the electronic structure using the method of Density Functional Theory with the B3LYP hybrid functional and basis set 6-31++G. new conformations it were found, for which geometrical characteristics, conformation energies, vibrational spectra simulation and finally the electrostatic potential maps and the frontier orbitals, were analyzed.

A indústria farmacêutica tem como principal objetivo planejar, sintetizar e caracterizar compostos químicos que possuam atividade biológica e que sejam úteis no controle e combate de doenças e sintomas que acometem as populações. Estes compostos são referidos como ingredientes farmacêuticos ativos e podem, no estado sólido, apresentar diferentes arranjos de suas moléculas dentro de um cristal (polimorfismo). A cada um desses arranjos estão associadas propriedades físico-químicas que são de fundamental importância para o efeito terapêutico dos fármacos. Nesse contexto, este estudo teve como objetivo caracterizar as propriedades de estado sólido de novas formas cristalinas de três compostos farmacêuticos, Clorpropamida (CPA), Nevirapina (NVP) e Dietilcarbamazina (DEC). A CPA trata-se de um hipoglicemiante oral, utilizado no tratamento da Diabetes mellitus tipo II, apresentando na literatura cinco polimorfos conformacionais, dos quais dois foram caracterizados nesse estudo: as Formas IV e VI. A Forma IV cristaliza-se grupo espacial não centrossimétrico monoclínico P21, com Z = 2 e a Forma VI no grupo espacial centrossimétrico ortorrômbico Pbca, com Z = 8. Ambas apresentaram o mesmo padrão de interações intermoleculares clássicas, sendo que a principal diferença entre elas reside nas interações intermoleculares não clássicas, que levam a diferentes empacotamentos cristalinos. Por fim, as conformações moleculares dos cinco polimorfos da CPA foram comparadas entre si e as informações foram racionalizadas tomando como base os resultados provenientes de cálculos teóricos, que também indicaram a possibilidade de existência de novos polimorfos. A NVP, fármaco antiretroviral não nucleosídeo utilizado no tratamento da AIDS, também apresenta casos de polimorfismo na literatura. Neste trabalho, obteve-se um solvato não estequiométrico de butanol desse composto, que cristaliza no grupo espacial centrossimétrico triclínico P-1, com Z = 2, no qual as moléculas de butanol acomodaram-se em canais infinitos rodeados por moléculas de NVP. Esse tipo de empacotamento cristalino, diferente do reportado na literatura até o presente momento, possibilitou-nos propor que novos solvatos poderiam ser obtidos variando-se o solvente, proposta tal confirmada posteriormente. A DEC é amplamente utilizada na forma de um sal de citrato no tratamento da filariose linfática, não apresentado na literatura nenhuma caracterização de estado sólido. Assim, caracterizou-se não somente o sal utilizado nas formulações (DEC citrato), como também o composto puro (DEC). A forma pura, instável à temperatura ambiente, cristaliza no grupo espacial centrossimétrico P21/n à 250K. O sal, preferido como API por sua estabilidade, cristaliza à temperatura ambiente no grupo P21/c, porém com presença de desordem nas cadeias etílicas das moléculas de DEC. Para reduzir essa desordem, efetuou-se um estudo em função da temperatura, que acabou revelando a presença de três transições de fase sólido-sólido, gerando quatro fases cristalinas diferentes. Duas das transições exibiram efeito de histerese de acordo com a direção da rampa de temperatura. A terceira transição só foi obtida por resfriamento rápido do sistema. Estes dados foram comparados com os obtidos por DSC e espectroscopia Raman
One of the main goals of the pharmaceutical industry is to plan, synthesize and characterize chemical compounds with biological activity that can be useful in controlling diseases and symptoms that affect populations. These compounds are referred to as active pharmaceutical ingredients and may, in the solid state, present different crystal arrangements of its molecules (polymorphism). To each one of these crystalline arrays are associated physicochemical properties that are of fundamental importance for the therapeutic effect of the pharmaceutical drugs. In this context, the focus of this study was to characterize the solid state properties of new crystalline forms of three pharmaceutical compounds, Chlorpropamide (CPA), Nevirapine (NVP) and Diethylcarbamazine (DEC). CPA is an oral hypoglicemiant used in the treatment of type II Diabetes mellitus, and presents five conformational polymorphs reported in the literature, two of which were characterized in this study: Forms IV and VI. Form IV crystallizes in the monoclinic non-centrosymmetric space group P21, with Z = 2 and the Form VI in the orthorrombic centrosymmetric space group Pbca, with Z = 8. Both exhibited the same classical intermolecular interaction pattern; the main difference between them lay in the non-classical intermolecular interactions, which leads to different crystal packing. Finally, the molecular conformations of the five polymorphs of CPA were compared to each other and the information was rationalized taking as basis the results from theoretical calculations, which also indicated the possible existence of new polymorphs. NVP, a non-nucleoside antiretroviral pharmaceutical compound used in the treatment of AIDS, also presents polymorphism cases reported in the literature. In this study, we obtained a non-stoichiometric buthanol solvate of this compound, which crystallizes in the triclinic centrosymmetric space group P-1, with Z = 2, in which the buthanol molecules are positioned in infinite channels surrounded by NVP molecules. This kind of crystal packing, which is different from the one reported in the literature until now, has allowed us to propose that new solvates could be obtained by varying the solvent, being this proposal subsequently confirmed. DEC is largely used as a citrate salt form in the treatment of the lymphatic filariasis, not having any solid state characterization in the literature. Thus, we characterized not just the salt (DEC citrate) used in the formulation, but also the pure compound (DEC). The pure form, unstable at room temperature, crystallizes in the monoclinic centrosymmetric space group P21/n at 250K. The salt, preferred as API because of its stability, crystallizes at room temperature in the monoclinic centrosymmetric space group P21/c, but with the presence of disorder in the ethyl chains of the DEC molecules. To reduce this disorder, we performed a study in function of temperature, which revealed the presence of three solid-solid structural phase transitions, generating four different crystalline phases. Two of these transitions showed a hysteresis effect according to the direction of the temperature ramp. The third transition was only obtained by fast cooling of the system. These data where compared with the ones obtained by DSC and Raman spectroscopy.

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Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
A provocação por via respiratória com ovalbumina (OVA) em camundongos sensibilizados promove, na medula óssea (MO), eosinopoiese, resposta exacerbada à Interleucina(IL)-5, e mudanças no padrão de resposta em cultura à eotaxina, à IL- 13 e aos antiinflamatórios não esteroidais (NSAIDs). Em cultura de MO, a Prostaglandina (PG) E2 induz apoptose de eosinófilos, por via dependente de NO sintase indutível (iNOS) e ligante de CD95 (CD95L), enquanto a dexametasona (DEXA) promove eosinopoiese, gerando eosinófilos agregados e morfológicamente imaturos e protege contra da apoptose induzida por PGE2, provavelmente por mecanismos que regulem a expressão ou ativação de integrinas. No presente trabalho avaliamos se: a) in vitro, os efeitos dos NSAIDs, da IL-13 e da eotaxina dependem da produção de cisteinil-leucotrienos (CisLT) e da sinalização via receptor 1 de CisLT (CysLT1R); b) in vitro, a DEXA regula expressão de VLA-4, que promoveria a agregação e imaturidade dos eosinófilos, e se PGE2 contrapõe a ação da DEXA; c) in vivo, G-CSF e dietilcarbamazina (DEC) promoveriam eosinopenia medular e sistemica e se inibiriam a inflamação pulmonar alérgica. Resultados: a) NSAIDs, eotaxina e IL-13 potencializam a eosinopoiese via produção de CisLT e sinalização via CysLT1R. Os NSAIDs ainda protegem os eosinófilos da apoptose induzida por PGE2 exógena. b) A interação farmacológica entre PGE2 e DEXA modificam a ação de ambas, de forma estreitamente relacionada sobre a expressão de VLA-4 e, em condições específicas, esses agentes sinergizam gerando quantidades aumentadas de eosinófilos maduros. c) A DEC, inibidor da síntese de LTs, que na filariose experimental possivelmente atua via iNOS, inibe a eosinopoiese e os efeitos da provocação sobre o pulmão e a MO, através da via iNOS-CD95L. O Fator Estimulante de Colônias de Granulócitos (G-CSF), estimulante da neutropoiese, igualmente inibiu a inflamação pulmonar alérgica através da inibição da eosinopoiese. Este trabalho é parte do projeto intitulado "Eosinofilia na Asma Experimental", licenciado pela Comissão de Ética no Uso de Animais (CEUA) da Fiocruz, sob nos L010/04 e L002/09.
Our laboratory has previously shown that airway allergen challenge in ovalbumin-sensitized mice rapidly induces an increase in bone-marrow (BM) eosinophil production (eosinopoiesis), along with an increased response to Interleukin(IL)-5 in BM culture, changes in the ex vivo responses to cytokines and immunomodulators, including nonsteroidal anti-inflammatory drugs (NSAIDs) and cysteinyl-leukotrienes (CysLT), and colonization of the lungs by eosinophil progenitors. Early in the course of IL-5-induced eosinophil differentiation in BM culture, Prostaglandin E2 (PGE2) induces apoptosis, through a pathway dependent on the inducible isoform of NO synthase (iNOS) and the ligand for CD95 (CD95L). NSAIDs enhance eosinopoiesis and protect eosinophils in this critical period from exogenous PGE2, through a novel mechanism of action at the celular level. In this study, we show that indomethacin and aspirin act through endogenously synthesized CysLT, by establishing the essential roles of 5-lipoxygenase, LTC4 synthase and CysLT1R receptors, as well as the cytoprotective effect of CysLT against exogenous PGE2. The similarity between the effects of NSAIDs and those of eotaxin and IL-13 prompted us to reevaluate the contribution of endogenous CysLT to the effects of these cytokines. We confirmed that eotaxin and IL-13 act through this mechanism, and expand therefore the list of agents that, through CysLT, enhance eosinopoiesis, protecting immature eosinophils from apoptosis induced through the iNOS-CD95L pathway. Dexamethasone promotes BM eosinopoiesis, generating aggregated, cytologically immature eosinophils, which are nevertheless protected from PGE2- induced apoptosis. We examined therefore the possibility that dexamethasone upregulates integrin expression/activation, thereby maintaining an immature celular phenotype in cultured eosinophils, while PGE2 would have opposite effects on both integrin function and cytological maturation. We show that the proapoptotic effects of PGE2 are profoundly modified by its pharmacological interaction with dexamethasone, paralleling the effects of both drugs on integrins, and leading to a synergic generation of increased numbers of mature eosinophils, in very specific experimental conditions. Diethylcarbamazine (DEC) is an antihelminthic drug that blocks leukotriene synthesis, and possibly acts in experimental filarial infection through iNOS. We have examined, for the first time, the effects of DEC in a model of allergic pulmonary inflammation, showing that DEC is very effective in preventing the impact of airway allergen challenge on BM and lungs, through the in vivo operation of the iNOS-CD95L pathway. Granulocyte Colony-stimulating Factor (G-CSF), which stimulates neutropoiesis, mobilizes CD34+ hemopoietic progenitors from BM, and exerts complex immunoregulatory effects, was shown in our study to have a strong impact in a murine model of allergic pulmonary inflammation. Like DEC, G-CSF suppressed BM eosinopoiesis, although through a different mechanism, since DEC suppressed neutrophilia in the lungs with no effect on BM neutrophilia/neutropoiesis, while G-CSF promoted neutropoiesis and induced blood neutrophilia, even though it suppressed eosinopoiesis. This work was part of the Research Project “Eosinophilia in Experimental Asthma”, licensed by the Committee on the Ethical Use of Laboratory Animals (CEUA) at FIOCRUZ, under numbers L010/04 and L002/09.

Over the past 35 years, diethylcarbamazine (DEC) has been the most widely used agent for the treatment of filarial diseases. However, in spite of millions of individuals treated, the mode of action of this drug remained unexplained until recently when we reported that the microfilaricidal activity of DEC was mediated by blood platelets with the additional triggering of a filarial excretory antigen (FEA) (Nature, 1987).To set up the mechanism of the larvicidal action of platelets activatedby both DEC and FEA, various inhibitors of the arachidonic acid metabolism were added in the cytotoxic assay. Aspirin failed to modify the platelet activity, whilst nordihydroguaiaretic acid, esculetin, and 5,8,11,14-heneicosatetraynoic acid dose-dependently inhibited the killing of parasites. This relationship suggested the production of a putative cytotoxic lipoxygenase product. Surprisingly, no increase in oxygenated metabolites was noted both by thin layer chromatography and by high pressure liquid chromatography.Thus, we investigated the involvement of oxygen free radicals. The hydroxyl radical scavengers tested (benzoate, uric acid, mannitol, methylene blue... ) more or less inhibited the platelet killing activity. In addition, Fe2 + (down to 10-11M) enhanced the DEC-induced cytotoxicity which was abolished in the presence of the Fe2 + chelator o-phenantroline. Finally, using the electronspin resonance technique it was possible to drop OH radicals from platelets with DMPO, but only in the presence of both DEC and FEA.These results, taken with those concerning the interaction of either IgE/anti-IgE (Nature, 1983, 303, 810-812) or CRP (Science, 1986, 231, 153-156) with platelets, should be regarded as a significant insight into the involvement of platelets in various pathological processes.