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Zika still poses a threat to global health owing to its association with serious neurological conditions and the absence of a vaccine and treatment. Sofosbuvir, an anti-hepatitis C drug, has shown anti-Zika effects in animal and cell models. Thus, this study aimed to develop and validate novel LC-MS/MS methods for the quantification of sofosbuvir and its major metabolite (GS-331007) in human plasma and cerebrospinal (CSF) and seminal fluid (SF), and apply the methods to a pilot clinical trial. The samples were prepared by liquid-liquid extraction and separated using isocratic mode on Gemini C18 columns. Analytical detection was performed using a triple quadrupole mass spectrometer equipped with an electrospray ionization source. The validated ranges for sofosbuvir were 0.5-2,000 ng/mL (plasma) and 0.5-100 ng/mL (CSF and SF), while for the metabolite they were 2.0-2,000 ng/mL (plasma), 5.0-200 ng/mL (CSF) and 10-1,500 ng/mL (SF). The intra-day and inter-day accuracies (90.8-113.8%) and precisions (1.4-14.8%) were within the acceptance range. The developed methods fulfilled all validation parameters concerning selectivity, matrix effect, carryover, linearity, dilution integrity, precision, accuracy and stability, confirming the suitability of the method for the analysis of clinical samples.
Assuntos
Infecção por Zika virus , Zika virus , Animais , Humanos , Cromatografia Líquida/métodos , Limite de Detecção , Plasma , Reprodutibilidade dos Testes , Sofosbuvir , Espectrometria de Massas em Tandem/métodosRESUMO
BACKGROUND: Vivax malaria is a neglected disease. There is an irrefutable need for better treatments with higher acceptability and efficacy. The treatment efficacy is influenced by many factors, including bioavailability. Hence, a straightforward strategy to improve vivax malaria treatment efficacy is the deployment of good quality formulations of primaquine and chloroquine. As these treatments were developed more than 70 years ago, many of the available data on blood levels of both drugs are based on obsolete analytical methodologies or pharmaceutical formulations, which are not available anymore. Herein, the results of three bioequivalence studies are presented, providing individual pharmacokinetic data on chloroquine and primaquine of more than a hundred healthy volunteers and using up-to-date analytical methods. METHODS: Three trials were designed as a single centre, randomized, single dose, open label, fasting, crossover bioequivalence studies comparing a new coated chloroquine tablet to the uncoated tablet, and 5 and 15 mg primaquine formulations to either an international reference product or the currently distributed tablets. Plasma concentrations of chloroquine and primaquine were measured using a validated HPLC-MS/MS method in accordance with current international regulatory requirements for bio-analytical methods. RESULTS: In total, a hundred eleven healthy volunteers of both genders were included in the three studies (n = 32; 30 and 56 respectively). No serious adverse events occurred. Drugs levels were measured in 5,520 blood samples. The estimated ratio of the geometric means of Cmax, AUC0-t and AUC0-inf of test and reference drugs and their 90% CI for chloroquine 150 mg, primaquine 15 mg and primaquine 5 mg were: 95.33% (89.18; 101.90), 86. 85% (82.61; 91.31), and 84.45% (76.95; 92.67); 93.28% (81.76; 106.41), 94.52% (86.13; 103.73) and 93.93% (85.83; 102.79); 97.44% (90.60; 104.78), 93.70% (87.04; 100.87) and 91.36% (85.27; 97.89), respectively. As Cmax and AUC0-t 90% CI were within the acceptance interval of 80-125% in all cases, the formulations tested were bioequivalent. CONCLUSIONS: In conclusion, the three studies provided detailed chloroquine and primaquine pharmacokinetic data in accordance with current regulatory standards. Together with other open data initiatives, this individual data may increase the accuracy of pharmacokinetic models guiding best dose, new combinations, regimens and formulations to optimize the current chloroquine and primaquine treatments for vivax malaria. The data presented here may support the deployment of high-quality drugs and evidence-based public health policies.
Assuntos
Antimaláricos/farmacocinética , Cloroquina/farmacocinética , Primaquina/farmacocinética , Adulto , Brasil , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Malária Vivax/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Comprimidos , Adulto JovemRESUMO
O acesso a medicamentos pode ser facilitado por programas globais de desenvolvimento farmacêutico, mas há necessidade de que as agencias regulatórias e as indústrias farmoquímicas e farmacêuticas interajam e haja um consenso quanto as exigências para o registro de medicamentos. Este artigo examinou a legislação especifica sobre bi isenção com base no Sistema de Classificação Biofarmacêutica, comparando os cenários do Brasil e do mundo. A partir dessa análise, identificou os entraves a aplicação dos critérios internacionais na realidade regulatória nacional, identificando algumas fragilidades da legislação, como no caso de pro-fármacos. Analisaram-se os critérios de cinco organismos regulatórios (Agência Europeia de Medicamentos, Food and Drug Administration, Health Canada, Conselho Internacional para Harmonização de Requisitos Técnicos para Medicamentos de Uso Humano e Organização Mundial da Saúde) frente aos requisitos da Agência Nacional de Vigilância Sanitária, pontuando as diferenças e o que já se encontra pacificado no tocante a classe do Sistema de Classificação Biofarmacêutica aceita, a comparabilidade entre formulação teste e de referência, solubilidade, permeabilidade intestinal e perfil de dissolução in vitro. Concluiu--se que a Agência Nacional de Vigilância Sanitária deve internalizar os preceitos e critérios da bioisenção com base no Sistema de Classificação Biofarmacêutica por meio de um novo marco regulatório. Além disso, para que esse marco regulatório seja bem-sucedido e produza resultados palpáveis, em especial na área de saúde publica e vigilância sanitária, a agência brasileira deve estar aberta ao diálogo com o setor regulado e as inovações e orientações da academia, sem desviar o foco de sua missão institucional.
Access to medicines can be facilitated by global pharmaceutical development programs, but there is a need for regulatory agencies and the pharmochemical and pharmaceutical industries to interact and to have a consensus on the requirements for drug registration. This article examined the specific legislation concerning to biowaiver based on the Biopharmaceutical Classification System, comparing the scenario in Brazil and worldwide. Based on this analysis, it identified the obstacles to the application of international criteria in the national regulatory reality, identifying some weaknesses of the legislation, as in the case of prodrugs. The criteria of five regulatory bodies (European Medicines Agency, Food and Drug Administration, Health Canada, International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use and World Health Organization) were analyzed in relation to the requirements of the Brazilian Health Regulatory Agency (Anvisa), pointing out the differences and what has already been settled regarding the accepted class of the Biopharmaceutical Classification System, the comparability between test and reference formulations, solubility, intestinal permeability and in vitro dissolution profile. It was concluded that Anvisa should internalize the percepts and criteria of the biowaiver based on Biopharmaceutical Classification System, through a new regulatory framework. Moreover, for this regulatory framework to be successful and produce tangible results, especially in the area of public health and health surveillance, Anvisa must be open to dialogue with the regulated sector and to innovations and guidance from academia, without losing focus of its institutional mission.
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Atazanavir (ATV) has already been considered as a potential repurposing drug to 2019 coronavirus disease (COVID-19); however, there are controversial reports on its mechanism of action and effectiveness as anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Through the pre-clinical chain of experiments: enzymatic, molecular docking, cell-based and in vivo assays, it is demonstrated here that both SARS-CoV-2 B.1 lineage and variant of concern gamma are susceptible to this antiretroviral. Enzymatic assays and molecular docking calculations showed that SARS-CoV-2 main protease (Mpro) was inhibited by ATV, with Morrison's inhibitory constant (Ki) 1.5-fold higher than GC376 (a positive control) dependent of the catalytic water (H2Ocat) content. ATV was a competitive inhibitor, increasing the Mpro's Michaelis-Menten (Km) more than sixfold. Cell-based assays indicated that different lineages of SARS-CoV-2 is susceptible to ATV. Using oral administration of ATV in mice to reach plasmatic exposure similar to humans, transgenic mice expression in human angiotensin converting enzyme 2 (K18-hACE2) were partially protected against lethal challenge with SARS-CoV-2 gamma. Moreover, less cell death and inflammation were observed in the lung from infected and treated mice. Our studies may contribute to a better comprehension of the Mpro/ATV interaction, which could pave the way to the development of specific inhibitors of this viral protease.
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Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na+ channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively. JME-173 (1-(4-bromo-3,5-dimethylphenoxy)propan-2-amine) was the most effective among the four mexiletine analogues investigated. JME-173 was then studied in vivo using a murine model of lung inflammation induced by cigarette smoke (CS) and in vitro using neutrophil chemotaxis and mast cell degranulation assays. Finally, the JME-173 pharmacokinetic profile was assessed using HPLC-MS/MS bioanalytical method. JME-173 directly inhibited IL-8 (CXCL8)- and FMLP-induced human neutrophil chemotaxis and allergen-induced mast cell degranulation. After oral administration 1 h before CS exposure, JME-173 (50 mg/kg) strongly reduced the increased number of macrophages and neutrophils recovered in the bronchoalveolar effluent without altering lymphocyte counts. Pharmacokinetic experiments of JME-173 (10 mg/kg, orally) showed values of maximum concentration (Cmax), maximum time (Tmax), area under the blood concentration-time curve (AUC0-t) and area under the blood concentration-time curve from 0-Inf (AUC0-inf) of 163.3 ± 38.3 ng/mL, 1.2 ± 0.3 h, 729.4 ± 118.3 ng*h/ml and 868.9 ± 117.1 ng*h/ml (means ± S.E.M.), respectively. Collectively, these findings suggest that JME-173 has the potential to be an effective oral treatment for diseases associated with bronchoconstriction and inflammation.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Mexiletina/análogos & derivados , Mexiletina/farmacologia , Parassimpatolíticos/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Área Sob a Curva , Líquido da Lavagem Broncoalveolar/citologia , Degranulação Celular/efeitos dos fármacos , Humanos , Masculino , Mastócitos/efeitos dos fármacos , Camundongos , Infiltração de Neutrófilos/efeitos dos fármacos , Técnicas de Patch-Clamp , Pneumonia/induzido quimicamente , Pneumonia/tratamento farmacológico , Ratos , Ratos Wistar , Fumaça , Relação Estrutura-Atividade , Produtos do TabacoRESUMO
BACKGROUND: Activation of hypnozoites of vivax malaria causes multiple clinical relapses, which contribute to the Plasmodium vivax burden and continuing transmission. Artemisinin-based combination therapy (ACT) is effective against blood-stage P. vivax but requires co-administration with primaquine to achieve radical cure. The therapeutic efficacy of primaquine depends on the generation of a therapeutically active metabolite via cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 metabolism has been associated with primaquine treatment failure. This study investigated the association between impaired CYP2D6 genotypes, drug-exposure to the long-acting ACT component (schizonticidal drugs) and tolerance and efficacy. METHODS: Adult patients with acute vivax malaria were enrolled in a recently completed trial and treated with artesunate-mefloquine, chloroquine or artemether-lumefantrine. All received concomitant primaquine (0.5 mg/kg/day for 7-9 days). The association between efficacy and safety and drug exposure was explored using area-under-the-curve (AUC) and half-life (t1/2) estimates obtained by non-compartmental analysis of the long half-life drugs. Parasite recurrences by day 63 were categorized as related relapses or re-infections/unrelated hypnozoite activation by genotyping three microsatellite loci and two polymorphic loci of merozoite surface antigen-1. The CYP2D6 genotype was identified with Taqman assays by real-time PCR to 9 polymorphisms (8 SNPs and one deletion). Impaired CYP2D6 activity was inferred using the Activity Score System. RESULTS: Most recurrences in the ASMQ (67%), CQ (80%) and AL (85%) groups were considered related relapses. Eight of nine (88.9%) of the patients with impaired CYP2D6 activity relapsed with related parasite compared to 18/25 (72%) with normal activity (RR = 1.23, 0.88; 1.72, p = 0.40). There were no associations between the measured PK parameters and recurrence. Patients with longer chloroquine half-lives had more pruritus (RR = 1.09, 1.03; 1.14, p = 0.001). Higher CQ AUCs were associated with reduced falls in haemoglobin by day 14 (Coef - 0.02, - 0.005; - 0.03, p = 0.01). All regimens were well tolerated. CONCLUSION: Genotyping of P. vivax showed that activation of related (homologous) hypnozoites was the most frequent cause of recurrence. The high proportion of the impaired CYP2D6 activity among patients with recurrent infections suggests that slow primaquine metabolism might influence related relapse rates in Brazil among patients receiving primaquine for radical cure, although confirmatory studies are needed. There was no association between drug exposure of the long-acting ACT component (schizonticidal drugs) and risk of related relapse. ACT was well tolerated. These results provide further re-assurance about the safety and efficacy of ACT when combined with short course primaquine to treat uncomplicated malaria vivax in Brazil. Trial registration RBR-79s56s ( http://www.ensaiosclinicos.gov.br/rg/RBR-79s56s/ ).
Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Cloroquina/farmacologia , Primaquina/farmacologia , Adulto , Idoso , Antimaláricos/farmacocinética , Artemisininas/farmacocinética , Brasil , Cloroquina/farmacocinética , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Primaquina/farmacocinética , Adulto JovemRESUMO
Epidemiological studies found that hepatitis E virus genotype 3 (HEV-3) infection was associated with chronic hepatitis and cirrhosis in immunocompromised patients. Our study aimed to investigate the relationship between the host immunosuppressive status and the occurrence of HEV-related chronic hepatitis. Here we describe a successful experimental study, using cynomolgus monkeys previously treated with tacrolimus, a potent calcineurin inhibitor immunosuppressant, and infected with a Brazilian HEV-3 strain isolated from naturally infected pigs. HEV infected monkeys were followed up during 160 days post infection (dpi) by clinical signs; virological, biochemical and haematological parameters; and liver histopathology. The tacrolimus blood levels were monitored throughout the experiment. Immunosuppression was confirmed by clinical and laboratorial findings, such as: moderate weight loss, alopecia, and herpes virus opportunistic infection. In this study, chronic HEV infection was characterized by the mild increase of liver enzymes serum levels; persistent RNA viremia and viral faecal shedding; and liver histopathology. Three out of four immunosuppressed monkeys showed recurrent HEV RNA detection in liver samples, evident hepatocellular ballooning degeneration, mild to severe macro and microvesicular steatosis (zone 1), scattered hepatocellular apoptosis, and lobular focal inflammation. At 69 dpi, liver biopsies of all infected monkeys revealed evident ballooning degeneration (zone 3), discrete hepatocellular apoptosis, and at most mild portal and intra-acinar focal inflammation. At 160 dpi, the three chronically HEV infected monkeys showed microscopic features (piecemeal necrosis) corresponding to chronic hepatitis in absence of fibrosis and cirrhosis in liver parenchyma. Within 4-months follow up, the tacrolimus-immunosuppressed cynomolgus monkeys infected with a Brazilian swine HEV-3 strain exhibited more severe hepatic lesions progressing to chronic hepatitis without liver fibrosis, similarly as shown in tacrolimus-immunosuppressed solid organ transplant (SOT) recipients. The cause-effect relationship between HEV infection and tacrolimus treatment was confirmed in this experiment.
Assuntos
Vírus da Hepatite E/patogenicidade , Imunossupressores/imunologia , Macaca fascicularis/imunologia , Macaca fascicularis/virologia , Animais , Brasil , Feminino , Genótipo , Anticorpos Anti-Hepatite/imunologia , Hepatite E/imunologia , Hepatite E/virologia , Vírus da Hepatite E/genética , Vírus da Hepatite E/imunologia , Terapia de Imunossupressão/métodos , Fígado/imunologia , Fígado/virologia , Cirrose Hepática/imunologia , Cirrose Hepática/virologia , Testes de Função Hepática/métodos , Masculino , RNA Viral/genética , Eliminação de Partículas Virais/imunologiaRESUMO
Nifedipine (NFD) has been used for the treatment of cutaneous lesions caused by peripheral vascular disease and diabetic ulcers. NFD was formulated at 8% in three semi-solid formulations: Polaxamer 407 Lecithin Organogel (PLO), PLO plus Transcutol(®), and an oil-in-water (o/w) emulsion. In vitro release and permeation tests were carried out using a synthetic (cellulose acetate) or natural membrane (pig ear skin), respectively, mounted in a Franz-type diffusion cell at 37°C in a constant water bath. As a receptor solution, isotonic phosphate buffer at pH 7.4 was used. All samples were analyzed by high-performance liquid chromatography by employing a previously validated method. The drug flow values were 6.126 ± 0.288, 4.030 ± 0.081, and 6.660 ± 0.254 µg/cm(2)/h for PLO, PLO plus Transcutol(®), and o/w emulsion, respectively. The three formulations did not show significant differences in drug flow, considering p > 0.05. Furthermore, their penetration profiles in both the epidermis and dermis were statistically different. Thus, the incorporation of NFD in PLO, PLO plus Transcutol(®), and o/w emulsion changed the drug thermodynamic activity, as expected. In addition, Transcutol(®) increased the solubility of NFD in the formulation and promoted its penetration in both the epidermis and dermis.
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Bloqueadores dos Canais de Cálcio/química , Nifedipino/química , Doenças Vasculares Periféricas/tratamento farmacológico , Pele/metabolismo , Administração Tópica , Animais , Química Farmacêutica , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Géis , Concentração de Íons de Hidrogênio , Lecitinas/química , Nifedipino/farmacocinética , Permeabilidade , Poloxâmero/química , Solubilidade , SuínosRESUMO
The dissolution test for oral dosage forms has recently widened to a variety of special dosage forms such as suspensions. For class II drugs, such as nimesulide (NMS), this study is very important because formulation problems may compromise drug bioavailability. In the present work, tests with four brands of commercially available NMS (RA, TS, TB, and TC) have been performed in order to study their dissolution at different conditions. The suspensions have been characterized relatively to particle size, pH, and density besides NMS assay and the amount of drug in solution in the suspension vehicles. The dissolution study was conducted using the following media: simulated intestinal fluid, pH 6.8, containing polysorbate 80 (P80) or sodium lauryl sulfate (SLS); phosphate buffer, pH 7.4, with P80 and aqueous solution of SLS. Concerning the quantitative analysis, the UV-VIS spectrophotometry could have been used in substitution to high-performance liquid chromatography since the methodology had been adequately validated. The influence of the drug particle size distribution was significant on the dissolution profiles of NMS formulations, confirming to be a factor that should be strictly controlled in the development of oral suspensions.