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1.
Int J Pharm ; 650: 123721, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38110011

RESUMO

Mebendazole (MBZ) is a broad-spectrum active pharmaceutical ingredient (API) indicated for treating parasitosis, and it has three solid-state forms, A, B, and C. These solid forms exhibit significant differences in dissolution properties, which cause considerable changes in the therapeutic effect. When at least 30 % of Form A is present in the formulation, it has a similar effect to the placebo. The aim of this study was to develop a reliable quantitative method for MBZ (Forms A and C) suspensions that allowed to study the solid-state stability and the kinetics of the solid-state transformation of MBZ suspensions under the recommended pharmaceutical industry conditions. One method was developed to carry out the drying process and the other one to quantify Forms A and C of MBZ suspensions; both were evaluated. For the stability study, samples were prepared with different starting reference concentrations of Form A and stored from 1 to 24 months under long-term stability conditions (30 ± 2 °C and 75 ± 5 % RH) and from 1 to 6 months under accelerated stability conditions (40 ± 2 °C and 75 ± 5 % RH). Data collection was performed by powder X-ray diffraction (PXRD). The Rietveld method (RM) and Topas's program were used to solid form quantification. Avrami's equation was used to determine the kinetic parameters. The results showed that the combination of the drying process and solid form quantification developed method for suspension was a very accurate methodology for solid-state stability studies. Furthermore, in long-term and accelerated solid-state conditions, suspension with an initial value of 1 % of Form A were sufficient to cause a solid-state transformation (Form C to A) greater than 30 % in the first and second months, with a complete transformation in nine and six months respectively. These results demonstrate that suspensions show complete solid-state transformation (Form C to A) in a shorter time than the product's shelf life (∼2 years). In this work, a reliable methodology was developed to quantify MBZ (Forms A and C) suspensions. This methodology could be used to control the different solid forms for MBZ and other APIs to avoid solid-state transformation problems.


Assuntos
Mebendazol , Difração de Raios X , Pós , Solubilidade , Cristalização , Suspensões
3.
Drug Dev Ind Pharm ; 48(4): 146-157, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35876070

RESUMO

Oseltamivir phosphate is used to treat influenza. For registration of a generic product, bioequivalence studies are crucial, however, in vitro studies can sometimes replace the conventional human pharmacokinetic. To assess whether the dissolution profile is comparable with the in vivo release, physiologically based pharmacokinetic absorption models (PBPK) are being used. The aim of the study was to develop a generic capsule of oseltamivir phosphate 30 mg with process understanding and control, development of PBPK model and comparison of virtual bioequivalence study (VBE) to the real bioequivalence study that was also performed. For that, 30 mg capsules were prepared by wet granulation according to 22 full factorial design. The biobatch was prepared with the selected process and a batch was made with the API from the second manufacture. Both manufactures presented polymorph A and the second manufacture showed higher particle size. Product batches produced without adding water during granulation showed higher dissolution. The addition of water associated with higher conical mill speed, lowered the average weight of the capsules. The biobatch dissolution was similar to Tamiflu; also, they were bioequivalent. The crossover VBE between the biobatch and Tamiflu corroborated with the real bioequivalence study. The same result was found for the batch with higher particle size. PBPK model showed that computer simulations can help pharmaceutical companies to replace in vivo studies.


Assuntos
Modelos Biológicos , Oseltamivir , Cápsulas , Desenvolvimento de Medicamentos , Humanos , Fosfatos , Equivalência Terapêutica , Água
4.
Ecology ; 103(2): e03580, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34727372

RESUMO

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.


Assuntos
Ecossistema , Florestas , Animais , Biodiversidade , Solo , América do Sul
5.
Braz. J. Pharm. Sci. (Online) ; 58: e18800, 2022. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1364431

RESUMO

Abstract Efavirenz is one of the most commonly used drugs in HIV therapy. However the low water solubility tends to result in low bioavailability. Drug nanocrystals, should enhance the dissolution and consequently bioavailability. The aim of the present study was to obtain EFV nanocrystals prepared by an antisolvent technique and to further observe possible effect, on the resulting material, due to altering crystallization parameters. A solution containing EFV and a suitable solvent was added to an aqueous solution of particle stabilizers, under high shear agitation. Experimental conditions such as solvent/antisolvent ratio; drug load; solvent supersaturation; change of stabilizer; addition of milling step and solvents of different polarities were evaluated. Suspensions were characterized by particle size and zeta potential. After freeze- dried and the resulting powder was characterized by PXRD, infrared spectroscopy and SEM. Also dissolution profiles were obtained. Many alterations were not effective for enhancing EFV dissolution; some changes did not even produced nanosuspensions while other generated a different solid phase from the polymorph of raw material. Nevertheless reducing EFV load produced enhancement on dissolution profile. The most important modification was adding a milling step after precipitation. The resulting suspension was more uniform and the powder presented grater enhancement of dissolution efficacy.


Assuntos
Eficácia/classificação , HIV/patogenicidade , Cristalização/instrumentação , Dissolução/métodos , Tamanho da Partícula , Solubilidade , Preparações Farmacêuticas/administração & dosagem , Excipientes/farmacologia , Dissolução/classificação , Nanopartículas/administração & dosagem , Métodos
6.
Braz. J. Pharm. Sci. (Online) ; 58: e19759, 2022. tab
Artigo em Inglês | LILACS | ID: biblio-1383977

RESUMO

Abstract Dissolution is a key step in the uptake of oral drugs. In order to compare the behaviour of the dissolution of two formulations, the dissolution profile test was used. This assay must be discriminative and should mimic in vivo conditions. Many dissolution media described in pharmacopoeias are not predictive of bioavailability. Due to this, biorelevant media are used as an alternative to solve this problem. The objective of this work is to evaluate the relevance of biorelevant dissolution media to predict in vivo drug dissolution. For this, a bibliographic search was carried out in scientific databases. The search was first performed for articles verifying the physicochemical properties of human gastrointestinal fluids. Subsequently, a comparison was made between the properties of gastrointestinal fluids and those of biorelevant and pharmacopoeial media. Finally, the results of bioequivalence studies and dissolution profile tests in biorelevant media described in the literature were compared. The results revealed that there are a few publications that have analysed some physicochemical properties of gastrointestinal fluids. In addition, high variability was observed for some properties. Regarding the comparison of these properties with pharmacopoeial media and biorelevant media, the analysis showed that the biorelevant media are more similar to gastrointestinal fluids than the pharmacopoeial media. Finally, the in vitro dissolution profile results were similar to the results obtained in vivo. Thus, biorelevant media may be useful for analysing dissolution profiles.


Assuntos
Equivalência Terapêutica , Dissolução , Liberação Controlada de Fármacos , Publicações/classificação , Técnicas In Vitro/instrumentação , Preparações Farmacêuticas/análise
7.
Ars pharm ; 62(4): 358-370, oct.-dic. 2021. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-216444

RESUMO

Introducción: Los productos orales sólidos de liberación inmediata que contienen fármacos muy solubles y perme-ables son candidatos para el proceso de bioexención. Este trabajo tiene como objetivo comparar datos in vitro, in silico e in vivo para establecer si las formulaciones de comprimidos orales de prednisona publicadas anteriormente son candidatas a la bioexención. Método: Para lograr este objetivo se realizaron estudios de permeación en células Caco-2. Se aplicó un estudio de bioequivalencia previo entre la formulación de prueba y el medicamento de referencia en una evaluación in silicoutilizando Gastroplus® para evaluar la bioequivalencia de otras dos formulaciones propuestas anteriormente. Resultados: El coeficiente de permeabilidad aparente para prednisona presentó un valor de 3,69 x 10-5 cm/s en 180 minutos. El estudio de bioequivalencia muestra que el producto probado y de referencia era equivalente. Las simulaciones in silicopredijeron con éxito la farmacocinética de las formulaciones probadas y las otras dos, ya que fueron validadas con el estudioin vivo. Ambos exhiben los mismos perfiles de concentración plasmática frente a tiempo. Conclusiones: A través de los resultadosin silico, es posible inferir que las otras dos formulaciones ensayadas pueden ser bioequivalentes respecto al producto de referencia. Este resultado puede ser útil en la solicitud de bio-exenciones. Para reducir los costos y el uso de seres humanos en los estudios de bioequivalencia, este enfoque podría ser una forma esencial de trabajar en la industria farmacéutica. (AU)


Introduction: The immediate-release solid oral products containing very soluble and permeable drugs are candidates for the biowaiver process. This work aims to compare in vitro, in silico, and in vivo data to establish if previously published prednisone oral tablet formulations are biowaiver candidates. Method: To achieve this goal, permeation studies were conducted on Caco-2 cells. A previous bioequivalence study between the test and the reference drug product was applied on an in silico evaluation using Gastroplus® to assess the bioequivalence of two other previously proposed formulations. Results: The apparent permeability coefficient for prednisone presented a value of 3.69 x 10-5 cm/s in 180 minutes. The bioequivalence study shows that the tested and reference product was equivalent. The in silico simulations successfully predicted the pharmacokinetics of the tested and the other two formulations since they were validated with the in vivo study. Both exhibit the same plasma concentration vs. time profiles. Conclusions: Through the in silico results, it is possible to infer that the other two formulations tested may be bioequivalent concerning the reference product. This result may be helpful in biowaiver requesting. Toward to reduce costs and the use of human beings in bioequivalence studies, this approach could be an essential way to work in the pharmaceutical industry. (AU)


Assuntos
Humanos , Disponibilidade Biológica , Técnicas In Vitro , Prednisona , Células CACO-2 , Comprimidos
8.
Anaesthesiol Intensive Ther ; 52(4): 297-303, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33165880

RESUMO

BACKGORUND: Current evidence suggests that intraoperative goal-directed haemodynamic therapy (GDT) should be considered for high-risk patients undergoing major gastrointestinal surgery. We aimed to evaluate if an algorithm using venoarterial carbon dioxide difference (CO2 gap) and pulse pressure variation (PPV) as therapeutic targets during GDT would decrease the major complications after gastrointestinal surgery. METHODS: This was a before-and-after study (n = 204) performed in a tertiary hospital on patients who underwent elective open major gastrointestinal surgeries. The inclusion criteria were surgeries expected to last more than two hours, family and physician's agreement on total postoperative support, and survival expectancy of at least three months. The exclusion criteria were previous haemodynamic instability, presence of infection, cardiac arrhythmias, and emergency surgery. In the intervention group (IG), an algorithm was applied using fluids, dobutamine, and noradrenaline during the intraoperative period aiming at MAP > 65 mm Hg, SpO2 > 95%, CO2 gap < 6 mm Hg, and PPV < 13%. The control group (CG) comprised consecutive eligible patients who were operated by the same team before the institution of the algorithm. RESULTS: The rates of moderate and severe postoperative complications were lower in the IG (11% vs. 23%; IC: RR = 0.47, 95% CI: 0.246-0.929; P = 0.025). The respective 90- and 180-day mortality rates in the IG and CG were 9.8% vs. 22.5% (P = 0.014) and 12.6% vs. 25.5% (P = 0.020). CONCLUSIONS: An algorithm aiming to minimise the CO2 gap and normalise PPV was feasible and effective in decreasing rates of moderate and severe complications after surgery in high-risk patients.


Assuntos
Pressão Sanguínea/fisiologia , Dióxido de Carbono/sangue , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Hemodinâmica/efeitos dos fármacos , Complicações Pós-Operatórias/prevenção & controle , Idoso , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
9.
Toxins (Basel) ; 12(11)2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33137918

RESUMO

Alkaloids are important metabolites found across a variety of organisms with diverse ecological functions. Of particular interest are alkaloids found in ants, organisms well known for dominating the ecosystems they dwell in. Within ants, alkaloids are found in venom and function as potent weapons against heterospecific species. However, research is often limited to pest species or species with parasitic lifestyles and thus fails to address the broader ecological function of ant venom alkaloids. Here we describe a new species of free-living Megalomyrmex ant: Megalomyrmex peetersi sp. n. In addition, we identify its singular venom alkaloid (trans-2-butyl-5-heptylpyrrolidine) and elucidate the antibiotic and insecticidal functions of its venom. Our results show that Megalomyrmex peetersi sp. n. venom is an effective antibiotic and insecticide. These results are comparable to venom alkaloids found in other ant species, such as Solenopsis invicta. This research provides great insight into venom alkaloid function, and it is the first study to explore these ideas in the Megalomyrmex system.


Assuntos
Alcaloides/toxicidade , Venenos de Formiga/toxicidade , Antibacterianos/toxicidade , Formigas , Inseticidas/toxicidade , Alcaloides/química , Animais , Venenos de Formiga/química , Antibacterianos/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Feminino , Inseticidas/química , Isópteros/efeitos dos fármacos , Dose Letal Mediana , Masculino
10.
Food Res Int ; 133: 109168, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32466931

RESUMO

Araticum (Annona crassiflora Mart.) is a native fruit from Brazilian Cerrado widely used by folk medicine. Nevertheless, the biological effects of its seeds and peel have not been extensively evaluated. We evaluate herein the antioxidant, antiproliferative and healing potential of araticum peel and seeds extracts. HPLC-ESI-MS/MS analysis showed flavonoids, namely epicatechin and quercetin, as the main compounds in peel and seeds extracts, respectively. These extracts showed high content of phenolic compounds (7254.46 and 97.74 µg/g extract) and, as consequence, high antioxidant capacity. Interesting, the seeds extract was more effective than peel extract against all tested cancer cells, especially on NCI-ADR/RES (multidrug resistant ovary adenocarcinoma) cell line. In the cell migration assay by using HaCaT (keratinocyte), the seeds extract induced migration, while the peel extract showed an inhibitory effect. In this way, phenolic content could be related to antioxidant capacity, but it was not related to antiproliferative and healing effect. The araticum seeds extract showed an interesting response to in vitro biological assay although of its low content of phenolic compounds. Unidentified compounds, such as alkaloids and annonaceous acetogenins could be related to it. Araticum has potential to be used as therapeutic plant especially as antiproliferative and healing drug.


Assuntos
Annona , Antioxidantes/farmacologia , Brasil , Sementes , Espectrometria de Massas em Tandem
11.
Int J Pharm ; 556: 125-135, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30543891

RESUMO

Olanzapine (OLZ), a drug for the treatment of schizophrenia, presents in more than 60 crystal forms. Polymorphs I, II and III were reported, however, the preparation conditions for pure II and III have not been reported. Polymorph IV was reported but this form is actually polymorph II described at different temperature. The diversity of solid forms of OLZ, the change in the nomenclature found in the literature and the presence of polymorphic mixture in samples, increase the difficulty for a correct solid state characterization. Therefore, the goal was the polymorphic identification of three OLZ raw materials, highlighting the limitation of conventional techniques (typically used in analytical control) and the necessity to use a combination of advanced ones to solve this challenge. The samples were studied by conventional techniques such as powder X-ray diffraction, thermoanalytical techniques, infrared spectroscopy. In apart from that, synchrotron powder X-ray diffraction (SPXRD) and solid state nuclear magnetic resonance (ss-NMR) were used. All samples were in accordance with the pharmacopoeia criteria. However, the conventional techniques were not specific for the complete polymorphic identification. Therefore, a combination of advanced techniques (SPXRD and ss-NMR) was necessary to identify the mixture of polymorphs (I, II and III) in all samples.


Assuntos
Antipsicóticos/química , Espectroscopia de Ressonância Magnética/métodos , Olanzapina/química , Difração de Raios X/métodos , Cristalização , Espectrofotometria Infravermelho , Síncrotrons , Tecnologia Farmacêutica/métodos
12.
Cien Saude Colet ; 23(10): 3267-3276, 2018 Oct.
Artigo em Português, Inglês | MEDLINE | ID: mdl-30365846

RESUMO

The world is currently experiencing complex threats to privacy in health (PH) in the context of the growing virtualization of bodies and biographies exposed in social networks. This paper aims to identify the approaches to PH in Brazilian scientific production in the light of Collective Health (CH). This is an exploratory, analytical-descriptive study reviewingpapers from Brazilian Collective Health journals of excellence from 2000 to 2017. Papers employing PH as their object were selected for further analysis. We found that papers are commonly anchored in the perspective that the "professional's fear of punishment" is the borderline inhibiting PH violation actions. However, neither the legal-normative framework nor the technological security apparatus sufficed. In the Unified Health System (SUS), threats escalate in initiatives of the SUS Card, PEP, Regulatory Centers and Telehealth. The results corroborate a hypothetic gap in the production of the subject in Collective Health journals of excellence. The discussion is about institutional omission; adoption of the ICF for the use of individual data; opacity on the revenue of public expenditure in the technological security apparatus. Respect for PH must bethe result of a political-ethical agreement, in which all start to act ethically in defense of privacy by choice and not coercion and fear of penalties.


A atualidade vivencia complexas ameaças à privacidade na saúde (PS), no contexto de crescente virtualização dos corpos e de biografias expostas nas redes sociais. O artigo objetiva conhecer as abordagens sobre a PS na produção científica brasileira à luz da Saúde Coletiva (SC). Realiza estudo exploratório, analítico-descritivo, com revisão de artigos de periódicos brasileiros de excelência da SC de 2000 a 2017. Foram selecionados artigos que adotam a PS como objeto. Evidenciou-se que, em comum, ancoram-se na perspectiva de que o 'medo do profissional à punição' é a fronteira para inibir ações de violação da PS. Porém, nem o arcabouço jurídico-normativo, nem o apparatus tecnológico de segurança, tem sido suficiente. No SUS, ameaças se intensificam em iniciativas do Cartão SUS, PEP, Centrais de Regulação e Telessaúde. Os resultados corroboram com a hipótese de que existe uma lacuna na produção sobre a temática em periódicos de excelência da SC. Discute-se: omissão das instituições; adoção de TCLE para uso de dados individuais; opacidade sobre o faturamento dos gastos públicos no apparatus tecnológico de segurança. O respeito à PS precisa tornar-se fruto de um pacto político-ético, onde todos passem a agir eticamente na defesa da privacidade por opção e não por coação e medo de penalidades.


Assuntos
Confidencialidade , Internet , Programas Nacionais de Saúde/organização & administração , Rede Social , Brasil , Comportamento de Escolha , Medo , Humanos , Publicações Periódicas como Assunto/normas , Privacidade
13.
Int J Pharm ; 553(1-2): 261-271, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30366068

RESUMO

The drug carvedilol, used to treat cardiovascular conditions, is known to exist in distinct crystalline forms. Polymorphs II and III and the hydrate are characterized by variations in their molecular packing and conformation. This study deals with the spectroscopic (supported by quantum chemistry calculations) characterization of carvedilol structures. Band assignments were performed considering the isolated molecules and periodic calculations. We discuss the correlation between the vibrational modes and the intermolecular forces in the crystalline structures. Towards a better understanding of the intermolecular interactions, Hirshfeld surface was used. Besides band shifts related to stretching vibrations of N-H and O-H groups, differences between other modes have shown the possibility of using infrared spectroscopy to distinguish the crystal forms; technique routinely used in quality control of pharmaceutics. According to the spectroscopic analysis, the N-H groups participate in stronger bonds in the polymorph III, which contributes to its greater stability. With Hirshfeld surface we concluded that the bond with the nitrogen of the aliphatic chain participating as hydrogen acceptor in polymorph II is responsible for the pointy peaks in the fingerprint plot. This can explain why polymorph II shows lower dissolution in acid medium, as described in a previous work of our group.


Assuntos
Antagonistas Adrenérgicos beta/química , Carvedilol/química , Análise Espectral/métodos , Química Farmacêutica/métodos , Cristalização , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Teoria Quântica , Espectrofotometria Infravermelho , Vibração
14.
Ciênc. Saúde Colet. (Impr.) ; 23(10): 3267-3276, Out. 2018. tab
Artigo em Português | LILACS | ID: biblio-974685

RESUMO

Resumo A atualidade vivencia complexas ameaças à privacidade na saúde (PS), no contexto de crescente virtualização dos corpos e de biografias expostas nas redes sociais. O artigo objetiva conhecer as abordagens sobre a PS na produção científica brasileira à luz da Saúde Coletiva (SC). Realiza estudo exploratório, analítico-descritivo, com revisão de artigos de periódicos brasileiros de excelência da SC de 2000 a 2017. Foram selecionados artigos que adotam a PS como objeto. Evidenciou-se que, em comum, ancoram-se na perspectiva de que o 'medo do profissional à punição' é a fronteira para inibir ações de violação da PS. Porém, nem o arcabouço jurídico-normativo, nem o apparatus tecnológico de segurança, tem sido suficiente. No SUS, ameaças se intensificam em iniciativas do Cartão SUS, PEP, Centrais de Regulação e Telessaúde. Os resultados corroboram com a hipótese de que existe uma lacuna na produção sobre a temática em periódicos de excelência da SC. Discute-se: omissão das instituições; adoção de TCLE para uso de dados individuais; opacidade sobre o faturamento dos gastos públicos no apparatus tecnológico de segurança. O respeito à PS precisa tornar-se fruto de um pacto político-ético, onde todos passem a agir eticamente na defesa da privacidade por opção e não por coação e medo de penalidades.


Abstract The world is currently experiencing complex threats to privacy in health (PH) in the context of the growing virtualization of bodies and biographies exposed in social networks. This paper aims to identify the approaches to PH in Brazilian scientific production in the light of Collective Health (CH). This is an exploratory, analytical-descriptive study reviewingpapers from Brazilian Collective Health journals of excellence from 2000 to 2017. Papers employing PH as their object were selected for further analysis. We found that papers are commonly anchored in the perspective that the "professional's fear of punishment" is the borderline inhibiting PH violation actions. However, neither the legal-normative framework nor the technological security apparatus sufficed. In the Unified Health System (SUS), threats escalate in initiatives of the SUS Card, PEP, Regulatory Centers and Telehealth. The results corroborate a hypothetic gap in the production of the subject in Collective Health journals of excellence. The discussion is about institutional omission; adoption of the ICF for the use of individual data; opacity on the revenue of public expenditure in the technological security apparatus. Respect for PH must bethe result of a political-ethical agreement, in which all start to act ethically in defense of privacy by choice and not coercion and fear of penalties.


Assuntos
Humanos , Confidencialidade , Internet , Rede Social , Programas Nacionais de Saúde/organização & administração , Publicações Periódicas como Assunto/normas , Brasil , Comportamento de Escolha , Privacidade , Medo
15.
AAPS PharmSciTech ; 18(8): 3011-3020, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28493004

RESUMO

Efavirenz is a fundamental drug in the HIV therapy; however, it has a low bioavailability due to low water solubility. Particle nanonization should enhance its dissolution and therefore its bioavailability. Nanocrystallization is a promising technique for preparing drug nanocrystals. A solution containing efavirenz (EFV) and methanol was added to an aqueous solution of particle stabilizers, under sonication. The adequate polymer stabilizer and its concentration and drug load were evaluated. Particle size and zeta potential of suspensions were measured. Nanosuspensions were freeze-dried and the resulting powder was characterized by some techniques, with special attention to dissolution. Particle size and zeta potential analysis showed that HMPC and PVP were the most suitable polymers. All samples prepared with these stabilizers had nanosized particles and proper zeta potential; however, sedimentation and particle growth were detected with Turbiscan™. Time-related destabilization occurred when the lowest polymer concentration of 20% was used. SEM analysis of the dried powder shows film formation for suspensions with 40% of polymer and particle aggregation in samples with less polymer. Dissolution profiles of samples were higher than EFV raw material, although the lower the polymer concentration, the higher the dissolution.


Assuntos
Benzoxazinas/química , Benzoxazinas/metabolismo , Sonicação/métodos , Alcinos , Disponibilidade Biológica , Ciclopropanos , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Liofilização/métodos , Nanopartículas/química , Tamanho da Partícula , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/metabolismo , Solubilidade , Difração de Raios X
16.
Eur J Pharm Sci ; 99: 310-317, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28042101

RESUMO

Efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor (NNRTI), is part of first-line therapy for the treatment of human immunodeficiency virus type 1 infection (HIV-1/AIDS). This drug shows relatively low oral absorption and bioavailability, as well as high intra- and inter-subject variability. Several studies have shown that treatment failure and adverse effects are associated with low and high EFV plasma concentrations, respectively. Some studies suggest different EFV formulations to minimize inter-patient variability and improve its solubility and dissolution; however, all of these formulations are complex, using for instance, cyclodextrins, dendrimers and polymeric nanoparticles, rendering them inviable industrially. The aim of this work was to prepare simple and low-cost suspensions of EFV for improvement of solubility and dissolution rate by using colloid mill, spray or freeze-drying, and characterization of the powders obtained. The results demonstrated an increase in the dissolution rate of EFV, using 0.2% of sodium lauryl sulfate (SLS) and 0.2% of hydroxypropylcellulose (HPC) or hydroxypropylmetilcellulose (HPMC) in both freeze and spray dried powders. The pharmacokinetic studies demonstrated improved pharmacokinetic parameters for the formulation containing SLS and HPC. The powders obtained, which present enhanced dissolution properties, can be incorporated in a solid dosage form for treatment of AIDS in paediatric patients with promising results.


Assuntos
Benzoxazinas/química , Benzoxazinas/farmacocinética , Coloides/química , Alcinos , Animais , Celulose/análogos & derivados , Celulose/química , Química Farmacêutica/métodos , Ciclopropanos , Composição de Medicamentos , Nariz Eletrônico , Liofilização/métodos , Masculino , Nanopartículas/química , Tamanho da Partícula , Pós/química , Pós/farmacocinética , Ratos , Ratos Wistar , Dodecilsulfato de Sódio/química , Solubilidade , Suspensões/química , Suspensões/farmacocinética
17.
Braz. J. Pharm. Sci. (Online) ; 53(4): e00088, 2017. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-889424

RESUMO

ABSTRACT Solid dosage forms for oral use, particularly tablets, are the most highly used dosage forms in therapy because they are easily administered, have high productivity and relatively low cost and provide a more stable drug to form a semi-solid net. Numerous parameters influence the quality of the final dosage form. In this study, the dissolution profile of 20-mg prednisone tablets bioequivalent to the reference product and three test formulations were evaluated using stability testing. During the study, prednisone tablets and the active pharmaceutical ingredient (API) prednisone from two different manufacturers were characterized with respect to their physical and physicochemical properties. The results showed that the dissolution profiles of the test batches and the reference product did not retain pharmaceutical equivalence throughout all the stability study. Notably, both samples of API prednisone were of the same crystal form, and any phase transition that occurred during the study could not be attributed to dissolution variation during stability.


Assuntos
Prednisona/administração & dosagem , Estabilidade de Medicamentos , Dissolução/análise , Preparações Farmacêuticas/normas , Fenômenos Químicos , Dosagem
18.
Rev. bras. entomol ; 60(2): 117-122, Apr.-June 2016. graf
Artigo em Inglês | LILACS | ID: lil-783865

RESUMO

ABSTRACT Ricardo von Diringshofen (1900–1986) was a Natural History enthusiast who collected an incredible variety of objects, mostly insects, which amount to over 2 million specimens. We present here a brief biography of Ricardo von Diringshofen, including the history of his insect collection and the processes of purchase and incorporation of his collection by the Museu de Zoologia da Universidade de São Paulo.

19.
Pharm Dev Technol ; 21(7): 856-866, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26336079

RESUMO

Carvedilol is an antihypertensive drug with non-selective blockade (moderate selectivity for ß1 and ß2 adrenoceptors) and vasodilating properties due to α receptor blockade. Its molecule has one chiral centre; therefore, the drug has two enantiomers. Furthermore, it presents different polymorphs depending on the synthesis route and crystallization procedure. Carvedilol is a weak base that is substantially insoluble in water, acidic solutions, and gastric and intestinal fluids; it is classified as a Class II drug in the Biopharmaceutical Classification System. The solubility of carvedilol varies according to the solvent pH. This study aimed to evaluate and correlate the physicochemical and processability properties of carvedilol. Samples of the active ingredient from three different manufacturers were characterized according to their flowability, particle size and apparent density and using microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, intrinsic dissolution and powder dissolution tests. It was determined that the tested samples presented the same polymorphic form, did not present good flowability, and presented different particle size distributions. The tests to evaluate flowability and compressibility were shown to be discriminative, and slight differences among the samples were noted.


Assuntos
Carbazóis/química , Propanolaminas/química , Varredura Diferencial de Calorimetria/métodos , Carvedilol , Química Farmacêutica/métodos , Cristalização , Microscopia Eletrônica de Varredura/métodos , Tamanho da Partícula , Difração de Pó/métodos , Pós/química , Solubilidade , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Tecnologia Farmacêutica/métodos , Difração de Raios X/métodos
20.
Saudi Pharm J ; 22(5): 445-53, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25473333

RESUMO

This study aimed to examine the adhesion of glibenclamide 5 mg tablets to the tools of compression machines. This problem is not commonly reported in the literature, since it is considered as tacit knowledge. The starting point was the implementation of three technical alternatives: changing the parameters of compression, evaluating the humidity of the powder blend and the manufacturer of the lubricant magnesium stearate. The adhesion was directly related to the characteristics of magnesium stearate from different manufacturers, and the feasibility of evaluating powder flow characteristics by different techniques that are not routinely followed in various pharmaceutical companies. In vitro dissolution tests showed that the magnesium stearate manufacturer can influence on the dissolution profile of glibenclamide tablets. This study presented various aspects of tablet adhesion to compression machine punches. Troubleshooting approaches can be, most of times, conducted based on previous experience, or an experimental research needs to be implemented in order to have confident results.

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