15 results on '"Regina G. Kelmann"'
Search Results
2. Trametinib, a MEK1/2 Inhibitor, Protects Mice from Cisplatin- and Noise-Induced Hearing Loss
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Richard D. Lutze, Matthew A. Ingersoll, Regina G. Kelmann, and Tal Teitz
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MAPK pathway ,MEK1/2 ,trametinib ,hearing protection ,drug repurposing ,oral delivery ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
Hearing loss is one of the most common types of disability; however, there is only one FDA-approved drug to prevent any type of hearing loss. Treatment with the highly effective chemotherapy agent, cisplatin, and exposure to high-decibel noises are two of the most common causes of hearing loss. The mitogen-activated protein kinase (MAPK) pathway, a phosphorylation cascade consisting of RAF, MEK1/2, and ERK1/2, has been implicated in both types of hearing loss. Pharmacologically inhibiting BRAF or ERK1/2 is protective against noise- and cisplatin-induced hearing loss in multiple mouse models. Trametinib, a MEK1/2 inhibitor, protects from cisplatin-induced outer hair cell death in mouse cochlear explants; however, to the best of our knowledge, inhibiting MEK1/2 has not yet been shown to be protective against hearing loss in vivo. In this study, we demonstrate that trametinib protects against cisplatin-induced hearing loss in a translationally relevant mouse model and does not interfere with cisplatin’s tumor-killing efficacy in cancer cell lines. Higher doses of trametinib were toxic to mice when combined with cisplatin, but lower doses of the drug were protective against hearing loss without any known toxicity. Trametinib also protected mice from noise-induced hearing loss and synaptic damage. This study shows that MEK1/2 inhibition protects against both insults of hearing loss, as well as that targeting all three kinases in the MAPK pathway protects mice from cisplatin- and noise-induced hearing loss.
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- 2024
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3. Fatores associados à autopercepção de saúde entre idosos de grupos comunitários
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Andréia Cristiane Carrenho Queiroz, Nízia Araújo Vieira Almeida, Clarice Lima Alvares da Silva, Camila Teixeira Vaz, Regina G. Kelmann, and Maria Cristina de Albuquerque Barbosa
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education.field_of_study ,lcsh:R5-920 ,Waist ,Descriptive statistics ,idoso ,business.industry ,lcsh:Public aspects of medicine ,Population ,estudos transversais ,lcsh:RA1-1270 ,General Medicine ,Anthropometry ,Logistic regression ,fatores de risco ,Test (assessment) ,Social group ,Outcome variable ,Medicine ,autopercepção ,education ,business ,lcsh:Medicine (General) ,Demography - Abstract
Objetivo: Investigar a associação entre a autopercepção negativa de saúde e características individuais entre idosos de grupos comunitários do Sudeste do Brasil. Métodos: Trata-se de estudo transversal, realizado entre os anos 2014 a 2017, com amostra de 157 idosos participantes de 2 grupos de convivência de dispositivos sociais e/ou religiosos da cidade de Juiz de Fora, Minas Gerais, Brasil. Por meio de um questionário estruturado, baseado em questões utilizadas em inquérito populacional e de aferição de medidas antropométricas de peso, altura e circunferência da cintura (CC), avaliou-se a autopercepção de saúde (variável resposta) por meio da seguinte pergunta: o(a) senhor(a) diria que sua saúde está: ruim, razoável, boa ou muito boa? As respostas foram categorizadas em autopercepção de saúde negativa (ruim e razoável) e positiva (boa e muito boa). Realizaram-se estatísticas descritivas, testes Mann-Whitney, Fisher e qui-quadrado e regressão logística multivariada. Resultados: A proporção de autopercepção negativa de saúde foi de 32,5%. A autopercepção negativa de saúde associou-se à menor renda (OR=5,02; IC95%: 2,08 - 12,08), à inatividade física (OR=3,51; IC95%: 1,26 - 9,78) e à presença de duas ou mais doenças (OR=4,96; IC95%: 2,10 - 11,72), independentemente da idade e do sexo. Conclusão: A autopercepção negativa de saúde associou-se à menor renda familiar, à inatividade física e à presença de duas ou mais doenças associadas.
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- 2020
4. Simultaneous extraction and obtention of a novel nano-dispersion from Mikania glomerata Spreng: Monitoring coumarin content and increasing the biological and industrial potential of a classical cultivated herb
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José Carlos Tavares Carvalho, Rodrigo A.S. Cruz, Jesús Rafael Rodríguez Amado, Anna E.M.F.M. Oliveira, Maria do Carmo Pimentel Batitucci, Esdras Andrade Santana, Railane Ferreira Rodrigues, Hildegardo Seibert França, Conxita Solans, Poliana da Silva Ferreira, Jean Carlos Vencioneck Dutra, Regina G. Kelmann, Fernanda B. de Almeida, and Caio P. Fernandes
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0106 biological sciences ,Nano dispersion ,food.ingredient ,Chromatography ,Aqueous solution ,010405 organic chemistry ,Chemistry ,Cytotoxicity ,Dispersity ,Extraction (chemistry) ,Nonionic surfactants ,Extraction ,Low energy method ,Coumarin ,01 natural sciences ,0104 chemical sciences ,Mikania glomerata ,chemistry.chemical_compound ,food ,Herb ,Zeta potential ,Guaco ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Guaco is a traditional medicinal plant that was not previously object of studies within this area, despite its great commercial importance and crop production. To our knowledge, few efforts were carried out for a method that simultaneously extract plant material and generate nano-dispersions. Extraction of leaves with surfactant aqueous solutions allowed obtention of nano-dispersions with mean droplet size and polydispersity index below 300 nm and 0.3, respectively. Zeta potential was around – 30 mV. Chemical analysis indicated that guaco chemical marker (coumarin) was extracted. Guaco nano-dispersion was considered effective against cytotoxic effects induced by cyclophosphamide and significantly reduced micronucleated polychromatic erythrocytes frequency. Moreover, it presented improved bioactivity, when compared to guaco ethanolic extract obtained by classical method. Considering the several advantages of simultaneous extraction/nanoformulation methodology, including reducing costs and quickness of nano-dispersion preparation, the present study successfully used a simple, low-energy method and ecofriendly approach. © 2019 Elsevier B.V., Authors would like to thank CNPQ (Rede Amazônica de Pesquisa em Biofármacos – 407768/2013-0) and FAPEAP (Prodetec Araguari – process nº 250.203.035/2013) for the financial support, INCAPER (Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural) for the plant material and FAPES (Fundação de Amparo a Pesquisa do Espírito Santo) for the pos-graduate grant of the mastering student (first author).
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- 2019
5. Pentyl Gallate Nanoemulsions as Potential Topical Treatment of Herpes Labialis
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Sávia Caldeira de Araújo Lopes, Morgana Pistore, Letícia Scherer Koester, Ricardo José Nunes, Caroline Rigotto, Mariana Colombo, Izabella Thaís Silva, Cláudia Maria Oliveira Simões, Regina G. Kelmann, Helder Ferreira Teixeira, Silvane Souza Roman, and Daniele Dall Agnol
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Male ,Swine ,Stereochemistry ,Administration, Topical ,Skin Absorption ,Pharmaceutical Science ,Topical treatment ,Herpesvirus 1, Human ,02 engineering and technology ,Pharmacology ,Virus Replication ,medicine.disease_cause ,Antiviral Agents ,Skin Diseases ,030226 pharmacology & pharmacy ,Dosage form ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Drug Stability ,Dermis ,Gallic Acid ,medicine ,Animals ,Distribution (pharmacology) ,Gallic acid ,Rats, Wistar ,Herpes Labialis ,021001 nanoscience & nanotechnology ,Rats ,Herpes simplex virus ,medicine.anatomical_structure ,Solubility ,chemistry ,Toxicity ,Irritants ,Emulsions ,0210 nano-technology - Abstract
Previous studies have demonstrated the antiherpes activity of pentyl gallate (PG), suggesting that it could be a promising candidate for the topical treatment of human herpes labialis. PG low aqueous solubility represents a major drawback to its incorporation in topical dosage forms. Hence, the feasibility of incorporating PG into nanoemulsions, the ability to penetrate the skin, to inhibit herpes simplex virus (HSV)-1 replication, and to cause dermal sensitization or toxicity were evaluated. Oil/water nanoemulsions containing 0.5% PG were prepared by spontaneous emulsification. The in vitro PG distribution into porcine ear skin after topical application of nanoemulsions was assessed, and the in vitro antiviral activity against HSV-1 replication was evaluated. Acute dermal toxicity and risk of dermal sensitization were evaluated in rat model. Nanoemulsions presented nanometric particle size (from 124.8 to 143.7 nm), high zeta potential (from -50.1 to -66.1 mV), loading efficiency above 99%, and adequate stability during 12 months. All formulations presented anti-HSV-1 activity. PG was able to reach deeper into the dermis more efficiently from the nanoemulsion F4. This formulation as well as PG were considered safe for topical use. Nanoemulsions seem to be a safe and effective approach for topically delivering PG in the treatment of human herpes labialis infection.
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- 2016
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6. Optimization of Copaiba oil-based nanoemulsions obtained by different preparation methods
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Letícia G. Lucca, Valdir F. Veiga, Helder Ferreira Teixeira, Regina G. Kelmann, Mariana Colombo, Samuel Kaiser, Daiane Dias, Letícia Scherer Koester, and Renata Pereira Limberger
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Preparation method ,Chromatography ,High pressure homogenization ,biology ,Chemistry ,Copaifera ,Medium chain triacylglycerols ,Fractional factorial design ,biology.organism_classification ,Agronomy and Crop Science ,Copaiba Oil - Abstract
Copaiba oil has been widely used in popular medicine because of its anti-inflammatory properties. The oil is extracted from trees of the genus Copaifera , found mainly in the Brazilian Amazon. A study was conducted using a 2 IV 4-1 fractional factorial design to evaluate the effects of oil core and surfactants composition on physicochemical properties of nanoemulsions produced by high-pressure homogenization and spontaneous emulsification. Also, the stability of the formulations stored at 4 °C and 25 °C was monitored for 90 days. The high-pressure homogenization method proved to be the most efficient technique to obtain stable Copaiba oil nanoemulsions with reduced loss of volatile fraction within 90 days of storage at the recommended temperature (4 °C). The most suitable nanoemulsion composition was achieved adding 20% Copaiba oil, 10% medium chain triglycerides, 3% Span 80 ® and 1% Tween 20 ® . The use of medium chain triglycerides was shown to be a good strategy to fix volatile fractions of Copaiba oil incorporated into nanoemulsions during preparation and storage.
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- 2014
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7. Preparation of a Nanoemulsion with Carapa guianensis Aublet (Meliaceae) Oil by a Low-Energy/Solvent-Free Method and Evaluation of Its Preliminary Residual Larvicidal Activity
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Anna E.M.F.M. Oliveira, Raimundo Nonato Picanço Souto, José Carlos Tavares Carvalho, Marcelino Carneiro Guedes, Rodrigo A.S. Cruz, Regina G. Kelmann, Jonatas Lobato Duarte, Fernanda B. de Almeida, Caio P. Fernandes, Ricardo Marcelo dos Anjos Ferreira, Conxita Solans, Flávia L M Jesus, A. C. Lira-Guedes, FLÁVIA L. M. JESUS, Programa de Pós-Graduação em Biodiversidade Tropical, Unifap, FERNANDA B. DE ALMEIDA, Unifap, JONATAS L. DUARTE, Unifap, ANNA E. M. F. M. OLIVEIRA, Unifap, RODRIGO A. S. CRUZ, Unifap, RAIMUNDO N. P. SOUTO, Unifap, RICARDO M. A. FERREIRA, Unifap, REGINA GENDZELEVSKI KELMANN, UFJF, JOSÉ C. T. CARVALHO, Unifap, ANA CLAUDIA LIRA GUEDES, CPAF-AP, MARCELINO CARNEIRO GUEDES, CPAF-AP, CONXITA SOLANS, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), and CAIO P. FERNANDES, Unifap.
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Limonins ,Carapa guianensis ,Article Subject ,Extensive spectroscopic ,Dispersity ,ved/biology.organism_classification_rank.species ,Raw material ,01 natural sciences ,Essential oil ,Palmitic acid ,chemistry.chemical_compound ,Botany ,Meliaceae ,Polysorbate ,Chromatography ,biology ,010405 organic chemistry ,ved/biology ,Phytosterol ,Medicinal plant ,lcsh:Other systems of medicine ,biology.organism_classification ,lcsh:RZ201-999 ,Controlled release ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,chemistry ,Planta medicinal ,Óleo essencial ,Andiroba ,Research Article - Abstract
Andiroba (Carapa guianensis) seeds are the source of an oil with a wide range of biological activities and ethnopharmacological uses. However, few studies have devoted attention to innovative formulations, including nanoemulsions. The present study aimed to obtain a colloidal system with the andiroba oil using a low-energy and organic-solvent-free method. Moreover, the preliminary residual larvicidal activity of the nanoemulsion against Aedes aegypti was evaluated. Oleic and palmitic acids were the major fatty acids, in addition to the phytosterol β-sitosterol and limonoids (tetranortriterpenoids). The required hydrophile-lipophile was around 11.0 and the optimal nanoemulsion was obtained using polysorbate 85. The particle size distribution suggested the presence of small droplets (mean diameter around 150 nm) and low polydispersity index (around 0.150). The effect of temperature on particle size distribution revealed that no major droplet size increase occurred. The preliminary residual larvicidal assay suggested that the mortality increased as a function of time. The present study allowed achievement of a potential bioactive oil in water nanoemulsion that may be a promising controlled release system. Moreover, the ecofriendly approach involved in the preparation associated with the great bioactive potential of C. guianensis makes this nanoemulsion very promising for valorization of this Amazon raw material. © 2017 Flávia L. M. Jesus et al., he authors thank FAPEAP (Prodetec Araguari, Process no. 250.203.035/2013) and MarketPlace LAC/Brazil, Suriname University/Embrapa Amapá (Process Funarbe 9740, ID 552) for the financial support, Karen Mustin for her English revision of the manuscript, and CAPES for the student scholarship awarded to the first author. They also thank Pro-Rectory of Cooperation and Interinstitutional of the Amapá Federal University Relations for the international mobility grant to Dr. Caio Pinho Fernandes and thank the Group of Colloidal and Interfacial Chemistry of the Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) for receiving him and the student Fernanda Borges de Almeida.
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- 2017
8. Preliminary Study on the Development of Nanoemulsions for Carbamazepine Intravenous Delivery: An Investigation of Drug Polymorphic Transition
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Helder Ferreira Teixeira, Letícia Scherer Koester, Regina G. Kelmann, and Gislaine Kuminek
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Drug ,Spectrophotometry, Infrared ,Chemistry, Pharmaceutical ,media_common.quotation_subject ,medicine.medical_treatment ,Pharmaceutical market ,Pharmaceutical Science ,Pharmacology ,Differential scanning calorimetry ,Drug Stability ,Pharmaceutical technology ,Drug Discovery ,medicine ,Chemical Precipitation ,Particle Size ,media_common ,Chromatography ,Calorimetry, Differential Scanning ,business.industry ,Organic Chemistry ,Carbamazepine ,Anticonvulsant ,Polymorphism (materials science) ,Emulsifying Agents ,Oral suspensions ,Nanoparticles ,Anticonvulsants ,Emulsions ,business ,medicine.drug - Abstract
Carbamazepine (CBZ) is available on the pharmaceutical market as tablets, capsules, and oral suspensions, but not as a parenteral formulation for clinical use. Parenteral emulsions are a good alternative to poorly water-soluble drugs such as CBZ. In this way, four different emulsions containing 3 mg/mL of CBZ were developed, but during a period of storage, drug crystal precipitates appeared. To investigate this phenomenon, differential scanning calorimetry, infrared spectroscopy, and light microscopy were employed. The results suggested a polymorphic transition from beta form to dehydrate form, resulting in drug precipitation, although the emulsions themselves remained stable for at least three months.
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- 2008
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9. Carbamazepine parenteral nanoemulsions prepared by spontaneous emulsification process
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Letícia Scherer Koester, Gislaine Kuminek, Helder Ferreira Teixeira, and Regina G. Kelmann
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Drug ,Castor Oil ,Chemical Phenomena ,Chemistry, Pharmaceutical ,Drug Compounding ,Microdialysis ,medicine.medical_treatment ,media_common.quotation_subject ,Kinetics ,Pharmaceutical Science ,Excipients ,Viscosity ,Microscopy, Electron, Transmission ,medicine ,Zeta potential ,Particle Size ,Chromatography, High Pressure Liquid ,media_common ,Chromatography ,Chemistry, Physical ,Chemistry ,Carbamazepine ,Factorial experiment ,Anticonvulsant ,Solubility ,Injections, Intravenous ,Emulsion ,Anticonvulsants ,Emulsions ,Oils ,medicine.drug - Abstract
Carbamazepine (CBZ), a widely used anticonvulsant drug, is a poorly soluble drug with no parenteral treatment available for patients. This study was aimed at developing a nanoemulsion for CBZ intravenous delivery. The spontaneous emulsification method was used to prepare different formulations containing 2 mg/mL CBZ. Likewise, a 2 2 full factorial experimental design was applied to study the influence of two independent variables (type of oil and type of lipophilic emulsifier) on emulsion physicochemical characteristics. The nanoemulsions were evaluated concerning droplet size, zeta potential, viscosity, drug content and association to oily phase. The formulation, which presented the best characteristics required for intravenous administration was selected and refined with respect to the lipophilic emulsifier content (increase from 5% to 6% of soy lecithin). This formulation was characterized and kept its properties in a satisfactory range over the evaluated period (3 months), i.e. droplet size around 150 nm, drug content around 95% and zeta potential around −40 mV. The transmission electron microscopy revealed emulsion droplets almost spherical in shape with an amorphous core, whereas the in vitro release profile assessed by dialysis bags demonstrated a release kinetics square root time dependent, with 95% of ca. having been released within 11 h.
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- 2007
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10. Determination of Carbamazepine in Parenteral Nanoemulsions: Development and Validation of an HPLC Method
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Helder Ferreira Teixeira, Letícia Scherer Koester, Gislaine Kuminek, and Regina G. Kelmann
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Drug elution ,Accuracy and precision ,Chromatography ,Chemistry ,Organic Chemistry ,Clinical Biochemistry ,Analytical chemistry ,Carbamazepine ,Biochemistry ,High-performance liquid chromatography ,Quantitative determination ,Dosage form ,Analytical Chemistry ,medicine ,Hplc method ,Quantitative analysis (chemistry) ,medicine.drug - Abstract
A high performance liquid chromatographic method was developed and validated for the quantitative determination of carbamazepine in intravenous nanoemulsions. The method validation yielded good results with respect to linearity, specificity, precision and accuracy. The method was carried out on a RP-18 column with a mobile phase composed of methanol–water (70:30 v/v) subjected to a gradient of acetonitrile after drug elution, and detection at 286 nm. The linearity in the range of 10.0–50.0 μg mL−1 presented a determination coefficient (r 2) of 0.9996, calculated by least-squares regression; the RSD values for intra-day and inter-day precision for % recovered were
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- 2007
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11. Thermoanalytical study of fluoxetine hydrochloride
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Fábio S. Murakami, Marcos Antonio Segatto Silva, Tatiane Sartori, F. Carmignan, Charise Dallazem Bertol, Andréa Granada, Regina G. Kelmann, Talize Foppa, and Ariane P. Cruz
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Thermogravimetric analysis ,Chemistry ,Thermal decomposition ,Analytical chemistry ,Excipient ,Condensed Matter Physics ,Dosage form ,Fluoxetine Hydrochloride ,Thermogravimetry ,Differential scanning calorimetry ,medicine ,Physical and Theoretical Chemistry ,Thermal analysis ,medicine.drug - Abstract
The thermal behaviour of fluoxetine hydrochloride and five capsules available in Florianopolis, Brazil was investigated. The raw material’s purity, kinetic parameters, thermal behaviour and melting characteristics were determined by differential scanning calorimetry and thermogravimetric analysis, as well as the thermal study of the capsules. The purity was 99.12±0.15%. The thermal decomposition followed a zero order kinetic, activation energy of 88.67 kJ mol–1 and frequency factor of 3.539·107 min–1. DSC curves obtained from the capsules suggest compatibility between the drug and excipient.
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- 2007
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12. Citotoxic activity evaluation of essential oils and nanoemulsions of Drimys angustifolia and D. brasiliensis on human glioblastoma (U-138 MG) and human bladder carcinoma (T24) cell lines in vitro
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Renata Pereira Limberger, Madson Ralide Fonseca Gomes, Roselena Silvestri Schuh, Letícia Scherer Koester, Regina G. Kelmann, Sérgio Augusto de Loreto Bordignon, Otávio Américo Augustin, Maria M. Campos, Marina P. Gehring, Daiane Dias, Fernanda Bueno Morrone, and Ana Laura Bemvenuti Jacques
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bladder carcinoma ,nanoemulsions ,education.field_of_study ,Chromatography ,Population ,glioblastoma ,lcsh:RS1-441 ,Biology ,Cell counting ,In vitro ,Drimys angustifolia ,lcsh:Pharmacy and materia medica ,Pharmacology, Toxicology and Pharmaceutics(all) ,Óleos essenciais ,Cell culture ,Apoptosis ,Drimys brasiliensis ,Botany ,MTT assay ,Viability assay ,General Pharmacology, Toxicology and Pharmaceutics ,education ,Cytometry ,essential oils - Abstract
The species Drimys angustifolia Miers and D. brasiliensis Miers, commonly known as “casca-de-anta”, have in their leaves essential oils that can confer cytotoxic effects. In this study, we evaluated the citotoxic effects of the volatile oils from these two species. We also proposed a nanoemulsion formulation for each of the species and assessed the in vitro cytotoxicity on U-138 MG (human glioblastoma) and T24 (human bladder carcinoma) cell lines. The plant chemical composition was evaluated by gas chromatography coupled to mass spectrometer. Furthermore, the nanoemulsions were prepared and characterized. Our results showed that; bicyclogermacrene (19.6%) and cyclocolorenone (18.2%) were the most abundant for the D angustifolia oil and D brasiliensis oil, respectively. Both nanoemulsions, D angustifolia and D brasiliensis appeared macroscopically homogeneous and opalescent bluish liquids, with nanometric mean diameters of 168 nm for D brasiliensis and 181 nm for D angustifolia. The polydispersity indices were below 0.10, with an acid pH of 4.7–6.3, and negative zeta potentials about -34 mV. The results of transmission electron microscopy showed that droplets are present in the nanometer range. Only the D brasiliensis oil was efficient in reducing the cell viability of both U-138 MG (42.5% ± 7.0 and 67.8% ± 7.8) and T24 (33.2% ± 2.8, 60.3% ± 1.6 and 80.5% ± 8.8) cell lines, as assessed by MTT assay. Noteworthy, similar results were obtained with cell counting. Finally, D brasiliensis oil incubation caused an increase of annexin-V and propidium iodite population, according to evaluation by cytometry analysis, what is characteristic of late apoptosis. The results presented herein lead us to consider the potential therapeutic effects of the essential oils and nanoformulations as novel strategies to inhibit tumor growth. Key words: bladder carcinoma, Drimys angustifolia, Drimys brasiliensis, essential oils, glioblastoma, nanoemulsions
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- 2012
13. Optimization of headspace solid-phase microextraction for analysis of β-caryophyllene in a nanoemulsion dosage form prepared with copaiba (Copaifera multijuga Hayne) oil
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Tatiane Pereira de Souza, Regina G. Kelmann, Valquiria Linck Bassani, Helder Ferreira Teixeira, Letícia Scherer Koester, Daiane Dias, Mariana Colombo, Renata Pereira Limberger, and Valdir F. Veiga
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Ultraviolet Rays ,Solid-phase microextraction ,Sesquiterpene ,Biochemistry ,Copaiba Oil ,Dosage form ,Analytical Chemistry ,chemistry.chemical_compound ,Copaiba ,Oils, Volatile ,Environmental Chemistry ,Nanotechnology ,Dimethylpolysiloxanes ,Spectroscopy ,Solid Phase Microextraction ,Polycyclic Sesquiterpenes ,Chromatography ,Caryophyllene ,Hydrolysis ,Temperature ,Fabaceae ,Factorial experiment ,chemistry ,Forced degradation ,Emulsions ,Oxidation-Reduction ,Sesquiterpenes - Abstract
Recent studies have shown the anti-inflammatory activity of Copaiba oils may be addressed to the high content of β-caryophyllene, the most common sesquiterpene detected, especially in the Copaifera multijuga Hayne species. In the present study, nanoemulsions were proposed as a delivery system for copaiba oil in view to treat locally inflamed skin. This article describes the optimization and validation of a stability-indicating SPME-GC method, for β-caryophyllene analysis in the nanoemulsions produced by high pressure homogenization. SPME methods are performed with PDMS (polydimethylsiloxane) fiber (100 μm). Three SPME parameters were evaluated by a three-level-three-factor Box-Behnken factorial design as potentially affecting the technique efficiency. According to the results obtained, the best conditions to extract β-caryophyllene were: (i) sampling temperature of 45°C, (ii) sampling time of 20 min and (iii) no NaCl addition. Results coming from the forced degradation tests showed a reduction of β-caryophyllene peak area when both caryophyllene methanolic solution and nanoemulsions were exposed to acid hydrolysis, UV-A irradiation, oxidative (H(2)O(2)) and thermolitic (60°C) conditions. Such reduction occurred in lower extent in the nanoemulsions, suggesting a protective effect of the formulation to β-caryophyllene content. Since no degradation products were detected in the same retention time of β-caryophyllene, the specificity of the method was demonstrated. The method was linear in the range of 0.14-0.68 μg mL(-1) of β-caryophyllene (r(2)>0.999), and was also validated for precision (R.S.D.≤5.0%), accuracy (97.85-101.87%) and robustness. Finally, the method was applied to quantification of β-caryophyllene content in the developed formulations.
- Published
- 2011
14. Pharmacokinetic study of a carbamazepine nanoemulsion in beagle dogs
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Gislaine Kuminek, Cláudia Maria Oliveira Simões, Jadel M. Kratz, Bibiana Verlindo de Araújo, Helder Ferreira Teixeira, Rodrigo Fernandes Ribeiro, Regina G. Kelmann, and Letícia Scherer Koester
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medicine.medical_treatment ,Pharmaceutical Science ,Pharmacology ,Beagle ,Excipients ,2-Hydroxypropyl-beta-cyclodextrin ,Random Allocation ,Dogs ,Pharmacokinetics ,Pharmaceutical technology ,medicine ,Animals ,Cross-Over Studies ,Chemistry ,beta-Cyclodextrins ,Carbamazepine ,Crossover study ,Anticonvulsant ,Plasma concentration ,Injections, Intravenous ,Nanoparticles ,Anticonvulsants ,Emulsions ,Female ,medicine.drug - Abstract
This work describes the pharmacokinetics of a novel carbamazepine nanoemulsion. The plasma concentration profiles were determined in beagle dogs after i.v. bolus administration of a 5 mg/kg carbamazepine nanoemulsion and compared to the corresponding carbamazepine/hydroxypropyl-beta-cyclodextrin complex solution. Both formulations showed similar pharmacokinetic profiles and could represent valuable formulations in case of emergencies, when a rapid action in the central nervous system is desirable.
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- 2008
15. Development and characterization of parenteral nanoemulsions containing thalidomide
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R.B. Finatto, Bibiana Verlindo de Araújo, Helder Ferreira Teixeira, Regina G. Kelmann, Fabrício Aguiar de Araújo, and Letícia Scherer Koester
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Pharmacokinetic simulation ,Nanoemulsions ,Analytical chemistry ,Pharmaceutical Science ,Crystallography, X-Ray ,Polyvinyl alcohol ,law.invention ,chemistry.chemical_compound ,Dynamic light scattering ,Microscopy, Electron, Transmission ,law ,Spectroscopy, Fourier Transform Infrared ,Zeta potential ,Nanotechnology ,Infusions, Parenteral ,Crystallization ,Fourier transform infrared spectroscopy ,Crystal habit ,Solubility ,Reverse dialysis ,Polymorphism ,Polysorbate ,Viscosity ,Spontaneous emulsification ,Thalidomide ,chemistry ,Emulsions ,Nuclear chemistry - Abstract
This study reports the development of nanoemulsions intended for intravenous administration of thalidomide (THD). The formulations were prepared by spontaneous emulsification method and optimized with respect to thalidomide (0.01–0.05%, w/w), and hydrophilic emulsifier (polysorbate 80; 0.5–4.0%, w/w) content. The formulations were evaluated concerning physical appearance and drug crystallization; droplet size; zeta potential and drug assay. Only the formulation containing 0.01% THD and 0.5% polysorbate kept its properties in a satisfactory range over the evaluated period (60 days), i.e. droplet size around 200nm, drug content around 95% and zeta potential around −30mV. The transmission electron microscopy revealed emulsion droplets almost spherical in shape confirming the results obtained by photon correlation spectroscopy. Drug crystallization observed for higher content (THD 0.05%, w/w) nanoemulsions was investigated. The crystals observed at optical microscopy presented a different crystal habit compared to that of the raw material used. It was speculated whether the kind of THD polymorph employed could influence nanoemulsion formulation. Formulations were prepared with either one of THD polymorphs (β- or α-) and crystals were characterized by fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD). It was observed that regardless of the polymorph employed (β- or α-), drug crystallization occurs in the α-form. THD solubility in oils was not influenced by the polymorphic form. In addition, the in vitro dissolution profile of the selected formulation (THD 0.01%, w/w; polysorbate 0.5%, w/w) was assessed by bulk-equilibrium reverse dialysis sac technique and demonstrated a release profile similar to that of a THD acetonitrile solution, with around 95% THD being dissolved within 4h. Finally, a pharmacokinetic simulation of an intravenous infusion of 250mL of the selected nanoemulsion suggests that the parenteral administration of a dose as low as 25mg might lead to therapeutic plasma concentrations of thalidomide.
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