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1.
Braz J Biol ; 83: e274084, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37585932

RESUMEN

This work aimed to evaluate the chemical composition, antioxidant and antimicrobial activities from crude extract and fractions from leaves of Eugenia uniflora Linn. The crude extract was obtained by turbo extraction and their fractions by partitioning. Chromatographic analysis were performed, and the antioxidant capacity was verified by two methods (DPPH• and ABTS•+). The Minimal Inhibitory/Bactericidal Concentration were conducted against twenty-two bacteria, selecting five strains susceptible to extract/fractions and resistant to the antibiotics tested. Ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with Ethyl Acetate Fraction (EAF) against multidrug-resistant strains in modulatory and checkerboard tests. The chromatographic data showed gallic acid, ellagic acid, and myricitrin in crude extract, with enrichment in the EAF. The electron transfer activity demonstrated in the antioxidant tests is related to the presence of flavonoids. The Gram-positive strains were more susceptible to EAF, and their action spectra were improved by association, comprising Gram-negative bacilli. Synergisms were observed to ciprofloxacin and gentamicin against Pseudomonas aeruginosa colistin-resistant. The results demonstrate that the extract and enriched fraction obtained from the leaves of E. uniflora act as a promising natural alternative against multidrug-resistant bacteria.


Asunto(s)
Eugenia , Extractos Vegetales , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antioxidantes , Eugenia/química , Pruebas de Sensibilidad Microbiana , Bacterias , Ciprofloxacina , Gentamicinas
2.
Braz. j. biol ; 82: 1-12, 2022. graf, tab
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468436

RESUMEN

Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-¹ and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-¹ . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-¹) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-¹). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-¹). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN-γ and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.


Plectranthus barbatus Andrews (Lamiaceae) é amplamente distribuída no mundo e com uma série de indicações terapêuticas populares. Este trabalho teve como objetivo avaliar a caracterização fitoquímica de dois extratos da folha de P. barbatus e seu potencial antimicrobiano, antineoplásico e imunomodulador. Após coleta, herborização e obtenção do extrato aquoso (PBA) e acetona: água 7: 3 (orgânico) (PBO) de P. barbatus, a caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi realizada para determinar a concentração inibitória mínima (CIM) contra oito cepas bacterianas usando o teste de microdiluição e o fungo Trichophyton rubrum por ensaio de difusão em disco e teste de microdiluição. A citotoxicidade foi avaliada por métodos MTT e azul de tripan em células normais mononucleares do sangue periférico (CMSP) em concentrações variadas entre 0,1 a 100 µg.mL-¹ e nas linhagens celulares neoplásicas Toledo, K562, DU-145 e PANC-¹ em 1, 10 e 100 µg.mL-¹ . A atividade imunomoduladora foi avaliada por ELISA sanduíche de citocinas pró-inflamatórias em sobrenadante de culturas de esplenócitos de camundongos BALB/c. Ambos os extratos apresentaram flavonoides, derivados cinâmicos, esteróides e ácido elágico. O PBO mostrou atividade bacteriostática contra Acinetobacter baumannii (CIM = 250 µg.mL-¹) e atividade fungistática do PBA contra Trichophyton rubrum (CIM = 800 µg.mL-¹). Os extratos não apresentaram toxicidade para CMSP e células neoplásicas (IC50 > 100 µg.mL-¹). Além disso, o PBO a 100 µg.mL-¹ inibiu significativamente as citocinas IFN-γ e IL-17A (p = 0,03). Plectranthus barbatus é um candidato potencial para uso terapêutico devido à sua baixa toxicidade em células humanas saudáveis e exibe atividade de interesse médico como bacteriostática, fungistática e imunomoduladora.


Asunto(s)
Fitoterapia , Plantas Medicinales/química , Plectranthus/química
3.
Braz. j. biol ; 822022.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468623

RESUMEN

Abstract Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-1 and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-1 . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-1) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-1). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-1). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN- and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.


Resumo Plectranthus barbatus Andrews (Lamiaceae) é amplamente distribuída no mundo e com uma série de indicações terapêuticas populares. Este trabalho teve como objetivo avaliar a caracterização fitoquímica de dois extratos da folha de P. barbatus e seu potencial antimicrobiano, antineoplásico e imunomodulador. Após coleta, herborização e obtenção do extrato aquoso (PBA) e acetona: água 7: 3 (orgânico) (PBO) de P. barbatus, a caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi realizada para determinar a concentração inibitória mínima (CIM) contra oito cepas bacterianas usando o teste de microdiluição e o fungo Trichophyton rubrum por ensaio de difusão em disco e teste de microdiluição. A citotoxicidade foi avaliada por métodos MTT e azul de tripan em células normais mononucleares do sangue periférico (CMSP) em concentrações variadas entre 0,1 a 100 µg.mL-1 e nas linhagens celulares neoplásicas Toledo, K562, DU-145 e PANC-1 em 1, 10 e 100 µg.mL-1 . A atividade imunomoduladora foi avaliada por ELISA sanduíche de citocinas pró-inflamatórias em sobrenadante de culturas de esplenócitos de camundongos BALB/c. Ambos os extratos apresentaram flavonoides, derivados cinâmicos, esteróides e ácido elágico. O PBO mostrou atividade bacteriostática contra Acinetobacter baumannii (CIM = 250 µg.mL-1) e atividade fungistática do PBA contra Trichophyton rubrum (CIM = 800 µg.mL-1). Os extratos não apresentaram toxicidade para CMSP e células neoplásicas (IC50 > 100 µg.mL-1). Além disso, o PBO a 100 µg.mL-1 inibiu significativamente as citocinas IFN- e IL-17A (p = 0,03). Plectranthus barbatus é um candidato potencial para uso terapêutico devido à sua baixa toxicidade em células humanas saudáveis e exibe atividade de interesse médico como bacteriostática, fungistática e imunomoduladora.

4.
Braz. j. biol ; 82: e236297, 2022. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1153472

RESUMEN

Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-1 and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-1 . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-1) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-1). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-1). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN-γ and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.


Plectranthus barbatus Andrews (Lamiaceae) é amplamente distribuída no mundo e com uma série de indicações terapêuticas populares. Este trabalho teve como objetivo avaliar a caracterização fitoquímica de dois extratos da folha de P. barbatus e seu potencial antimicrobiano, antineoplásico e imunomodulador. Após coleta, herborização e obtenção do extrato aquoso (PBA) e acetona: água 7: 3 (orgânico) (PBO) de P. barbatus, a caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi realizada para determinar a concentração inibitória mínima (CIM) contra oito cepas bacterianas usando o teste de microdiluição e o fungo Trichophyton rubrum por ensaio de difusão em disco e teste de microdiluição. A citotoxicidade foi avaliada por métodos MTT e azul de tripan em células normais mononucleares do sangue periférico (CMSP) em concentrações variadas entre 0,1 a 100 µg.mL-1 e nas linhagens celulares neoplásicas Toledo, K562, DU-145 e PANC-1 em 1, 10 e 100 µg.mL-1 . A atividade imunomoduladora foi avaliada por ELISA sanduíche de citocinas pró-inflamatórias em sobrenadante de culturas de esplenócitos de camundongos BALB/c. Ambos os extratos apresentaram flavonoides, derivados cinâmicos, esteróides e ácido elágico. O PBO mostrou atividade bacteriostática contra Acinetobacter baumannii (CIM = 250 µg.mL-1) e atividade fungistática do PBA contra Trichophyton rubrum (CIM = 800 µg.mL-1). Os extratos não apresentaram toxicidade para CMSP e células neoplásicas (IC50 > 100 µg.mL-1). Além disso, o PBO a 100 µg.mL-1 inibiu significativamente as citocinas IFN-γ e IL-17A (p = 0,03). Plectranthus barbatus é um candidato potencial para uso terapêutico devido à sua baixa toxicidade em células humanas saudáveis e exibe atividade de interesse médico como bacteriostática, fungistática e imunomoduladora.


Asunto(s)
Animales , Conejos , Plectranthus , Leucocitos Mononucleares , Extractos Vegetales/farmacología , Pruebas de Sensibilidad Microbiana , Arthrodermataceae , Fitoquímicos/farmacología , Ratones Endogámicos BALB C
5.
Braz J Biol ; 82: e236297, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33787716

RESUMEN

Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-1 and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-1 . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-1) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-1). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-1). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN-γ and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.


Asunto(s)
Plectranthus , Animales , Arthrodermataceae , Leucocitos Mononucleares , Ratones , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Fitoquímicos/farmacología , Extractos Vegetales/farmacología
6.
J Ethnopharmacol ; 141(1): 517-25, 2012 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-22472105

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Persea americana Mill. (Lauraceae) have been popularly used in the treatment of diabetes in countries in Latin America and Africa. AIM OF THE STUDY: To investigate the hypoglycaemic properties and to determine the molecular mechanism by which the hydroalcoholic extract of the leaves of Persea americana reduce blood glucose levels in streptozotocin (STZ)-induced diabetes in rats via the enzymatic pathway of protein kinase B (PKB/Akt). METHODS: The hydroalcoholic extract of the leaves of Persea americana (0.15 and 0.3g/kg/day), vehicle and metformin (0.5g/kg/day) were administered orally to STZ-diabetic rats (n=7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation and the expression of PKB in the liver and soleus muscle were determined by Western blot. RESULTS: The hydroalcoholic extract of the leaves of Persea americana reduced blood glucose levels and improved the metabolic state of the animals. Additionally, PKB activation was observed in the liver and skeletal muscle of treated rats when compared with untreated rats. CONCLUSION: The results indicate that the hydroalcoholic extract of the leaves of Persea americana has anti-diabetic properties and possibly acts to regulate glucose uptake in liver and muscles by way of PKB/Akt activation, restoring the intracellular energy balance.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Activadores de Enzimas/farmacología , Hipoglucemiantes/farmacología , Hígado/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Persea , Extractos Vegetales/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Administración Oral , Animales , Glucemia/efectos de los fármacos , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/enzimología , Ingestión de Líquidos/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Activación Enzimática , Activadores de Enzimas/administración & dosificación , Activadores de Enzimas/aislamiento & purificación , Etanol/química , Prueba de Tolerancia a la Glucosa , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/aislamiento & purificación , Insulina/sangre , Hígado/enzimología , Masculino , Músculo Esquelético/enzimología , Persea/química , Fosforilación , Fitoterapia , Extractos Vegetales/administración & dosificación , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta , Plantas Medicinales , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Solventes/química , Factores de Tiempo , Aumento de Peso/efectos de los fármacos
7.
Rev. bras. plantas med ; 14(3): 548-555, 2012. ilus, tab
Artículo en Portugués | LILACS | ID: lil-658137

RESUMEN

Plantas medicinais são utilizadas mundialmente como uma das principais formas de cuidado primário de saúde. No entanto, a literatura indica que muitas espécies podem apresentar composição química variável, toxicidade ou difícil identificação. O objetivo do presente estudo foi obter critérios úteis para o controle de qualidade farmacognóstico das principais espécies vegetais de uso popular no estado do Rio Grande do Norte, utilizando metodologias de análise botânica (morfodiagnose macro e microscópica) e química (triagem fitoquímica e cromatografia em camada delgada), evitando assim adulterações ou uso inadequado dessas plantas medicinais no estado. No total, sete espécies foram analisadas Acmella oleracea, Chenopodium ambrosioides, Lippia alba, Mentha piperita, Ocimum gratissimum, Peumus boldus e Rosmarinus officinalis. Diversos marcadores botânicos e fitoquímicos foram identificados, contribuindo dessa forma para a correta identificação destas espécies de plantas medicinais importantes no estado do Rio Grande do Norte.


Medicinal plants are worldwide used as one of the main forms of primary healthcare. However, the literature indicates that many species may have variable chemical composition, toxicity, or even difficult identification. The aim of this study was to obtain useful criteria for pharmacognostic quality control of the main plant species of popular use in the state of Rio Grande do Norte, using methods of botanical (macro and microscopic morphodiagnosis) and chemical (phytochemical screening and thin-layer chromatography) analysis, thus preventing adulteration or inappropriate use of these medicinal plants in the state. In total, seven species were analyzed Acmella oleracea, Chenopodium ambrosioides, Lippia alba, Mentha piperita, Ocimum gratissimum, Peumus boldus and Rosmarinus officinalis. Several botanical and phytochemical markers were identified, thereby contributing to the correct identification of these important medicinal plant species in the state of Rio Grande do Norte.


Asunto(s)
Plantas Medicinales/metabolismo , Control de Calidad , Botánica/métodos , /métodos , Cromatografía en Capa Delgada/métodos
8.
J Ethnopharmacol ; 137(3): 1533-41, 2011 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-21911047

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The tea from the stem bark of Caesalpinia ferrea Martius (Leguminosae) has been popularly used in the treatment of diabetes in Brazil. AIM OF THE STUDY: To investigate the hypoglycaemic properties and to elucidate the mechanisms by which the aqueous extract of the stem bark of Caesalpinia ferrea reduces blood glucose levels in streptozotocin-induced diabetic rats via the enzymatic pathways of protein kinase B (PKB/Akt), AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). MATERIALS AND METHODS: The aqueous extract of the stem bark of Caesalpinia ferrea (300 and 450 mg/kg/day), vehicle and metformin (500 mg/kg/day) were administered orally to STZ-diabetic rats (n = 7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation (P) and the expression of Akt, AMPK and ACC in the liver and skeletal muscle were determined using Western blot. RESULTS: The aqueous extract of the stem bark of Caesalpinia ferrea reduced blood glucose levels and improved the metabolic state of the animals. P-Akt was increased in the liver and skeletal muscle of the treated animals, P-AMPK was reduced only in the skeletal muscle of these animals and P-ACC was reduced in both when compared with untreated rats. CONCLUSION: The results indicate that the aqueous extract of the stem bark of Caesalpinia ferrea has hypoglycaemic properties and possibly acts to regulate glucose uptake in liver and muscles by way of Akt activation, restoring the intracellular energy balance confirmed by inhibition of AMPK activation.


Asunto(s)
Glucemia/efectos de los fármacos , Caesalpinia , Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Extractos Vegetales/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Administración Oral , Animales , Glucemia/metabolismo , Western Blotting , Peso Corporal/efectos de los fármacos , Caesalpinia/química , Diabetes Mellitus Experimental/sangre , Ingestión de Líquidos/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Prueba de Tolerancia a la Glucosa , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/aislamiento & purificación , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Metformina/farmacología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/enzimología , Fosforilación , Corteza de la Planta , Extractos Vegetales/administración & dosificación , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Factores de Tiempo
9.
Phytochem Anal ; 20(4): 265-71, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19333915

RESUMEN

BACKGROUND: Investigations in the field of pharmaceutical analysis and quality control of medicines require analytical procedures that achieve suitable performance. An analytical curve is one of the most important steps in the chemical analysis presenting a direct relationship to features such as linearity. OBJECTIVE: This study has the aim of developing a new methodology, the stationary cuvette, to derive analytical curves by spectroscopy for drug analysis. METHODOLOGY: The method consists basically of the use of a cuvette with a path length of 10 cm, containing a constant volume of solvent in which increasing amounts of a stock solution of the sample are added, droplet by droplet. After each addition, the cuvette is stirred and the absorbance is measured. This procedure was compared with the currently used methodology, which requires a labour-intensive dilution process, and possible sources of variation between them were evaluated. RESULTS: The results demonstrated that the proposed technique presented high sensitivity and similar reproducibility compared with the conventional methodology. In addition, a number of advantages were observed, such as user-friendliness, cost-effectiveness, accuracy, precision and robustness. CONCLUSION: The stationary cuvette approach may be considered to be an appropriate alternative to derive analytical curves for analysing drug content in raw materials and medicines through UV-VIS spectrophotometry.


Asunto(s)
Hidrocortisona/química , Ibuprofeno/química , Kalanchoe/química , Penicilina G Benzatina/química , Extractos Vegetales/química , Espectrofotometría/métodos , Reproducibilidad de los Resultados
10.
Int J Pharm ; 344(1-2): 158-60, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17614224

RESUMEN

The aim of this work was to investigate the influence of a lipophilic drug, Ibuprofen, on the stability of o/w emulsions. Five formulations were prepared by the phase inversion temperature (PIT) method, and Ibuprofen was incorporated into their oil phase. Emulsion stability was evaluated by short- and long-term studies. Concerning the former, stability under centrifugation showed an improved profile for Ibuprofen-loaded emulsions. The latter confirmed such findings. In conclusion, a rather resistant interfacial film may take place when Ibuprofen was incorporated into the emulsions. Therefore, the critical hydrophilic-lipophilic-balance (HLB) of o/w emulsions can be affected by a lipophilic drug into their oil phase. Such approach is of great importance on the development of lipid carriers for therapeutic drug targeting.


Asunto(s)
Antiinflamatorios no Esteroideos/química , Portadores de Fármacos/química , Emulsiones/química , Ibuprofeno/química , Antiinflamatorios no Esteroideos/administración & dosificación , Estabilidad de Medicamentos , Emulsionantes/química , Concentración de Iones de Hidrógeno , Ibuprofeno/administración & dosificación , Aceite Mineral/química , Reología , Agua/química
11.
J Pharm Biomed Anal ; 36(4): 787-90, 2004 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-15533671

RESUMEN

A reverse phase-LC method was developed and validated for separation and quantification of catechin and epicatechin in aqueous extractives from leaves of Maytenus ilicifolia. The analysis was performed using a C(18) column with acetic acid-acetonitrile gradient elution. The detection was carried out by UV at 280 nm and the peak identification was based on the retention times and by co-chromatography with reference substances. High coefficients of determination were achieved for both catechin and epicatechin peaks from the standard solutions (0.9996 and 0.9999), as well as from extractives (0.9981 and 0.9982, respectively). The method showed good repeatability (R.S.D. <1.5%), reproducibility (R.S.D. <5%) and good accuracy for both catechin and epicatechin peaks (101.4%, R.S.D. = 1.18% and 100.6%, R.S.D. = 2.07%, respectively).


Asunto(s)
Catequina/aislamiento & purificación , Maytenus , Cromatografía Liquida/métodos , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta
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