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1.
Biol Trace Elem Res ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743318

RESUMO

Medicinal plants comprise a spectrum of constituents, encompassing both organic and inorganic elements. Elemental composition of 27 species of medicinal plants of Lamiaceae (including 17 endemic) family grown in Turkey was carried out by ICP-MS. The following elements were determined in analysed samples: Na, Mg, Al, K, Ca, Sc, Cr, Mn, Fe, Co, Zn, As, Rb, Sr, Cs, Ba, La, Ce, Sm, U, Se. Quantitative analysis of specific primary and secondary metabolites was carried out. Na and K are major constituents in plants. The concentrations of Na range from 332,495.590 g/kg (in sample 10SA) to 279,690.674 g/kg (in sample 4SA), while those of K vary from 67,492.456 g/kg (in sample 15SA) to 3347.612 g/kg (in sample 1A). Some metals such as Al, Cr, Mn, Fe, Co, Zn, As, Se, Rb, Sr, Cs, and Ba were also detected. Flavonoids, carbohydrates and tannins were present in all sample. Saponins were found in all samples except 1C and 2O. Coumarin were detected in samples 2N, 1 T, 1O, 1Z, 3SA, 1C, 4SA, 6SA, 8SA, 1 M, 11SA, 13SA, 2O, 14SA, 1H, and 16SI. Lipids were present in samples 6S, 9S, 1A, 10S, 1 M, 11SA, 12SA, 13SA, 14SA, and 16SI. Plants contain essential, rare earth, and trace elements at mg/kg concentrations, while major elements such as K and Na are present in high levels. Toxic element As (arsenic) was detected in all analyzed plants, but in most samples, its concentration was below the threshold set by World Health Organization.

2.
Biol Trace Elem Res ; 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38197903

RESUMO

Isotretinoin is an effective treatment against acne vulgaris, but it also causes many side effects during and after the treatment. The relationship between the changes in the levels of plasma trace elements of patients with AV after 3 months of isotretinoin treatment and the side effects was investigated in the study. Plasma samples of 35 patients were collected before and after isotretinoin treatment. Samples were analyzed by Inductively Coupled Plasma-Mass Spectrometer. After treatment, the levels of phosphorus, magnesium, and zinc in plasma increased statistically, while the level of potassium decreased (p < 0.05). The treatment had differing effects on zinc levels based on the gender of the individuals. With treatment, the levels of zinc in the plasma of men showed a greater increase compared to women (p = 7.3e-04). Additionally, the correlation matrix analysis revealed a strong correlation (R > 0.8) between magnesium and calcium. According to the study results, the change in phosphorus and potassium levels shows that isotretinoin affects kidney functions. The results suggest that phosphorus, potassium, magnesium, and zinc are associated with fatigue, dry skin and chapped lips, hair loss, and sebum secretion, respectively. Consequently, the study emphasizes the need for a comprehensive pre-treatment assessment, including monitoring of liver and kidney function as well as the levels of phosphorus and potassium in patients.

3.
Artigo em Inglês | MEDLINE | ID: mdl-36095936

RESUMO

Pulmonary hypertension (PH) is frequent in the general population and is linked to an increased risk of death. Riociguat is a kind of endothelin receptor antagonist that is often used to treat PH. For pharmacokinetic studies and the determination of riociguat in PH patients, a new, quick, easy, and sensitive UPLC-MS/MS approach was designed and validated. Riociguat and irbesartan (IS) were detected using ESI in positive ion and multiple reaction monitoring mode, respectively, by monitoring the mass transitions m/z 423.0 â†’ 391.0 and 429.1 â†’ 206.9. A reverse-phase C18 column (5 µm, 4.6 × 150 mm) was used with an isocratic mobile phase of water containing 0.1 % formic acid-acetonitrile (25:75, v/v) at a flow rate of 1 ml/min for chromatographic separation. In the range of 5-400 ng/ml, the calibration curve was linear and had a good correlation coefficient (0.9972). This is the first UPLC-MS/MS technique that has been developed and validated for determining riociguat from human plasma. The developed analytical method was extensively validated for linearity, selectivity, specificity, accuracy, precision, sensitivity, stability, matrix effect and recovery, according to FDA criteria. The devised approach was successfully used for a pharmacokinetic research and riociguat determination in PH patients.


Assuntos
Antagonistas dos Receptores de Endotelina , Espectrometria de Massas em Tandem , Acetonitrilas , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Humanos , Irbesartana , Pirazóis , Pirimidinas , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos , Água
4.
Amino Acids ; 53(10): 1569-1588, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34605988

RESUMO

The pandemic of the coronavirus disease (COVID-19) caused by SARS-CoV-2 affects millions of people worldwide. There are still many unknown aspects to this infection which affects the whole world. In addition, the potential impacts caused by this infection are still unclear. Amino acid metabolism, in particular, contains significant clues in terms of the development and prevention of many diseases. Therefore, this study aimed to compare amino acid profile of COVID-19 and healthy subject. In this study, the amino acid profiles of patients with asymptomatic, mild, moderate, and severe/critical SARS-CoV-2 infection were scanned with LC-MS/MS. The amino acid profile encompassing 30 amino acids in 142 people including 30 control and 112 COVID-19 patients was examined. 20 amino acids showed significant differences when compared to the control group in COVID-19 patient groups with different levels of severity in the statistical analyses conducted. It was detected that the branched-chain amino acids (BCAAs) changed in correlation with one another, and L-2-aminobutyric acid and L-phenylalanine had biomarker potential for COVID-19. Moreover, it was concluded that L-2-aminobutyric acid could provide prognostic information about the course of the disease. We believe that a new viewpoint will develop regarding the diagnosis, treatment, and prognosis as a result of the evaluation of the serum amino acid profiles of COVID-19 patients. Determining L-phenylalanine and L-2-aminobutyric levels can be used in laboratories as a COVID-19-biomarker. Also, supplementing COVID patients with taurine and BCAAs can be beneficial for treatment protocols.


Assuntos
Aminoácidos/sangue , COVID-19/sangue , SARS-CoV-2/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , COVID-19/diagnóstico , Cromatografia Líquida , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Prognóstico
5.
J Chromatogr Sci ; 59(6): 502-509, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33884406

RESUMO

For the quantification of flurbiprofen in rat plasma, a simple UPLC-MS/MS method with high sensitivity and short retention time for flurbiprofen was developed and validated using specific parameters. Etodolac was used as internal standard. The transitions (precursor to the product) of flurbiprofen and internal standard were obtained using the electrospray ionization in the negative ion multiple reaction monitoring mode, 243.2 â†’ 199.2, 286.2 â†’ 212.1, respectively. For chromatographic separation, C18 column was used for the stationary phase and gradient elution was used for the mobile phase. This mobile phase consisted of a methanol (A) and a 5 mM ammonium formate solution (B), which varied at a flow rate of 0.4 mL/min. For flurbiprofen, LLOQ was determined as 5 ng/mL. Quantification of flurbiprofen in the rat plasma with a linear calibration curve of 5-5000 ng/mL (r > 0.9991 for plasma) is possible with a retention time of 1.89 min. The total analysis time of the method was 3 min. The proposed method was validated. The intraday and inter-day precision (RSD%) and accuracy (RE%) were within 10% in all cases for flurbiprofen. The stability of flurbiprofen was evaluated under conditions such as short-term, long-term, autosampler and freeze/thaw. After method validation, flurbiprofen was succesfully quantified in real rat plasma samples.


Assuntos
Anti-Inflamatórios não Esteroides/sangue , Cromatografia Líquida de Alta Pressão/métodos , Flurbiprofeno/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Monitoramento de Medicamentos/métodos , Limite de Detecção , Masculino , Ratos , Ratos Wistar
6.
Chem Biodivers ; 18(3): e2000812, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33464702

RESUMO

In this study, phenolic composition, and in vitro biological activities of ethyl acetate (EAE) and methanol (ME) extracts obtained from the aerial parts of endemic Tanacetum erzincanense were investigated. Total phenolic and flavonoid content of the extracts were determined by Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. Antioxidant capacity of the extracts was evaluated over radical scavenging (DPPH and ABTS) and metal ion reducing power (FRAP and CUPRAC) tests. Individual phenolic compounds in ME was analyzed by high-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS). Cell inhibitory potential of the extracts was tested against colorectal adenocarcinoma (HT-29), breast adenocarcinoma (MCF-7), and hepatocarcinoma (HepG2) cells by 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. The results showed that ME contains higher TPC (64.4 mg GAE/g) and TFC (62.2 mg QE/g) than those of EAE (41.5 mg GAE/g and 40.0 mg QE/g). LC-ESI-QTOF/MS analysis revealed that ME is rich in phenolic compounds, namely, chlorogenic acid, apigenin, quercetin, luteolin, and diosmetin. Antioxidant assay results indicated that ME possess stronger activity than EAE and a power that competes with synthetic antioxidants. XTT assay results demonstrated that although both extracts displayed a considerable cytotoxicity against the tested cancer cell lines in a time and dose-dependent manner, ME expressed its selective inhibitory action towards MCF-7 cells with an IC50 value of 20.4 µg/mL for 72 h. These results may serve as a basis for further in vivo studies to examine the potential applications of T. erzincanense in food and pharmaceutical industries.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Fenóis/química , Tanacetum/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade , Células Tumorais Cultivadas
7.
Biol Trace Elem Res ; 199(8): 2844-2850, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33037493

RESUMO

Elevated levels of heavy metals like cadmium (Cd) and manganese (Mn) are known to lead to oxidative damage-related oto-toxicity and decreased levels of chromium (Cr) and selenium (Se) are known to lead to oto-toxicity due to reduced anti-oxidant activity. The aim of the present study was to evaluate serum levels of Cd, Mn, Cr, and Se and their relationship with tinnitus. A total of 48 patients with tinnitus (Group 1) and 40 healthy controls (Group 2) were included in the study. All participants were applied audiology tests. Severity of tinnitus was measured with Tinnitus Severity Index Questionnaire (TSIQ) in group 1. Serum Mn, Cd, Cr, and Se measurements were done by using The Agilent ICP-MS system consisted of a 7700 coupled plasma mass spectrometry (ICP-MS). Serum Cd, Mn, and Cr levels were higher in group 1 and Se level was lower in group 1 than that of group 2. We may conclude that Cd, Mn, Cr, and Se levels could play an important role in etio-pathogenesis of tinnitus, and thereby supplementation or reduction of these elements could be considered as novel therapeutic goals.


Assuntos
Selênio , Zumbido , Oligoelementos , Cádmio , Cromo , Humanos , Manganês
8.
Biomed Chromatogr ; 33(5): e4502, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30725476

RESUMO

Macitentan is an endothelin receptor antagonist commonly used in the treatment of pulmonary arterial hypertension (PAH). A novel, rapid, simple and sensitive UPLC-MS/MS method was developed and validated for pharmacokinetic study and the determination of macitentan in PAH patients. Macitentan and bosentan, which are used as internal standards, were detected using atmospheric pressure chemical ionization in positive ion and multiple reaction monitoring mode by monitoring the mass transitions m/z 589.1 → 203.3 and 552.6 → 311.5, respectively. Chromatographic separation was performed on a reverse-phase C18 column (5 µm, 4.6 × 150 mm) with an isocratic mobile phase, which consisted of water containing 0.2% acetic acid-acetonitrile (90:10, v/v) at a flow rate of 1 mL/min. Retention times were 1.97 and 1.72 min for macitentan and IS, respectively. The calibration curve with high correlation coefficient (0.9996) was linear in the range 1-500 ng/mL. The lower limit of quantitation and average recovery values were determined as 1 ng/mL and 89.8%, respectively. This method is the first UPLC-MS/MS method developed and validated for the determination of macitentan from human plasma. The developed analytical method was fully validated for linearity, selectivity, specificity, accuracy, precision, sensitivity, stability, matrix effect and recovery according to US Food and Drug Administration guidelines. The developed method was applied successfully for pharmacokinetic study and the determination of macitentan in PAH patients.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Hipertensão Pulmonar/tratamento farmacológico , Pirimidinas/sangue , Sulfonamidas/sangue , Espectrometria de Massas em Tandem/métodos , Monitoramento de Medicamentos , Estabilidade de Medicamentos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sulfonamidas/farmacocinética , Sulfonamidas/uso terapêutico
9.
Iran J Pharm Res ; 15(3): 369-378, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27980572

RESUMO

This paper describes two rapid, sensitive and specific methods for the determination of fulvestrant in pharmaceutical preparations by high performance liquid chromatography (HPLC) and linear sweep voltammetry (LSV). HPLC method was used to study the degradation behaviour. Fulvestrant was subjected to degradation under the conditions of hydrolysis (acid and alkali), oxidation (30% H2O2). The linearity was established over the concentration range of 5-50 m g mL-1 for LSV and 0.5-20 m g mL-1 for HPLC method. The intra- and inter-day relative standard deviation (RSD) was less than 3.96 and 3.07% for LSV and HPLC, respectively. Limits of quantification were determined as 5.0 and 0.50 m g mL-1 for LSV and HPLC, respectively. No interference was found from tablet excipients at the selected assay conditions. The methods were applied for the quality control of commercial fulvestrant dosage form to quantify the drug and to check the formulation content uniformity.

10.
Mater Sci Eng C Mater Biol Appl ; 58: 1082-9, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26478407

RESUMO

Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN-HA composites in rat femurs. All rats were (n=126) divided into five experimental groups (n=24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100 HA (Group2), femoral defect + %2.5 hBN + %97.5 HA (Group3), femoral defect + %5 hBN + %95 HA (Group4), femoral defect + %10 hBN + %90 HA (Group5), femoral defect + %100 hBN (Group6). The femoral defect was created in the distal femur (3mm drill-bit). Each implant group was divided into four different groups (n=24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN-HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN-HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers.


Assuntos
Apatitas/química , Compostos de Boro/química , Boro/sangue , Fêmur/cirurgia , Nanocompostos/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Boro/metabolismo , Compostos de Boro/farmacocinética , Ratos , Ratos Sprague-Dawley
11.
Chem Pharm Bull (Tokyo) ; 63(9): 720-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26329865

RESUMO

Thymus praecox ssp. grossheimii (RONNIGER) JALAS var. grossheimii (Lamiaceae) is used as an herbal tea for cold, stomachache, cough, and infections in Turkey. There are no phytochemical studies on this species. We performed phytochemical studies and quantitative analysis of rosmarinic acid and luteolin 5-O-ß-D-glucopyranoside in the methanol extract of the plant. Several chromatographic methods were used for the isolation of major compounds. HPLC methods were applied for quantitative analysis of rosmarinic acid and luteolin 5-O-ß-D-glucopyranoside in the methanol extract. In this study, ursolic acid (1), oleanolic acid (2), methyl rosmarinate (3), ethyl rosmarinate (4), rosmarinic acid (5), luteolin 5-O-ß-D-glucopyranoside (6), and thymoquinol 2,5-O-ß-diglucopyranoside (7) were isolated from the aerial parts of the plant. The relative contents of rosmarinic acid and luteolin 5-O-ß-D-glucopyranoside in the extract were 15.2 and 57.8 mg/g of dry weight, respectively. Compounds isolated from this plant and the contents of rosmarinic acid and luteolin 5-O-ß-D-glucopyranoside provided reasonable evidence for the traditional usages of this plant.


Assuntos
Cinamatos/análise , Depsídeos/análise , Flavonas/análise , Glucosídeos/análise , Compostos Fitoquímicos/análise , Thymus (Planta)/química , Cromatografia Líquida de Alta Pressão , Conformação Molecular , Ácido Rosmarínico
12.
Iran J Pharm Res ; 14(2): 443-51, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25901151

RESUMO

In this study, simple, fast and reliable cyclic voltammetry (CV), linear sweep voltammetry (LSV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV) methods were developed and validated for determination of bosentan in pharmaceutical preparations. The proposed methods were based on electrochemical oxidation of bosentan at platinum electrode in acetonitrile solution containing 0.1 M TBACIO4. The well-defined oxidation peak was observed at 1.21 V. The calibration curves were linear for bosentan at the concentration range of 5-40 µg/mL for LSV and 5-35 µg/mL for SWV and DPV methods, respectively. Intra- and inter-day precision values for bosentan were less than 4.92, and accuracy (relative error) was better than 6.29%. The mean recovery of bosentan was 100.7% for pharmaceutical preparations. No interference was found from two tablet excipients at the selected assay conditions. Developed methods in this study are accurate, precise and can be easily applied to Tracleer and Diamond tablets as pharmaceutical preparation.

13.
J Pharm Biomed Anal ; 97: 33-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24803031

RESUMO

A rapid, simple and sensitive UFLC-MS/MS method was developed and validated for the determination of bosentan in rat plasma using etodolac as an internal standard (IS) after liquid-liquid extraction with diethyl ether-chloroform (4:1, v/v). Bosentan and IS were detected using electrospray ionization in positive ion multiple reaction monitoring mode by monitoring the transitions m/z 551.90→201.90 and 288.20→172.00, respectively. Chromatographic separation was performed on the inertsil ODS-4 column with a gradient mobile phase, which consisted of 0.1% acetic acid with 5mM ammonium acetate in water for solvent A and 5mM ammonium acetate in acetonitrile-methanol (50:50, v/v) for solvent B at a flow rate of 0.3mL/min. The method was sensitive with 0.5ng/mL as the lower limit of quantitation (LLOQ) and the standard calibration curve for bosentan was linear (r>0.997) over the studied concentration range (0.5-2000ng/mL). The proposed method was fully validated by determining specificity, linearity, LLOQ, precision and accuracy, recovery, matrix effect and stability. The validated method was successfully applied to plasma samples obtained from rats.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Antagonistas dos Receptores de Endotelina/sangue , Extração Líquido-Líquido/métodos , Sulfonamidas/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Bosentana , Estabilidade de Medicamentos , Masculino , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Pharm Dev Technol ; 18(3): 570-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-21864098

RESUMO

The aim of the present study was to develop and characterize metformin HCl-loaded nanoparticle formulations. Nanoparticles were prepared by the nanoprecipitation method using both a single polymer (Eudragit(®)RSPO) and a polymer mixture (Eudragit/PLGA). The mean particle size ranged from 268.8 to 288 nm and the nanoparticle surface was positively charged (9.72 to 10.1 mV). The highest encapsulation efficiency was observed when Eudragit®RSPO was used. All formulations showed highly reproducible drug release profiles and the in vitro drug release in phosphate buffer (pH = 6.8) ranged from 92 to 100% in 12 h. These results suggest that Eudragit(®)RSPO or Eudragit/PLGA nanoparticles might represent a promising sustained-release oral formulation for metformin HCl, reducing the necessity of repeated administrations of high doses to maintain effective plasma concentrations, and thus, increasing patient compliance and reducing the incidence of side-effects.


Assuntos
Química Farmacêutica/métodos , Ácido Láctico/síntese química , Metformina/síntese química , Nanopartículas/química , Ácido Poliglicólico/síntese química , Ácidos Polimetacrílicos/síntese química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/farmacocinética , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Ácido Láctico/farmacocinética , Metformina/farmacocinética , Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ácidos Polimetacrílicos/farmacocinética , Reprodutibilidade dos Testes
15.
Iran J Pharm Res ; 12(4): 659-69, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24523745

RESUMO

The forced degradation study of lidocaine HCl was carried out according to the ICH guideline Q1A (R2). The degradation conditions were assessed to be hydrolysis, oxidation, photolysis and dry heat during 24 h, 48 h and 72 h and then the samples were investigated by GC-FID method and nuclear magnetic resonance (NMR) spectroscopy. According to these results, the degradation products were not observed in all reaction conditions during the 72 h period. Only spectral changes in the 1H and 13C-NMR spectrum were observed in hydrogen peroxide and acid degradation. As a result of this degradation, n-oxide was formed. After acid-induced degradation with HCl, the secondary amine salt was formed. Furthermore, trifluoroacetic acid (TFA) was used as the acidic media, and the decomposition products were observed. A simple and reliable gas chromatography method with flame ionization detection (GC-FID) was developed and validated for the determination of lidocaine HCl in pharmaceutical formulations in the form of a cream and injections. The GC-FID method can be used for a routine analysis of lidocaine HCl in pharmaceutical formulations and the proposed method, together with NMR spectroscopy, can be applied in stability studies.

16.
AAPS PharmSciTech ; 11(3): 1250-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20697984

RESUMO

The aim of this study was to formulate and characterize Eudragit® L100 and Eudragit® L100-poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing diclofenac sodium. Diclofenac generates severe adverse effects with risks of toxicity. Thus, nanoparticles were prepared to reduce these drawbacks in the present study. These nanoparticles were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, and in vitro drug release in pH 6.8. The prepared nanoparticles were almost spherical in shape, as determined by atomic force microscopy. The nanoparticles with varied size (241-274 nm) and 25.8-62% of entrapment efficiency were obtained. The nanoparticles formulations produced the release profiles with an initial burst effect in which diclofenac sodium release ranged between 38% and 47% within 4 h. The extent of drug release from Eudragit® L100 nanoparticles was up to 92% at 12 h. However, Eudragit®/PLGA nanoparticles showed an initial burst release followed by a slower sustained release. The cumulative release at 72 h was 56%, 69%, and 81% for Eudragit®/PLGA (20:80), Eudragit®/PLGA (30:70) and Eudragit®/PLGA (50:50) nanoparticles, respectively. The release profiles and encapsulation efficiencies depended on the amount of Eudragit in the blend. These data demonstrated the efficacy of these nanoparticles in sustaining the diclofenac sodium release profile.


Assuntos
Preparações de Ação Retardada/síntese química , Diclofenaco/química , Ácido Láctico/química , Nanocápsulas/química , Ácido Poliglicólico/química , Ácidos Polimetacrílicos/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Diclofenaco/administração & dosagem , Difusão , Composição de Medicamentos/métodos , Nanocápsulas/ultraestrutura , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
17.
Biomed Chromatogr ; 21(10): 1077-82, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17583875

RESUMO

The accurate determination of prilocaine HCl levels in plasma is important in both clinical and pharmacological/toxicological studies. Prilocaine HCl is quickly hydrolyzed to o-toluidine, causing methemoglobinemia. For this, the present work describes the methodology and validation of a GC-MS assay for determination of prilocaine HCl with lidocaine HCl as internal standard in plasma. The validation parameters of linearity, precision, accuracy, recovery, specificity, limit of detection and limit of quantification were studied. The range of quantification for the GC-MS was 20-250 ng/mL in plasma. Within-day and between-day precision, expressed as the relative standard deviation (RSD) were less than 6.0%, and accuracy (relative error) was better than 9.0% (n = 6). The analytical recovery of prilocaine HCl and IS from plasma has averaged 94.79 and 96.8%, respectively. LOQ and LOD values for plasma were found to be 20 and 10 ng/mL, respectively. The GC-MS method can be used for determination from plasma of prilocaine HCl in routine measurement as well as in pharmacokinetic studies for clinical use.


Assuntos
Anestésicos Locais/sangue , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lidocaína/sangue , Prilocaína/sangue , Calibragem , Fracionamento Químico , Humanos , Lidocaína/normas , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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