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1.
Artigo em Inglês | MEDLINE | ID: mdl-39293158

RESUMO

Herein, we describe the utilization of an ionic liquid (IL)/Carbowax 20 M-functionalized sol-gel sorbent for the capsule phase microextraction of doxycycline in authentic human urine samples. This green sample preparation method combines stirring and filtration in a single, standalone sample preparation device, streamlining the sample preparation process. Additionally, it provides rapid extraction kinetics and high extraction efficiency. The experimental conditions (i.e. sorbent type, sample pH and volume, extraction time, ionic strength, elution solvent, and volume) affecting the extraction efficiency of the analyte were studied and optimized. The method was linear in the range of 0.1 - 5.0 µg/mL with a coefficient of determination higher than 0.995. The achieved LOD was found to be 0.02 µg/mL while the lower limit of quantitation (LLOQ) was 0.1 µg/mL. The IL/Carbowax 20 M-functionalized microextraction capsules were reusable at least 30 times for urine samples. The relative recoveries (% RR) ranged between 93.4 - 115.9 % while the precision (expressed as % RSD) was better than 8.1 % in all cases. The robustness of the microextraction procedure and the instrumental HPLC method were separately investigated using Plackett-Burman experimental designs. The analytical protocol demonstrated cost-effectiveness, ease of handling, and speed, leading to increased sample throughput. The green character of the developed method was evaluated using the Green Analytical Procedure Index (GAPI) and Blue Applicability Grade Index (BAGI). Finally, the method's applicability was demonstrated by analyzing authentic human urine samples after oral administration of a doxycycline-containing pharmaceutical formulation.

2.
Molecules ; 29(17)2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39274924

RESUMO

In this report, a polytetrahydrofuran-coated polyester fabric phase sorptive extraction (FPSE) for the determination of doxycycline in human urine was described. The sol-gel polytetrahydrofuran sorbent proved to be superior against other sol-gel coated cellulose and polyester membranes tested. The effect of the extraction parameters including membrane surface area, sample pH and volume, salt concentration, extraction time, stirring rate, etc., on the extraction efficiency of the analyte was studied using the "one-factor-at-a-time" (OFAT) and Box-Behnken design approaches. The analytical method proposed was validated in compliance with FDA guidelines for bioanalytical procedures. The method was linear in the determination range of 100-5000 ng/mL with the determination coefficient of 0.9953. The limit of detection (LOD) and the lower limit of quantification for doxycycline was 17 and 100 ng/mL, respectively. The relative recoveries for intra-day and inter-day studies ranged from 98.5-112.2% and 89.6-96.8%, respectively. The relative standard deviation was lower than 14.7% in all cases, exhibiting good precision. The sol-gel polytetrahydrofuran-modified FPSE membranes were reusable for at least 30 times. The greenness of the developed method was evaluated using Sample Preparation Metric of Sustainability (SPMS) and Blue Applicability Grade Index (BAGI) metric tools. Finally, the analytical scheme was successfully employed for the quantitation of urinary doxycycline collected at various time points following the administration of doxycycline-containing tablets.


Assuntos
Doxiciclina , Furanos , Poliésteres , Humanos , Doxiciclina/urina , Doxiciclina/química , Poliésteres/química , Furanos/urina , Furanos/química , Limite de Detecção , Extração em Fase Sólida/métodos
3.
Int J Pharm ; 664: 124627, 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39179008

RESUMO

3D-printed dosage forms comprised of Carbopol and Eudragit were fabricated through semi-solid extrusion, combining Enoxaparin (Enox) and the permeation enhancer SNAC in a single-step process without subsequent post-processing. Inks were characterized using rheology and Fourier-transform infrared (FTIR) spectroscopy. The stability of Enox in the fabricated dosage forms was assessed by means of Nuclear Magnetic Resonance (NMR) and Circular Dichroism (CD) analysis. In vitro release studies revealed the release of Enox in a sustained manner, whereas ex vivo experiments demonstrated the mucoadhesive properties of the 3D-printed dosage forms and their ability to enhance Enox permeability across intestinal mucosa. Cellular assays (CCK-8 assay) revealed a dose- and time-dependent response following incubation with the 3D-printed dosage forms. The encapsulation of SNAC in the 3D-printed dosage forms demonstrated their capacity to increase the transcellularly transport of macromolecule across Caco-2 monolayer in a reversible manner, as confirmed by Transepithelial Resistance (TEER) measurements.


Assuntos
Liberação Controlada de Fármacos , Enoxaparina , Impressão Tridimensional , Comprimidos , Células CACO-2 , Humanos , Administração Oral , Enoxaparina/administração & dosagem , Enoxaparina/farmacocinética , Enoxaparina/química , Resinas Acrílicas/química , Animais , Ácidos Polimetacrílicos/química , Mucosa Intestinal/metabolismo , Masculino , Sistemas de Liberação de Medicamentos/métodos , Adesividade , Permeabilidade , Polivinil/química , Anticoagulantes/administração & dosagem , Anticoagulantes/farmacocinética , Anticoagulantes/química
4.
J Chromatogr A ; 1730: 465157, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39025028

RESUMO

Capsule phase microextraction (CPME) is an efficient bioanalytical technique that streamlines the sample preparation by integrating the filtration and stirring mechanism directly into the device. A novel composite sorbent designed to be selective towards the target analytes consisting of mixed-mode sorbent chemistry synthesized by sol-gel technology is found promising and superior to the conventional C18 sorbents. Herein we describe the encapsulation of an ionic liquid (IL)/Carbowax 20M-functionalized sol-gel sorbent (sol-gel IL/Carbowax 20 M) in the lumen of porous polypropylene tubes for the capsule phase microextraction of three phosphodiesterase-5 inhibitors namely avanafil, sildenafil, and tadalafil in human serum and urine samples. The CPME device was characterized by Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FT-IR). The experimental parameters of CPME procedure (e.g. sample pH and ionic strength, extraction time, stirring rate, elution solvent and volume) were carefully optimized to achieve the highest possible extraction efficiency for the analytes. Method validation was conducted in terms of precision, linearity, accuracy, matrix effect, lower limits of quantification, and limits of detection (LOD). The method linearity was investigated in the range of 50-1000 ng mL-1 for all analytes while the precision was less than 11.8 % in all cases. For all analytes, the LOD values were 17 ng mL-1. The IL/CW 20M-functionalized microextraction capsules could be reused at least 25 times both for urine and serum samples. The green character and the applicability of the proposed method were evaluated using the ComplexGAPI and BAGI indexes. The optimized CPME protocol exhibited reduced consumption of organic solvent and generation of waste, cost-effectiveness, and simplicity. Finally, the proposed method was successfully applied to the analysis of sildenafil in human urine after administration of drug-containing formulation.


Assuntos
Líquidos Iônicos , Microextração em Fase Líquida , Inibidores da Fosfodiesterase 5 , Humanos , Líquidos Iônicos/química , Limite de Detecção , Espectrometria de Massa com Cromatografia Líquida , Microextração em Fase Líquida/métodos , Inibidores da Fosfodiesterase 5/sangue , Inibidores da Fosfodiesterase 5/urina , Inibidores da Fosfodiesterase 5/química , Reprodutibilidade dos Testes , Citrato de Sildenafila/sangue , Citrato de Sildenafila/urina , Microextração em Fase Sólida/métodos
5.
J Pharm Biomed Anal ; 248: 116324, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38924878

RESUMO

Since 3D printing technology is an emerging field in pharmaceutical technology, the present study aimed at the development of a mixed-mode liquid chromatographic method for the separation and determination of hydrochlorothiazide, diltiazem, and propranolol to investigate their in-vitro release performance from 3D printed tablets. Due to the unique properties of the mixed-mode stationary phase, the three drugs were separated in less than 8 min under isocratic elution. Method development was accomplished following the Analytical Quality by Design principles and was evaluated using risk assessment and multivariate analysis. The influences of critical method parameters on critical method attributes (were screened using a 2-level fractional factorial design and subsequently optimized through a central composite design. The method operable design region was approved by the establishment of a robust zone using Monte Carlo simulation and capability analysis. The validation of the HPLC method was performed based on the total error concept. The relative bias was varied between ─ 11.6 % and 10.5 % and the RSD values for repeatability and intermediate precision were below 4.4 % in all cases. The limits of detection (LOD) ranged between 0.17 - 0.90 µg/mL and were adequate for the specific application. The developed method was successfully applied to the analysis of the studied drugs in in-vitro drug release samples obtained from 3D-printed tablets combining the above-mentioned active pharmaceutical ingredients (APIs).


Assuntos
Diltiazem , Liberação Controlada de Fármacos , Hidroclorotiazida , Limite de Detecção , Impressão Tridimensional , Propranolol , Comprimidos , Hidroclorotiazida/análise , Hidroclorotiazida/química , Cromatografia Líquida de Alta Pressão/métodos , Diltiazem/análise , Diltiazem/química , Propranolol/análise , Propranolol/química , Reprodutibilidade dos Testes , Tecnologia Farmacêutica/métodos , Método de Monte Carlo , Química Farmacêutica/métodos
6.
J Pharm Biomed Anal ; 248: 116317, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38936170

RESUMO

An instrumental-free, high-throughput assay has been developed for the quantification of thiocyanate in human saliva. The proposed green method is based on the rapid reaction of the analyte with Fe(III) under acidic pH in a microplates format to form a colored complex that is captured as an image by an overhead book scanner. Optimization included the effects of the amount concentration of Fe(III), acidity and reaction time / complex stability using a total volume of 300 µL per well. Validation towards the matrix effect was focused on the specific application and was performed using both artificial and human saliva. The linearity of the developed assay was up to 500 µM thiocyanate offering a lower limit of quantification (LLOQ) of 30 µM. The green potentials were evaluated by both the Green Analytical Procedure (GAPI) and Blue Applicability Grade (BAGI) indexes. The thiocyanate content in the saliva of non-smoking volunteers ranged between 750 and 1350 µΜ, while elevated concentrations were verified in smoking individuals (1860-3080 µΜ). Statistical agreement with a corroborative method was assessed using the Bland-Altman plot.


Assuntos
Ensaios de Triagem em Larga Escala , Saliva , Tiocianatos , Tiocianatos/análise , Saliva/química , Humanos , Ensaios de Triagem em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/instrumentação , Limite de Detecção , Química Verde/métodos , Concentração de Íons de Hidrogênio , Fumar
7.
Pharmaceuticals (Basel) ; 17(4)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38675384

RESUMO

Herein, a sensitive and selective gas chromatography-electron capture detector (GC-ECD) method was developed and validated for the quantification of trace levels of five bromo-containing genotoxic impurities in Febuxostat active pharmaceutical ingredient (API) after headspace sampling (HS). Multivariate experimental designs for the optimization of static headspace parameters were conducted in two stages using fractional factorial design (FFD) and central composite design (CCD). The optimum headspace conditions were 5 min of extraction time and a 120 °C extraction temperature. Baseline separation on the analytes against halogenated solvents was carried out using an Agilent DB-624 (30 m × 0.32 mm I.D., 1.8 µm film thickness) stationary phase under isothermal conditions. The method was validated according to ICH guidelines in terms of specificity, linearity, the limits of detection and quantification, precision and accuracy. The linearity was assessed in the range of 5-150% with respect to the specification limit. The achieved LOD and LOQ values ranged between 0.003 and 0.009 and 0.01 and 0.03 µg mL-1, respectively. The accuracy of the method (expressed as relative recovery) was in the range of 81.5-118.2%, while the precision (repeatability, inter-day) was less than 9.9% in all cases. The validated analytical protocol has been successfully applied to the determination of the impurities in various Febuxostat API batch samples.

8.
Int J Pharm ; 655: 124058, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38552754

RESUMO

Polypharmacy is a common issue, especially among elderly patients resulting in administration errors and patient inconvenience. Hypertension is a prevalent health condition that frequently leads to polypharmacy, as its treatment typically requires the co-administration of more than one different Active Pharmaceutical Ingredients (API's). To address these issues, floating hollow torus-shaped dosage forms were developed, aiming at providing prolonged gastric retention and sustained drug release. The dosage forms (polypills) containing three anti-hypertensive API's (diltiazem (DIL), propranolol (PRP) and hydrochlorothiazide (HCTZ)) were created via Fused Deposition Modelling 3D printing. A multitude of the dosage forms were loaded into a capsule and the resulting formulation achieved prolonged retention times over a 12-hour period in vitro, by leveraging both the buoyancy of the dosage forms, and the "cheerios effect" that facilitates the aggregation and retention of the dosage forms via a combination of surface tension and shape of the objects. Physicochemical characterization methods and imaging techniques were employed to investigate the properties and the internal and external structure of the dosage forms. Furthermore, an ex vivo porcine stomach model revealed substantial aggregation, adhesion and retention of the 3D printed dosage forms in porcine stomach. In vitro dissolution testing demonstrated almost complete first-order release of PRP and DIL (93.52 % and 99.9 %, respectively) and partial release of HCTZ (65.22 %) in the 12 h timeframe. Finally, a convolution-based single-stage approach was employed in order to predict the pharmacokinetic (PK) parameters of the API's of the formulation and the resemblance of their PK behavior with previously reported data.


Assuntos
Anti-Hipertensivos , Diltiazem , Humanos , Idoso , Preparações de Ação Retardada/química , Comprimidos/química , Liberação Controlada de Fármacos , Hidroclorotiazida , Impressão Tridimensional , Tecnologia Farmacêutica/métodos
9.
Bull Environ Contam Toxicol ; 112(3): 48, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459992

RESUMO

This study aimed on the development of a SPE-UHPLC-MS/MS method for the simultaneous determination of pesticide residues in drinking water samples. A chemometric approach was applied to optimize the efficiency of the SPE pretreatment procedure. This study involved (i) the application of a Full Factorial Design for the screening of the significant factors, (ii) the application of a Central Composite Design for the determination of the optimal conditions and (iii) the evaluation and validation of the significance of the statistically proposed models. Oasis HLB cartridges were used for the extraction. The optimum sample volume was 300 mL and the elution solvent 3 mL of the mixture of methanol:ethylacetate 70:30 v/v. The method was validated according to the international guidelines. Recoveries were ranged from 63 to 116% and the detection limits were between 0.1 and 1.5 pg mL- 1. The validated method could be used in routine analysis for pesticides screening.


Assuntos
Praguicidas , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Quimiometria , Extração em Fase Sólida/métodos , Água
10.
Artigo em Inglês | MEDLINE | ID: mdl-38417274

RESUMO

Clomipramine (CLP) is a tricyclic antidepressant drug, and its determination in biological samples is of high importance in clinical and forensic evaluations to assure appropriate drug concentrations. In the present study, benzoic acid was employed as a pH-switchable hydrophilicity solvent (SHS) for the microextraction of CLP from authentic human urine samples prior to its determination by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The microextraction protocol was based on the phase transition of the SHS through pH alteration that resulted in its rapid dispersion and simultaneous phase separation. The obtained solid was collected in a syringe filter, dissolved in methanol, and analyzed. The main parameters that affected the efficiency of the microextraction procedure were studied and optimized to ensure high extraction efficiency for CLP and the analytical method was validated. Under optimum conditions, good linearity was observed between 0.05 and 5.0 µg mL-1. The limit of detection and limit of quantification were found to be 0.015 and 0.05 µg mL-1, respectively. The RSD values for intra-day repeatability and inter-day precision were 2.4-8.9 % and 1.7-9.1 %, respectively. The relative recovery values were within 90.0 and 110.0 % in all cases, demonstrating good method accuracy. The proposed SHS microextraction showed cost-efficiency, handling simplicity, and rapidity resulting in enhanced sample throughput. Moreover, the proposed method exhibited a green character and good applicability based on its evaluation by Green Analytical Procedure Index and Blue Applicability Grade Index.


Assuntos
Clomipramina , Microextração em Fase Líquida , Humanos , Clomipramina/urina , Solventes , Microextração em Fase Líquida/métodos , Interações Hidrofóbicas e Hidrofílicas , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Limite de Detecção
11.
J Chromatogr A ; 1717: 464674, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38290172

RESUMO

In this research, a sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based capsule phase microextraction (CPME) device was developed in combination with liquid chromatography-post column derivatization for the first ever reported determination of a somatostatin analogue - lanreotide in human urine. The sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent was encapsulated in the lumen of a polypropylene capillary tube and characterized by FT-IR spectroscopy and SEM with energy dispersive X-ray spectroscopy (EDS). The main steps of the CPME workflow were optimized to obtain high extraction efficiency for the target analyte. After the separation of the analyte on a C8 stationary phase, the peptide was derivatized online with o-phthalaldehyde before the fluorescence detection. The main experimental parameters of CPME and the post-column procedures were systematically investigated and optimized. The method was validated in terms of selectivity, linearity, accuracy, precision, limits of detection (LOD), and limits of quantification (LOQ). The relative bias ranged between 88.8 and 115.6 % for the peptide, while the RSD values for repeatability and intermediate precision were less than 14.3 %. The achieved limit of detection (LOD) was 0.2 µΜ while the limit of quantitation (LOQ) was established as 0.9 µΜ. Finally, the sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based microextraction capsules were found to be reusable for at least 20 extractions. The developed method presented adequate overall performance, and it could be applied in the analysis of selected peptide in human urine samples.


Assuntos
Líquidos Iônicos , Microextração em Fase Líquida , Somatostatina/análogos & derivados , Humanos , Cromatografia Líquida de Alta Pressão/métodos , Polietilenoglicóis , Líquidos Iônicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Microextração em Fase Sólida/métodos , Peptídeos Cíclicos , Limite de Detecção
12.
Mikrochim Acta ; 190(11): 428, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37796344

RESUMO

A sol-gel Carbowax 20 M/3-[(3-Cholamidopropyl) dimethyl ammonio]-1-propanesulfonate composite sorbent-based capsule phase microextraction device has been fabricated and characterized for the determination of four statins (pravastatin, rosuvastatin, pitavastatin, and atorvastatin) in human urine. The presence of ionizable carboxyl functional groups in statins requires pH adjustment of the sample matrix to ensure that the target molecules are in their protonated form (pH should be 2 units below their pKa values) which not only is cumbersome but also risks unintended contamination of the sample. This challenge was addressed by introducing zwitterionic ionic liquid in addition to neutral, polar Carbowax 20 M polymer in the sol-gel-derived composite sorbent. As such, the composite zwitterionic multi-modal sorbent can simultaneously extract neutral, cationic, and anionic species. This particular attribute of the composite sorbent eliminates the necessity of the matrix pH adjustment and consequently simplifies the overall sample preparation workflow. Various experimental parameters such as the sample amount, extraction time, salt addition, stirring rate, and elution solvent type that may affect the extraction performance of the statins were investigated using a central composite design and the one-parameter-at-a-time approach. The analytes and the internal standard were separated on a C18 column with gradient elution using phosphate buffer (20 mM, pH 3) and acetonitrile as mobile phase. The analytes were detected at 237 nm. The method was validated, and linearity was observed in the range 0.10-2.0 µg mL-1 for all compounds. The method precision was better 9.9% and 10.4% for intra-day and inter-day, respectively, while the relative recoveries were acceptable, ranging between 83.4 and 116% in all cases. Method greenness was assessed using the ComplexGAPI index. Finally, the method's applicability was demonstrated in the determination of the statins in authentic human urine after oral administration of pitavastatin and rosuvastatin-containing tablets.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Líquidos Iônicos , Humanos , Polietilenoglicóis , Rosuvastatina Cálcica , Lipídeos
13.
Molecules ; 28(17)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37687035

RESUMO

A high-throughput fluorimetric assay for histidine was developed, using a 96-well plates platform. The analyte reacts selectively with o-phthalaldehyde under mild alkaline conditions to form a stable derivative. Instrumental-free detection was carried out using a smartphone after illumination under UV light (365 nm). The method was proved to be linear up to 100 µM histidine, with an LLOQ (lower limit of quantification) of 10 µM. The assay was only prone to interference from glutathione and histamine that exist in the urine samples at levels that are orders of magnitude lower compared to histidine. Human urine samples were analyzed following minimum treatment and were found to contain histidine in the range of 280 to 1540 µM. The results were in good agreement with an HPLC corroborative method.


Assuntos
Ensaios de Triagem em Larga Escala , Histidina , Smartphone , Fluorometria/métodos , Histidina/urina , Humanos , o-Ftalaldeído/química
14.
Bioanalysis ; 15(15): 937-954, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37638635

RESUMO

Microextraction techniques have attracted the attention of many researchers working in the field of bioanalysis due to their unique advantages, mainly in downsizing the scale of sample preparation steps. In parallel, analytical derivatization offers a powerful combination in terms of additional sensitivity, selectivity and compatibility with modern separation techniques. The aim of this review is to discuss the most recent advances in bioanalytical sample preparation based on the combination of microextraction and analytical derivatization. Both innovative fundamental reports and analyte-targeted applications are included and discussed. Dispersive liquid-liquid extraction and solid-phase microextraction are the most common techniques that typically combined with derivatization, while the development of novel and greener protocols is receiving substantial consideration in the field of analytical chemistry.


Assuntos
Química Analítica , Extração Líquido-Líquido , Humanos , Pesquisadores , Microextração em Fase Sólida , Manejo de Espécimes
15.
Drug Dev Ind Pharm ; 49(3): 249-259, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37014319

RESUMO

OBJECTIVE: Vaginal administration is an important alternative to the oral route for both topical and systemic use. Therefore, the development of reliable in silico methods for the study of drugs permeability is becoming popular in order to avoid time-consuming and costly experiments. METHODS: In the current study, Franz cells and appropriate HPLC or ESI-Q/MS analytical methods were used to experimentally measure the apparent permeability coefficient (Papp) of 108 compounds (drugs and non-drugs). Papp values were then correlate with 75 molecular descriptors (physicochemical, structural, and pharmacokinetic) by developing two Quantitative Structure Permeability Relationship (QSPR) models, a Partial Least Square (PLS) and a Support Vector Machine (SVM). Both were validated by internal, external and cross-validation. RESULTS: Based on the calculated statistical parameters (PLS model A: R2 = 0.673 and Q2 = 0.594, PLS model B: R2 = 0.902 and Q2 = 0.631, SVM: R2 = 0.708 and Q2 = 0.758). SVM presents higher predictability while PLS adequately interprets the theory of permeability. CONCLUSIONS: The most important parameters for vaginal permeability were found to be the relative PSA, logP, logD, water solubility and fraction unbound (FU). Respectively, the combination of both models could be a useful tool for understanding and predicting the vaginal permeability of drug candidates.


Assuntos
Relação Quantitativa Estrutura-Atividade , Humanos , Feminino , Preparações Farmacêuticas/química , Permeabilidade da Membrana Celular , Permeabilidade , Administração Intravaginal
16.
Talanta ; 258: 124482, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36989615

RESUMO

In this study, a simple and rapid fabric phase sorptive extraction (FPSE) protocol combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the monitoring of salivary vitamin B12 levels. Different sol-gel coated cellulose and polyester membranes were evaluated and sol-gel Carbowax 20 M coated polyester membranes were chosen for the selective extraction of the target analyte from saliva samples. Face-centered central composite design (FC-CCD) was employed for the investigation and optimization of sample volume, extraction time and stirring rate, while the other experimental factors were investigated using the classical one-factor-at-a- time" (OFAT) method. Validation of the FPSE-HPLC-UV method was conducted according to the FDA guidelines for bioanalytical methodologies. The lower limit of quantification for vitamin B12 was 0.10 µg mL-1 and the linear range was 0.10-10.0 µg mL-1. The relative recoveries for intra-day and inter-day studies were 87.5-113.8% and 88.2-119.2%, respectively. The relative standard deviation was better than 8.2% in all cases, demonstrating good method precision. The sol-gel Carbowax 20 M coated FPSE membranes were found to be reusable for up to 25 times. Finally, the proposed scheme was successfully employed for the quantitation of salivary vitamin B12 at different time points following the administration of sublingual tablets and oral sprays.


Assuntos
Polietilenoglicóis , Vitamina B 12 , Cromatografia Líquida de Alta Pressão/métodos , Sprays Orais , Poliésteres , Comprimidos , Vitaminas
17.
Molecules ; 28(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36677945

RESUMO

In this communication, we describe the first analytical method for the determination of free histidine in hair care products (shampoos and conditioners). Cation-exchange chromatography combined with postcolumn derivatization and fluorimetric detection enabled the accurate (recovery: 83.5-114.8%) and precise (2.4-5.6% RSD) determination of free histidine without matrix interferences at concentration levels down to 1.5 mg kg-1. Real commercially available samples were found to contain the amino acid at levels ranging between 70 and 535 mg kg-1.


Assuntos
Preparações para Cabelo , Histidina , Humanos , Cromatografia Líquida de Alta Pressão/métodos , Fluorometria , Indicadores e Reagentes
18.
J Chromatogr A ; 1690: 463791, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36682104

RESUMO

In the current article, we propose an alternative approach to reduce the consumption of the reagents in liquid chromatography coupled to on-line post column derivatization. In our proposal post column reagents do not flow continuously but they are instead introduced as well-defined pulses (at microliter levels) that are merged on-line with the eluted analytes through precise tuning (Pulsed-Post Column Derivatization, Pulsed-PCD). The profiles of the pulses in terms of time and flow rate were investigated "visually" using caffeine as model compound (at 274 nm). The robustness of the procedure was evaluated by Monte Carlo simulations and was verified taking into account the precisions of typically used propulsion systems. As a proof of concept, we selected the determination of histidine in human urine after separation by cation exchange chromatography and Pulsed-PCD derivatization with o-phthalaldehyde. The consumption of the derivatizing reagent was downscaled to the microliter level per run, while the analytical results were within the expected ranges (110 - 1520 µmol L-1) and with good agreement with the corroborative method based on classic HPLC-PCD.


Assuntos
o-Ftalaldeído , Humanos , Indicadores e Reagentes , Cromatografia Líquida de Alta Pressão/métodos
19.
J Pharm Biomed Anal ; 224: 115186, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36455394

RESUMO

Herein, the development of a HILIC method for the determination of imidazole (Imp E) in sildenafil citrate API and its final formulations is reported. The main goal of this study was to develop a robust, application-specific HPLC method according to the Analytical Quality by Design principles for the analysis of the above impurity. After the risk assessment study, the high-risk method parameters were sequentially screened and optimized by using 2-level fractional factorial and Box-Behnken designs. The mathematical models were combined with the Monte-Carlo simulations to identify the Method Operable Design Region. The method was thoroughly validated between 25 % and 150 % of the target concentration limit of the imidazole using the total-error concept. The relative bias varied between 1.6 % and 5.6 % and the RSD values were lower than 5.8 % for repeatability and intermediate precision. The limit of detection and the lower limit of quantification were satisfactory and found to be 0.025 and 0.125 µg mL-1 imidazole, respectively. The applicability of the proposed approach has been demonstrated in the analysis of several sildenafil citrate API batches and final products.


Assuntos
Imidazóis , Citrato de Sildenafila , Cromatografia Líquida de Alta Pressão/métodos , Reprodutibilidade dos Testes , Limite de Detecção
20.
J Sep Sci ; 45(21): 3955-3965, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36054076

RESUMO

A fast and green ultra-high-performance liquid chromatographic method was developed for the determination of ibuprofen in milk-containing simulated gastrointestinal media to monitor the dissolution of three-dimensional printed formulations. To remove interfering compounds, protein precipitation using methanol as a precipitation reagent was performed. The separation of the target analyte was performed on a C18 column using a mobile phase consisting of 0.05% v/v aqueous phosphoric acid solution: methanol, 25:75% v/v. Method validation was conducted using the total error concept. The ß-expectation tolerance intervals did not exceed the acceptance criteria of ±15%, meaning that 95% of future results will be included in the defined bias limits. The relative bias ranged between ─1.1 and +3.2% for all analytes, while the relative standard deviation values for repeatability and intermediate precision were less than 2.8% and 3.9%, respectively. The achieved limit of detection was 0.01 µg/ml and the lower limit of quantitation was established as 2 µg/ml. The proposed method was simple, and it required reduced organic solvent consumption following the requirements of Green Analytical Chemistry. The method was successfully employed for the determination of ibuprofen in real biorelevant media obtained from dissolution studies.


Assuntos
Ibuprofeno , Leite , Animais , Leite/química , Ibuprofeno/análise , Solubilidade , Metanol , Limite de Detecção , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos
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