Sensitive detection of antidiabetic compounds and one degradation product in wastewater samples by a new SPE-LC-MS/MS method.

As environment emerging contaminants of anthropogenic origin, antidiabetic drugs are present in the range of high ng/L to ng/mL in the influent and the effluent of the waste water treatment plant (WWTP). The metformin compound is the most used hypoglycemic agent in the world. The aim of this study was to develop a new analytic method, based on solid phase extraction followed by liquid chromatography coupled with mass spectrometric detector (SPE-LC-MS/MS), for identification and quantification of 5 antidiabetic compounds (glibenclamide/glyburide, glimepiride, metformin, glipizide, guanyl urea, gliclazide) and one degradation product (guanyl urea). The investigated environmental samples were the influent and the effluent of four urbans WWTP's. By validating of the analytical method, it was obtained low LOQ's (0.2-4.5 ng/L), satisfactory recovery rates (53.6-116.8%), and corresponding performance parameters: inter-day precision (4.9-8.4%) and reproducibility (11.3-14.6%). The concentrations of antidiabetics were as follow in influent and effluent: metformin 76-2041ng/L and 2-206ng/L, gliclazide (14.1-42.4 ng/L, and 3.3-19.1), glipizide (7.5-11.2 ng/L and 6.5-10ng/L), guanyl urea (6.2-7.3 and 8.3-21.3 ng/L). The efficiency of elimination of the antidiabetics in WWTP's was maximum for metformin (67.6-98.5%), followed, by gliclazide (72.9-78.2%). The lowest elimination efficiency was calculated for glipizide (10.7-13.3%). The guanyl urea undergoes a formation process (74.5-84.2%) in effluent, from the metformin contained in influent.

Transplacental transfer of glyburide in women with gestational diabetes and neonatal hypoglycemia risk.

BACKGROUND: In pregnant women with gestational diabetes, glyburide can be an alternative to insulin despite concerns about its transplacental transfer. However, transplacental transfer of glyburide is poorly quantified and the relationship between cord blood glyburide concentration and hypoglycemia has not been studied. Our objective was to quantify the transplacental transfer of glyburide at delivery and to study the association between the cord blood glyburide concentration and the risk of neonatal hypoglycemia in patients with gestational diabetes treated with glyburide. METHODS AND FINDINGS: INDAO was a multicenter, noninferiority, randomized trial conducted between May 2012 and November 2016 in 914 women with singleton pregnancies and gestational diabetes. An ancillary study was conducted in the 87 patients of the Bicêtre University Hospital Center. The sample consisted of 46 patients with utilizable assays at delivery. The relationships between glyburide concentration and the time since the last intake of glyburide and between fetal glyburide concentration and neonatal hypoglycemia were modeled with linear or logistic regressions using fractional polynomials. There was placental transfer of glyburide at a fetal to maternal ratio of 62% (95% CI [50; 74]). Umbilical cord blood glyburide concentration decreased steeply after the last maternal glyburide intake. After 24 hours, the mean umbilical cord blood concentration was less than 5 ng/mL. Neonatal hypoglycemia risk was increased with an odds ratio of hypoglycemia equal to 3.70 [1.40-9.77] for each 10 ng/mL increase in the cord blood glyburide concentration. However, no newborns were admitted to the NICU because of clinical signs of hypoglycemia or for treatment of hypoglycemia. CONCLUSION: Considering that neonatal glyburide exposure may be limited by stopping treatment a sufficient time before labor, there may still be a place for glyburide in the management of gestational diabetes.

A Sensitive HPTLC Method for the Estimation of Glibenclamide, Rosiglitazone Maleate and Metformin Hydrochloride from a Multicomponent Dosage Form.

A sensitive, rapid and cost-effective method based on HPTLC with UV detection was developed for the quantitation of Glibenclamide (GLIBEN), Rosiglitazone maleate (ROSI) and Metformin hydrochloride (MET) from a combined dosage form. Pre-coated RP-18 F254s aluminum sheets were used as the stationary phase. Methanol-tetrahydrofuran-water-glacial acetic acid (16: 3.6: 4: 0.4, v/v) used as the mobile phase, along with chamber saturation of 10 min offered an optimum migration (Rf = 0.54, 0.62 and 0.80 for GLIBEN, ROSI and MET, respectively). TLC Scanner 3 was used for densitometric evaluation of the chromatograms. DigiStore 2 Documentation System with winCATS software version 1.4.10 was used for the quantitation and photodocumentation. The LOD for GLIBEN, ROSI and MET was found to be 80 ng, 80 ng and 48 ng, respectively. Moreover, the LOQ was 200 ng, 200 ng and 120 ng for GLIBEN, ROSI and MET, respectively. The method was linear for GLIBEN (r = 0.9991), ROSI (r = 0.9993) and MET (r = 0.9988) within the tested range (200-1000, 200-1000 and 120-600 ng/band, respectively). The method was found to be precise and accurate for all the three drugs. The method was applied for the analysis of Triglucored tablets, and it proved to be a reliable quality control tool for the routine analysis of GLIBEN, ROSI and MET in a combined dosage form.

Effect of berberine on in vitro metabolism of sulfonylureas: A herb-drug interactions study.

Patients with type 2 diabetes may co-ingest herbal and prescription medicines to control their blood sugar levels. Competitive binding of drug and herb may mutually affect their metabolism. This can alter the level of drug and its kinetics in the body, potentially causing toxicities or loss of efficacy. Understanding how the metabolism of sulfonylureas like glyburide and gliclazide can be affected by the presence of berberine and vice versa can provide valuable information on the possible risk of toxicities caused by co-ingestion of drugs. METHODS: Berberine and sulfonylureas (glyburide and gliclazide) were co-incubated with rat liver microsomes in the presence of a NADPH-regenerating system. The metabolites of berberine and sulfonylureas were analysed using liquid chromatography with high-resolution mass spectrometry in the positive ion mode. The role of individual isozymes in the metabolism of berberine, glyburide and gliclazide was investigated by using specific inhibitors. RESULTS: In vitro metabolism of berberine led to the formation of demethyleneberberine (B1a) and its isomer B1b through demethylenation. Berberrubine (B2a) and its isomer B2b were formed through demethylation. The isozymes CYP3A and CYP2D were found to be involved in the metabolism of berberine. In vitro metabolism of glyburide and gliclazide led to the formation of hydroxylated metabolites. The isozymes CYP3A and CYP2C were found to be involved in the metabolism of glyburide. Gliclazide was metabolised by CYP2C. In vitro co-incubation of glyburide or gliclazide with berberine showed that each drug's metabolism was compromised as they share a common isozyme. A strong negative linear correlation of glyburide or gliclazide metabolite levels and the concentration of berberine confirmed the effect of berberine on the metabolism of sulfonylureas. CONCLUSIONS: The metabolism of sulfonylureas and berberine was affected when these compounds were co-incubated with each other. This may be attributable to competitive binding of the herb and drug to the catalytic sites of the same isozymes.

Ultrasensitive detection of glibenclamide based on its enhancing effect on the fluorescence emission of CdTe quantum dots.

Glibenclamide (GB), as a sulfonylurea-based medication is commonly prescribed for the treatment of type 2 diabetes. Due to its increasing consumption, there is a need to develop a simple, fast, and reliable detection method to follow its concentration in pharmaceutical and biological samples. Herein, a novel fluorometric method is developed for the sensitive measurement of GB. The method is based on the enhancing effect of GB on the fluorescence emission of mercaptopropionic acid (MPA) capped cadmium telluride quantum dots (CdTe QDs). QDs were synthesized in aqueous solution and were characterized by fluorescence spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Fluorescence intensity of QDs was enhanced by adding GB in a very low concentration. The effect of operative factors such as pH, buffer, contact time and concentration of CdTe QDs were investigated and in the optimized condition, a linear increase was achieved for the emission intensity of QDs by increasing GB concentration in the range 49-345 ng mL-1 , with a detection limit of 17.84 ng mL-1 . The offered method has an acceptable precision (relative standard deviations were < 2.8%) and was satisfactorily applied for the determination of GB in pharmaceutical products and human urine samples.

Hollow porous molecularly imprinted polymer for highly selective clean-up followed by influential preconcentration of ultra-trace glibenclamide from bio-fluid.

In the present work, hollow porous molecularly imprinted polymer (HPMIP) was prepared via adopting a sacrificial support approach using glibenclamide (GB) as template, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate as cross-linker (EGDMA) and mesoporous MCM-48 nanospheres as support. Owing to a short thickness of the foresaid HPMIP, a suitable steric structure was readily available that lead to fast and effective mass transfer of target analyte to sorbent and consequently supply high binding capacity. After ultrasonic-assisted dispersive solid phase extraction of urine sample, the analyte of interest was quantitatively pre-concentrated and determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). Influence of factors affecting the extraction efficiency such as sonication time, sample pH, sorbent dosage, and volumes of eluent and washing agents as well as their significant interactions were simultaneously optimized by experimental design methodology. Under optimized conditions, present method has linear response over concentration range of 10.0-3000.0µgL-1 in human urine samples with a satisfactory detection limit close to 3.5µgL-1. The inter-day precisions of the current method (coefficient of variation) are lower than 5%, while recoveries are more than 89.5%.

Rapid Simultaneous Separation of Four Oral Antidiabetic Drugs and Quantitative Determination of Glibenclamide Using Conventional and Fused-Core Silica Columns.

Diabetes mellitus is a chronic disease with high and growing prevalence worldwide. Therefore, the development of fast and efficient methods for the QC of antidiabetic drugs is of fundamental importance. Two ultra-fast methods, using a conventional (C18 100 × 2.1 mm, 5 µm fully porous particle) column or a fused-core (C18 100 × 2.1 mm, 2.7 µm fused-core particle) column, were developed for the simultaneous determination of four antidiabetic drugs (chlorpropamide, glibenclamide, gliclazide, and glimepiride). The developed methods were compared in terms of efficiency, speed of analysis, resolution, and peak symmetry. Both methods were validated with respect to selectivity, system suitability, linearity, precision, accuracy, LOD, LOQ, and robustness, using glibenclamide as model. Conventional and fused-core methods were shown to be appropriate for the determination of glibenclamide in tablets; however, the fused-core column presented higher efficiency, detectability, and resolution. Also, it enabled faster analysis, with separation of the four drugs in less than 1 min.

Fast and Simultaneous Analysis of Combined Anti-Diabetic Drugs by Capillary Zone Electrophoresis.

A fast capillary zone electrophoretic method with photodiode array detection (CZE-PAD) was established and validated for assays of commonly prescribed anti-diabetic drugs [metformin (MET), glibenclamide (GBM) and gliclazide (GCZ)] in 13 samples including raw material, single and combined tablets. CZE optimization revealed baseline separation of the analytes (Rs > 5.39) in 8 min, in 50 mM borate buffer (pH 9.0), using a capillary with an effective length of 56.0 cm and an inner diameter of 50 µm, a voltage of 20 kV, a temperature of 25°C and a detection wavelength at 210 nm. The method provides excellent linearity, precision (%RSDs < 1.90%), recovery (99.8-101.0%) and low detection and quantitation limits (<4 and 12 µg/mL, respectively). The procedure was fast (seven samples per hour) and cost effective, since no organic solvent, sample pre-treatments or clean-up procedures were required. Importantly, the method was accurate, sensitive and reliable for routine quality control of MET, GBM and GCZ in pharmaceutical products both in single and combined formulations.

Diabetes mellitus tipo 2 en el paciente anciano institucionalizado / Type 2 diabetes mellitus in elderly institutionalized patients

Una mujer de 93 años de edad ingresa en una planta de hospitalización convencional por una infección respiratoria aguda. La paciente tiene diabetes mellitus tipo 2 de unos 15 años de evolución y no presenta otras comorbilidades asociadas, salvo progresiva dependencia por senescencia y un ingreso hospitalario previo por neumonía hace 6 meses; actualmente vive en una residencia asistida. En un análisis reciente tenía una HbA1c de 7,8%, con una creatinina sérica de 1,3mg/dl (MDRD: 45ml/min). Su tratamiento habitual consistía en glibenclamida 5mg al día y metformina 850mg cada 12h. ¿Qué pauta debemos seguir una vez hospitalizada? ¿Precisa de alguna modificación de su tratamiento al alta? (AU)

A 93-year-old woman is admitted to a conventional hospital ward for an acute respiratory infection. The patient has type 2 diabetes mellitus of approximately 15 years evolution and has no other associated comorbidities, except for progressive dependence due to senescence and a previous hospitalization for pneumonia 6 months ago. She is currently in an assisted-living residence. A recent laboratory test revealed an HbA1c level of 7.8%, with a serum creatinine level of 1.3mg/dl (MDRD, 45ml/min). Her standard treatment consists of 5mg of glibenclamide a day and 850mg of metformin every 12hours. What regimen should we follow once she is hospitalized? Does she require any change in her treatment at discharge? (AU)

Cannabidiol enhances xenobiotic permeability through the human placental barrier by direct inhibition of breast cancer resistance protein: an ex vivo study.

OBJECTIVE: Drugs of abuse affect pregnancy outcomes, however, the mechanisms in which cannabis exerts its effects are not well understood. The aim of this study was to examine the influence of short-term (1-2 hours) exposure to cannabidiol, a major phytocannabinoid, on human placental breast cancer resistance protein function. STUDY DESIGN: The in vitro effect of short-term exposure to cannabidoil on breast cancer resistance protein in BeWo and Jar cells (MCF7/P-gp cells were used for comparison) was tested with mitoxantrone uptake, and nicardipine was used as positive control. The ex vivo perfused cotyledon system was used for testing the effect of cannabidoil on glyburide transport across the placenta. Glyburide (200 ng/mL) was introduced to maternal and fetal compartments through a recirculating 2 hour perfusion, and its transplacental transport was tested with (n = 8) or without (n = 8) cannabidoil. RESULTS: (1) Cannabidoil inhibition of breast cancer resistance protein-dependent mitoxantrone efflux was concentration dependent and of a noncell type specific nature (P < .0001); (2) In the cotyledon perfusion assay, the administration of cannabidoil to the maternal perfusion media increased the female/male ratio of glyburide concentrations (1.3 ± 0.1 vs 0.8 ± 0.1 at 120 minutes of perfusion, P < .001). CONCLUSION: (1) Placental breast cancer resistance protein function is inhibited following even a short-term exposure to cannabidoil; (2) the ex vivo perfusion assay emphasize this effect by increased placental penetration of glyburide to the fetal compartment; and (3) these findings suggest that marijuana consumption enhances placental barrier permeability to xenobiotics and could endanger the developing fetus. Thus, the safety of drugs that are breast cancer resistance protein substrates is questionable during cannabis consumption by pregnant women.

Selective separation and enrichment of glibenclamide in health foods using surface molecularly imprinted polymers prepared via dendritic grafting of magnetic nanoparticles.

In this paper, the novel surface molecularly imprinted polymers based on dendritic-grafting magnetic nanoparticles were developed to enrich and separate glibenclamide in health foods. The density functional theory method was used to give theoretical directions to the synthesis of molecularly imprinted polymers. The polymers were prepared by using magnetic nanoparticles as supporting materials, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. The characteristics of magnetic nanoparticles and polymers were measured by transmission electron microscope and SEM, respectively. The enriching ability of molecularly imprinted polymers was measured by Freundlich Isotherm. The molecularly imprinted polymers were used as dispersive SPE materials to enrich, separate, and detect glibenclamide in health foods by HPLC. The average recoveries of glibenclamide in spiked health foods were 81.46-93.53% with the RSD < 4.07%.

Estudo das propriedades físico-químicas da glibenclamida e excipientes que influem sobre resultados do ensaio de dissolução para medicamento similar e genérico / Effect of the physicochemical properties of glyburide on the results of dissolution test for generic and similar drugs

Alguns insumos farmacêuticos ativos (IFA) possuem como característica, a possibilidade de apresentarem o polimorfismo, que pode se desenvolver em alguma das etapas do processo de produção na indústria. No caso deste não ser caracterizado e especificado, um diferente polimorfo poderá ser utilizado equivocadamente durante o processo de fabricação. A ocorrência de polimorfismo pode originar importantes variações nas propriedades físico-químicas dos IFAs, principalmente quanto à solubilidade. Alguns medicamentos de glibenclamida (GLIB) apresentaram denúncias de ineficácia terapêutica e a presença de polimorfos pode ser uma das possíveis causas. Neste trabalho foram analisados cinco medicamentos e cinco IFAS de diferentes fornecedores. Para os medicamentos foram feitos testes característicos de verificação de equivalência farmacêutica. Nos IFAS, as diversas técnicas empregadas não evidenciaram presença de polimorfos ou alterações importantes nas propriedades físico-químicas e na velocidade de dissolução intrínseca. Entretanto, os perfis de dissolução dos medicamentos, principalmente, entre os dois similares A e B demonstraram diferenças apontadas pelos valores do fator f2, respectivamente, de 20 e 42, os quais indicaram associação destes valores com a presença de distintos excipientes, como por exemplo o manitol e diferentes processos de produção industrial.

Some active pharmaceutical ingredients (API) might present polymorphism at any stage of the industryproduction process. In caseit is not characterized and specified, a different polymorph might beerroneously used during the manufacturing procedure. Polymorphisms cause some variations in thephysicochemical properties of APIs, especially in solubility. Therapeutic inefficacy was detected in someglyburide drug products, and the occurrence of polymorphs might be one of the possible reasons. Thisstudy analyzed five drug products and five APIs., The characteristic pharmaceutical equivalence testswere used for analyzing the drug products. The techniques employed to evaluate the APIs showed nodifferences in polymorphism, no significant changes in the physicochemical properties or in the intrinsicdissolution rate. However, the dissolution profiles of the drug products, mainly between two similarproducts A and B, showed significant differences in the f2 factor values, being 20 and 42, respectively,indicating that these values were related to the occurrence of different excipients, such as mannitol.

Molecular imprinting-based micro-stir bar sorptive extraction for specific analysis of Glibenclamide in herbal dietary supplements.

A novel molecularly imprinted polymers (MIPs) coated micro-stir bar (MSB) for Glibenclamide (GM) was developed. The MIPs, with GM as template molecular and methacrylic acid as functional monomer, were synthesized at the surface of the silylated MSB that was filled with magnetic core as substrate. Computational simulation was used for the optimal selection of functional monomers and porogen. The thickness of MIPs coating for MSB was about 10 µm, the adsorption and desorption time were about 40 and 20 min, respectively. The MIPs coated MSB possessed mechanical stability, high adsorption capacity, and good selectivity for GM. To achieve the optimum extraction performance, several parameters including extraction and desorption time, stirring rate, extraction and desorption solvent were investigated. A method for the determination of GM in herbal dietary supplements by MIPs coated MSB coupled with HPLC-UV was established. The results exhibited good linear ranges of 10-6250 µg L(-1) with the low limit of detection of GM (3.05 µg L(-1)) and the good recoveries (81.9-101.4%).

Fast and environmentally friendly quantitative analysis of active agents in anti-diabetic tablets by an alternative laser-induced breakdown spectroscopy (LIBS) method and comparison to a validated reversed-phase high-performance liquid chromatography (RP-HPLC) method.

Laser-induced breakdown spectroscopy (LIBS) is evaluated as a potential analytic technique for rapid screening and quality control of anti-diabetic tablets. This paper proposes a simple LIBS-based method for the quantitative analysis of two active pharmaceutical ingredients (APIs): metformin (Met) and glybenclamide (Gly). In order to quantify both APIs, chlorine (Cl) concentration was estimated by employing the Cl/Br optical emission ratio, where Br was introduced as internal standard. Calibration curves were prepared, achieving linearity higher than 99%. On the other hand, for comparison to the proposed method, an isocratic reversed-phase high-performance liquid chromatography (RP-HPLC) method was also developed for quantitative determination of the same analytes by ultraviolet (UV) detection. The chromatographic separation was achieved on a Phenomenex Hypersil C18, 250 mm × 4.6 mm, 5 µm column. The mobile phase was K(2)HPO(4)/H(3)PO(4)-CH(3)OH and flow rate was 1.0 mL min(-1). The method is linear over a range of 10-60 µg mL(-1) for Gly and 5-30 µg mL(-1) for Met and the correlation coefficients were ≥0.99. Recoveries were found to be in the range of 95-101%. Furthermore, four different commercial brands of each active agent were evaluated by both proposed LIBS and chromatographic methods and results were compared with each other. The comparison was satisfactorily validated by analysis of variance (ANOVA).

Rapid extraction, identification and quantification of oral hypoglycaemic drugs in serum and hair using LC-MS/MS.

A sensitive and accurate LC-MS/MS method for the identification and quantification of 5 oral anti-diabetics (glipizide, glibenclamide, gliclazide, gliquidone and metformin) in serum and hair was developed using glibornuride as the internal standard. We have developed a rapid and robust extraction procedure by using acetonitrile for serum protein precipitation and methanol for the extraction of anti-diabetics from hair. Anti-diabetics (ADs) were separated by UPLC over a C18 column and detection was performed on a Waters Xevo TQ MS mass spectrometer in positive ionization mode using electrospray ionization. Each AD was identified by three specific ion transitions in multiple reaction monitoring (MRM) mode. The method was validated according to international guidelines. For all compounds the variation coefficient (CV) was <20%, and accuracies ranged from 85 to 115% in serum and hair. The limits of detection (LODs) were <1.5 ng/mL for all ADs in serum and <3.59 pg/mg in hair. Recoveries varied from 56.41% (gliclazide) to 67.58% (glipizide) in serum and from 68% (gliclazide) to 91.2% (metformin) in hair. The method was successfully applied to quantify ADs in serum of 33 patients and in hair of 15 patients.

High-performance liquid chromatography quadrupole time-of-flight mass spectrometry method for the analysis of antidiabetic drugs in aqueous environmental samples.

Antidiabetic compounds are among the most prescribed pharmaceuticals. Nevertheless, their presence in the environment has been scarcely evaluated as there is no method for their determination in environmental samples. This paper reports the development of an analytical method for the determination of traditionally used antidiabetics (metformin and glibenclamide) and novel antidiabetics (vildagliptin, sitagliptin and pioglitazone). The method is based on solid-phase extraction and determination by high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. The method was applied to effluent wastewater, river water and tap water. Mean recoveries of glibenclamide, vildagliptin, sitagliptin and pioglitazone in the matrices evaluated were in the range 78-83%; limits of quantification were in the range 0.4-4.3 ng L(-1); and precision values were in the range 2.2-13%. The high hydrophilicity and polarity of metformin complicated its simultaneous extraction. Chromabond Tetracycline cartridges and sample pH 8.5 were applied to the extraction of glibenclamide, vildagliptin, sitagliptin and pioglitazone. Oasis HLB cartridges, neutral sample pH and SDS as ion-pair reagent were used for the extraction of metformin. Validation results of metformin were not as favorable as those of the other antidiabetic drugs but were comparable with others previously reported. The developed method was applied to the first-time determination of the concentrations of the five antidiabetic drugs in wastewater, river water and tap water. Metformin was the antidiabetic drug at the highest concentration in wastewater and surface water (up to 253 ng L(-1) and 104 ng L(-1), respectively). Two of the antidiabetic drugs of recent prescription, sitagliptin and vildagliptin, were found in effluent wastewater at concentrations of 117 ng L(-1) and 12 ng L(-1), respectively, and in river water at concentrations of 35 ng L(-1) and 6 ng L(-1), respectively, whereas the classic antidiabetic drug glibenclamide and the novel drug pioglitazone were not detected.

Non-destructive detection of adulterated tablets of glibenclamide using NIR and solid-phase fluorescence spectroscopy and chemometric methods.

This study describes a method for non-destructive detection of adulterated glibenclamide tablets. This method uses near infrared spectroscopy (NIRS) and fluorescence spectroscopy along with chemometric tools such as Soft Independent Modeling of Class Analogy (SIMCA), Partial Least Squares-Discriminant Analysis (PLS-DA) and Unfolded Partial Least Squares with Discriminant Analysis (UPLS-DA). Both brand name (Daonil) and generic glibenclamide tablets were used for analysis. The levels of glibenclamide in each type of tablet were evaluated by derivative spectrophotometry in the ultraviolet region. The results obtained from the NIR and fluorescence spectroscopy along with those obtained from multivariate data classification show that this combined technique is an effective way to detect adulteration in drugs for the treatment of diabetes. In the future, this method may be extended to detect different types of counterfeit medications.

Exploiting adsorption and desorption at solid-liquid interface for the fluorometric monitoring of glibenclamide in adulterated drinks.

Nowadays, the use of a drug to modify a person's behavior with criminal intentions has become a growing public concern. In fact, stealthy drink spiking with certain drugs can cause the incapacitation of a potential victim of assault and in extreme cases can even lead to death. Belonging to the group of drugs used to commit drug-facilitated crimes is glibenclamide, which not only exhibits high sedation secondary effects but when subject to an overdose intake can lead to intense hypoglycemic episodes that could end with death. Suicide attempts and homicides through overdose with glibenclamide have already been reported. In this work and for the first time, it was developed a new methodology for detection of glibenclamide in spiked liquid samples (teas) by fluorometry (λ(ex)=300 nm; λ(em)=404 nm). The novel methodology was also implemented in a miniaturized and portable automatic flow system based in the concept of multipumping with an in-line pre-separation unit. The separation of the drug from the liquid samples was achieved through adsorption of the drug into activated charcoal packed within a mini column followed by elution with a solution composed by ethanol, hydrochloric acid and the surfactant CTAB (70%, 1.0 mol L(-1), 0.01 mol L(-1), respectively). The results allowed to obtain a linear working range for glibenclamide concentrations of up to 50 mg L(-1) (r=0.9999) and the detection limit was about 0.81 mg L(-1) of glibenclamide.

Simultaneous spectrophotometric determination of metformin hydrochloride and glibenclamide in binary mixtures using combined discrete and continuous wavelet transforms.

In this work, a combined discrete and continuous wavelet transform analysis was developed for simultaneous spectrophotometric determinations of metformin hydrochloride and glibenclamide, two antidiabetic drugs, in binary mixtures without any chemical pretreatment. Absorption spectra were subjected to the 4-level db4 discrete wavelet transform (DWT) for signal de-noising. Selected continuous wavelet transform (CWT) families (rbio3.1 with scaling factor, a = 80, and gaus2, a = 60) were applied on these de-noised signals. Finally, a zero-crossing technique was used for the construction of calibration curves for both drugs. The proposed method was validated by analyzing synthetic mixtures of the investigated drugs with various concentrations. The amount of metformin hydrochloride and glibenclamide were determined by using CWT amplitudes in zero-crossing points. The mean recovery values of metformin hydrochloride and glibenclamide were found between 98.6-102.0 and 97.9-102.4% for rbio3 and 98.3-101.2 and 97.1-101.4% for gaus2 families, respectively. The obtained results showed that the developed method is a simple, rapid and precise procedure for the simultaneous determination of metformin hydrochloride and glibenclamide in binary mixtures.