Dispersive liquid-liquid microextraction based on solidification of floating organic drop and high-performance liquid chromatography to the analysis of cocaine’s major adulterants in human urine

Sena, Laís Cristina Santana; Matos, Humberto Reis; Dórea, Haroldo Silveira; Pimentel, Maria Fernanda; Santana, Danielle Cristine Almeida Silva de; Santana, Fernando José Malagueño de

doi:10.1016/j.tox.2016.04.008

Cited by 27 publications

(7 citation statements)

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“…Cocaine is a highly addictive psychostimulant and is rarely obtained on the illegal market in its pure form (Cole et al, 2011 ). Forensic analyses of seized illicit cocaine samples usually report variable quantities of caffeine (López-Hill et al, 2011 ; Sena et al, 2017 ). Caffeine deserves a special consideration on its own.…”

Section: Introductionmentioning

confidence: 99%

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Cocaine and Caffeine Effects on the Conditioned Place Preference Test: Concomitant Changes on Early Genes within the Mouse Prefrontal Cortex and Nucleus Accumbens

Muñiz

Prieto

González

et al. 2017

Front. Behav. Neurosci.

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Caffeine is the world's most popular psychostimulant and is frequently used as an active adulterant in many illicit drugs including cocaine. Previous studies have shown that caffeine can potentiate the stimulant effects of cocaine and cocaine-induced drug seeking behavior. However, little is known about the effects of this drug combination on reward-related learning, a key process in the maintenance of addiction and vulnerability to relapse. The goal of the present study was thus to determine caffeine and cocaine combined effects on the Conditioned Place Preference (CPP) test and to determine potential differential mRNA expression in the Nucleus Accumbens (NAc) and medial prefrontal cortex (mPFC) of immediate-early genes (IEGs) as well as dopamine and adenosine receptor subunits. Mice were treated with caffeine (5 mg/kg, CAF), cocaine (10 mg/kg, COC), or their combination (caffeine 5 mg/kg + cocaine 10 mg/kg, CAF-COC) and trained in the CPP test or treated with repeated injections inside the home cage. NAc and mPFC tissues were dissected immediately after the CPP test, after a single conditioning session or following psychostimulant injection in the home cage for mRNA expression analysis. CAF-COC induced a marked change of preference to the drug conditioned side of the CPP and a significant increase in locomotion compared to COC. Gene expression analysis after CPP test revealed specific up-regulation in the CAF-COC group of Drd1a, cFos, and FosB in the NAc, and cFos, Egr1, and Npas4 in the mPFC. Importantly, none of these changes were observed when animals received same treatments in their home cage. With a single conditioning session, we found similar effects in both CAF and CAF-COC groups: increased Drd1a and decreased cFos in the NAc, and increased expression of Drd1a and Drd2, in the mPFC. Interestingly, we found that cFos and Npas4 gene expression were increased only in the mPFC of the CAF-COC. Our study provides evidence that caffeine acting as an adulterant could potentiate reward-associated memories elicited by cocaine. This is associated with specific changes in IEGs expression that were observed almost exclusively in mice that received the combination of both psychostimulants in the context of CPP memory encoding and retrieval. Our results highlight the potential relevance of caffeine in the maintenance of cocaine addiction which might be mediated by modifying neural plasticity mechanisms that strengthen learning of the association between drug and environment.

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Section: Introductionmentioning

confidence: 99%

“…Caffeine deserves a special consideration on its own. Energy drinks marketed as dietary supplements or beverages usually contain caffeine as their active ingredient (Sena et al, 2017 ). Such supplements are taken to enhance cognitive performance but might also influence mood and sleep (Childs, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Cocaine and Caffeine Effects on the Conditioned Place Preference Test: Concomitant Changes on Early Genes within the Mouse Prefrontal Cortex and Nucleus Accumbens

Muñiz

Prieto

González

et al. 2017

Front. Behav. Neurosci.

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“…Given the elevated octanol–water partition coefficients (LogP) of the active substance and two preservative benzoate derivatives (1.96 and 3.04, respectively, for MB and PB), a reverse phase C18 column (5 µm, 250 mm × 4 mm) was chosen for the tests 16 17. Separation was initially tested with variable proportions of a mobile phase comprising acetonitrile and a (0.1 M) phosphate buffer at a fixed wavelength of 210 nm.…”

Section: Resultsmentioning

confidence: 99%

Management of diabetic foot ulcers: a 25% lidocaine topical cream formulation design, physicochemical and microbiological assessments

et al. 2018

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BackgroundGiven the importance of surgical debridement in healing of diabetic foot ulcers, effective local anaesthesia is required to manage the related extreme pain. The pharmaceutical proprietary products currently available have low concentrations and do not exceed 5% w/w local anaesthetic.ObjectiveFormulation design of a lidocaine cream of 25% and assessment of the intrinsic stability.MethodsA cream pharmaceutical form was chosen for its ability to cross the skin barrier and effectively anaesthetise the skin. The choice of cream formula is based on changes in the size of the emulsions and resistance to physical stress. Stability tests were assessed over a 6-month period in terms of physical (evaluation of oil droplets), microbiological (germ count and identification, and preservative antimicrobial efficacy) and chemical parameters (content and pH).ResultsUnder the study conditions, the drug product displayed good physicochemical and microbiological stability for 6 months at 20°C and 40°C, and no degradation product was detected. Due to the systemic adverse effects of lidocaine, the pH stability guarantee the drug product tolerance along with very weak systemic passage.ConclusionsGiven the good physicochemical and microbiological stability of the drug product over 6-month period, it has been made available to the clinical unit. An average of 250 patients per year benefit from the treatment with an excellent efficacy/tolerability ratio.

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“…The p K a of the PBs in this study are between 8.27 and 8.47, which means an alkali condition makes the PBs nonionized and increases the mass transfer from the aqueous phase to the extraction phase. However, excessive change of pH in sample solution may lead to degradation of target analytes and precipitation of possible interfering substances such as uric acid, urea, and calcium oxalate . Consequently, pH 9–11 was selected as the optimal regions for the DLLME‐SFODs procedure.…”

Section: Resultsmentioning

confidence: 99%

Application of dispersive liquid-liquid microextraction for the preconcentration of eight parabens in real samples and their determination by high-performance liquid chromatography

et al. 2017

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A simple and sensitive method for the simultaneous determination of eight parabens in human plasma and urine samples was developed. The samples were preconcentrated using dispersive liquid-liquid microextraction based on the solidification of floating organic drops and determined by high-performance liquid chromatography with ultraviolet detection. The influence of variables affecting the extraction efficiency was investigated and optimized using Placket-Burman design and Box-Behnken design. The optimized values were: 58 μL of 1-decanol (as extraction solvent), 0.65 mL methanol (as disperser solvent), 1.5% w/v NaCl in 5.0 mL of sample solution, pH 10.6, and 4.0 min centrifugation at 4000 rpm. The extract was injected into the high-performance liquid chromatography system for analysis. Under the optimum conditions, the linear ranges for eight parabens in plasma and urine were 1.0-1000 ng/mL, with correlation coefficients above 0.994. The limit of detection was 0.2-0.4 and 0.1-0.4 ng/mL for plasma and urine samples, respectively. Relative recoveries were between 80.3 and 110.7%, while relative standard deviations were less than 5.4%. Finally, the method was applied to analyze the parabens in 98 patients of primary breast cancer. Results showed that parabens existed widely, at least one paraben detected in 96.9% (95/98) of plasma samples and 98.0% (96/98) of urine samples.

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Dispersive liquid-liquid microextraction based on solidification of floating organic drop and high-performance liquid chromatography to the analysis of cocaine’s major adulterants in human urine

Cited by 27 publications

References 41 publications

Cocaine and Caffeine Effects on the Conditioned Place Preference Test: Concomitant Changes on Early Genes within the Mouse Prefrontal Cortex and Nucleus Accumbens

Cocaine and Caffeine Effects on the Conditioned Place Preference Test: Concomitant Changes on Early Genes within the Mouse Prefrontal Cortex and Nucleus Accumbens

Management of diabetic foot ulcers: a 25% lidocaine topical cream formulation design, physicochemical and microbiological assessments

Application of dispersive liquid-liquid microextraction for the preconcentration of eight parabens in real samples and their determination by high-performance liquid chromatography

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