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Environmental Toxicology and Chemistry Feb 2022In spite of recent reports about the presence of pharmaceuticals in African water bodies, their prevalence has still not been sufficiently quantified. The few available...
Target and Suspect Screening of Pharmaceuticals and their Transformation Products in the Klip River, South Africa, using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry.
In spite of recent reports about the presence of pharmaceuticals in African water bodies, their prevalence has still not been sufficiently quantified. The few available studies have mostly focused on a limited number of pharmaceuticals. In the present study, a suspect screening of 92 compounds (mainly pharmaceuticals and their transformation products) along the Klip River, South Africa was conducted, followed by target monitoring of 21 of the detected pharmaceuticals. The experimental approach was based on solid-phase extraction followed by analysis with ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS). The results revealed 47 pharmaceuticals, 31 of which were detected for the first time in South African waters. Seven detected pharmaceuticals (propyphenazole, sulfamerazine, levamisole, tryptophan, dibucaine, albuterol, and fenpropimorph) are not approved medications in South Africa. Six pharmaceutical metabolites were detected for the first time in South Africa. Pharmaceuticals with the highest concentrations in river water were flumequine (0.257 µg L ), oxolinic acid (0.355 µg L ), and acetaminophen (0.432 µg L ). Oxolinic acid presented the highest hazard quotient, 48.6, indicating a risk of toxicity to aquatic organisms. Hazard quotients for other pharmaceuticals were below 1, except that of flumequine, which reached 1.285. These results suggest a need for further research into the fate of pharmaceuticals in surface waters, and a quantification of the risks associated with the identified drugs because they are likely to accumulate in the tissues of fish/aquatic organisms, thus affecting humans. Environ Toxicol Chem 2022;41:437-447. © 2021 SETAC.
Topics: Animals; Aquatic Organisms; Chromatography, High Pressure Liquid; Environmental Monitoring; Mass Spectrometry; Oxolinic Acid; Pharmaceutical Preparations; Rivers; South Africa; Water; Water Pollutants, Chemical
PubMed: 34888926
DOI: 10.1002/etc.5265 -
Journal of Chromatographic Science May 2017Cinchocaine hydrochloride (CIN) and betamethasone valerate (BMV) are co-formulated in pharmaceutical formulations that could be used for local treatment of hemorrhoids....
Cinchocaine hydrochloride (CIN) and betamethasone valerate (BMV) are co-formulated in pharmaceutical formulations that could be used for local treatment of hemorrhoids. Both drugs are susceptible to hydrolytic degradation. Two sensitive and precise stability-indicating chromatographic methods were developed for the simultaneous determination of both active pharmaceutical ingredients. The developed methods were applied for quantitation of CIN and BMV in their pure forms, in presence of their corresponding degradation products and in their pharmaceutical formulation. The first method was a high performance liquid chromatographic (HPLC) one, separation and quantitation was achieved using a Waters Spheriosorb® 5 μm ODS2 C18 analytical column and an isocratic mobile phase formed of acetonitrile-acetate buffer (pH 6.5 ± 0.1) in a ratio of (55:45, v/v). The mobile phase was pumped at a flow rate of 1.2 mL/min. UV-detection was done at 240 nm using photodiode array detector. The second method was based on thin layer chromatography (TLC) fractionation coupled with densitometric determination. Separation was done on high performance thin layer chromatography (HPTLC) silica gel 60F254 plates using a developing system formed of chloroform-toluene-ethanol-acetic acid in a ratio of (4.5:4.5:1:1, by volume). The separated bands were scanned densitometrically at 240 nm. For the HPLC method, linearity was confirmed over concentration ranges of 4-300 and 4-350 μg/mL for CIN and BMV, respectively. For the HPTLC-densitometric method, the obtained ranges were 0.5-12 and 0.5-10 μg/band for CIN and BMV, respectively. The developed methods were optimized and validated according to the ICH guidelines. CIN acid degradation products were separated and identified by mass spectroscopy. The developed HPLC method was used to study the kinetics of acid and alkali degradation of the both drugs. The results obtained were statistically analyzed and compared with those obtained by applying the official methods for both drugs.
Topics: Betamethasone Valerate; Calibration; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Densitometry; Dibucaine; Drug Stability; Hydrolysis; Kinetics; Linear Models; Reproducibility of Results; Sensitivity and Specificity
PubMed: 28168304
DOI: 10.1093/chromsci/bmx004 -
Forensic Science International Aug 2016A high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI) procedure for the simultaneous determination of nine...
A high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI) procedure for the simultaneous determination of nine local anesthetic drugs (procaine, mepivacaine, lidocaine, ropivacaine, oxybuprocaine, tetracaine, bupivacaine, T-caine and dibucaine) in human serum is described. The chromatographic separation was performed on a Mightysil-RP-18 GP II column (2.0mm×150mm, particle size 5μm). The mobile phase consisted of 10mM acetic ammonium buffer (pH 5.4) and acetonitrile and was delivered at a flow rate of 0.20mL/min. The triple quadrupole mass spectrometer was operated in positive ion mode, and multiple reaction monitoring was used for drug quantification. Solid-phase extraction of the nine local anesthetic drugs added to the human serum was performed with an Oasis(®) HLB extraction cartridges column. The method was linear for the investigated drugs over the concentration range of 10-100ng/mL. The recoveries of these drugs were in the range of 81.4-144%. The standard deviation (SD) values for all analytes were <0.10 for both intraday and interday accuracy and precision. The selectivity, accuracy and precision of this method are satisfactory for clinical and forensic applications. The sensitive and selective method offers the opportunity for the simultaneous screening and quantification, for clinical and forensic purposes, of almost all local anesthetics available in Japan.
Topics: Anesthetics, Local; Chromatography, Liquid; Forensic Toxicology; Humans; Predictive Value of Tests; Substance Abuse Detection; Substance-Related Disorders; Tandem Mass Spectrometry
PubMed: 26986505
DOI: 10.1016/j.forsciint.2016.02.044 -
European Journal of Hospital Pharmacy :... Jul 2016This work aimed to evaluate the quality of non-sterile formulations compounded at Centro Hospitalar Cova da Beira (Covilhã, Portugal) immediately after preparation and...
OBJECTIVES
This work aimed to evaluate the quality of non-sterile formulations compounded at Centro Hospitalar Cova da Beira (Covilhã, Portugal) immediately after preparation and up to the defined 'beyond-use date'.
METHODS
Microbiological quality control tests were performed in accordance with monograph 5.1.4 of the European Pharmacopoeia 8.0. Samples of compounded products were collected from January to December 2014 after preparation and were analysed immediately and reanalysed after storage under the established conditions, for each preparation.
RESULTS
In the test period, 392 preparations were analysed, corresponding to 24 different formulations (8 intermediate preparations, 11 oral solutions/suspensions and 5 topical preparations). All preparations were in accordance with the pharmacopoeia specifications immediately after preparation. However, for the formulations 'prednisolone oral solution (5 mg/mL)' and 'nitroglycerine and cinchocaine ointment (0.25%/0.5%)', the microbial counts of some batches exceeded the defined limits after storage up to the beyond-use date.
CONCLUSIONS
These results show that the compounding practices implemented at this pharmacy department are able to ensure the microbiological quality of compounded products. This microbiological quality control methodology also allowed identification of the need to replace formulations shown not to be stable throughout the storage period. On the basis of these results, a monthly routine of microbiological control of a random sample of compounded medicines was established in order to ensure their quality and safety for use.
PubMed: 31156854
DOI: 10.1136/ejhpharm-2015-000769 -
Journal of Integrative Neuroscience 2018To investigate the relationship between acetyl cholinesterase associated collagen gene (COLQ) mutation in patients with acetyl cholinesterase deficiency and its clinical...
To investigate the relationship between acetyl cholinesterase associated collagen gene (COLQ) mutation in patients with acetyl cholinesterase deficiency and its clinical characteristics. Serum and red blood cell acetyl cholinesterase from patients with acetyl cholinesterase deficiency (n=6) and normal controls (n=20) were measured by butyryl thiocholine substrate. COLQ gene variations were detected by sequencing. And the cholinesterase (ChE) genotypes were measured by dibucaine inhibition in vitro. The distributions of ChE surrounded the blood vessels and nerve fibers in lung or pancreas tissues were detected by immunohistochemical staining and indirect immunofluorescence. Serum lactic acid, ammonia and other clinical data were analyzed. Serum ChE in patients with acetyl cholinesterase deficiency were only 1/50 to 1/1000 fold of normal controls. Comparing to controls, dibucaine inhibition values of patients were significantly lower, while there were no differences in red blood cells acetyl cholinesterase. Serum lactic acid and ammonia in patients were significantly higher than controls. Inser 1281-1282 GC of COLQ gene was found in 2 patients, while IVS 6 + 21 T > A, IVS 6 + 30 G > T, IVS 6 + 34 T > C and IVS66 + 12 inser T mutations were found in the other 4 patients, respectively. In addition, the patients with COLQ gene mutation were resistant to regular doses of anesthetics. COLQ gene mutation may be an important reason for the lack of serum ChE in patients with acetyl cholinesterase deficiency.
Topics: Acetylcholinesterase; Collagen; Humans; Lung; Metabolism, Inborn Errors; Muscle Proteins; Mutation; Pancreas
PubMed: 29630557
DOI: 10.3233/JIN-180080 -
Biochimica Et Biophysica Acta Mar 2015Interactions of two local anesthetics, dibucaine and tetracaine have been studied with phospholipid vesicles containing cholesterol and/or monosialogangliosides (GM1)...
Interactions of two local anesthetics, dibucaine and tetracaine have been studied with phospholipid vesicles containing cholesterol and/or monosialogangliosides (GM1) using fluorescence spectroscopy. The fluorescence intensity of tetracaine showed a marked increase with the increasing molar ratio of the phospholipid to tetracaine, while that of dibucaine showed opposite effects. Steady state anisotropy and the wavelength of maximum emission (λmax) decreased with the increasing phospholipids to tetracaine ratio. The extent of such changes in anisotropy and λmax in the presence and absence of two important components of neuronal membranes, cholesterol and GM1 indicated differential membrane localization of the two local anesthetics. To understand the intercellular mode of action of local anesthetics, we have also studied the interactions of dibucaine and tetracaine with brain spectrin which indicate differential spectrin interactions with similar binding strength. Thermodynamic parameters associated with such binding reveal that binding is favored by entropy. Tetracaine brings about distinct structural changes in spectrin compared to dibucaine, as reflected in the tryptophan mean lifetime and far-UV CD spectra. Tetracaine also exhibits a detergent-like property inducing concentration dependent decrease in spectrin anisotropy, further indicating structural changes in brain spectrin with probable implications in its anesthetic potential.
Topics: Algorithms; Anesthetics, Local; Animals; Brain; Cell Membrane; Cholesterol; Circular Dichroism; Dibucaine; G(M1) Ganglioside; Kinetics; Membrane Lipids; Models, Chemical; Models, Molecular; Phospholipids; Protein Binding; Sheep; Spectrin; Spectrometry, Fluorescence; Tetracaine; Thermodynamics
PubMed: 25482358
DOI: 10.1016/j.bbamem.2014.11.022 -
Korean Journal of Family Medicine Sep 2019It has been reported that in 62.5% of cases of incurable cancer pain, the complaint is due to myofascial pain syndrome. Trigger point injections using dibucaine...
BACKGROUND
It has been reported that in 62.5% of cases of incurable cancer pain, the complaint is due to myofascial pain syndrome. Trigger point injections using dibucaine hydrochloride help patients with such cancer pain. This study evaluated the efficacy of trigger point injections for alleviating pain in patients with advanced cancer.
METHODS
Twenty patients with advanced cancer who had a life expectancy of 6 months or less and had been diagnosed with myofascial pain syndrome were treated with trigger point injections. Prior to treatment, a Visual Analog Scale (VAS) was used to measure the resting pain level and discomfort upon application of pressure on the site of pain. These values were compared with last treatment measurements.
RESULTS
The mean pre-treatment VAS scores for pain at rest and upon application of pressure on the pain site were 7.3 and 9.0, respectively. These scores decreased significantly to 1.95 and 3.2, respectively, after the treatment (P<0.05).
CONCLUSION
Trigger point injection is an alternative and effective pain control modality for advanced cancer patients with myofascial pain syndrome.
PubMed: 31487973
DOI: 10.4082/kjfm.18.0065 -
Methods in Molecular Biology (Clifton,... 2020Caveolins are integral membrane proteins that are the principal structural component of caveolae. Newly synthesized caveolin self-associates into oligomers that further...
Caveolins are integral membrane proteins that are the principal structural component of caveolae. Newly synthesized caveolin self-associates into oligomers that further assemble into higher-order structures. Imaging fluorescently labeled caveolin at the plasma membrane with total internal reflection fluorescence (TIRF) microscopy reveals a spatially heterogeneous distribution with aggregates of various sizes. In this chapter, we present a set of image-processing tools to quantify the spatial organization and mobility of caveolin aggregates seen in TIRF images. We apply a spot detection algorithm to identify punctate features on multiple length scales, and computationally estimate the area and integrated fluorescence signal of each detected feature. We then partition the original image into two disjoint sets: one containing pixels within punctae, and the other containing pixels on the rest of the plasma membrane. From these partitions, we estimate the relative fraction of caveolin that is punctate versus diffuse. Finally, we analyze the mobility of caveolin aggregates by tracking them and classify individual trajectories as diffusive or subdiffusive using a moment scaling spectrum analysis. Together, these analyses capture multiple facets of caveolin organization and dynamics. To demonstrate their utility, we quantify the distribution of fluorescent Caveolin 1 stably transfected in HeLa cells. We analyze cells at baseline and after being exposed to the anesthetic Dibucaine that is known to scramble membrane phospholipids. Our analysis shows how this perturbation dramatically alters caveolin aggregation and mobility.
Topics: Algorithms; Caveolins; Cell Membrane; Green Fluorescent Proteins; HeLa Cells; Humans; Image Processing, Computer-Assisted; Microscopy, Fluorescence; Transfection
PubMed: 32548818
DOI: 10.1007/978-1-0716-0732-9_5 -
International Journal of Pharmaceutics Apr 2021Colloidal lipid emulsions are a promising formulation option for poorly water-soluble drugs. Due to their complex composition, they provide different sites for the...
Colloidal lipid emulsions are a promising formulation option for poorly water-soluble drugs. Due to their complex composition, they provide different sites for the localization of drugs. Drug molecules can be situated in the lipid matrix, in the aqueous phase with its structures formed by an excess of emulsifier or at the droplet interface. The interface and the mechanism of stabilization is mainly characterized by the emulsifier. In this study, the main focus was on the influence of drug localization on the stability of emulsions sterically stabilized with poloxamer188. In addition to 5% of this non-ionic emulsifier, the emulsions contained 10% soybean oil. The localization of the drugs fenofibrate, curcumin, betamethasone valerate, cinnarizine, dibucaine and flufenamic acid within the emulsion system at a physiological pH of 7.4 as well as their influence on emulsion stability were examined. The results indicated that the stability of poloxamer 188-stabilized emulsions can be influenced in a positive or negative way by the localization of drug molecules in the interface of emulsion droplets. Applying cinnarizine as model substance at pH 5, 7.4 and 10, no pronounced change in the localization was detected as a result of alterations in the charge of the drug.
Topics: Drug Stability; Emulsifying Agents; Emulsions; Poloxamer; Soybean Oil; Water
PubMed: 33675931
DOI: 10.1016/j.ijpharm.2021.120394 -
Physical Chemistry Chemical Physics :... Jun 2016(14)N ultra-wideline (UW), (1)H{(15)N} indirectly-detected HETCOR (idHETCOR) and (15)N dynamic nuclear polarization (DNP) solid-state NMR (SSNMR) experiments, in...
(14)N ultra-wideline (UW), (1)H{(15)N} indirectly-detected HETCOR (idHETCOR) and (15)N dynamic nuclear polarization (DNP) solid-state NMR (SSNMR) experiments, in combination with plane-wave density functional theory (DFT) calculations of (14)N EFG tensors, were utilized to characterize a series of nitrogen-containing active pharmaceutical ingredients (APIs), including HCl salts of scopolamine, alprenolol, isoprenaline, acebutolol, dibucaine, nicardipine, and ranitidine. A case study applying these methods for the differentiation of polymorphs of bupivacaine HCl is also presented. All experiments were conducted upon samples with naturally-abundant nitrogen isotopes. For most of the APIs, it was possible to acquire frequency-stepped UW (14)N SSNMR spectra of stationary samples, which display powder patterns corresponding to pseudo-tetrahedral (i.e., RR'R''NH(+) and RR'NH2(+)) or other (i.e., RNH2 and RNO2) nitrogen environments. Directly-excited (14)N NMR spectra were acquired using the WURST-CPMG pulse sequence, which incorporates WURST (wideband, uniform rate, and smooth truncation) pulses and a CPMG (Carr-Purcell Meiboom-Gill) refocusing protocol. In certain cases, spectra were acquired using (1)H → (14)N broadband cross-polarization, via the BRAIN-CP (broadband adiabatic inversion - cross polarization) pulse sequence. These spectra provide (14)N electric field gradient (EFG) tensor parameters and orientations that are particularly sensitive to variations in local structure and intermolecular hydrogen-bonding interactions. The (1)H{(15)N} idHETCOR spectra, acquired under conditions of fast magic-angle spinning (MAS), used CP transfers to provide (1)H-(15)N chemical shift correlations for all nitrogen environments, except for two sites in acebutolol and nicardipine. One of these two sites (RR'NH2(+) in acebutolol) was successfully detected using the DNP-enhanced (15)N{(1)H} CP/MAS measurement, and one (RNO2 in nicardipine) remained elusive due to the absence of nearby protons. This exploratory study suggests that this combination of techniques has great potential for the characterization of solid APIs and numerous other organic, biological, and inorganic systems.
PubMed: 27314503
DOI: 10.1039/c6cp02855a