Determination Of Pharmaceutical Compounds Research Articles

Determination of Vancomycin Hydrochloride in Pharmaceutical Forms and Urine Samples Using Modified Magnetic Iron Oxide Nanoparticles

Magnetic solid-phase extraction is an efficient and low-cost spectrophotometric method that can be utilized for extraction and determination of pharmaceutical compounds. Vancomycin is an antibiotic used in the treatment of life-threatening infections caused by Gram-positive bacteria. This study utilized magnetic solid-phase extraction for the determination of vancomycin hydrochloride (VAN) in different matrices. The separation and determination performed on magnetic iron oxide nanoparticles (IONPs) was modified using cetyltrimethylammonium bromide (CTAB). An azo dye product results from the coupling of VAN with the diazotized 4-aminoacetophenone in alkaline medium. This product was extracted and measured spectrophotometrically at λmax of 456 nm. Factors affecting the efficiency of removing the dye, such as pH of the solution, volume of reagent, CTAB amount, adsorbent amount, extraction time and desorption conditions, were studied. Under optimal extraction conditions, the linearity concentrations range was 0.1–6 µg/mL. The limit of detection and the limit of quantification was calculated to be 0.075 and 0.25 µg/mL, respectively. The method was applied successfully for the fast analysis of VAN in its dosage forms using the CTAB-coated IONPs, and the extraction process could be completed within 10 min.

Determination of pharmaceutical compounds in hospital wastewater and their elimination by advanced oxidation processes

ABSTRACTThis study investigates the mineralization efficiency, i.e. removal of total organic carbon (TOC) in hospital wastewater by direct ozonation, ozonation with UV radiation (O3/UV), homogeneous catalytic ozonation (O3/Fe2+) and homogeneous photocatalytic ozonation (O3/Fe2+/UV). The influence of pH and reaction time was evaluated. For the best process, toxicity and degradation efficiency of the selected pharmaceutical compounds (PhCs) were determined. The results showed that the PhCs detected in the hospital wastewater were completely degraded when the mineralization efficiency reached 54.7% for O3/UV with 120 minutes of reaction time using a rate of 1.57 g O3 h−1. This process also achieved a higher chemical oxygen demand removal efficiency (64.05%), an increased aromaticity reduction efficiency (81%) and a toxicity reduction.

Determination of pharmaceutical compounds in sewage sludge using a standard addition method approach

An analytical method for the simultaneous determination of eight pharmaceutical compounds in biosolids from urban wastewater treatment plants (WWTPs) was developed and validated. The compounds evaluated were non-steroidal anti-inflammatory drugs (naproxen, diclofenac, and ibuprofen), lipid regulators (clofibric acid), and antibiotics (sulfathiazole, sulfapyridine, sulfamethazine, and sulfamethoxazole). Ultrasound assisted extraction with a water–methanol solvent mixture (1:1, v:v) was performed and the compounds were then determined by liquid chromatography coupled with tandem mass spectrometry. The design of the method was based on the application of the standard addition calibration methodology to reduce matrix interferences. Validation procedures were conducted with rabbit excrements as blank samples. Recoveries of the target analytes ranged from 76 to 131% in spiked samples at 50, 200 or 1000 ng g−1 dry weight (dw). The relative standard deviations were in the range of 5–15% and the method detection limits ranged from 2 to 12 ng g−1dw. The method was applied to monitor pharmaceutical concentrations in biosolids from different WWTPs over an eight-month period (May to December 2011). Diclofenac, sulfapyridine and ibuprofen were detected in most of the samples whereas sulfamethazine and ibuprofen were the pharmaceuticals found in the highest concentrations (>200 ng g−1 dw on average).

Simultaneous determination of pharmaceutical compounds in environmental samples by solid-phase extraction and gas chromatography–mass spectrometry

Pharmaceutical substances are synthetic compounds with very widespread usage due to their therapeutic biological effects. These compounds and their bioactive metabolites are continually introduced into the aquatic environment as complex mixtures via sewage treatment plants (incomplete destruction), animal farms or leaching from landfills. In this study, an analytical procedure involving solid-phase extraction and gas chromatography–mass spectrometry was developed to determine pharmaceutical compounds (caffeine, diclofenac, ketoprofen and ibuprofen) in aqueous samples (wastewater and surface water). The results demonstrated the suitability of the method at trace levels (ng·L −1) for multi-residue analysis of different types of water matrices.

Determination of pharmaceutical compounds in hospital effluents and their contribution to wastewater treatment works

A method was developed for the simultaneous determination of almost 40 pharmaceuticals; including antidepressants, non-steroidal anti-inflammatories, analgesics, hypolipidemics, α- and β-blockers, an anti cancer drug, anti-fungal agents, an opiate, an antibiotic, an anti-coagulant, a diuretic, an anti-anginal and an anti-diabetic compound. This was used to assess the contribution of pharmaceuticals originating from hospital effluents to one of Oslo city's wastewater treatment works. Some pharmaceuticals were found to contribute to more of the wastewater loading than others. 11% of the propranolol entering the wastewater treatment works stems from hospital effluent, approximately 2% of the atenolol, carbemazepine, metaprolol and atorvastatin, and for several other compounds the contribution is less than 1%. This assessment shows that point sources discharges from hospitals typically make a small contribution to the overall pharmaceutical load when compared to municipal areas, however this varies from substance to substance and is not the case when a drug's use is primarily hospital based.

LC with Electrochemical Detection. Recent Application to Pharmaceuticals and Biological Fluids

Many pharmaceutical compounds have electroactive groups and are readily measurable and detectable by liquid chromatography with electrochemical detection (LC–EC). LC–EC techniques have many advantages as measurement systems and new materials have been developed for working electrodes. Use of modern electroanalytical techniques for detection in LC of pharmaceutical compounds is discussed in this review. EC detection in LC often results in improved selectivity and detection limits for electroactive pharmaceutical compounds. Selected literature on the determination of pharmaceutical compounds in their dosage forms and in biological samples are reported.

Determination of pharmaceutical compounds in aqueous dimethyl sulfoxide by electrospray ionization mass spectrometry

Standard solutions of reserpine, dextromethorphan, imipramine and amitriptyline in dimethyl sulfoxide (DMSO), DMSO containing 0.1% formic acid, and DMSO/H(2)O (1:1, v/v) containing 0.1% formic acid were analyzed by positive electrospray ionization mass spectrometry (ESI-MS). A triple-quadrupole mass spectrometer equipped with a TurboIonspray (TIS) interface was used for the ESI-MS analyses. The samples dissolved in the respective DMSO solution were infused directly into the mass spectrometer at 10 microL/min using an infusion pump. The positive Q1 full-scan (m/z 50-650) mass spectrum of DMSO (MW = 78) showed three main peaks at m/z 79, 101 and 179, corresponding to the protonated molecule [DMSO+H](+), and the sodiated adducts [DMSO+Na](+) and [2DMSO+Na](+), respectively. The ESI of the compounds in DMSO and DMSO containing 0.1% formic acid was promoted by using the TIS gas (GS2) combined with the nebulizer gas (GS1), and TIS source temperature set to 250 degrees C. In contrast, samples dissolved in DMSO/H(2)O (1:1, v/v) containing 0.1% formic were sprayed at a lower temperature (100 degrees C) using only the nebulizer gas. The TIS voltage (V) was optimized in order to establish the lowest voltage necessary to achieve optimum ESI of each pharmaceutical compound with the voltage maintained below the onset potential required to produce a corona discharge at the TIS probe (sprayer). Detection limits of 10 ng/mL were achieved for reserpine, dextromethorphan, imipramine and amitriptyline in each solvent composition.

Determination of pharmaceutical compounds in skin by imaging matrix‐assisted laser desorption/ionisation mass spectrometry

Matrix-assisted laser desorption/ionisation (MALDI) quadrupole time-of-flight mass spectrometry (Q-TOFMS) has been used to detect and image the distribution of a xenobiotic substance in skin. Porcine epidermal tissue was treated with 'Nizoral', a medicated shampoo containing ketoconazole (+/-)-1-acetyl-4-[p-[[(2R,4S)-2-(2,4-dichlorophenyl)-2-(imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazine) as active ingredient. Following incubation for 1 h at 37 degrees C all excess formulation was washed from the surface. A cross-section of the drug-treated tissue was then blotted onto a cellulose membrane, precoated in matrix (alpha-cyano-4-hydroxycinnamic acid (CHCA)), by airspray deposition. In separate experiments the tissue surface was treated with Nizoral within a triangular former, and subsequently blotted onto a matrix-coated membrane. Sample membranes were then mounted into the recess of specialised MALDI targets with adhesive tape. All samples were analysed by MALDI-TOFMS using an Applied Biosystem 'Q-star Pulsar i' hybrid Q-TOF mass spectrometer fitted with an orthagonal MALDI ion source and imaging software. Detection of the protonated molecule was readily achievable by this technique. Treatment of the tissue within a template gave rise to images depicting the expected distribution of the drug, demonstrating that this technique is capable of producing spatially useful data. Ion images demonstrating the permeation of the applied compound into the skin were achieved by imaging a cross-sectional imprint of treated tissue. A calibration graph for the determination of ketoconazole was prepared using the sodium adduct of the matrix ion as an internal standard. This enabled construction of a quantitative profile of drug in skin. Conventional haematoxylin and eosin staining and microscopy methods were employed to obtain a histological image of the porcine epidermal tissue. Superimposing the mass spectrometric and histological images appeared to indicate drug permeation into the dermal tissue layer.

Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography–electrospray ionization mass spectrometry

Commonly used prescription and over-the-counter pharmaceuticals are possibly present in surface- and ground-water samples at ambient concentrations less than 1 μg/L. In this report, the performance characteristics of a combined solid-phase extraction isolation and high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) analytical procedure for routine determination of the presence and concentration of human-health pharmaceuticals are described. This method was developed and used in a recent national reconnaissance of pharmaceuticals in USA surface waters. The selection of pharmaceuticals evaluated for this method was based on usage estimates, resulting in a method that contains compounds from diverse chemical classes, which presents challenges and compromises when applied as a single routine analysis. The method performed well for the majority of the 22 pharmaceuticals evaluated, with recoveries greater than 60% for 12 pharmaceuticals. The recoveries of angiotensin-converting enzyme inhibitors, a histamine (H2) receptor antagonist, and antihypoglycemic compound classes were less than 50%, but were retained in the method to provide information describing the potential presence of these compounds in environmental samples and to indicate evidence of possible matrix enhancing effects. Long-term recoveries, evaluated from reagent-water fortifications processed over 2 years, were similar to initial method performance. Method detection limits averaged 0.022 μg/L, sufficient for expected ambient concentrations. Compound-dependent matrix effects on HPLC/ESI-MS analysis, including enhancement and suppression of ionization, were observed as a 20–30% increase in measured concentrations for three compounds and greater than 50% increase for two compounds. Changing internal standard and more frequent ESI source maintenance minimized matrix effects. Application of the method in the national survey demonstrates that several pharmaceuticals are routinely detected at 0.010–0.100 μg/L concentrations.

Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography?electrospray ionization mass spectrometry

Commonly used prescription and over-the-counter pharmaceuticals are possibly present in surface- and ground-water samples at ambient concentrations less than 1 μg/L. In this report, the performance characteristics of a combined solid-phase extraction isolation and high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) analytical procedure for routine determination of the presence and concentration of human-health pharmaceuticals are described. This method was developed and used in a recent national reconnaissance of pharmaceuticals in USA surface waters. The selection of pharmaceuticals evaluated for this method was based on usage estimates, resulting in a method that contains compounds from diverse chemical classes, which presents challenges and compromises when applied as a single routine analysis. The method performed well for the majority of the 22 pharmaceuticals evaluated, with recoveries greater than 60% for 12 pharmaceuticals. The recoveries of angiotensin-converting enzyme inhibitors, a histamine (H2) receptor antagonist, and antihypoglycemic compound classes were less than 50%, but were retained in the method to provide information describing the potential presence of these compounds in environmental samples and to indicate evidence of possible matrix enhancing effects. Long-term recoveries, evaluated from reagent-water fortifications processed over 2 years, were similar to initial method performance. Method detection limits averaged 0.022 μg/L, sufficient for expected ambient concentrations. Compound-dependent matrix effects on HPLC/ESI-MS analysis, including enhancement and suppression of ionization, were observed as a 20–30% increase in measured concentrations for three compounds and greater than 50% increase for two compounds. Changing internal standard and more frequent ESI source maintenance minimized matrix effects. Application of the method in the national survey demonstrates that several pharmaceuticals are routinely detected at 0.010–0.100 μg/L concentrations.

Determination of pharmaceutical compounds containing covalently-bound halogen by means of ion-selective electrodes

Organic compounds containing covalently bound halogen can be determined by potentiometric techniques with ion-selective electrodes in different ways. Apart from potentiometric titration of the halide after combustion, direct potentiometric determination of the halide produced at appropriate pH in the solution of the compound in the presence of silver(I) catalyst dissolved from the ion-selective electrode is possible in some cases. In the latter case, the chain length is critical; the chain must have at least three carbon atoms for hydrolysis to take place. Titration with a silver nitrate solution is also possible; prior pH adjustment is then needed for myelobromol but not for the other compounds tested.