Current Pharmaceutical Analysis - Volume 18, Issue 1, 2022

Background: Sulfonamides are the anti-bacterial and anti-inflammatory drugs synthesized, which are widely used as medical and veterinary antibiotics. However, the excess dosage of sulfonamides can harm human health. Drug residues in animal products also can harm human health through the food chain. The long-term consumption of animal food containing drug residues will cause some toxicity and side effects on human body functions, which will seriously threaten human health. Methods: Electroanalytical methods are attracting much attention because of their advantage over conventional methods, as they are quick, low-cost, high sensitivity, and portable. This review examines the progress made in the selective electrochemical determination of sulfonamides in the last 20 years. Results: In this review, we describe the development of electrochemical methods for sulfonamides determination. Then, we pay special attention to the detection of sulfonamides using molecular imprinting technology. The linear detection range with the limit of detection has been listed for comparison. Conclusion: Electrochemical determination of sulfonamides is a fast, simple, sensitive, and cost-effective approach. The surface modification of commercial electrodes can significantly improve the sensing performance.

Background: Glucose detection is of great significance in biomedicine. In clinical medicine, diabetes seriously endangers human health. By accurately measuring the blood glucose content of diabetic patients, diabetes can be effectively monitored and treated. At present, there are many methods for measuring glucose content, such as chromatography, spectroscopy, and electrochemical methods. Among them, electrochemical glucose sensors are widely used because of their high reliability, low cost, and easy operation. Methods: Combining graphene with other nanomaterials (including graphene, metal oxides, semiconductor nanoparticles, polymers, dye molecules, ionic liquids and biomolecules) is an effective way to expand or enhance the sensing performance. Results: The composite of graphene and nanomaterials is an effective way to enhance the functionality of the electrochemical sensor. Graphene can accelerate electron transfer and realize direct electrochemistry and biological sensing. At the same time, graphene derivatives with rich composition and structure provide the possibility to further regulate their electrochemical performance. These graphene composite-based biosensors have shown excellent sensitivity and selectivity for glucose detection. Conclusion: Electrochemical glucose sensors based on graphene composite have received extensive attention. Although these materials have made significant progress in improving the sensitivity, lowering the detection limit and broadening the linear range, there are still facing challenges that require further study.

Background: Pain not only affects the quality of life of an individual but can also cause mental illness due to the lack of effective treatment for long-term pain. Analgesics refer to drugs that can partially or completely relieve pain, including non-steroidal anti-inflammatory drugs and central analgesics. Methods: In recent years, the cross integration of electrochemical analysis technology with biochemistry, materials science, biomedicine and other disciplines has driven the vigorous development of electrochemical sensing technology in the field of life sciences. The electrochemical sensor has many advantages, such as simple equipment, good specificity, high sensitivity, economy and convenience. As a newly emerging technology, electrochemical sensing technology has been increasingly used in drug analysis. Results: This review introduces the recent advances of the detection of analgesics using electrochemical technology. We deliberately selected three representative drugs for discussion: aspirin, ibuprofen and paracetamol. Conclusion: Electrochemical sensing technology has the advantages of high sensitivity, a low detection limit and simple operation. However, sensors still have some technical problems, such as the existence of many interference factors in actual samples in blood drug concentration monitoring and the need to further optimize the method conditions for multi-channel detection. With the continuous advancement of research, the application of new detection methods, nanomaterials, and biomolecules has enabled electrochemical technology to make certain progress in the field of drug analysis. In particular, the emergence of new nanomaterials will greatly promote the development of electrochemical sensing technology in drug analysis. As a cutting-edge technology, electrochemical sensing technology has enormous potential application value.

Athletes are not allowed to use performance-enhancing drugs. Despite many efforts, the use of performance-enhancing drugs still persists in sports. Doping testing in athletes is the main way to determine drug consumption. Taking biological samples from athletes can be used to detect doping. The least invasive method is urine, while hair and saliva can be sampled using a minimally invasive procedure. In contrast, blood sampling is the most invasive method. The development of sample analysis and detection technology is crucial for any kind of sampling method. This review details the progress of electrophoresis and electrochemical detection of diuretics in stimulants.

Background: Flavonoids are a large class of phenolic compounds, which generally refer to two benzene rings (A ring, B ring) with phenolic hydroxyl groups connected to each other through three central carbon atoms, that is, a series of C6-C3-C6 basic core compounds. Due to its potential medicinal value, the research on flavonoids has aroused great interest. Methods: This review aims to identify the research progress and development trends of electrochemical analysis of flavonoids. We retrieved published papers (1998-2020) from the Scientific Citation Index Expanded (SCIE) database of the WoS with a topic search related to the electrochemical analysis of flavonoids. Results: In this paper, the research progress in electrochemical analysis of flavonoids has been reviewed. The antioxidant activity of flavonoids has attracted considerable attention because it directly affects the application of flavonoids. Different analytical methods also received the attention of researchers, such as cyclic voltammetry and capillary electrophoresis. This is because the advanced analysis technology can be useful for evaluating the property of flavonoids. Conclusion: The research progress and development trends were analyzed based on CiteSpace software of text mining and visualization. Most research papers on this topic were published in the years 2004-2005, 2011-2013 and 2016-2018. Different countries are conducting research on the electrochemical analysis of flavonoids, which are not related to each other.

The review aims to present the importance of implementing microextraction-, capillary electrophoresis- and ionic liquid-based approaches in biomedical research. These analytical strategies could improve the biochemical diagnosis of various life-threatening diseases, aid in the search for therapeutic agents, and discover drug targets. They could be used when designing newer, safer medicinal products. All the proposed analytical approaches meet the requirements of “green chemistry”- based methods, which is relevant nowadays in view of the pollution of the Earth becoming a severe problem. The review is divided into three main sections, and biomedical examples of the application of each presented approach are discussed. It is assumed that the undoubted advantages of ionic liquid-, microextraction- and capillary electrophoresis-based methods will speed up their use in the study of various clinically important analytes from different biological fluids and tissue samples.

Introduction: Asari Radix et Rhizoma (ARR) and dried ginger (Zingiber officinalis) (DG) are often used together in drug preparations in traditional Chinese medicine (TCM) to treat respiratory diseases, including cold, bronchitis and pneumonia. Previous studies suggested that ARR and/or DG may influence the pharmacokinetics of other herbal components. In the current study, we examined pharmacokinetic interactions between ARR and DG in rats after oral administration. Methods: We developed a method based on ultra-high-performance liquid chromatographytandem mass spectrometry to simultaneously measure serum concentrations of two active components each in ARR (L-asarinin and sesamin) and DG (6-gingerol and 6-shogaol). Adult Sprague- Dawley rats were starved overnight, then given ARR extract, DO extract, or a co-decoction of ARR and DG by gastric gavage (6 g raw material per kg body weight; n = 6 per group). Blood samples were collected prior to drug administration and at the following times (h) afterward: 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0 and 24.0. Pharmacokinetic parameters were compared using Student’s t test for independent samples. Results: A simple, rapid, sensitive analytical method has been developed to detect four bioactive components simultaneously in the ARR-DG herbal pair. Pharmacokinetic parameters including Cmax, Tmax, T1/2 and AUC(0~t) were calculated using the non-compartmental model with the DAS 2.0 pharmacokinetic software. For L-asarinin, Tmax was 2.00 ± 0.00 h in ARR animals and 1.67±0.26 h in ARR-DG animals (P<0.05), T1/2 was 8.58 ± 1.75 h in ARR and 11.93 ± 2.13 h in ARR-DG (P<0.05). For 6-gingerol, Cmax was 350.48 ± 23.85 ng/mL in DG animals and 300.21 ± 20.02 ng/mL in ARR-DG (P<0.01), Tmax was 2.83 ± 0.41 h in DG and 2.17 ± 0.41 h in ARR-DG (P<0.05) and AUC(0~t) was 1.93 ± 0.15 mg/mL.h in ARR and 1.70 ± 0.15 mg/mL.h in ARR-DG (P<0.05). For 6-shogaol, Cmax was 390.28 ± 26.02 ng/mL in DG animals and 455.63 ± 31.01 ng/mL in ARR-DG (P<0.01), Tmax was 2.93 ± 0.10 h in DG and 1.92 ± 0.10 h in ARR-DG (P<0.01), T1/2 was 3.74 ± 0.29 h in DG and 3.28 ± 0.22 h in ARR-DG (P<0.01), and AUC(0~t) was 2.15 ± 0.18 mg/mL.h in DG and 2.73 ± 0.15 mg/mL.h in ARR-DG (P<0.01). Conclusion: Pharmacokinetic interactions between ARR and DG decreased Tmax, increased T1/2 but did not affect the overall bioavailability of L-asarinin in ARR. The interactions in ARR-DG decreased Cmax and Tmax but increased T1/2 and AUC(0~t) of 6-gingerol in DG. The interactions increased Cmax and AUC(0~t) but decreased Tmax and T1/2 of 6-shogaol in DG. Interactions in ARRDG did not affect the pharmacokinetics of sesamin.

Aims: To establish a rapid and simultaneous determination of multiple effective ingredients in anti-cold drugs. Background: Anti-cold drugs are stock medicines at home, and most anti-cold formulations are compound preparations. Although the active ingredients of compound preparations have significant effects on the treatment of colds, the excessive dosage or long-term use can produce a series of adverse reactions, including dependence, liver and kidney function damage, digestive system reaction, blood system damage. Now, there are many mature methods for analyzing the active ingredients of anti-cold drugs. However, these methods may have shortcomings, such as a long analysis time or a small number of analysis components. Objective: Establish a gas chromatography-flame ionization detector method for the simultaneous determination of six active ingredients, including acetaminophen, dextromethorphan hydrobromide, pseudoephedrine hydrochloride, chlorpheniramine maleate, diphenhydramine hydrochloride, and caffeine in anti-cold drugs. Methods: After the standard was accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. After the actual sample was removed from the coating, ground and crushed, accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. Results: The six components can be completely separated within 7.0min. This method has good sensitivity, precision, accuracy and recovery rate. Under the optimum testing conditions, the limit of detection was 0.360-2.50μg/mL, the limit of quantification was 1.20-8.30μg/mL. The calibration curves showed good linearity (R2≥0.9932) over the investigated concentration range between 1.20 and 400μg/mL. The recoveries were 89.2% to 109.2%. The RSD of intra-day precision was less than 1.0%. The RSD of inter-day precision was less than 3.2%. The established method was used to determine the ingredients of three anti-cold drugs on the market, and the results showed that the method can accurately determine the ingredients. Conclusion: The method can quickly and simultaneously determine multiple active ingredients in anti-cold medicines. Compared with the published methods in literature, the proposed method has the advantages of fast, the number of analysis components wide application range, convenience, low cost, etc. It provides a reference method for quality control of active ingredients of anti-cold drugs.

Background: Aluminum (Al) is classified as other elements by ICH, and its permitted daily exposure (PDE) has not been established. As it might cause compromised renal function, guidelines, regional regulations and practices need to be addressed. According to the United States Pharmacopeia 41 and the Japanese Pharmacopoeia 17, the aluminum content of large-volume parenterals (LVPs) used in total parenteral nutrition (TPN) therapy must not exceed 25 ng mL^-1. Therefore, the package insert of LVPs used in TPN therapy must state the content of aluminum. Objective: A new microwave assisted acid digestion pretreatment together with inductively coupled plasma mass spectrometry (ICP-MS) method was developed for the determination of aluminum content in Dextran 40 Glucose Injection. The method was successfully applied for quality evaluation of commercial Dextran 40 Glucose Injection. Methods: Samples were digested by a mixture of nitric acid and hydrochloric acid, with the assistance of microwave. After that, ICP-MS in KED mode was employed to analyze the samples. Results: The method showed a good linearity (r²=0.9999) within the range of 2~100 ng mL^-1, with the limit of detection and quantitation of 0.482 ng mL^-1 and 1.61 ng mL^-1, respectively. A good precision was obtained with relative standard deviation (RSD) of 8.8% (n=6). The spike recoveries with low, middle and high Al content in 9 sample were 102.2%~107.4%. Conclusion: The developed method was successfully applied for the analysis of Al content in 44 batches of Dextran 40 Glucose Injection produced by 9 pharmaceutical companies from domestic or international enterprises. The Al content of Dextran 40 Glucose Injection varied greatly between different enterprises or different batches. Meanwhile, among total of 44 batches, the Al content in 3 batches of Dextran 40 Glucose Injection exceeded the limitation of 25 ng mL^-1, which might cause potential safety problems.

Introduction: Phillyrin, the main pharmacological component of Forsythia suspensa, exhibits a wide variability of therapeutic activities, such as anti-oxidative stress, free radicalclearing, antibacterial activity, hepatic protection, restoration of endothelial glycocalyx damage, prevention of bone loss, attenuation of inflammatory responses, and so on. Previous research has found that phillyrin is not easily absorbed by the body and is rarely excreted into bile, excrement and urine, suggesting that phillyrin circulates primarily in the form of metabolites. Materials and Methods: In the present study, HPLC-ESI-MS/MS method was used for the simultaneous detection of phillyrin and its three metabolites in rat bile, excrement and urine samples. Liquid-liquid extraction with ethyl acetate was carried out for the pretreatment of bile and urine samples, while excrement samples were subjected to ultrasonic pretreatment with acetone. Chromatographic separation was performed on a C18 column with gradient elution. A tandem mass system coupled with a TurboIonSpray interface operating in simultaneous positive and negative ion multiple reaction monitoring modes was employed for the simultaneous detection of the analytes. Results: The proposed method demonstrated excellent accuracy and repeatability. Conclusion: This method was successfully applied for the pharmacokinetic evaluation of phillyrin and its three metabolites simultaneously.

Background: Lipoic acid is the only known chiral antioxidant that is both lipidsoluble and water-soluble. It is often used as a treatment for peripheral polyneuropathy caused by diabetes, alcohol, and chemicals. However, only a few long-term toxicological studies have been conducted on R-α-lipoic acid, which is a bioactive ingredient in lipoic acid. Objective: In this study, a simple, efficient, sensitive and stable LC-MS/MS method was used to determine RLA in rats, using deu-lipoic acid as an internal standard. Methods: The samples to be detected were plasma samples treated with protein precipitation and the simultaneous determination of the presence of R-α-lipoic acid and S-α-lipoic acid was conducted using LC-MS/MS. An isocratic elution program with a mobile phase composed of acetonitrile and 0.1% formic acid water solution (52/48) used for chromatographic separation was set up using a CHIRALPAK® IE C18 (250 mm × 4.6 mm, 5 μm) column with a flow rate of 0.9 mL/min. A negative electrospray ionization source was chosen, and the multiple monitoring (MRM) mode was applied. Results: R-α-lipoic acid and S-α-lipoic acid both were found to be present at a linear range of 5- 5000 ng/mL. The plasma samples were stable under various storage conditions and temperatures. The toxicokinetics study indicated that there were gender differences and that R-α-lipoic acid showed bioaccumulative toxicity after long-term daily administration. In addition, R-α-lipoic acid and S-α-lipoic acid were not converted into each other in the rats. Conclusion: The method established was successfully used for the long-term toxicokinetic study of R-α-lipoic acid administered to rats through caudal vein injection. The toxicokinetics results indicated the presence of gender differences and the toxic accumulation of R-α-lipoic acid. The two enantiomers were not converted into each other in the rats.

Background: As an anti-inflammatory prodrug, loxoprofen is metabolized into transloprofenol to treat diseases related to pain and inflammation. Although loxoprofen has fewer adverse effects than other NSAIDs, the safety of its usage during pregnancy remains unclear and needs to be considered. Fortunately, the toxicokinetics and tissue distribution study of transloxoprofen- alcohol in pregnant rats can resolve the problem. Objective: The purpose of this study is to establish a simple, sensitive, and effective LC-MS/MS analysis method for determining the concentration of trans-loxoprofen alcohol in plasma and tissues. Methods: The analytic samples were precipitated by methanol in one step and separated using a reverse-phase Poroshell 120 EC-C18 column (4.6 mm×50 mm; 2.7 μm). And the mobile gradient phase at a flow rate of 0.6 mL/min was composed of acetonitrile and 0.1% formic acid in water. The quantitative detection was achieved by multiple-reaction monitoring mode with a positive electrospray ionization source, transitional ion pairs of m/z 265.9>184.8 for trans-loxoprofenalcohol, and 268.8>187.9 for rac-trans-loxoprofen-D3 alcohol (Internal standard). Results: A good linearity of calibration curves for plasma and tissues was observed in the concentration range from 5.0 to 5000 ng/mL, and the lower limit of quantification was detected at 5.0 ng/mL. The intra-day and inter-day precision in plasma and tissues were within 8.94% and 7.26%, respectively. The mean extraction recovery and matrix effects in plasma and tissues were in the range of 89.08~109.27% and 89.00~106.80%, respectively. Precision of stability in plasma and tissues was within 8.91% and 7.08%, respectively. Conclusion: Complying with the requirements of bioanalytical guidelines by validation, this method was successfully adopted to the toxicokinetics and tissue distribution study after intravenously administrated trans-loxoprofen-alcohol into pregnant SD rats.

Background: The trough concentration (Cmin) of Imatinib (IM) is closely related to the treatment outcomes and adverse reactions of patients with gastrointestinal stromal tumors (GIST). However, the drug plasma level has great inter- and intra-individual variability, and therapeutic drug monitoring (TDM) is highly recommended. Objective: To develop a novel, simple, and economical two-dimensional liquid chromatography method with the ultraviolet detector (2D-LC-UV) for simultaneous determination of IM and its major active metabolite, N-desmethyl imatinib (NDIM) in human plasma, and then apply the method for TDM of the drug. Methods: The sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40#154;C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Results: IM and NDIM were separated well from other impurities and the entire analytical time for each run was 12.0 min. The calibration curves had good linearity in the range of 33.5-2678.4 ng/mL for IM, and 20.0-1600.0 ng/mL for NDIM, respectively. The extraction efficiency was more than 95%. The acceptable accuracy, precision, recovery and stability were also obtained. The Cmin of the drug in patients was measured with the validated method. Conclusion: The novel 2D-LC-UV method is simple, stable, highly automated and independent of specialized technicians, which greatly increases the real-time capability of routine TDM for IM in hospital.

Background: The risk of toxicity for the healthy individuals who are chronically exposed to cytostatic drugs was established in 1970s. Since then, many institutions have recommended monitoring occupational exposure to antineoplastic agents. Nevertheless, there is still a lack of analytical procedures for this inspection. The prodrug Capecitabine is an example of a cytostatic drug that has never been analyzed for the purpose of occupational exposure inspection. Thus, the objective of the present study was to develop a suitable protocol for its evaluation on workplace surfaces. Methods: The determination of the surface residue of Capecitabine has been carried out in a laboratory setting through аn HPLC-UV method, preceded by an appropriate sample preparation procedure,. It was used for the pre-and post-cleaning analysis of wipe samples from several working sites, which are assessed as the most likely ones for the occurrence of dermal contact with the prodrug. Results: The applied HPLC-UV method was assessed as accurate and precise, with an established limit of quantification of 0.05 μg/mL. The analytical procedure provided a recovery of Capecitabine of more than 90%. During the analytical protocol approbation, one surface sample containing Capecitabine was detected. To determine the efficiency of routine hygiene measures, wipe samples from all tested surfaces were analyzed after a cleaning procedure. However, the cytostatic presence was not determined on any area, including the area that gave a positive result. Conclusion: The analytical protocol developed here successfully permits, for the first time, to study the surface contamination with the cytotoxic agent, Capecitabine. Due to this, it can be concluded that the proposed method could be useful for institutions where a potential risk of contamination to the prodrug exists.

Objective: Chemical investigation of the extract of sponge-derived fungus, Aspergillus niger, was performed by liquid chromatography coupled with QExactive mass spectrometry for the first time. Method: A total number of 444 constituents were detected, 288 of which were identified positively or tentatively by the comprehensive utilization of accurate molecular weight and fragmentation information acquired from quadrupole orbitrap mass spectrometry. The identified compounds were divided into several types, namely, organic acid, alkaloid, saccharide, amino acid and cyclopeptide, terpenoid, polyketone, phenylpropanoid and other types of compounds. Systematic diagnostic ions and featured fragment patterns were summarized for each type, based on which 8 novel compounds belonging to the same type were characterized. Results: This work provided a rapid approach for the research of micro constituents in a complex analyte. Furthermore, the anti-tumor activity of the extract was evaluated on two different cell lines-Bel-7402 and Hela-S3 in vitro. The tumor-inhibitory effect of the Aspergillus niger extract was confirmed and may be mainly derived from its pro-apoptotic action. Moreover, the extract exerted more significant cytotoxicity in Bel-7402 cells than Hela-S3 cells, indicative of its selectivity on specific tumor cells. Conclusion: The evidence suggested that the Aspergillus niger extract may potentially serve as a remedy for the prevention and therapy of hepatic and breast carcinoma.