LC-ESI-MS/MS analysis of phosphodiesterase-5 inhibitors and their analogues in foods and dietary supplements in Korea

Highly sensitive plasmonic paper substrate fabricated via amphiphilic polymer self-assembly in microdroplet for detection of emerging pharmaceutical pollutants

We report an innovative and facile approach to fabricating an ultrasensitive plasmonic paper substrate for surface-enhanced Raman spectroscopy (SERS). The approach exploits the self-assembling capability of poly(styrene-b-2-vinyl pyridine) block copolymers to form a thin film at the air-liquid interface within the single microdroplet scale for the first time and the subsequent in situ growth of silver nanoparticles (AgNPs). The concentration of the block copolymer was found to play an essential role in stabilizing the droplets during the mass transfer phase and formation of silver nanoparticles, thus influencing the SERS signals. SEM analysis of the morphology of the plasmonic paper substrates revealed the formation of spherical AgNPs evenly distributed across the surface of the formed copolymer film with a size distribution of 47.5 nm. The resultant enhancement factor was calculated to be 1.2 × 107, and the detection limit of rhodamine 6G was as low as 48.9 pM. The nanohybridized plasmonic paper was successfully applied to detect two emerging pollutants-sildenafil and flibanserin-with LODs as low as 1.48 nM and 3.45 nM, respectively. Thus, this study offers new prospects for designing an affordable and readily available, yet highly sensitive, paper-based SERS substrate with the potential for development as a lab-on-a-chip device.

LC-HRMS analysis of 13 classes of pharmaceutical substances in food supplements

Food supplements should not contain substances considered unsafe or pose a health risk to consumers. In recent years illegal adulterants have been found in various functional foods without notification of their presence or amount in the labelling. In this study, a validated method was developed and applied as a screening method to detect 124 forbidden substances belonging to 13 classes of compounds in food supplements. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) and a simple and rapid extraction protocol was applied to 110 food supplements collected from the internet market or during official controls in Italy. The percentage of non-compliant samples was 4.5%, relatively high compared with the official control results for these substances usually obtained on other food matrices. The results suggested the need to strengthen controls in this field to detect food supplement adulteration, which represents a potential health risk for the consumer.

Lodenafil

Lodenafil is a class of drugs called an inhibitor of PDE5 which also include a wide range of other erectile medicines, such as sildenafil, tadalafil and vardenafil. It is part of a new generation of PDE5 inhibitors that includes udenafil and avanafil. Lodenafil is a prodrug manufactured in the form of lodenafil carbonate, the carbonate dimer that divides in the body into two active drug lodenafil molecules. The oral bioavailability of this formulation is higher than that of the parent drug. This article discusses, by a critical comprehensive review of the literature on lodenafil in terms of its description, names, formulae, elemental composition, appearance, and therapeutic uses. The article also discusses the methods for preparation of lodenafil, its physical-chemical properties, analytical methods for its determination, pharmacological-toxicological properties, and dosing information.

Efficient Matrix Cleanup of Soft-Gel-Type Dietary Supplements for Rapid Screening of 92 Illegal Adulterants Using EMR-Lipid dSPE and UHPLC-Q/TOF-MS

An efficient matrix cleanup method was developed for the rapid screening of 92 illegal adulterants (25 erectile dysfunction drugs, 15 steroids, seven anabolic steroids, 12 antihistamines, 12 nonsteroidal anti-inflammatory drugs (NSAIDs), four diuretics, and 17 weight-loss drugs) in soft-gel-type supplements by ultra-high performance liquid chromatography-quadrupole/time of flight-mass spectrometry (UHPLC-Q/TOF-MS). As representative green chemistry methods, three sample preparation methods (dispersive liquid-liquid microextraction (DLLME), “quick, easy, cheap, effective, rugged, and safe” dispersive solid-phase extraction (QuEChERS-dSPE), and enhanced matrix removal-lipid (EMR-Lipid) dSPE) were evaluated for matrix removal efficiency, recovery rate, and matrix effect. In this study, EMR-Lipid dSPE was shown to effectively remove complicated matrix contents in soft-gels, compared to DLLME and QuEChERS-dSPE. For the rapid screening of a wide range of adulterants, extracted common ion chromatogram (ECIC) and neutral loss scan (NLS) based on specific common MS/MS fragments were applied to randomly collected soft-gel-type dietary supplement samples using UHPLC-Q/TOF-MS. Both ECICs and NLSs enabled rapid and simple screening of multi-class adulterants and could be an alternative to the multiple reaction monitoring (MRM) method. The developed method was validated in terms of limit of detection (LOD), precision, accuracy, recovery, and matrix effects. The range of LODs was 0.1–16 ng/g. The overall precision values were within 0.09–14.65%. The accuracy ranged from 81.6% to 116.6%. The recoveries and matrix effects of 92 illegal adulterants ranged within 16.9–119.4% and 69.8–114.8%, respectively. The established method was successfully applied to screen and identify 92 illegal adulterants in soft-gels. This method can be a promising tool for the high-throughput screening of various adulterants in dietary supplements and could be used as a more environmentally friendly routine analytical method for screening dietary supplements illegally adulterated with multi-class drug substances.

Rapid Screening and Quantitative Determination of Illegal Phosphodiesterase Type 5 Inhibitors (PDE-5i) in Herbal Dietary Supplements

Phosphodiesterase type 5 inhibitors (PDE-5i) are the first-line medication for oral erectile dysfunction, which are used according to the prescription of doctors. However, these substances have been found illegally in supplementary foods. The quality and safety of dietary supplements for enhancing male sexual performance have been questioned, raising the need for continual development of analytical methods. Liquid chromatography coupled with high-resolution mass spectrometry has become one of the most effective methods to identify and measure PDE-5i concentration. In this research, we focused on (i) developing and validating an effective screening and quantitation method for more than 53 PDE-5i in ingredients and supplementary products using LC-Q-Exactive after a simple sample extraction and (ii) assessing PDE-5i content in natural-based supplementary products available in Vietnam market. The extraction method used a small amount of organic solvent, which makes it more environmentally friendly (greener). The developed method has a limit of detection of 0.4 mg/kg, a limit of quantitation of 1.2 mg/kg, recoveries from 80 to 110%, and repeatability lower than 15%. Ninety-two herbal supplementary foods and ingredients used for enhancement of male sexual performance available in Vietnamese markets were collected. Fourteen PDE-5i including conventional and novel analogous were detected and measured in eighteen food supplements and two formulation ingredient samples.

Contribution of sewage to occurrence of phosphodiesterase-5 inhibitors in natural water

Phosphodiesterase-5 inhibitors (PDE-5i, such as Sildenafil, Tadalafil and Vardenafil, mainly prescribed to treat erectile dysfunction) and their generic drug equivalents have been widely marketed and consumed in Korea. From the concentrations detected in wastewater, we could deduce that relatively large amounts of PDE-5i were consumed without a legal prescription. Thus, PDE-5i’s presence in the environment via sewage is unavoidable, and their environmental fate within a sewage treatment plant (STP) should be evaluated. In this study, we investigated the occurrence of three PDE-5i analogs in the influent and effluent of two STPs and the receiving water bodies. The PDE-5i concentration in total reached 62 ± 12 (STP#1) and 88 ± 37 ng L⁻¹ (STP#2) in the sewage influent; about 70% of it was Sildenafil in both STPs. However, they were hardly removed by the STPs as the removal efficiency of the STPs was less than 10% ± 5%. Therefore, the pharmaceuticals were detected in the receiving water (lower than 7 ng L⁻¹as a total amount) and the concentration slightly increased downstream of the STPs. A simple mass balance model applied for the compounds in the STP effluent and receiving water bodies also confirmed that the discharged PDE-5i were quite persistent. Lastly, we identified temporal and regional patterns in the consumption of the drugs from daily variations of PDE-5i in the influent to these two STPs. For instance, the levels of PDE-5i in the sewage significantly increased on weekends (from Friday to Saturday), and especially in the area where adult-entertainment businesses are common. We estimated that the amount of PDE-5i consumption in this area was 31% higher than that in the area with fewer nightlife spots. Considering that they are pharmaceutically active and resistant to treatment processes within an STP, it is advised that a regular monitoring and management program for PDE-5i should be developed to prevent the discharge of the pharmaceuticals into the water environment.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Simultaneous analysis of 23 illegal adulterated aphrodisiac chemical ingredients in health foods and Chinese traditional patent medicines by ultrahigh performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

This paper presents an application of ultra high-performance liquid-chromatography-quadrupole-TOF high resolution mass spectrometry (UHPLC-Q-TOF HRMS) for simultaneous analysis of 23 illegal adulterated aphrodisiac type chemical ingredients in health foods and Chinese Traditional Patent Medicines (CTPMs). The mass spectrometer was operated in Information Dependent Acquisition (IDA) mode, which provides crucial information for the elemental composition analysis, structure elucidation and quantitative analysis simultaneously. Quantitative analysis was performed using the peak areas of the precursor ions in the XICs. The method validation included assessment of selectivity, sensitivity, calibration curve, accuracy, precision, recovery, matrix effect and stability. The results show good linear relationship with the concentrations of the analytes over wide concentration ranges (e.g., 0.05–10 μg/g for sildenafil) as all the fitting coefficients of determination r² are >0.9984. The detection limits (LODs) were in the range of 0.002–0.1 μg/g. The recoveries were able to reach 82.5–103.6%, while the matrix effects ranged from 87.7 to 109.3%. The intra- and inter-day accuracies were in the range of 82.3–113.8%, while the intra- and inter-day precision ranged from 0.4 to 13.6%. Among 40 batches of health foods and 32 batches of CTPMs (including 28 capsules, 32 tablets, 10 liquid and 2 pills) samples, 28 batches of heath foods were positive. The detected chemical ingredients involved sildenafil, tadalafil, aildenafil and sulfoaildenafil. This method can be used for the screening, identification and quantification of illegal adulterated aphrodisiac chemical ingredients in health foods and CTPMs. Moreover, the LC-Q-TOF MS is very useful to structural elucidation of unknown compound.

Using In Silico Fragmentation to Improve Routine Residue Screening in Complex Matrices

Targeted residue screening requires the use of reference substances in order to identify potential residues. This becomes a difficult issue when using multi-residue methods capable of analyzing several hundreds of analytes. Therefore, the capability of in silico fragmentation based on a structure database ("suspect screening") instead of physical reference substances for routine targeted residue screening was investigated. The detection of fragment ions that can be predicted or explained by in silico software was utilized to reduce the number of false positives. These "proof of principle" experiments were done with a tool that is integrated into a commercial MS vendor instrument operating software (UNIFI) as well as with a platform-independent MS tool (Mass Frontier). A total of 97 analytes belonging to different chemical families were separated by reversed phase liquid chromatography and detected in a data-independent acquisition (DIA) mode using ion mobility hyphenated with quadrupole time of flight mass spectrometry. The instrument was operated in the MS^E mode with alternating low and high energy traces. The fragments observed from product ion spectra were investigated using a "chopping" bond disconnection algorithm and a rule-based algorithm. The bond disconnection algorithm clearly explained more analyte product ions and a greater percentage of the spectral abundance than the rule-based software (92 out of the 97 compounds produced ≥1 explainable fragment ions). On the other hand, tests with a complex blank matrix (bovine liver extract) indicated that the chopping algorithm reports significantly more false positive fragments than the rule based software. Graphical Abstract.

Deoxynivalenol in wheat, maize, wheat flour and pasta: surveys in Hungary in 2008-2015

Among Fusarium mycotoxins, deoxynivalenol (DON) is the most common contaminant in case of cereals and cereal-based foods in Hungary. In this study, Hungarian wheat (n = 305), maize (n = 108), wheat flour (n = 179) and pasta (n = 226) samples were analysed (N = 818). The samples were collected during 2008-2015 in Hungary. Applied methods of analysis were enzyme-linked immunosorbent assay and liquid-chromatography coupled with a mass spectrometer. Results were compared and evaluated with Hungarian weather data. Among cereal samples, in 2011, wheat was contaminated with DON (overall average ± standard deviation was 2159 ± 2818 µg kg^-1), which was above the maximum limit (ML). In case of wheat flour and pasta, no average values above ML were found during 2008-2015, but higher DON contamination could be observed in 2011 as well (wheat flour: 537 ± 573 µg kg^-1; pasta: 511 ± 175 µg kg^-1).

Phosphodiesterase-5 inhibitors and their analogues as adulterants of herbal and food products: analysis of the Malaysian market, 2014-16

Adulteration of herbal health supplements with phosphodiesterase-5 (PDE-5) inhibitors and their analogues is becoming a worldwide problem. The aim of this study was to investigate herbal and food products sold in the Malaysian market for the presence of these adulterants. Sixty-two products that claim to enhance men's sexual health were sampled between April 2014 and April 2016. These products included unregistered products seized by the Pharmacy Enforcement Division of the Ministry of Health (n = 39), products sent to the National Pharmaceutical Regulatory Agency for pre-registration testing (n = 9) and products investigated under the post-registration market surveillance programme (n = 14). The products were tested against an in-house spectral library consisting of 61 PDE-5 inhibitors and analogues using a validated liquid chromatography-mass spectrometry ion-trap-time-of-flight (LC-MS IT-TOF) method. Thirty-two (82%) of the unregistered products and two (14%) of the registered products were found to be adulterated with at least one PDE-5 inhibitor or analogue, while none of the pre-registration products contained adulterants. A total of 16 different adulterants were detected and 36% of the adulterated products contained a mixture of two or more adulterants. This study has demonstrated that the adulteration of unregistered herbal products in the Malaysian market is an alarming issue that needs to be urgently addressed by the relevant authorities.

Erectile dysfunction treatment and traditional medicine-can East and West medicine coexist?

Erectile dysfunction (ED) is a common sexual problem affecting many men irrespective of cultures, beliefs and nationalities. While medical therapy for ED has been revolutionized by the advent of oral phosphodiesterase type 5 inhibitors and intracavernosal injection of vasoactive agents, recent technological advances such stem cell therapy, low intensity shock wave and newer generation of penile prosthesis implant offer hope to men who do not respond to conventional medical therapy. In contrast, traditional and complementary medicine (TCM) focuses on the restoration and better overall bodily regulation with the use of various herbal and animal products as well as exercises to invigorate qi (energy) in vital organs. Western medicine involves an analysis of ED symptom and underlying causes that contribute to ED, while TCM emphases the concept of holism and harmonization of body organs to achieve natural sexual life. The following article reviews our current understanding regarding the philosophical approach, and evaluates the evidence surrounding various ED therapies between mainstream Western Medicine and TCM.

Aluminium content of foods originating from aluminium-containing food additives

Aluminium (Al) levels of 90 food samples were investigated. Nineteen samples contained Al levels exceeding the tolerable weekly intake (TWI) for young children [body weight (bw): 16 kg] when consuming two servings/week. These samples were purchased multiple times at specific intervals and were evaluated for Al levels. Al was detected in 27 of the 90 samples at levels ranging from 0.01 (limit of quantitation) to 1.06 mg/g. Of these, the Al intake levels in two samples (cookie and scone mix, 1.3 and 2 mg/kg bw/week, respectively) exceeded the TWI as established by European Food Safety Authority, although the level in the scone mix was equivalent to the provisional TWI (PTWI) as established by Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives. The Al levels markedly decreased in 14 of the 19 samples with initially high Al levels. These results indicated reductions in the Al levels to below the PTWI limits in all but two previously identified food samples.

Isolation and structural characterization of a new tadalafil analog (2-hydroxyethylnortadalafil) found in a dietary supplement

A screen for known PDE-5 inhibitors in a dietary supplement product marketed for "enhanced sexual performance" detected a compound that structurally resembled tadalafil. The compound was isolated from the supplement matrix using high-performance liquid chromatography with ultraviolet detection (HPLC-UV) and a fraction collector, and was further characterized using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), as well as high-resolution accurate mass mass spectrometry (HRAM-MS). The analog had an accurate mass of m/z 420.15614 (error is 1.77235ppm) for the protonated species [M+H](+), corresponding to a molecular formula of C23H22N3O5. Mass spectral fragmentation data suggested that the modification occurred in place of the CH3 located on the pyrazinopyridoindole-1,4-dione of tadalafil. NMR was utilized to further elucidate the configuration of the substitution. The analysis indicated that the moiety is a CH2CH2OH, hydroxyethyl group. The new analog has been named 2-hydroxyethylnortadalafil.