Identification and structural elucidation of three new tadalafil analogues found in a dietary supplement

Analytical methods for the detection and characterization of unapproved phosphodiesterase type 5 inhibitors (PDE-5i) used in adulteration of dietary supplements- a review

This article is an up-to-date review of 112 unapproved phosphodiesterase type 5 inhibitors (PDE-5i) found as adulterants in sexual enhancement dietary supplements and other products from 2003 to July 2023. Seventy-five of these unapproved PDE-5i are analogues of sildenafil (67%), followed by 26 analogues of tadalafil (23%), 9 analogues of vardenafil (8%) and 2 other type of compounds (2%). The products have been formulated in various packaging, primarily in capsule, tablet, and powder forms. Common screening techniques allowing detection of such analogues include high performance or ultra-high performance liquid chromatography in tandem with ultra-violet detector (HPLC-UV or UPLC-UV) (50%) and thin-layer chromatography in tandem with ultra-violet detection (TLC-UV) (7%). Screening by mass spectrometry (MS) is relatively less common with the use of single-, triple-quadrupole or time-of-flight (TOF) mass spectrometers (9%). Meanwhile, the combined detection by UV-MS has been recorded at 10% usage. Screening by proton nuclear magnetic resonance spectroscopy (NMR) (11%) has also been applied. For compound characterization, i.e. structural elucidation, NMR spectroscopy has been preferred (100 out of 112 compounds), followed by high-resolution mass spectrometry (HRMS) (74 out of 112 compounds) and Fourier-transform infrared spectroscopy (FTIR) (44 out of 112 compounds). Over the past two decades, analytical technology has been evolving with enhanced sensitivity and resolution. Despite this, structural elucidation of the new emerging analogues in adulterated dietary supplements remains a challenge, especially when the analogues involve complex structural modification. Therefore, the above-mentioned techniques may not be adequate to characterize the analogues. Additional work involving chiroptical methods, two-dimensional (2D) NMR experiments and X-ray crystallography are likely to be required in the future.

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.

An Analysis of Popular Online Erectile Dysfunction Supplements

INTRODUCTION

Erectile dysfunction supplements (ED-Ss) are featured on online marketplaces like Amazon.com, with dedicated pages and claims that they naturally treat ED. However, their efficacy and safety are largely unknown, limiting the ability to counsel patients regarding their use.

AIM

To evaluate the highest rated and most frequently reviewed ED-Ss on Amazon.com to facilitate patient counseling regarding marketing myths, ingredient profiles, and evidence for product efficacy and safety.

METHODS

The Amazon marketplace was queried using the key term "erectile dysfunction" with default search settings and ranking items based on relevance. The top 6 ED-S products identified on September 29, 2018, were reviewed based on price, ratings, reviews, manufacturer, and ingredients. Consumer reviews were categorized using subtopics within the International Index of Erectile Function (IIEF) questionnaire to better understand ED-S efficacy and then reanalyzed following filtration of untrustworthy comments using ReviewMeta.com, a proprietary Amazon review analysis software.

OUTCOMES

Quantitative and qualitative evaluation of ED-S products sold on Amazon.com.

RESULTS

The top 6 ED-Ss had an average of 2,121 ± 1,282 reviews and a mean rating of 3.92 ± 0.42 stars. A total of 21 ingredients were identified in these ED-Ss. Ginseng, horny goat weed, L-arginine, and tongkat ali were the most popular ingredients included in the analyzed products. Our literature review identified 413 studies involving the 21 identified ingredients, of which 59 (16%) involved human subjects. Among these 69 human studies, only 12 (17%) investigated supplement ingredients individually and reported improvement in ED. Analysis of top-ranked customer reviews from the first 2 pages of reviews for each supplement revealed differences in IIEF scores before and after ReviewMeta.com filtration. After filtration, we observed a 77% decrease in reviews reporting improved erection strength, an 83% decrease in reviews reporting improved ability to maintain erection, a 90% decrease in reviews reporting increased sexual satisfaction, an 88% decrease in reviews reporting increased enjoyment with intercourse, and an 89% decrease in reviews reporting increased erection confidence.

STRENGTHS & LIMITATIONS

Study strengths include a novel approach to ascertaining consumers' perceptions and satisfaction with ED-Ss and practical summary information that clinicians can provide to patients. Limitations include selection bias, the small number of supplements analyzed, and the proprietary nature of the Amazon review analysis software.

CONCLUSIONS

Our investigation revealed that human studies evaluating the efficacy of ED-S ingredients are limited and have yielded no definitive findings of the effects on ED. Patients considering ED-S use should receive appropriate counseling, given the prevalence of disingenuous reviews and the ready availability of Food and Drug Administration-approved drug therapies. Balasubramanian A, Thirumavalavan N, Srivatsav A, et al. An Analysis of Popular Online Erectile Dysfunction Supplements. J Sex Med 2019;16:843-852.

Chiroptical and vibrational spectroscopic study of genuine and counterfeit medicines containing tadalafil

The production and distribution of counterfeit pharmaceuticals present a serious problem worldwide. This is true especially in case of phosphodiesterase type 5 inhibitors for treating erectile dysfunction, where consumers often prefer buying them anonymously from unverified sources. In this study, genuine and counterfeit Cialis® 20 mg tablets were analyzed by electronic circular dichroism, vibrational circular dichroism, and infrared spectroscopy. The characteristic spectral patterns were identified by comparison with the spectra of tadalafil standard as an active pharmaceutical ingredient, and its presence was confirmed in all samples. The amount of tadalafil, however, was markedly lower in the case of counterfeit tablet as the observed band intensities were considerably lower. No other significant differences between the genuine and counterfeit tablets were revealed. Ab initio density functional theory calculations provided a detailed description of the stable conformers of tadalafil in a solution and enabled thorough interpretation of the experimental spectra.

Collision-induced dissociation pathways of H1-antihistamines by electrospray ionization quadrupole time-of-flight mass spectrometry

Over the past decades, mass spectrometry technologies have been developed to obtain mass accuracies of one ppm or less. Of the newly developed technologies, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) has emerged as being well suited to routine and high-throughput analyses of pharmaceuticals. Dietary supplements and functional foods have frequently been found to be contaminated with pharmaceuticals. In our continuous efforts to develop methodologies to protect public health against adulterated dietary supplements, we have constructed a mass spectral database for 21 H₁-antihistamines encountered as adulterants by using liquid chromatography-electrospray ionization (LC-ESI)/Q-TOF-MS, and have proposed their possible collision-induced dissociation pathways. This database will be very useful for the rapid and accurate detection of H₁-antihistamines (known) and their analogues (unknown) illegally added to dietary supplements as well as in other sample matrices.