Pretreatment of different biological matrices for exogenous testosterone analysis: a review

Addressing the ADME Challenges of Compound Loss in a PDMS-Based Gut-on-Chip Microphysiological System

Microphysiological systems (MPSs) are promising in vitro technologies for physiologically relevant predictions of the human absorption, distribution, metabolism, and excretion (ADME) properties of drug candidates. However, polydimethylsiloxane (PDMS), a common material used in MPSs, can both adsorb and absorb small molecules, thereby compromising experimental results. This study aimed to evaluate the feasibility of using the PDMS-based Emulate gut-on-chip to determine the first-pass intestinal drug clearance. In cell-free PDMS organ-chips, we assessed the loss of 17 drugs, among which testosterone was selected as a model compound for further study based on its substantial ad- and absorptions to organ chips and its extensive first-pass intestinal metabolism with well-characterized metabolites. A gut-on-chip model consisting of epithelial Caco-2 cells and primary human umbilical vein endothelial cells (HUVECs) was established. The barrier integrity of the model was tested with reference compounds and inhibition of drug efflux. Concentration-time profiles of testosterone were measured in cell-free organ chips and in gut-on-chip models. A method to deduce the metabolic clearance was provided. Our results demonstrate that metabolic clearance can be determined with PDMS-based MPSs despite substantial compound loss to the chip. Overall, this study offers a practical protocol to experimentally assess ADME properties in PDMS-based MPSs.

High throughput LC-MS/MS method for steroid hormone analysis in rat liver and plasma - unraveling methodological challenges

Comprehensive reference data for steroid hormones are lacking in rat models, particularly for early developmental stages and unconventional matrices as the liver. Therefore, we developed and validated an enzymatic, solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify a panel of 23 steroid hormones in liver and plasma from adult and neonatal rats. Our approach tackles methodological challenges, focusing on undesired byproducts associated with specific enzymatic treatment, and enables a thorough assessment of potential interferences in complex matrices by utilizing unstripped plasma and liver. We propose an optimized enzymatic hydrolysis protocol using a recombinant β-glucuronidase/sulfatase mix (BGS mix) to efficiently deconjugate steroid phase II conjugates. The streamlined sample preparation and high-throughput solid phase extraction in a 96-well plate significantly accelerate sample processing for complex matrices and alarge number of samples. We were able to achieve the necessary sensitivity for accurately measuring the target analytes, particularly estrogens, in small sample sizes of 5-20 mg of liver tissue and 100 μL of plasma. Through the analysis of liver and plasma samples from adult and neonatal rats, including both sexes, our study showed a novel set of steroid hormone reference intervals. This study provides a reliable diagnostic tool for the quantification of steroids in rat models and gives insight in liver and plasma-related steroid hormone dynamics at early developmental stages. In addition, the method covers several pathway intermediates and extend the list of steroid hormones to be investigated.

GC-MS/MS Determination of Steroid Hormones in Urine Using Solid-Phase Derivatization as an Alternative to Conventional Methods

Solid-phase analytical derivatization (SPAD) is a promising hybrid sample preparation technique combining the clean-up and preconcentration of the sample in a single step. In this work, a novel SPAD method based on the preparation of trimethylsilyl (TMS) derivatives of steroid hormones (testosterone, estrone, DHT, estriol, estradiol, and progesterone) in Phenomenex Strata C18-E (100 mg, 1 mL) cartridges has been developed and applied for their GC-MS/MS determination in human urine samples. The proposed procedure allows the detection and quantification of steroids with limits of 1.0–2.5 and 2.5–5 ng/mL, respectively. These characteristics are comparable with those obtained with a conventional liquid–liquid extraction, while the recovery of analytes in the proposed SPAD procedure is higher. The major advantages of SPAD are a short derivatization time, high efficiency, and the possibility to automatize the procedure. However, its cost-effectiveness in routine practice is still questionable.

Investigation on utility of some novel terpenes on transungual delivery of fluconazole for the management of onychomycosis

BACKGROUND

Onychomycosis, the most prevailing affliction of the nail, accounts for approximately 90% of the toenail infection worldwide. Owing to this infection, the affected patients experience reduced quality of their life as its awful appearance undermines their daily activities and social interactions. Onychomycosis is notoriously strenuous to cure. Systemic therapy, though effective, possess severe complication of toxicities, contra-indication, and drug-drug interaction. Albeit topical therapy is favorable to its localized effect, its potency relates to the effective concentration of the antifungal drugs achieved at the infection site. An approach to accomplish this goal would be acquiring benefits from the terpenes as penetration enhancers from natural sources. This investigation aimed to study the effectiveness of six terpenes, namely safranal, lavandulol, rose oxide, 3-methyl-2-butene-1-ol, linalool, and limonene, as potential penetration enhancers for improved nail permeation of fluconazole through the human nail.

METHODS

Ex vivo permeation experiments were carried out by soaking the nail clippings of human volunteers in control and working solutions containing fluconazole (5 mg/ml) per se and fluconazole (5 mg/ml) with 6% of each terpene, including safranal, lavandulol, rose oxide, 3-methyl-2-butene-1-ol, linalool, and limonene, respectively, for 48 hours. The amount of fluconazole in nail clippings was quantified using an HPLC method.

RESULTS

Statistical analysis showed that fluconazole transungual permeation was influenced by the studied terpenes in the following order: safranal > lavandulol acetate > limonene > rose oxide (P-value > 0.05) while the other terpenes showed no significant difference with the control group and safranal represents as the most effective permeation enhancer for the transungual delivery of fluconazole.

CONCLUSION

It is concluded that the safranal can be successfully used as a safe and potential permeation enhancer to enhance the transungual delivery of fluconazole for the treatment of onychomycosis.

Potential Association Between Anabolic Androgenic Steroid Abuse and Pituitary Apoplexy: A Case Report

INTRODUCTION

Pituitary apoplexy (PA) is a rare, and potentially life-threatening condition, caused by hemorrhage or infarction into the pituitary gland with a rapid expansion of the contents of the sella turcica, associated with sudden intense headache, neurological and endocrinological deterioration. The identification of risk factors is crucial for prevention and optimal management. Herein we report a case of PA occurring 1 month after the initiation of anabolic androgenic steroid abuse for bodybuilding.

CASE REPORT

A 40-year-old male patient presents with abrupt onset headache associated with left partial third cranial nerve palsy. The MRI shows a sellar lesion involving left cavernous sinus with a heterogenous anterior aspect of the lesion with hemorrhagic zones in favor of PA. Endocrine work-up shows high testosterone level in patient who was using exogenous testosterone without a medical prescription for a month.

CONCLUSION

We report a case of PA of a pituitary neuroendocrine tumor occurring shortly after AAS. The association between PA and AAS should be considered as a potential risk.

Can Serum be a Match for Urine in the Regulatory Analysis of Boldenone in Cattle? A Systematic Comparison Between Detection Window, Stability, and Enzymatic Hydrolysis

This work involved a systematic comparison between serum and urine for the monitoring of anabolic androgenic steroids in livestock. Incurred samples were collected over 120 days from crossbred steers treated with intramuscular injections containing boldenone undecylenate. Independent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) methods were used for the assessment of the respective detection windows, which were larger for serum samples. Both matrices presented adequate performance in terms of long-term stability, assessed using an isochronous approach during 196 days at -20 °C and for five freeze-thaw cycles. The effectiveness of the enzymatic hydrolysis reaction using Helix pomatia juice was also compared. The calculated concentrations in serum samples were not statistically influenced by the deconjugation reaction. On the other hand, urine hydrolysis conditions were studied using a 3³ Box-Behnken Design, in which a central point condition led to a satisfactory deconjugation performance. It could be observed that serum exhibited equivalent or better performance than urine for most of the evaluated criteria; thus, its inclusion in the regulatory analysis of boldenone in cattle is supported.

Effect of monoterpenes on ex vivo transungual delivery of itraconazole for the management of onychomycosis

BACKGROUND

Onychomycosis, a fungal nail infection, is an important problem as it may cause local pain, paresthesia, difficulties in performing activities of daily life, and impair social interactions. Systemic treatment of onychomycosis presents safety issues due to possible drug-drug interactions and severe side effects. Although topical therapy of onychomycosis is advantageous due to its localized effect, the efficacy of such therapy depends on achieving effective concentrations of antifungal agents at the infection site. An approach to reach to this end would be driving benefit from synergic activity of antifungal agents for example itraconazole and monoterpenes. However, because of low transungual penetration of itraconazole, a molecule with high molecular weight and very low water-solubility, the effect of the latter compounds on itraconazole nail delivery should be investigated, which was the aim of this study.

METHODS

Ex vivo permeation experiments were carried out through soaking the nail clippings of ten healthy volunteers in control and working solutions containing itraconazole (1 mg mL^-1 ) and itraconazole (1 mg mL^-1 ) plus 6% of each monoterpene including camphor, eucalyptol, menthol, and thymol, respectively, for 36 hours. The amount of itraconazole in nail clippings was quantified hereafter using a validated HPLC method.

RESULTS

Statistical analysis showed that itraconazole transungual permeation was not influenced by the studied monoterpenes (P value > .05).

CONCLUSION

These results provided a new perspective for designing topical dosage forms for the treatment of onychomycosis.