Background: Recent studies have suggested a potential increase in the incidence of osteoporosis for patients receiving tenofovir disoproxil fumarate (TDF), but this issue remains controversial.Methods: The retrospective cohort study of 1224 Asian chronic hepatitis B (CHB) patients greater than 18 years without baseline osteopenia/osteoporosis seen at four US centers from 2008 to 2016. Patients were categorized into three groups—treatment‐naive patients who initiated therapy with TDF (1) or entecavir (ETV) (2), or untreated patients (3). Patients were followed until the development of osteopenia/osteoporosis or end of the study.Results: Of the 1224 study patients, 276 were treated with TDF, 335 with ETV, and 613 were untreated. The prevalence of cirrhosis was lower for untreated patients (2.6% vs 16.3% for TDF and 17.6% for ETV; P < 0.001). The 8‐year cumulative incidence rate of osteopenia/osteoporosis was 13.17% for TDF, 15.09% for ETV, and 10.17% for untreated patients, with no statistically significant difference among the three groups ( P = 0.218). On multivariate Cox regression controlling for demographics, osteoporosis risk factors, albumin, and hepatitis B virus (HBV) DNA levels, neither TDF (adjusted hazard ratio [HR] = 0.74; 95% confidence interval [CI]: 0.34 and 1.59) nor ETV (adjusted HR = 0.98; 95% CI: 0.51 and 1.90) were associated with increased osteopenia/osteoporosis risk compared with untreated patients.Conclusions: Our retrospective study suggests that there is no significant increase in the incidence of osteopenia/osteoporosis for patients with CHB treated with TDF or ETV during a median follow‐up of about 4 to 5 years. However, further study with longer follow‐up is needed as an anti‐HBV therapy, which is often lifelong or long‐term and the development of osteopenia/osteoporosis can be a slow process.

Background/Objectives: With the ongoing efforts in supporting the discovery of novel targeted drug delivery systems for the upper region of the female reproductive tract (FRT), it is imperative to understand the local drug disposition pathways. We aim to obtain a comprehensive profile of the drug transporters and drug-metabolizing enzymes in the human ectocervix, uterus, and fallopian tubes, as these factors may substantially influence mucosal penetration, tissue exposure, drug disposition, and the risk of drug–drug interactions. Methods: Gene expression of 12 drug transporters and 21 drug-metabolizing enzymes was quantified using RT-qPCR. Protein expression of highly expressed transporters was assessed using immunohistochemistry (IHC). Results: Among the 12 transporters analyzed, the efflux transporters P-gp, BCRP, and MRP4 exhibited the highest expression across the ectocervix, endometrium, myometrium, and fallopian tubes, with P-gp consistently showing the greatest abundance in all evaluated FRT tissues. Expression of these transporters was significantly higher (6–17×) in myometrium compared with ectocervix. IHC demonstrated strong localization of P-gp, BCRP, and MRP4 to epithelial layers facing the lumen, as well as to stromal and vascular endothelial cells. For drug-metabolizing enzymes, all 21 phase I and II enzymes were detectable across the FRT, and 15 were expressed at comparatively higher levels across all tissue types. These included CYP1A1, CYP1B1, CYP2B6, CYP2C8, CYP2C19, CYP3A4, UGT1A1, UGT1A3, UGT1A4, UGT1A7, UGT1A8, UGT1A10, UGT2B4, UGT2B15, and UGT2B17. Conclusions: The gene expression and localization data obtained from this work may improve our understanding of drug disposition in the FRT, which will inform selection, design, and optimization of drugs intended for targeted delivery within the FRT.

Students and trainees are integral to clinical pharmacology, as they have the potential to shape the field. This perspective highlights how the ASCPT Student and Trainee Community engages members worldwide, providing opportunities and resources to advance scientific and professional development. It also discusses strategies to foster equitable access and how these efforts promote pharmacoequity, including peer mentorship, international engagement, fair access to leadership roles, and diverse representation.

Background/Objectives: Given the potential for achieving high concentrations at the target site while limiting systemic exposure, delivering drugs directly to the female reproductive tract (FRT) is emerging as a promising strategy for enhancing women’s reproductive health. However, quantitative data describing matrix-specific solubility, matrix-specific binding, and permeability across FRT tissues remain limited, constraining development of physiologically based pharmacokinetic (PBPK) models for intravaginal and intrauterine therapies. Methods: Our work was conducted to help fill this critical gap, evaluating four model drugs with diverse physicochemical and transporter profiles, dapivirine (DPV), levonorgestrel (LNG), MK-2048, and 4′-ethynyl-2-fluoro-2′-deoxyadenosine (EFdA; also known as islatravir or MK-8591) in in vitro and ex vivo human models. Plasma solubility, matrix-specific binding in plasma, cervicovaginal fluid, and FRT tissues, and bidirectional permeability across FRT tissues were quantified. Results: Our results demonstrated that the plasma solubility varied markedly across compounds, following lipophilicity trends, with DPV (34.14 ± 1.04 µg/mL) and EFdA (1808.02 ± 67.36 µg/mL) exhibiting the lowest and highest solubility, respectively. Hydrophobicity-dependent solubility enhancement by plasma proteins (~2× to >30× higher comparing to aqueous solubility in the literature) was observed for all four model drugs. Apparent binding in plasma, cervicovaginal fluid, and FRT tissues was highly correlated with the model compounds’ lipophilicity, with DPV having the most highly matrix-specific binding (97–99%) and EFdA having the least matrix-specific binding with the greatest variability (15–62%). Regional permeability differed significantly across FRT tissues: the human ectocervix, myometrium, endometrium, and fallopian tubes demonstrated distinct transport patterns consistent with epithelial architecture and the transporter-substrate status of the model compounds. Efflux transporter involvement was evident for MK-2048 and EFdA in Caco-2 models (efflux ratios 2.59 and 7.14, respectively), but was less pronounced in the 3D vaginal model and ex vivo tissues. Across all datasets, permeability and binding were strongly influenced by drug lipophilicity and ionization characteristics. Conclusions: Collectively, these findings demonstrate the interplay among solubility, matrix-specific binding, and tissue permeability in governing local drug distribution within the FRT. The experimentally derived parameters provide quantitative inputs for FRT PBPK model development, and are expected to inform design of safe and effective localized therapies for women’s reproductive health.