Secondary pharmacology has become an established component of modern drug discovery and nonclinical safety assessment, supporting the early identification of off-target activities that may contribute to unintended pharmacological clinical effects. Although current regulatory guidance does not prescribe specific panel compositions, secondary pharmacology data are commonly expected to support first-in-human submissions and non-clinical safety assessments. However, practices remain heterogeneous with respect to panel design, assay format, testing strategy, and data interpretation. This perspective provides a contract research organization (CRO)-based overview of current secondary pharmacology practices, based on anonymized operational data from more than 550 sponsor organizations and contextual insights from voice-of-customer activities and routine scientific interactions. Standard catalog panels accounted for more than 90% of panel use and were favored across sponsor categories, whereas customized panels were used less frequently and mainly to address specific scientific or safety questions. Small panels (≤50 targets) were the most commonly used format. Binding assays remained the predominant screening modality, particularly for early compound triage, while functional assays were mainly applied for follow-up characterization or tiered testing strategies. Panel selection was influenced by regulatory considerations, historical experience, target coverage, operational constraints, and project-specific needs. Our analysis highlights ongoing challenges related to dataset sufficiency, regulatory expectations, and the biological interpretation of secondary pharmacology data. Greater harmonization of testing strategies, interpretation frameworks, and regulatory guidance will be important to maximize the value of secondary pharmacology in drug discovery while supporting implementation of the 3Rs principles.

Integrating safety pharmacology (SP) endpoints into repeated-dose toxicology studies enables the simultaneous assessment of organ toxicity and determination of functional safety risks within a single study, a practice endorsed by regulatory guidelines. Initiated by the Chinese Safety Pharmacology Society, this questionnaire-based survey assessed the implementation of such integrated studies across 19 Chinese institutions compliant with good laboratory practice and qualified to support submissions to the National Medical Products Administration (NMPA, China), FDA, and EMA. The survey compared integration practices for new chemical entities (NCEs) versus biopharmaceuticals, including animal models, monitoring technologies, statistical design, regulatory acceptance, and technical challenges. Furthermore, the survey solicited recommendations regarding revisions to the current ICH S7A guideline. For biopharmaceuticals, integration was common, with 16 of 19 institutions applying it in more than 75% of projects, primarily using non-human primates. Endpoint coverage in these studies included the cardiovascular system in all 19 institutions, the respiratory system in 16 of 19, and the central nervous system in 11 of 19, alongside an average 18% reduction in animal use. Respondents reported that data from these studies were fully accepted by the NMPA, FDA, and EMA in regulatory submissions. Conversely, integration was rarely used for NCEs, with 18 of 19 institutions reporting limited implementation. The primary barriers cited were interference with toxicokinetic sampling and lower statistical power compared to standalone crossover designs. As the first systematic survey of SP-integration practices across Chinese GLP institutions, these findings provide valuable real-world evidence to optimize non-clinical safety assessment strategies and support future revisions of the ICH S7A guideline.

ICH S7A (2000) defined the foundational framework for safety pharmacology studies supporting the registration of human pharmaceuticals. Overall, the guidance applied a risk-based, rational scope combined with a prescriptive framework of core battery endpoints collected under GLP guidelines that were required prior to first-in-human testing. Because of the evolving landscape of pharmaceutical modalities, nonclinical methodologies, and regulatory science over the last two decades, a critical examination of its relationship to weight-of-evidence (WoE) and risk-based reasoning is warranted. The central challenge is not that S7A lacks scientific flexibility in principle, but that its operational default has become a checklist that is often easier to execute, review and defend than an explicitly reasoned alternative. In the absence of an explicit WoE or probabilistic framework, sponsors and regulators are drawn toward the established paradigm of completing the S7A core battery, which renders the guideline's broader flexibility more aspirational than operational. The persistence of this 'default' is structurally understandable; sponsors, contract research organizations, and regulators each have legitimate institutional reasons to prefer a defined expectation over open-ended case-by-case judgment. A revision that simply endorses WoE in principle, without providing operational architecture for its application, is therefore unlikely to change practice and improve nonclinical safety assessment. This manuscript examines the structural tension within S7A, identifies the implicit WoE provisions already present in the guidance, analyzes the institutional forces that sustain prescriptive implementations, and proposes a practical resolution in which integrated evidence is used to select among a limited number of predefined assessment strategies, illustrated here with worked examples spanning contemporary modalities. In this way, the manuscript argues not for a departure from the original intent of the ICH S7A guidance but rather a reframing of the content to reflect contemporary drug development needs while accommodating the future modality landscape.

This study aimed to validate an ultra-performance liquid chromatography method for the identification and quantification of terbinafine hydrochloride, an antifungal agent widely used in the treatment of dermatophyte infections. Accurate quantification of terbinafine hydrochloride in pharmaceutical samples is essential for quality control and regulatory compliance. In addition to method validation, the influence of syringe filter selection during sample preparation on analytical accuracy was systematically evaluated. Hydrophilic polytetrafluoroethylene membranes (0.22 μm) demonstrated superior performance, yielding higher and more consistent analyte concentrations compared to hydrophobic filters. This behavior may be explained by reduced non-specific adsorption of protonated terbinafine during filtration. In aqueous media, the analyte is predominantly present in its protonated form, which can increase its interaction with polar surfaces. In contrast, the surface-modified hydrophilic membrane likely minimizes these interactions, reducing analyte loss and improving recovery. The validated method showed consistent analytical performance, with linearity over the tested range (r[2] = 0.9981), low limits of detection (0.08 mg·mL[-1]) and quantification (0.25 mg·mL[-1]), high precision (relative standard deviation <2%), and recovery values between 98.0% and 102.0%. Robustness testing confirmed that small variations in flow rate, column temperature, and mobile phase composition did not significantly affect quantification. These results demonstrate that syringe filter selection is a critical parameter in terbinafine hydrochloride analysis and highlight the importance of optimized sample preparation in pharmaceutical quality control.

Analytical methods utilizing the donor-acceptor phenomenon for proguanil (PRGL), an antimalarial medication, that are straightforward, quick, and possess a wide linear dynamic range for drug quantification and its toxicity assessment have not been published in the literature. This study spectrophotometrically validated two economical and effective analytical methods based on the complexation of PRGL with π-acceptors, chloranilic acid (CHLA) and 7,7,8,8-Tetracyanoquinodimethane (TCNQ) along with its Insilco toxicity evaluation using ADMET tool. Multiple analytical variables were examined. The linear dynamic range was notably effective, spanning from 5 to 80 μg mL[-1] for CHLA and from 2 to 30 μg mL[-1] for TCNQ techniques. The solid charge transfer complexes produced were assessed through different analytical techniques, such as UV-DRS, Fourier transform infrared spectroscopy, TGA-DTA, and powder X-ray diffraction. This study investigated the biological evolution of charge transfer (CT) complexes through the analysis of BSA protein binding and antimicrobial activity. The interaction between the CT complex and BSA was revealed by UV - Vis spectral analysis. The antibacterial efficacy of both CT complexes demonstrates significant effects. The CT complexes may exhibit promising biological activity and could be considered for further investigation as potential bioactive candidates in future studies. The molecular docking results verified the outcomes of the experiment. The outcomes obtained are appropriate for estimating the PRGL in its pharmaceutical formulation. The developed method's greenness was evaluated according to the AGREE guidelines and found satisfactory.

This editorial introduces the annual themed issue of the Journal of Pharmacological and Toxicological Methods (JPTM) dedicated to methodologies in safety pharmacology. The issue draws on content presented at the 2025 Safety Pharmacology Society Annual Meeting in Utrecht, The Netherlands, which featured 124 posters, many of which are reproduced as abstracts in this volume. The manuscripts primarily focus on advances in core battery safety evaluations and data analysis methodologies, while also highlighting emerging areas of investigation, including applications of artificial intelligence, digital monitoring technologies for enhanced safety assessment, in vitro assays recapitulating a range of organ systems and assessment of the hERG IC10 value as an alternative to the conventional IC50 value. The continued publication of these themed issues over the more than two decades underscores the importance of methodological innovation and evaluation, as well as the central role of safety pharmacology in driving these advancements.

The human ether-à-go-go-related gene (hERG) K+ channel is the principal off-target mediator of drug-induced QT prolongation, and hERG IC50 remains the only required in vitro cardiac safety assay. However, clinically relevant QT prolongation (ΔΔQTc ≥10 ms) typically occurs at much lower hERG inhibition (5-20%), and requires that IC50 be transformed into a safety margin to assess risk at therapeutic exposures. Thus, we examined the relationship between hERG inhibition and clinical ΔΔQTc to determine whether inhibition metrics closer to clinical concentrations improve prediction. Across 44 drug/dose pairs, 13.1% hERG inhibition corresponded to mean 10-ms ΔΔQTc, while 10.1% inhibition elicited 10-ms ΔΔQTc at the upper confidence interval (UCI). As a predictor, raw IC10 demonstrated comparable sensitivity (mean ΔΔQTc: 95.5% vs. 100%; UCI: 85.7% vs. 92.9%) and specificity (mean: 77.3% vs. 76.2%; UCI: 87.5% vs. 53.3%) to FDA safety margins calculated from IC50. Logistic regression using IC10 improved discrimination of ΔΔQTc UCI ≥ 10 ms over IC50 (AUC 0.95 vs. 0.90, p = 0.076). In contrast, performance for mean ΔΔQTc ≥10 ms was similar (AUC ∼0.96 for both). The improvement in ΔΔQTc UCI prediction by IC10 was explained by differences in Hill slope between drugs. Those with shallower Hill slope were more readily predicted unsafe by IC10 and those with steeper Hill slope were more readily predicted safe. These findings suggest that hERG IC10 provides a direct index of QT liability, which takes advantage of differences in Hill slope to improve prediction of ΔΔQTc liabilities near critical hERG inhibition of ∼10%.

The ongoing emergence of respiratory viral pathogens, including novel variants and established threats such as influenza, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Respiratory Syncytial Virus (RSV), continues to challenge global health systems due to limited specific therapeutic options. Intranasal antiviral delivery represents a promising approach for targeting respiratory tract infections; however, drug development frequently fails due to inappropriate pharmacokinetic properties. This study employed computational ADMET Predictor tools to systematically evaluate the physicochemical and potential pharmacokinetic properties of ten reference compounds, including nine approved antiviral drugs and ivermectin, a repurposed antiparasitic agent with reported antiviral activity and prior intranasal investigation: Zanamivir, Ribavirin, Oseltamivir, Favipiravir, Remdesivir, Nitazoxanide, Acyclovir, Lopinavir, Molnupiravir, and Ivermectin. Computational predictions were validated against experimental literature data to establish evidence-based criteria ranges. Key parameters related to intranasal drug delivery, covering physicochemical, absorption, distribution, metabolism, elimination, and toxicity properties, were systematically analyzed. The analysis resulted in revised criteria including molecular weight (Mwt), pH, lipophilicity (Log P), water solubility (Sw and SpH), Volume of distribution (Vd), P-glycoproteins substrate (Pgp substrate), and skin sensitization (Sens_Skin) to demonstrate 80% concordance with approved drug properties. This framework provides the preliminary evidence-based screening criteria as a tool to identify promising drug candidates suitable for preclinical evaluation in intranasal formulation development.

Vascular interventions can damage the endothelial glycocalyx and disrupt endothelial junction proteins, potentially leading to thrombosis, increased vascular permeability and the transmigration of leukocytes and lipoproteins. Drug-coated endovascular implants are typically evaluated in animal models; however, animals often exhibit exaggerated hyperproliferative responses to vascular injury and more rapid endothelial regeneration than humans. As a result, they may not accurately predict the risk of late vascular complications arising from delayed or incomplete endothelial healing. The development of advanced in vitro systems that incorporate human-derived cells, replicate physiologically relevant blood-flow patterns, and enable intercellular crosstalk could provide a valuable platform for assessing endothelial function. Microfluidic platforms serve as the basis of physiologically relevant in vitro vascular microphysiological systems that recapitulate key aspects of the in vivo vascular environment. Integration of these platforms with functionalized endothelium-on-chip technology creates biologically relevant vascular models, which could provide critical information to bridge data gaps from animal studies. This review highlights recent advances in microfluidic endothelium-on-chip platforms incorporating human-derived cells and discusses their potential applications for evaluating the effects of drug-coated endovascular biomaterial implants on endothelial function and risk assessments of vascular hyperpermeability and thrombogenesis during the early stages of product development.

The electrochemical analysis of dapsone (DP) was carried out using a poly-L-cysteine (poly-L-Cys) modified pencil graphite electrode (poly-L-Cys/PGE) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The method was optimised by examining the experimental parameters, including how the scan rate, DP concentration, and pH affected the current response. The electrochemical behavior of DP at the modified electrode showed that the process mainly relies on adsorption. Under these optimised conditions, the anodic peak current from DPV measurements showed a linear relationship with DP concentrations between 1.0 × 10[-6] and 12.0 × 10[-6] M, yielding a detection limit (LOD) of 5.37 × 10[-7] M. The method showed great sensitivity, selectivity, and stability. To test its practical use, the technique was successfully applied for the quantitative determination of DP in commercial tablet formulations and urine samples. Additionally, examination of the effects of common interfering substances confirmed minimal interference with DP detection. This electroanalytical approach offers a reliable, cost-effective alternative for routine DP determination in clinical laboratories, pharmaceutical analysis, and quality control.