AAPS Journal最新文献

P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance transporter 2 (MRP2) are efflux transporters involved in the absorption, excretion, and distribution of drugs. Bidirectional cell assays are recognized models for evaluating the potential of new drugs as substrates or inhibitors of efflux transporters. However, the assays are complicated by a lack of selective substrates and/or inhibitors, as well simultaneous expression of several efflux transporters in cell lines used in efflux models. This project aims to evaluate an in vitro efflux cell assay employing model substrates and inhibitors of P-gp, BCRP and MRP2 with knockout (KO) cell lines. The efflux ratios (ER) of P-gp (digoxin, paclitaxel), BCRP (prazosin, rosuvastatin), MRP2 (etoposide, olmesartan) and mixed (methotrexate, mitoxantrone) substrates were determined in wild-type C2BBe1 and KO cells. For digoxin and paclitaxel, the ER decreased to less than 2 in the cell lines lacking P-gp expression. The ER decreased to less than 3 for prazosin and less than 2 for rosuvastatin in the cell lines lacking BCRP expression. For etoposide and olmesartan, the ER decreased to less than 2 in the cell lines lacking MRP2 expression. The ER of methotrexate and mitoxantrone decreased in single- and double-KO cells without BCRP and MRP2 expression. These results show that KO cell lines have the potential to better interpret complex drug-transporter interactions without depending upon multi-targeted inhibitors or overlapping substrates. For drugs that are substrates of multiple transporters, the single- and double-KO cells may be used to assess their affinities for the different transporters.

A soft-core oil-in-water (o/w) nanoemulsion (NE) is composed of nanometer (nm) sized oil droplets, stabilized by a surfactant layer and dispersed in a continuous bulky water phase. Characterization of the o/w NE molecule arrangements non-invasively, particularly the drug phase distribution (DPD) and its correlation to oil globule size (OGS), remains a challenge. Here we demonstrated the analytical methods of intact ¹⁹F Nuclear Magnetic Resonance (NMR) and ¹H diffusion ordered spectroscopy (DOSY) NMR for their specificity in measuring DPD and OGS, respectively, on three NE formulations containing the active ingredient difluprednate (DFPN) at the same concentration. The results illustrated synchronized molecular rearrangement reflected in the DPD and OGS upon alterations in formulation. Addition of surfactant resulted in a higher DPD in the surfactant layer, and concomitantly smaller OGS. Mechanic perturbation converted most of the NE globules to the smaller thermodynamically stable microemulsion (ME) globules, changing both DPD and OGS to ME phase. These microstructure changes were not observed using 1D ¹H NMR; and dynamic light scattering (DLS) was only sensitive to OGS of ME globule in mechanically perturbed formulation. Collectively, the study illustrated the specificity and essential role of intact NMR methods in measuring the critical microstructure attributes of soft-core NE systems quickly, accurately, and non-invasively. Therefore, the selected NMR approach can be a unique diagnostic tool of molecular microstructure or Q3 property in o/w NE formulation development, and quality assurance after manufacture process or excipient component changes.

Dose-scale pharmacodynamic bioequivalence is recommended for evaluating the consistency of generic and innovator formulations of certain locally acting drugs, such as orlistat. This study aimed to investigate the standard methodology for sample size determination and the impact of study design on dose-scale pharmacodynamic bioequivalence using orlistat as the model drug. A population pharmacodynamic model of orlistat was developed using NONMEM 7.5.1 and utilized for subsequent simulations. Three different study designs were evaluated across various predefined relative bioavailability ratios of test/reference (T/R) formulations. These designs included Study Design 1 (2×1 crossover with T1 60 mg, R1 60 mg, and R2 120 mg), Study Design 2 (2×1 crossover with T2 120 mg, R1 60 mg, and R2 120 mg), and Study Design 3 (2×2 crossover with T1 60 mg, T2 120 mg, R1 60 mg, and R2 120 mg). Sample sizes were determined using a stochastic simulation and estimation approach. Under the same T/R ratio and power, Study Design 3 required the minimum sample size for bioequivalence, followed by Study Design 1, while Study Design 2 performed the worst. For Study Designs 1 and 3, a larger sample size was needed on the T/R ratio < 1.0 side for the same power compared to that on the T/R ratio > 1.0 side. The opposite asymmetry was observed for Study Design 2. We demonstrated that Study Design 3 is most effective for reducing the sample size for orlistat bioequivalence studies, and the impact of T/R ratio on sample size shows asymmetry.

The paper highlights the necessity for a robust regulatory framework for assessing nanomedicines and their off-patent counterparts, termed as nanosimilar, which could be considered as 'similar' to the prototype nanomedicine,based on essential criteria describing the 'similarity'. The term 'similarity' should be focused on criteria that describe nanocarriers, encompassing their physicochemical, thermodynamic, morphological, and biological properties, including surface interactions and pharmacokinetics. Nanocarriers can be regarded as advanced self-assembled excipients (ASAEs) due to their complexity and chaotic behavior and should be evaluated by using essential criteria in order for off-patent nanomedicines be termed as nanosimilars, from a regulatory perspective. Collaboration between the pharmaceutical industry, regulatory bodies, and artificial intelligence (AI) startups is pivotal for the precise characterization and approval processes for nanomedicines and nanosimilars and embracing innovative tools and terminology facilitates the development of a sustainable regulatory framework, ensuring safety and efficacy. This crucial shift toward precision R&D practices addresses the complexity inherent in nanocarriers, paving the way for therapeutic advancements with economic benefits.

Blood microsampling has increasingly attracted interest in the past decades as a more patient-centric sampling approach, offering the possibility to collect a minimal volume of blood following a finger or arm prick at home. In addition to conventional dried blood spots (DBS), many different devices allowing self-sampling of blood have become available. Obviously, the success of home-sampling can only be assured when (inexperienced) users collect samples of good quality. Therefore, the feasibility of six different microsampling devices to collect capillary blood by inexperienced adolescents at home was evaluated. Participants (n = 95) were randomly assigned to collect blood (dried or liquid) at different time points using four of six different self-sampling devices (i.e., DBS, Mitra volumetric absorptive microsampling (VAMS), Capitainer B, Tasso M20, Minicollect tube and Tasso⁺ serum separator tube (SST)). The quality of the samples was visually inspected and analytically determined. Moreover, the participants' satisfaction was assessed via questionnaires. Although a majority succeeded based on the visual inspection, the success rate differed largely between the different devices. In general, the lowest success rate was obtained for the Minicollect tubes, although there is an opportunity and need for improvement for the other self-sampling devices as well. Hence, this also emphasizes the importance to assess the quality of samples collected by the target population prior to study initiation. In addition, visual classification by a trained individual was confirmed based on assessment of the analytical variability between replicates. Finally, self-sampling at home was overall (very) positively received by the participants.

The selection of skin is crucial for the in vitro permeation test (IVPT). The purpose of this study was to investigate the influence of different freezing-thawing processes on the barrier function of skin and the transdermal permeability of granisetron and lidocaine. Rat and hairless mouse skins were thawed at three different conditions after being frozen at -20℃ for 9 days: thawed at 4℃, room temperature (RT), and 32℃. There were no significant differences in the steady-state fluxes of drugs between fresh and thawed samples, but compared with fresh skin there were significant differences in lag time for the permeation of granisetron in rat skins thawed at RT and 32℃. Histological research and scanning electron microscopy images showed no obvious structural damage on frozen/thawed skin, while immunohistochemical staining and enzyme-linked immunosorbent assay for the tight junction (TJ) protein Cldn-1 showed significantly impaired epidermal barrier. It was concluded that the freezing-thawing process increases the diffusion rate of hydrophilic drugs partly due to the functional degradation of TJs. It's recommended that hairless, inbred strains and identical animal donors should be used, and the selected thawing method of skin should be validated prior to IVPT, especially for hydrophilic drugs.

We aim to characterize industry-funded trials that have posted the informed consent forms (ICFs), and to assess whether the role played by industry as 'sponsor' or 'collaborator' could impact several relevant variables. A cross-sectional study was conducted on ClinicalTrials.gov on all industry-funded trials registered on or before 25 February 2023. We registered types of intervention, current recruitment status, design, enrollment, and countries involved. For trials with special interest to potential participants and investigators and/or clinicians an analysis of the role played by industry as 'sponsor' or 'collaborator' was performed. Of 116,281 industry-funded trials registered, 741 (0.6%) had posted ICFs. Most of these trials were categorized as 'completed' (n = 408) or 'terminated' (n = 107). The review of a sample of 359 trials showed that most were on drugs and/or biologics (59%), were randomized (51%), conducted exclusively in the USA (72%), and had posted results (79%), protocols (92%), and statistical analysis plans (SAPs) (89%). Trials in which industry participated as 'collaborator' were significantly more likely to post ICFs when trials were in the 'active, not recruiting' phase (OR 4.70, 99.71% CI 1.59-13.9, p < 0.001) than industry-sponsored trials. This was also the case when assessing drugs/biologics (OR 2.64, 99.71% CI 1.25-5.58, p < 0.001). Conversely, companies acting as 'sponsors' were significantly more likely to post ICFs with trials assessing devices, radiation interventions and/or diagnostic tests (OR 0.37, 99.71% CI 0.17-0.79, p < 0.001) than when participating as 'collaborators'. While industry-funded trials rarely post ICFs, when they do, they are highly compliant with transparency requirements. Regulations and ethics codes should consider requiring posting of protocols, SAPs, and ICFs for all clinical trials, regardless the type of sponsor.

Dose selection for investigations of intrinsic and extrinsic factors of pharmacokinetic variability as well as safety is a challenging question in the early clinical stage of drug development. The dose of an investigational product is chosen considering the compound information available to date, feasibility of the assessments, regulatory requirements, and the intent to maximize information for later regulatory submission. This review selected 37 programs as case examples of recently approved drugs to explore the doses selected with focus on studies of drug interaction, renal and hepatic impairment, food effect and concentration-QTc assessment.The review found that regulatory agencies may consider alternative approaches if justified and safe as illustrated in these examples. It is thus recommendable to use the first in human trial as an opportunity to assess QT-prolongation and drug interactions using probes or endogenous markers while maximizing the DDI potential, increasing sensitivity and ensuring safety. Early understanding of dose proportionality assists dose finding and simple and fast to conduct DDI study designs are advantageous. Single dose impairment studies despite non-proportional/time-dependent PK are often acceptability.Overall, the early understanding of the drug's safety profile is essential to ensure the safety of doses selected while preventing clinical trials with unnecessary exposure when using high doses or multiple doses. The information collected in this retrospective survey is a good reminder to tailor the early clinical program to the profile and needs of the molecule and consider regulatory opportunities to streamline the development path.

Gefapixant is a weakly basic drug which has been formulated as an immediate release tablet for oral administration. A physiologically based biopharmaceutics model (PBBM) was developed based on gefapixant physicochemical properties and clinical pharmacokinetics to aid formulation selection, bioequivalence safe space assessment and dissolution specification settings. In vitro dissolution profiles of different free base and citrate salt formulations were used as an input to the model. The model was validated against the results of independent studies, which included a bioequivalence and a relative bioavailability study, as well as a human ADME study, all meeting acceptance criteria of prediction errors ≤ 20% for both Cmax and AUC.  PBBM was also applied to evaluate gastric pH-mediated drug-drug-interaction potential with co-administration of a proton pump inhibitor (PPI), omeprazole. Model results showed good agreement with clinical data in which omeprazole lowered gefapixant exposure for the free base formulation but did not significantly alter gefapixant pharmacokinetics for the citrate based commercial drug product. An extended virtual dissolution bioequivalence safe space was established.  Gefapixant drug product batches are anticipated to be bioequivalent with the clinical reference batch when their dissolution is > 80% in 60 minutes. PBBM established a wide dissolution bioequivalence space as part of assuring product quality.