Biopharmaceutics & Drug Disposition最新文献

The quantitative prediction of human pharmacokinetics (PK) including the PK profile and key PK parameters are critical for early drug development decisions, successful phase I clinical trials, and the establishment of a range of doses to enable phase II clinical dose selection. Here, we describe an approach employing physiologically based pharmacokinetic (PBPK) modeling (Simcyp) to predict human PK and to validate its performance through retrospective analysis of 18 Genentech compounds for which clinical data are available. In short, physicochemical parameters and in vitro data for preclinical species were integrated using PBPK modeling to predict the in vivo PK observed in mouse, rat, dog, and cynomolgus monkey. Through this process, the in vitro to in vivo extrapolation (IVIVE) was determined and then incorporated into PBPK modeling in order to predict human PK. Overall, the prediction obtained using this PBPK-IVIVE approach captured the observed human PK profiles of the compounds from the dataset well. The predicted C_max was within 2-fold of the observed C_max for 94% of the compounds while the predicted area under the curve (AUC) was within 2-fold of the observed AUC for 72% of the compounds. Additionally, important IVIVE trends were revealed through this investigation, including application of scaling factors determined from preclinical IVIVE to human PK prediction for each molecule. Based upon the analysis, this PBPK-based approach now serves as a practical strategy for human PK prediction at the candidate selection stage at Genentech.

GDC-9545 (giredestrant) is a highly potent, nonsteroidal, oral selective estrogen receptor antagonist and degrader that is being developed as a best-in-class drug candidate for early-stage and advanced drug-resistant breast cancer. GDC-9545 was designed to improve the poor absorption and metabolism of its predecessor GDC-0927, for which development was halted due to a high pill burden. This study aimed to develop physiologically-based pharmacokinetic/pharmacodynamic (PBPK-PD) models to characterize the relationships between oral exposure of GDC-9545 and GDC-0927 and tumor regression in HCI-013 tumor-bearing mice, and to translate these PK-PD relationships to a projected human efficacious dose by integrating clinical PK data. PBPK and Simeoni tumor growth inhibition (TGI) models were developed using the animal and human Simcyp V20 Simulator (Certara) and adequately described each compound's systemic drug concentrations and antitumor activity in the dose-ranging xenograft experiments in mice. The established PK-PD relationship was translated to a human efficacious dose by substituting mouse PK for human PK. PBPK input values for human clearance were predicted using allometry and in vitro in vivo extrapolation approaches and human volume of distribution was predicted from simple allometry or tissue composition equations. The integrated human PBPK-PD model was used to simulate TGI at clinically relevant doses. Translating the murine PBPK-PD relationship to a human efficacious dose projected a much lower efficacious dose for GDC-9545 than GDC-0927. Additional sensitivity analysis of key parameters in the PK-PD model demonstrated that the lower efficacious dose of GDC-9545 is a result of improvements in clearance and absorption. The presented PBPK-PD methodology can be applied to support lead optimization and clinical development of many drug candidates in discovery or early development programs.

PBPK applications published in the literature support a greater adoption of non-open source-code (NOSC) software as opposed to open source-code (OSC) alternatives. However, a significant number of PBPK modelers are still using OSC software, understanding the rationale for the use of this modality is important and may help those embarking on PBPK modeling. No previous analysis of PBPK modeling trends has included the rationale of the modeler. An in-depth analysis of PBPK applications of OSC software is warranted to determine the true impact of OSC software on the rise of PBPK. Publications focusing on PBPK modeling applications, which used OSC software, were identified by systematically searching the scientific literature for original articles. A total of 171 articles were extracted from the narrowed subset. The rise in the use of OSC software for PBPK applications was greater than the general discipline of pharmacokinetics (9 vs. 4), but less than the overall growth of the PBPK area (9 vs. 43). Our report demonstrates conclusively that the surge in PBPK usage is primarily attributable to the availability and implementations of NOSC software. Modelers preferred not to share the reasons for their selection of certain modeling software and no ‘explicit’ rationale was given to support the use of OSC analysed by this study. As the preference for NOSC versus OSC software tools in the PBPK area continues to be divided, initiatives to add the rationale in using one form over another to every future PBPK modeling report will be a welcomed and informative addition.

Physiologically-based pharmacokinetic (PBPK) models are more frequently used for supporting pediatric dose selection in small-molecule drugs. Through literature research, drug parameters of azithromycin and clinical data from different studies were obtained. Through parameter optimization of the absorption and dissolution process, the adult intravenous model was extended to the adult oral model. The adult intravenous and oral PBPK models are precise to meet the AAFE<2 standard, and the pharmacokinetic parameters of the predicted values of the model are all within the mean standard deviation of the clinical observations. The values of plasma protein unbound fraction, renal clearance, and gastric juice pH between adults and pediatrics were changed by using the age-dependent pediatric organ maturity formula, and the adult model was extrapolated to the pediatric model. The final developed pediatric PBPK model was used to evaluate optimal dosing for children of different developmental ages. The relationship between the frist dose and age was as follows: 8.8 mg/kg/day from 0.5 to 2 years old, 9.2 mg/kg/day from 3 to 6 years old, 9.4 mg/kg/day from 7 to 12 years old, and 8.2 mg/kg/day from 13 to 18 years old, taken in half for 2–5 days. Simultaneously, the simulated exposures achieved with the dosing regimen proposed were comparable to adult plasma exposures for treatment of community-acquired pneumonia. A reasonable azithromycin pharmacokinetic–pharmacodynamic model for adults and pediatrics has been established, which can be demonstrated by the use of literature pediatric data to develop pediatric PBPK models, expanding the scope of this powerful modeling tool.

Certain pathological conditions, such as inflammation, are known to affect basal cytochrome P450 (CYP) expression by modulating transcriptional regulation, and the pharmacokinetics of drugs can vary among patients. However, changes in drug-induced CYP expression under pathological conditions have not been elucidated in detail. Here, we investigated the effects of hepatic inflammation and injury on phenobarbital-induced expression of CYP isoforms in mice. Phenobarbital was administered once as a CYP inducer in the carbon tetrachloride-induced hepatitis model mice. The mRNA expression levels of Cyp3a11 and Cyp2b10 in the liver and small intestine were measured using reverse transcription polymerase chain reaction. The enzymatic activity of CYP3A in liver S9 was evaluated using midazolam as the substrate. Phenobarbital increased the mRNA expression of Cyp3a11 and Cyp2b10 in the liver of healthy mice, but not in the small intestine. Increased mRNA expression of hepatic Cyp3a11 and Cyp2b10 by phenobarbital was significantly suppressed in the hepatitis model mice. Hepatitis also suppressed the increased CYP3A enzymatic activity induced by phenobarbital in liver S9, consistent with the results of Cyp3a11 mRNA expression. These results suggest that the inducibility of CYP by phenobarbital may vary in patients with hepatitis, indicating that pharmacokinetic drug–drug interactions can be altered under certain pathological conditions.

The purpose of this work was to fabricate the microencapsulation of capsaicin using electrospray technology and polyvinylpyrrolidone (PVP) K30 as a carrier. The morphological characteristics of capsaicin-PVP electrosprayed microencapsulation complex under different processing parameters were observed by scanning electron microscope (SEM), while the best process was determined, wherein it comprised of 10 KV (voltage), 0.8 ml·h⁻¹ (solution flow rate), 0.9 mm (the inner diameter of the needle), and 10 cm (receiving distance). The X-ray diffraction results of the electrosprayed complex showed that capsaicin was present in the carrier in an amorphous form. The drug release properties of capsaicin powder and electrosprayed complex in different media were investigated. The results showed that in vitro release rates of the capsaicin complex in different media were much higher than that of capsaicin powder, with correspondingly improved bioavailability, defined by intravenous and oral dosing in rats in vivo, for the electrosprayed complex compared to that of capsacin powder. The dose absorbed of the electrosprayed complex was 2.2-fold that of the capsaicin powder. In short, electrospray technology can be used to prepare capsaicin-loaded electrosprayed microencapsulation complex. This technique can improve the solubility and bioavailability of capsaicin, and provide a new idea for the solubilization of other insoluble drugs.

Blood concentration monitoring plays an important role in the rational use of norvancomycin. However, the reference interval for the norvancomycin plasma concentration in the treatment of infections in hemodialysis patients with end stage kidney disease is undefined. To determine the safe and effective interval for the norvancomycin plasma trough concentration, 39 patients treated with hemodialysis and norvancomycin were analyzed retrospectively. The norvancomycin plasma concentration before hemodialysis was tested as the trough concentration. The associations of the norvancomycin trough concentration with efficacy and adverse reactions were evaluated. No norvancomycin concentration above 20 μg/mL was detected. The trough concentration, but not the dose, had a significant effect on the anti-infectious efficacy. Compared with the low norvancomycin trough concentration group (<9.30 μg/mL), the high concentration group (9.30–20.0 μg/mL) had improved efficacy (OR = 15.45, p < 0.01) with similar side effects (OR = 0.5417, p = 0.4069). It is beneficial to maintain the norvancomycin trough concentration at 9.30–20.0 μg/mL to achieve a good anti-infectious effect in hemodialysis patients with end stage kidney disease. Plasma concentration monitoring provides a data basis for the individual treatment of infections with norvancomycin in hemodialysis patients.

Pediatric drugs knowledge still leaves several gaps to be filled, all the while many biopharmaceutic properties applied to adults do not work in pediatrics. The solubility in many cases is extrapolated to pediatrics; however, sometimes it may not represent the real scenario. In this context, the aim of this study was to assess the possibility of the extrapolation of the solubility data assumed for adults to children aged 2–12 years using lamotrigine (LTG) as a model. LTG showed that its solubility is dependent on the pH of the medium, no precipitate formation was seen, and biomimetic media showed a greater capacity to solubilize it. Based on the dose number (D₀) in adults, the LTG was soluble in acidic pH media and poorly soluble in neutral to basic. Similar behavior was found in conditions which mimic children aged 10–12 years at a dose of 5 and 15 mg/kg. The D₀ for 5-year-old children at a dose of 15 mg/kg showed different behaviors between biorelevant and pharmacopeial buffers media. For children aged 2–3 years, LTG appeared to be poorly soluble under both gastric and intestinal conditions. Solubility was dependent on the volume of fluid calculated for each age group, and this may impact the development of better pharmaceutical formulations for this population, better pharmacokinetic predictions in tools as PBPK, and physiologically-based biopharmaceutics modeling, greater accuracy in the justifications for biowaiver, and many other possibilities.

Clopidogrel (Clop) is oxidized by cytochrome P450s (CYPs) to an active thiol metabolite, Clop-AM, to inhibit platelet activation and aggregation. As an irreversible inhibitor of CYP2B6 and CYP2C19, clopidogrel may inhibit its own metabolism after long-term administration. The study compared the pharmacokinetic profiles of clopidogrel and its metabolites in rats receiving a single or a 2 week administration of Clop. The mRNA and protein levels of hepatic clopidogrel-metabolizing enzymes and their enzymatic activities were analyzed to explore their contribution to any altered plasma exposure of Clop and its metabolites. The results showed that long-term treatment with clopidogrel significantly decreased the AUC_(0-t) and C_max values of Clop-AM in rats, accompanied with markedly impaired catalytic activities of Clop-metabolizing CYPs including CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP3A4. It suggests that consecutive administration of Clop to rats decreases hepatic CYPs activities, which may, in turn, inhibit clopidogrel metabolism and then reduce Clop-AM plasma exposure. Therefore, long-term treatment with clopidogrel has the potential to reduce its anti-platelet activity and to increase the risk of drug–drug interaction.