Biopharmaceutics classification system-based biowaivers for generic oncology drug products: case studies.

Establishing bioequivalence (BE) of drugs indicated to treat cancer poses special challenges. For ethical reasons, often, the studies need to be conducted in cancer patients rather than in healthy volunteers, especially when the drug is cytotoxic. The Biopharmaceutics Classification System (BCS) introduced by Amidon (1) and adopted by the FDA, presents opportunities to avoid conducting the bioequivalence studies in humans. This paper analyzes the application of the BCS approach by the generic pharmaceutical industry and the FDA to oncology drug products. To date, the FDA has granted BCS-based biowaivers for several drug products involving at least four different drug substances, used to treat cancer. Compared to in vivo BE studies, development of data to justify BCS waivers is considered somewhat easier, faster, and more cost effective. However, the FDA experience shows that the approval times for applications containing in vitro studies to support the BCS-based biowaivers are often as long as the applications containing in vivo BE studies, primarily because of inadequate information in the submissions. This paper deliberates some common causes for the delays in the approval of applications requesting BCS-based biowaivers for oncology drug products. Scientific considerations of conducting a non-BCS-based in vivo BE study for generic oncology drug products are also discussed. It is hoped that the information provided in our study would help the applicants to improve the quality of ANDA submissions in the future.

Regulatory utility of physiologically based pharmacokinetic modeling for assessing food impact in bioequivalence studies: A workshop summary report.

This workshop report summarizes the presentations and panel discussion related to the use of physiologically based pharmacokinetic (PBPK) modeling approaches for food effect assessment, collected from Session 2 of Day 2 of the workshop titled "Regulatory Utility of Mechanistic Modeling to Support Alternative Bioequivalence Approaches." The US Food and Drug Administration in collaboration with the Center for Research on Complex Generics organized this workshop where this particular session titled "Oral PBPK for Evaluating the Impact of Food on BE" presented successful cases of PBPK modeling approaches for food effect assessment. Recently, PBPK modeling has started to gain popularity among academia, industries, and regulatory agencies for its potential utility during bioavailability (BA) and/or bioequivalence (BE) studies of new and generic drug products to assess the impact of food on BA/BE. Considering the promises of PBPK modeling in generic drug development, the aim of this workshop session was to facilitate knowledge sharing among academia, industries, and regulatory agencies to understand the knowledge gap and guide the path forward. This report collects and summarizes the information presented and discussed during this session to disseminate the information into a broader audience for further advancement in this area.

The effect of food vehicles on in vitro performance of pantoprazole sodium delayed release sprinkle formulation.

Certain patient populations, including children, the elderly or people with dysphagia, find swallowing whole medications such as tablets and capsules difficult. To facilitate oral administration of drugs in such patients, a common practice is to sprinkle the drug products (e.g., usually after crushing the tablet or opening the capsule) on food vehicles before consumption which improves swallowability. Thus, evaluation of the impact of food vehicles on the potency and stability of the administered drug product is important. The aim of the current study was to evaluate the physicochemical properties (viscosity, pH, and water content) of common food vehicles used for sprinkle administration (e.g., apple juice, applesauce, pudding, yogurt, and milk) and their impacts on the in vitro performance (i.e., dissolution) of pantoprazole sodium delayed release (DR) drug products. The food vehicles evaluated exhibited marked difference in viscosity, pH and water content. Notably, the pH of the food as well as the interaction between food vehicle pH and drug-food contact time were the most significant factors affecting the in vitro performance of pantoprazole sodium DR granules. For example, the dissolution of pantoprazole sodium DR granules sprinkled on food vehicles of low pH (e.g., apple juice or applesauce) for short durations remained unchanged compared with the control group (i.e., without mixing with food vehicles). However, use of high pH food vehicles (e.g., milk) with prolonged contact time (e.g., 2 h) resulted in accelerated pantoprazole release, drug degradation and loss of potency. Overall, a thorough assessment of physicochemical properties of food vehicles and formulation characteristics are a necessary part of the development of sprinkle formulations.

Use of Partial Area Under the Curve in Bioavailability or Bioequivalence Assessments: A Regulatory Perspective.

Peak drug concentration (Cmax ) and total exposure, such as area under the concentration-time curve (AUC) from time zero to infinity may be insufficient for assessing relative bioavailability (BA) or bioequivalence (BE) among two products in cases where rapid onset of action or controlled duration of effect is needed to ensure similar drug efficacy. Regulatory agencies have recommended the use of partial AUC (pAUC) as an additional exposure measure for relative BA or BE assessments. The pAUC metric describes pharmacokinetic profiles with the focus on quantification of exposures over specific time intervals to support the determination of relative BA or BE for these drug products in relation to respective reference products. The principles and rationales for using pAUCs are included in the US Food and Drug Administration (FDA)'s general BA or BE guidances. Specific pAUC recommendations are also reflected in product-specific guidances for generic drug development published by the FDA. Rationales for the use of pAUCs in relative BA or BE assessments are based on drug-specific and product-specific considerations. This white paper introduces the general framework, including rationales for pAUC recommendations, and provides an overview of the current status, challenges, and the FDA considerations on the use of pAUC for relative BA or BE assessments in the United States.

The global bioequivalence harmonisation initiative: Report of EUFEPS/AAPS third conference.

The European Federation of Pharmaceutical Sciences (EUFEPS) and American Association of Pharmaceutical Scientists (AAPS) have collaborated since 2015 to organize international conferences to support global harmonization of regulatory requirements for bioequivalence (BE) assessment. This collaboration has resulted in three Global Bioequivalence Harmonization Initiative (GBHI) workshops which provided a unique opportunity for scientists from academia, industry, and regulatory agencies to discuss current, complex BE issues. The 3rd GBHI workshop was held in April 2018 in Amsterdam/The Netherlands and covered the following topics: (a) the necessity of multiple-dose studies in BE testing; (b) BE of transdermal delivery systems, and (c) liposomal parenteral preparations. This report summarizes the extensive discussions that led to better understanding of the similarities and differences across the major regulatory agencies on these topics and paved the way for future international harmonization.

2019 White Paper On Recent Issues in Bioanalysis: FDA BMV Guidance, ICH M10 BMV Guideline and Regulatory Inputs (Part 2 - Recommendations on 2018 FDA BMV Guidance, 2019 ICH M10 BMV Draft Guideline and Regulatory Agencies' Input on Bioanalysis, Biomarkers and Immunogenicity).

The 2019 13th Workshop on Recent Issues in Bioanalysis (WRIB) took place in New Orleans, LA on 1-5 April 2019 with an attendance of over 1000 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers, immunogenicity and gene therapy. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LCMS, hybrid LBA/LCMS, LBA cell-based/flow cytometry assays and qPCR approaches. This 2019 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2019 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on the 2018 FDA BMV guidance, 2019 ICH M10 BMV draft guideline and regulatory agencies' input on bioanalysis, biomarkers, immunogenicity and gene therapy. Part 1 (Innovation in small molecules and oligonucleotides and mass spectrometry method development strategies for large molecules bioanalysis) and Part 3 (New insights in biomarker assay validation, current and effective strategies for critical reagent management, flow cytometry validation in drug discovery and development and CLSI H62, interpretation of the 2019 FDA immunogenicity guidance and gene therapy bioanalytical challenges) are published in volume 10 of Bioanalysis, issues 22 and 24 (2019), respectively.

2017 White Paper: rise of hybrid LBA/LCMS immunogenicity assays (Part 2: hybrid LBA/LCMS biotherapeutics, biomarkers & immunogenicity assays and regulatory agencies' inputs).

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid ligand binding assay (LBA)/LCMS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for biotherapeutics, biomarkers and immunogenicity assays using hybrid LBA/LCMS and regulatory agencies' inputs. Part 1 (LCMS for small molecules, peptides and small molecule biomarkers) and Part 3 (LBA: immunogenicity, biomarkers and pharmacokinetic assays) are published in Volume 9 of Bioanalysis, issues 22 and 24 (2017), respectively.

2017 White Paper on recent issues in bioanalysis: aren't BMV guidance/guidelines 'Scientific'? (Part 1 - LCMS: small molecules, peptides and small molecule biomarkers).

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California from 3 April 2017 to 7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - A Full Immersion Week of Bioanalysis, Biomarkers and Immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid LBA/LCMS and ligand-binding assay (LBA) approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for Small Molecules, Peptides and Small Molecule Biomarkers using LCMS. Part 2 (Biotherapeutics, Biomarkers and Immunogenicity Assays using Hybrid LBA/LCMS and Regulatory Agencies' Inputs) and Part 3 (LBA: Immunogenicity, Biomarkers and PK Assays) are published in volume 9 of Bioanalysis, issues 23 and 24 (2017), respectively.

2016 White Paper on recent issues in bioanalysis: focus on biomarker assay validation (BAV): (Part 2 - Hybrid LBA/LCMS and input from regulatory agencies).

The 2016 10th Workshop on Recent Issues in Bioanalysis (10th WRIB) took place in Orlando, Florida with participation of close to 700 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations, and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - A Full Immersion Week of Bioanalysis including Biomarkers and Immunogenicity. As usual, it is specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecules involving LCMS, hybrid LBA/LCMS, and LBA approaches, with the focus on biomarkers and immunogenicity. This 2016 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. This White Paper is published in 3 parts due to length. This part (Part 2) discusses the recommendations for Hybrid LBA/LCMS and regulatory inputs from major global health authorities. Parts 1 (small molecule bioanalysis using LCMS) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) have been published in the Bioanalysis journal, issues 22 and 23, respectively.

2016 White Paper on recent issues in bioanalysis: focus on biomarker assay validation (BAV) (Part 1 - small molecules, peptides and small molecule biomarkers by LCMS).

The 2016 10th Workshop on Recent Issues in Bioanalysis (10th WRIB) took place in Orlando, Florida with participation of close to 700 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations, and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - A Full Immersion Week of Bioanalysis including Biomarkers and Immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid LBA/LCMS, and LBA approaches, with the focus on biomarkers and immunogenicity. This 2016 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. This white paper is published in 3 parts due to length. This part (Part 1) discusses the recommendations for small molecules, peptides and small molecule biomarkers by LCMS. Part 2 (Hybrid LBA/LCMS and regulatory inputs from major global health authorities) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will be published in the Bioanalysis journal, issue 23.

2015 White Paper on recent issues in bioanalysis: focus on new technologies and biomarkers (Part 2 - hybrid LBA/LCMS and input from regulatory agencies).

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of over 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. It is once again a 5-day week long event - a full immersion bioanalytical week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations that emerged from the extensive discussions held during the workshop, and is aimed at providing the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to advance scientific excellence, improve quality and deliver better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 2 covers the recommendations for hybrid LBA/LCMS and regulatory agencies' inputs. Part 1 (small molecule bioanalysis using LCMS) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will be published in volume 7 of Bioanalysis, issues 22 and 24, respectively.

2015 White Paper on recent issues in bioanalysis: focus on new technologies and biomarkers (Part 1 - small molecules by LCMS).

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of over 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. It is once again a 5-day week long event - a full immersion bioanalytical week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations that emerged from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to advance scientific excellence, improve quality and deliver better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 1 covers the recommendations for small molecule bioanalysis using LCMS. Part 2 (hybrid LBA/LCMS and regulatory agencies' inputs) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will also be published in volume 7 of Bioanalysis, issues 23 and 24, respectively.

2015 White Paper on recent issues in bioanalysis: focus on new technologies and biomarkers (Part 3--LBA, biomarkers and immunogenicity).

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5 day, week-long event - A Full Immersion Bioanalytical Week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS and LBA approaches, including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 3 discusses the recommendations for large molecule bioanalysis using LBA, biomarkers and immunogenicity. Part 1 (small molecule bioanalysis using LCMS) and Part 2 (hybrid LBA/LCMS and regulatory inputs from major global health authorities) have been published in volume 7, issues 22 and 23 of Bioanalysis, respectively.

Binding of polychlorinated biphenyls/metabolites to hemoglobin.

Polychlorinated biphenyls (PCBs) may form reactive electrophiles that can bind covalently to hemoglobin in vivo. Female C57/BL6 mice, pretreated with phenobarbital and P-naphthoflavone, were injected with either radiolabeled 4-chlorobiphenyl, 3,3',4.4'-tetrachlorobiphenyl, benzo[a]pyrene (B[a]P) or the corresponding non-labeled 4-chlorobiphenyl, 3.3',4.4'-tetrachlorobiphenyl, B[a]P or vehicle. Blood was collected at different time points. At 24 h a greater presence of 4-chlorobiphenyl and 3,3',4.4'-tetrachlorobiphenyl in the plasma, compared with the erythrocytes, was observed. For all three treatment groups the radioactivity in the hemolysate was found to be greater than the vehicle-treated group, except at 2 h after dosing, suggesting an association with hemoglobin. Covalent binding with globin was 10-fold greater for 4-chlorobiphenyl-treated animals compared with 3,3',4,4'-tetrachlorobiphenyl-treated animals. Liquid chromatography-mass spectral analysis of globin was used to identify adducts. Our preliminary data show an increase in mass corresponding to adducts of oxidized metabolites of PCBs. Detection of adducts of PCBs with hemoglobin could provide a valuable tool to evaluate acute exposure of a population.

Polychlorinated biphenyls are not substrates for the multidrug resistance transporter-1.

The multidrug resistance (MDR) transporter is a phosphorylated glycoprotein (P-gp) that has been implicated in the efflux of a large variety of xenobiotics, thereby protecting vital organs. This study examines the hypothesis that the multidrug resistance transporter is involved in restricting the entry of polychlorinated biphenyls (PCBs) into the brain. Three test systems were used. First, the ATPase activity of the human P-gp was measured as an indicator of the interaction of PCBs with the MDR transporter. PCB congeners and metabolites included in the study were PCB 153, PCB 169, PCB 77, and the 4-hydroxy and 4,4'-dihydroxy metabolites of PCB 77. An increase in ATPase activity was observed for all the PCBs tested except the 4-hydroxy metabolite of PCB 77. Second, we studied the transport of (14)C-PCB 77 and (14)C-PCB153 in a cell-culture model using porcine kidney cells expressing the human MDR1 or the mouse mdr1a gene and compared it to the transport in control cells. No difference in directional transport due to P-gp was observed with either of the congeners in any of the cell lines. Finally, the distribution pattern of (14)C-PCB 77 in mdr1a knockout mice and genetically matched wild-type mice was measured. No significant differences in tissue distribution, especially in the brain tissue, were observed between wild-type and mdr1a knockout mice. These results suggest that some PCB congeners can bind to the MDR1 transporter; however, they may not be transported by it.

Glucuronidation of hydroxylated polychlorinated biphenyls (PCBs).

Polychlorinated biphenyls (PCBs) may be metabolized to hydroxylated compounds. While many of these metabolites are further converted to either the glucuronic acid or the sulfate conjugates by phase II enzymes, which facilitates their excretion, some hydroxylated PCBs persist in the body. This may reflect their inability to be conjugated. A possible role of uridine diphosphate glucuronosyl transferase (UGT) in the elimination of hydroxylated metabolites of PCBs was therefore investigated. Glucuronidation studies of PCB metabolites included ones which are eliminated with relative ease and also ones which are reported to be retained in blood. Liver microsomes, prepared from male Wistar rats treated by intraperitoneal injections of phenobarbital for 3 days (400 micromol/kg/day), were used as the source of UGT. Enzyme kinetics (V(max) and K(m)) were determined for each of the metabolites. The efficiency of glucuronidation (V(max)/K(m)) was found to vary from <3 to 116 microL/min/mg and was dependent on the structure of the metabolites. Substitution of chlorine atoms on the nonhydroxylated ring greatly lowered the V(max) of the enzyme, with substitution in the meta and para positions being least favorable for enzyme activity. Steric hindrance around the hydroxyl group by chlorines on adjacent carbon atoms did not play a major role. A weak relationship between the calculated dihedral angle (planarity), pK(a), log D, and enzyme activity was determined (r(2) < 0.5). However, a stronger relationship for the surface area and surface volume of the molecule was observed (r(2) >or= 0.5). This study explains in part why some PCB metabolites persist in the body.