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Iliopoulos F, Tu D, Pence IJ, Li X, Ghosh P, Luke MC, Raney SG, Rantou E, Evans CL. Determining topical product bioequivalence with stimulated Raman scattering microscopy. J Control Release 2024; 367:864-876. [PMID: 38346503 DOI: 10.1016/j.jconrel.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/19/2024]
Abstract
Generic drugs are essential for affordable medicine and improving accessibility to treatments. Bioequivalence (BE) is typically demonstrated by assessing a generic product's pharmacokinetics (PK) relative to a reference-listed drug (RLD). Accurately estimating cutaneous PK (cPK) at or near the site of action can be challenging for locally acting topical products. Certain cPK approaches are available for assessing local bioavailability (BA) in the skin. Stimulated Raman scattering (SRS) microscopy has unique capabilities enabling continuous, high spatial and temporal resolution and quantitative imaging of drugs within the skin. In this paper, we developed an approach based on SRS and a polymer-based standard reference for the evaluation of topical product BA and BE in human skin ex vivo. BE assessment of tazarotene-containing formulations was achieved using cPK parameters obtained within different skin microstructures. The establishment of BE between the RLD and an approved generic product was successfully demonstrated. Interestingly, within the constraints of the current study design the results suggest similar BA between the tested gel formulation and the reference cream formulation, despite the differences in the formulation/dosage form. Another formulation containing polyethylene glycol as the vehicle was demonstrated to be not bioequivalent to the RLD. Compared to using the SRS approach without a standard reference, the developed approach enabled more consistent and reproducible results, which is crucial in BE assessment. The abundant information from the developed approach can help to systematically identify key areas of study design that will enable a better comparison of topical products and support an assessment of BE.
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Affiliation(s)
- Fotis Iliopoulos
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown 02129, MA, USA
| | - Dandan Tu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown 02129, MA, USA
| | - Isaac J Pence
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown 02129, MA, USA
| | - Xiaolei Li
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown 02129, MA, USA
| | - Priyanka Ghosh
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring 20993, MD, USA
| | - Markham C Luke
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring 20993, MD, USA
| | - Sam G Raney
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring 20993, MD, USA
| | - Elena Rantou
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring 20993, MD, USA
| | - Conor L Evans
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown 02129, MA, USA.
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Lim D, Rantou E, Kim J, Choi S, Choi NH, Grosser S. Adaptive designs for IVPT data with mixed scaled average bioequivalence. Pharm Stat 2023; 22:1116-1134. [PMID: 37555542 DOI: 10.1002/pst.2333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/19/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023]
Abstract
In vitro permeation tests (IVPT) offer accurate and cost-effective development pathways for locally acting drugs, such as topical dermatological products. For assessment of bioequivalence, the FDA draft guidance on generic acyclovir 5% cream introduces a new experimental design, namely the single-dose, multiple-replicate per treatment group design, as IVPT pivotal study design. We examine the statistical properties of its hypothesis testing method-namely the mixed scaled average bioequivalence (MSABE). Meanwhile, some adaptive design features in clinical trials can help researchers make a decision earlier with fewer subjects or boost power, saving resources, while controlling the impact on family-wise error rate. Therefore, we incorporate MSABE in an adaptive design combining the group sequential design and sample size re-estimation. Simulation studies are conducted to study the passing rates of the proposed methods-both within and outside the average bioequivalence limits. We further consider modifications to the adaptive designs applied for IVPT BE trials, such as Bonferroni's adjustment and conditional power function. Finally, a case study with real data demonstrates the advantages of such adaptive methods.
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Affiliation(s)
- Daeyoung Lim
- University of Connecticut, Storrs, Connecticut, USA
| | - Elena Rantou
- Office of Biostatistics, Office of Translational Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jessica Kim
- Office of Biostatistics, Office of Translational Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Sungwoo Choi
- Office of Biostatistics, Office of Translational Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Nam Hee Choi
- Office of Biostatistics, Office of Translational Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Stella Grosser
- Office of Biostatistics, Office of Translational Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
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3
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Senemar S, Kuzma BA, Ramezanli T, Ghosh P, Raney SG, Rantou E, Stagni G. Bioequivalence Evaluation of Topical Metronidazole Products Using Dermal Microdialysis in New Zealand Rabbits. AAPS PharmSciTech 2023; 24:204. [PMID: 37789133 DOI: 10.1208/s12249-023-02660-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 09/15/2023] [Indexed: 10/05/2023] Open
Abstract
Comparative assessment of cutaneous pharmacokinetics (cPK) by dermal microdialysis (dMD) appears to be suitable to evaluate the bioequivalence (BE) of topical dermatological drug products applied to the skin (TDDPs). Although dMD studies in the literature have reported inconclusive BE assessments, we have addressed several methodological deficiencies to improve dMD's capability to assess BE between reference (R) and approved generic (referred to as test (T)) gel and cream products of metronidazole (MTZ). The 90% confidence interval (CI) of the geometric mean ratios for the Ln(AUC0-24) and Ln(Cmax) endpoints was centered within the BE limits of 80-125%. The CIs extended outside this range as the proof-of-principle study was not statistically powered to demonstrate BE (N = 7 rabbits). A power analysis suggests that, with the variability observed in this study, 21 rabbits for the cream and 11 rabbits for the gel would be sufficient to support an evaluation of BE with the 2 probe replicates we used, and only 10 and 5 rabbits would be sufficient to power the study for the cream and gel, respectively, if 4 probe replicates are used for each treatment per rabbit. These results indicate that dMD when properly controlling variables can be used to support BE assessments for TDDPs.
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Affiliation(s)
- Sharareh Senemar
- Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy, Long Island University, 75 DeKalb Ave., Brooklyn, New York, 11201, USA
| | - Benjamin A Kuzma
- Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy, Long Island University, 75 DeKalb Ave., Brooklyn, New York, 11201, USA
- Drug Metabolism and Pharmacokinetics, Vertex Pharmaceuticals, Boston, Massachusetts, USA
| | - Tannaz Ramezanli
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Priyanka Ghosh
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Sam G Raney
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Elena Rantou
- Division of Biometrics VIII, Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Grazia Stagni
- Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy, Long Island University, 75 DeKalb Ave., Brooklyn, New York, 11201, USA.
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4
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Brito JP, Deng Y, Ross JS, Choi NH, Graham DJ, Qiang Y, Rantou E, Wang Z, Zhao L, Shah ND, Lipska KJ. Rates of, and factors associated with, switching among generic levothyroxine preparations in commercially insured American adults. Endocrine 2022; 76:349-358. [PMID: 35107758 PMCID: PMC9210352 DOI: 10.1007/s12020-022-02987-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/18/2022] [Indexed: 11/03/2022]
Abstract
IMPORTANCE Some practice guidelines warn against generic L-thyroxine preparation switching. OBJECTIVE To examine the rates of generic L-thyroxine preparation switching within one year of initiating L-thyroxine, and to examine factors associated with switching. DESIGN AND SETTING Retrospective study using national data from a large administrative claims database from January 2008 through November 2018. PATIENTS Medicare or commercially insured adults (≥18 years) who filled a generic L-thyroxine preparation. MAIN OUTCOME MEASURES At least one switch from one generic L-thyroxine preparation to another within 1 year of L-thyroxine initiation defined by prescription fills. RESULTS From January 2008 to November 2018, we included 483,390 patients who initiated generic L-thyroxine: mean (SD) age was 61.4 years (15.2), 75.2% were female, 72.6% were white. Within 1 year of initiating therapy, 98,013 (20%) switched to another L-thyroxine generic preparation at least once. In a multivariate logistic regression analysis, factors associated with switching included the number of pharmacies visited to fill L-thyroxine (>2 vs 1 adjusted OR [aOR] 7.15, 95% confidence interval [CI] 6.97-7.34), age ≥75 vs. <45 years (aOR 1.29, 95% CI 1.26-1.33), history of thyroid surgery (aOR 1.22, 95% CI 1.13-1.31), and first L-thyroxine fill date in 2018 vs. 2008 (aOR 3.32, 95% CI 3.14-3.51). CONCLUSIONS AND RELEVANCE One in five patients switched among generic L-thyroxine manufacturers within one year of treatment initiation. Generic L-thyroxine switching occurred more often when more pharmacies were used to fill L-thyroxine. Given existing guideline recommendations, additional studies should clarify the impact of generic L-thyroxine switching on thyroid hormone values.
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Affiliation(s)
- Juan P Brito
- Division of Endocrinology, Diabetes, Metabolism, Nutrition, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
| | - Yihong Deng
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Joseph S Ross
- Section of General Internal Medicine and the National Clinician Scholars Program, Yale School of Medicine, New Haven, CT, USA
- Department of Health Policy and Management, Yale School of Public Health, New Haven, CT, USA
- Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, CT, USA
| | - Nam Hee Choi
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | - David J Graham
- Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | - Yandong Qiang
- Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | - Elena Rantou
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | - Zhong Wang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | - Liang Zhao
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, White Oak, MD, USA
| | | | - Kasia J Lipska
- Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, CT, USA
- Section of Endocrinology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
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Brito JP, Deng Y, Ross JS, Choi NH, Graham DJ, Qiang Y, Rantou E, Wang Z, Zhao L, Shah ND, Lipska KJ. Association Between Generic-to-Generic Levothyroxine Switching and Thyrotropin Levels Among US Adults. JAMA Intern Med 2022; 182:418-425. [PMID: 35226058 PMCID: PMC8886450 DOI: 10.1001/jamainternmed.2022.0045] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
IMPORTANCE Switching among generic levothyroxine sodium products made by different manufacturers typically occurs at the pharmacy and may affect serum thyrotropin (TSH) levels. OBJECTIVE To compare TSH levels between patients who continued taking the same sourced generic levothyroxine product and those who switched. DESIGN, SETTING, AND PARTICIPANTS This comparative effectiveness research study with 1:1 propensity matching used data from OptumLabs Data Warehouse, a national administrative claims database linked to laboratory test results. Adults aged 18 years or older were included if they filled a generic levothyroxine prescription between January 1, 2008, and June 30, 2019, and had a stable drug dose, the same drug manufacturer, and a normal TSH level (0.3-4.4 mIU/L) for at least 3 months before either continuing to take the same product or switching among generic levothyroxine products (index date). Patients were excluded if they were pregnant, had diagnosed hypopituitarism or hyperthyroidism, or had a medical condition or used medications that could affect thyrotropin levels. They were also excluded if they filled a prescription for other forms of thyroid replacement therapy between 6 months before the index date and when the first TSH level was obtained 6 weeks to 12 months after the index date. Data were analyzed from December 1, 2019, to November 24, 2021. MAIN OUTCOMES AND MEASURES Proportion of individuals with a normal (0.3-4.4 mIU/L) or markedly abnormal (<0.1 or >10.0 mIU/L) TSH level using the first available laboratory result 6 weeks to 12 months after the index date. A propensity score model was developed to minimize confounding using logistic regression with the binary outcome of continuing the same sourced levothyroxine product vs switching generic levothyroxine. Covariates were demographics, comorbidities, and baseline TSH level. The balance among the treatment groups was evaluated by comparing standardized mean differences of baseline covariates between the groups. RESULTS A total of 15 829 patients filled generic levothyroxine (mean [SD] age, 58.9 [14.6] years; 73.4% [11 624] were women; 4.5% [705] were Asian, 10.2% [1617] were Black, 11.4% [1801] were Hispanic, and 71.4% [11 295] were White individuals); of these patients, 56.3% [8905] received a daily levothyroxine dose of 50 μg or less. A total of 13 049 patients (82.4%) continued taking the same sourced preparation, and 2780 (17.6%) switched among generic levothyroxine preparations. Among 2780 propensity-matched patient pairs, the proportion of patients with a normal TSH level after the index date was 82.7% (2298) among nonswitchers and 84.5% (2348) among switchers (risk difference, -0.018; 95% CI, -0.038 to 0.002; P = .07). The proportion of patients with a markedly abnormal TSH level after the index date was 3.1% (87) among nonswitchers and 2.5% (69) among switchers (risk difference, 0.007; 95% CI, -0.002 to 0.015; P = .14). The mean (SD) TSH levels after the index date were 2.7 (2.3) mIU/L among nonswitchers and 2.7 (3.3) mIU/L among switchers (P = .94). CONCLUSIONS AND RELEVANCE Results of this comparative effectiveness research study suggest that switching among different generic levothyroxine products was not associated with clinically significant changes in TSH level. These findings conflict with the current guideline recommendation that warns clinicians about potential changes in TSH level associated with switching among levothyroxine products sourced from different manufacturers.
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Affiliation(s)
- Juan P Brito
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Yihong Deng
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota
| | - Joseph S Ross
- Section of General Internal Medicine, Yale School of Medicine, New Haven, Connecticut.,National Clinician Scholars Program, Yale School of Medicine, New Haven, Connecticut.,Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut.,Center for Outcomes Research and Evaluation, Yale New Haven Hospital, New Haven, Connecticut
| | - Nam Hee Choi
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - David J Graham
- Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - Yandong Qiang
- Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - Elena Rantou
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - Zhong Wang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - Liang Zhao
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, White Oak, Maryland
| | - Nilay D Shah
- Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota.,Division of Health Care Policy and Research, Mayo Clinic, Rochester, Minnesota.,OptumLabs, Cambridge, Massachusetts
| | - Kasia J Lipska
- Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut.,Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
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Shin SH, Rantou E, Raney SG, Ghosh P, Hassan H, Stinchcomb A. Cutaneous Pharmacokinetics of Acyclovir Cream 5% Products: Evaluating Bioequivalence with an In Vitro Permeation Test and an Adaptation of Scaled Average Bioequivalence. Pharm Res 2020; 37:210. [PMID: 33001286 DOI: 10.1007/s11095-020-02821-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/09/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE The in vitro permeation test (IVPT) with a new statistical approach was investigated to evaluate the utility of an IVPT methodology as a sensitive tool to support a demonstration of bioequivalence (BE) for topical dermatological drug products. METHODS IVPT experiments were performed utilizing ex vivo human skin. The initial screening tests involved four differently formulated acyclovir 5% creams: the U.S. Zovirax® as the reference product and the U.K. Zovirax®, Aciclovir 1A Pharma® and Aciclostad® as test products. Subsequently, a pivotal BE study was conducted comparing the two Zovirax® creams. The resulting data was used to evaluate BE of test (T) versus reference (R), T versus T, and R versus R, with an adaption of scaled average BE approach to address high variability in IVPT data. RESULTS More acyclovir permeated into and through the skin from the two Zovirax® creams compared to the two non-Zovirax® creams. The U.S. Zovirax® cream showed a significantly higher Jmax and total amount permeated over 48 h, compared to the U.K. Zovirax® cream. The statistical analysis indicated that the test and reference products were not bioequivalent, whereas each product tested against itself was shown to be bioequivalent. CONCLUSIONS The current study demonstrated that the IVPT method, with an appropriate statistical analysis of the results, is a sensitive and discriminating test that can detect differences in the rate and extent of acyclovir bioavailability in the skin from differently formulated cream products.
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Affiliation(s)
- Soo Hyeon Shin
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street PHN521, MD, 21201, Baltimore, USA
| | - Elena Rantou
- Office of Biostatistics Office of Translational Sciences Center for Drug Evaluation and Research, United States Food and Drug Administration, White Oak Campus, MD, Silver Spring, USA
| | - Sam G Raney
- Office of Research and Standards Office of Generic Drugs Center for Drug Evaluation and Research, United States Food and Drug Administration, MD, 20993, Silver Spring, United States
| | - Priyanka Ghosh
- Office of Research and Standards Office of Generic Drugs Center for Drug Evaluation and Research, United States Food and Drug Administration, MD, 20993, Silver Spring, United States
| | - Hazem Hassan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street PHN521, MD, 21201, Baltimore, USA
- Department of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Audra Stinchcomb
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street PHN521, MD, 21201, Baltimore, USA.
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Bodenlenz M, Augustin T, Birngruber T, Tiffner KI, Boulgaropoulos B, Schwingenschuh S, Raney SG, Rantou E, Sinner F. Variability of Skin Pharmacokinetic Data: Insights from a Topical Bioequivalence Study Using Dermal Open Flow Microperfusion. Pharm Res 2020; 37:204. [PMID: 32989514 PMCID: PMC7522073 DOI: 10.1007/s11095-020-02920-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/28/2020] [Indexed: 11/30/2022]
Abstract
Purpose Dermal open flow microperfusion (dOFM) has previously demonstrated its utility to assess the bioequivalence (BE) of topical drug products in a clinical study. We aimed to characterize the sources of variability in the dermal pharmacokinetic data from that study. Methods Exploratory statistical analyses were performed with multivariate data from a clinical dOFM-study in 20 healthy adults evaluating the BE, or lack thereof, of Austrian test (T) and U.S. reference (R) acyclovir cream, 5% products. Results The overall variability of logAUC values (CV: 39% for R and 45% for T) was dominated by inter-subject variability (R: 82%, T: 91%) which correlated best with the subject’s skin conductance. Intra-subject variability was 18% (R) and 9% (T) of the overall variability; skin treatment sites or methodological factors did not significantly contribute to that variability. Conclusions Inter-subject variability was the major component of overall variability for acyclovir, and treatment site location did not significantly influence intra-subject variability. These results support a dOFM BE study design with T and R products assessed simultaneously on the same subject, where T and R treatment sites do not necessarily need to be next to each other. Localized variation in skin microstructure may be primarily responsible for intra-subject variability.
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Affiliation(s)
- Manfred Bodenlenz
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria
| | - Thomas Augustin
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria
| | - Thomas Birngruber
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria
| | - Katrin I Tiffner
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria
| | - Beate Boulgaropoulos
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria.,Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Simon Schwingenschuh
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria
| | - Sam G Raney
- Division of Therapeutic Performance Office of Research and Standards Office of Generic Drugs, United States (U.S.) Food and Drug Administration, 10903 New Hampshire Avenue, MD, 20993, Silver Spring, USA
| | - Elena Rantou
- Division of Biostatistics VIII, Office of Biostatistics, Office of Translational Sciences, United States (U.S.) Food and Drug Administration, 10903 New Hampshire Avenue, MD, 20993, Silver Spring, USA
| | - Frank Sinner
- HEALTH - Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010, Graz, Austria. .,Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.
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8
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Pensado A, Chiu WS, Cordery SF, Rantou E, Bunge AL, Delgado-Charro MB, Guy RH. Stratum Corneum Sampling to Assess Bioequivalence between Topical Acyclovir Products. Pharm Res 2019; 36:180. [PMID: 31728737 PMCID: PMC6856025 DOI: 10.1007/s11095-019-2707-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 11/01/2022]
Abstract
PURPOSE To examine the potential of stratum corneum (SC) sampling via tape-stripping in humans to assess bioequivalence of topical acyclovir drug products, and to explore the potential value of alternative metrics of local skin bioavailability calculable from SC sampling experiments. METHODS Three acyclovir creams were considered in two separate studies in which drug amounts in the SC after uptake and clearance periods were measured and used to assess bioequivalence. In each study, a "reference" formulation (evaluated twice) was compared to the "test" in 10 subjects. Each application site was replicated to achieve greater statistical power with fewer volunteers. RESULTS SC sampling revealed similarities and differences between products consistent with results from other surrogate bioequivalence measures, including dermal open-flow microperfusion experiments. Further analysis of the tape-stripping data permitted acyclovir flux into the viable skin to be deduced and drug concentration in that 'compartment' to be estimated. CONCLUSIONS Acyclovir quantities determined in the SC, following a single-time point uptake and clearance protocol, can be judiciously used both to objectively compare product performance in vivo and to assess delivery of the active into skin tissue below the barrier, thereby permitting local concentrations at or near to the site of action to be determined.
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Affiliation(s)
- A Pensado
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - W S Chiu
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - S F Cordery
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - E Rantou
- Office of Biostatistics, Office of Translational Sciences, Center for Drug Evaluation and Research, United States Food and Drug Administration, White Oak Campus, Silver Spring, MD, USA
| | - A L Bunge
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
| | - M B Delgado-Charro
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - R H Guy
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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9
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Hein N, Rantou E, Schuette P. Comparing methods for clinical investigator site inspection selection: a comparison of site selection methods of investigators in clinical trials. J Biopharm Stat 2019; 29:860-873. [PMID: 31462145 DOI: 10.1080/10543406.2019.1657134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background During the past two decades, the number and complexity of clinical trials have risen dramatically increasing the difficulty of choosing sites for inspection. FDA's resources are limited and so sites should be chosen with care. Purpose To determine if data mining techniques and/or unsupervised statistical monitoring can assist with the process of identifying potential clinical sites for inspection. Methods Five summary-level clinical site datasets from four new drug applications (NDA) and one biologics license application (BLA), where the FDA had performed or had planned site inspections, were used. The number of sites inspected and the results of the inspections were blinded to the researchers. Five supervised learning models from the previous two years (2016-2017) of an on-going research project were used to predict site inspections results, i.e., No Action Indicated (NAI), Voluntary Action Indicated (VAI), or Official Action Indicated (OAI). Statistical Monitoring Applied to Research Trials (SMARTTM) software for unsupervised statistical monitoring software developed by CluePoints (Mont-Saint-Guibert, Belgium) was utilized to identify atypical centers (via a p-value approach) within a study.Finally, Clinical Investigator Site Selection Tool (CISST), developed by the Center for Drug Evaluation and Research (CDER), was used to calculate the total risk of each site thereby providing a framework for site selection. The agreement between the predictions of these methods was compared. The overall accuracy and sensitivity of the methods were graphically compared. Results Spearman's rank order correlation was used to examine the agreement between the SMARTTM analysis (CluePoints' software) and the CISST analysis. The average aggregated correlation between the p-values (SMARTTM) and total risk scores (CISST) for all five studies was 0.21, and range from -0.41 to 0.50. The Random Forest models for 2016 and 2017 showed the highest aggregated mean agreement (65.1%) amongst outcomes (NAI, VAI, OAI) for the three available studies. While there does not appear to be a single most accurate approach, the performance of methods under certain circumstances is discussed later in this paper. Limitations Classifier models based on data mining techniques require historical data (i.e., training data) to develop the model. There is a possibility that sites in the five-summary level datasets were included in the training datasets for the models from the previous year's research which could result in spurious confirmation of predictive ability. Additionally, the CISST was utilized in three of the five site selection processes, possibly biasing the data. Conclusion The agreement between methods was lower than expected and no single method emerged as the most accurate.
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Affiliation(s)
- Nicholas Hein
- Department of Biostatistics, University of Nebraska Medical Center , Omaha , NE , USA
| | - Elena Rantou
- Office of Biostatistics/Office of Translational Sciences/Center for Drug Evaluation and Research, U.S. Food and Drug Administration , Silver Spring , MD , USA
| | - Paul Schuette
- Office of Biostatistics/Office of Translational Sciences/Center for Drug Evaluation and Research, U.S. Food and Drug Administration , Silver Spring , MD , USA
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