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Featured researches published by Sau L. Lee.


Aaps Journal | 2012

Effects of Device and Formulation on In Vitro Performance of Dry Powder Inhalers

Wallace P. Adams; Sau L. Lee; Robert Plourde; Robert Lionberger; Craig M. Bertha; William H. Doub; Jean-Marc Bovet; Anthony J. Hickey

The study examined the sensitivity of DPI in vitro performance to formulation and device changes. Rotahaler/Rotacaps was selected as the reference DPI drug product, and Aerolizer was selected as the test device. Since the test device was recognized to have much greater efficiency of dispersion, simple modifications to both formulation and device were made in an effort to provide a closer match to the in vitro performance of the reference product. The modifications included varying the drug and lactose particle sizes and/or lactose fine particle content in the test formulations, as well as lowering the specific resistance of the test device. These modifications were intended to address variables important for drug product performance for a defined experimental design and were not intended to mimic the extensive formulation and device design strategies that are employed in an industrial setting. Formulation and device modifications resulted in a modified test product that approached the reference product in the in vitro performance.


Aaps Journal | 2017

Liposomal Drug Product Development and Quality: Current US Experience and Perspective

Mamta Kapoor; Sau L. Lee; Katherine M. Tyner

ABSTRACTResearch in the area of liposomes has grown substantially in the past few decades. Liposomes are lipid bilayer structures that can incorporate drug substances to modify the drug’s pharmacokinetic profile thereby improving drug delivery. The agency has received over 400 liposomal drug product submissions (excluding combination therapies), and there are currently eight approved liposomal drug products on the US market. In order to identify the pain points in development and manufacturing of liposomal drug products, a retrospective analysis was performed from a quality perspective on submissions for new and generic liposomal drug products. General analysis on liposomal drug product submissions was also performed. Results indicated that 96% of the submissions were Investigational New Drug (IND) applications, 3% were New Drug Applications (NDAs), and the remaining 1% was Abbreviated New Drug Applications (ANDAs). Doxorubicin hydrochloride was the most commonly used drug substance incorporated into the liposomes (31%). The majority of the liposomal products were administered via intravenous route (84%) with cancer (various types) being the most common indication (63%). From a quality perspective, major challenges during the development of liposomal drug products included identification and (appropriate) characterization of critical quality attributes of liposomal drug products and suitable control strategies during product development. By focusing on these areas, a faster and more efficient development of liposomal drug products may be achieved. Additionally, in this way, the drug review process for such products can be streamlined.


International Journal of Pharmaceutics | 2016

Advancing pharmaceutical quality: An overview of science and research in the U.S. FDA's Office of Pharmaceutical Quality.

Adam C. Fisher; Sau L. Lee; Daniel P. Harris; Lucinda F. Buhse; Steven Kozlowski; Lawrence X. Yu; Michael Kopcha; Janet Woodcock

Failures surrounding pharmaceutical quality, particularly with respect to product manufacturing issues and facility remediation, account for the majority of drug shortages and product recalls in the United States. Major scientific advancements pressure established regulatory paradigms, especially in the areas of biosimilars, precision medicine, combination products, emerging manufacturing technologies, and the use of real-world data. Pharmaceutical manufacturing is increasingly globalized, prompting the need for more efficient surveillance systems for monitoring product quality. Furthermore, increasing scrutiny and accelerated approval pathways provide a driving force to be even more efficient with limited regulatory resources. To address these regulatory challenges, the Office of Pharmaceutical Quality (OPQ) in the Center for Drug Evaluation and Research (CDER) at the U.S. Food and Drug Administration (FDA) harbors a rigorous science and research program in core areas that support drug quality review, inspection, surveillance, standards, and policy development. Science and research is the foundation of risk-based quality assessment of new drugs, generic drugs, over-the-counter drugs, and biotechnology products including biosimilars. This is an overview of the science and research activities in OPQ that support the mission of ensuring that safe, effective, and high-quality drugs are available to the American public.


Aaps Journal | 2016

Advancing Product Quality: a Summary of the Second FDA/PQRI Conference

Lawrence X. Yu; Ilgaz Akseli; Barbara Allen; Gregory E. Amidon; Tara Gooen Bizjak; Ashley Boam; Margaret Caulk; David Doleski; Joseph Famulare; Adam C. Fisher; Scott Furness; Brian Hasselbalch; Henry A. Havel; Stephen W. Hoag; Robert Iser; Bruce D. Johnson; Robert Ju; Paula Katz; Emanuela Lacana; Sau L. Lee; Richard T. Lostritto; Grace McNally; Mehul Mehta; Ganapathy Mohan; Moheb Nasr; Roger Nosal; Mary Oates; Thomas O’Connor; James E. Polli; G. K. Raju

Lawrence X. Yu, Ilgaz Akseli, Barbara Allen, Gregory Amidon, Tara Gooen Bizjak, Ashley Boam, Margaret Caulk, David Doleski, Joseph Famulare, Adam C. Fisher1, Scott Furness, Brian Hasselbalch, Henry Havel, Stephen W. Hoag, Robert Iser, Bruce D. Johnson, Robert Ju, Paula Katz, Emanuela Lacana, Sau L. Lee, Richard Lostritto, Grace McNally, Mehul Mehta, Ganapathy Mohan, Moheb Nasr, Roger Nosal, Mary Oates, Thomas O’Connor, Jim Polli, G.K. Raju, Mahesh Ramanadham, Giuseppe Randazzo, Susan Rosencrance, Anna Schwendeman, Arzu Selen, Paul Seo, Vinod Shah, Ramesh Sood, Michael P. Thien, Tony Tong, Bernhardt L. Trout, Katherine Tyner, Siva Vaithiyalingam, Martin VanTrieste, Fionnuala Walsh3, Russell Wesdyk1, Janet Woodcock1, Geoffrey Wu, Larisa Wu, Louis Yu, Diane Zezza


Aaps Journal | 2013

A Sensitivity Analysis of the Modified Chi-square Ratio Statistic for Equivalence Testing of Aerodynamic Particle Size Distribution

Benjamin Weber; Sau L. Lee; Robert Lionberger; Bing V. Li; Yi Tsong; Guenther Hochhaus

Demonstration of equivalence in aerodynamic particle size distribution (APSD) is one key component for establishing bioequivalence of orally inhaled drug products. We previously proposed a modified version of the Chi-square ratio statistic (mCSRS) for APSD equivalence testing and demonstrated that the median of the distribution of the mCSRS (MmCSRS) is a robust metric when test (T) and reference (R) cascade impactor (CI) profiles are identical. Here, we systematically evaluate the behavior of the MmCSRS when T and R CI profiles differ from each other in their mean deposition and variability on a single and multiple sites. All CI profiles were generated by Monte-Carlo simulations based upon modified actual CI data. Twenty thousand sets of 30 T and 30 R CI profiles were simulated for each scenario, and the behavior of the MmCSRS was correlated to metrics that characterize the difference between T and R product in mean deposition and variability. The two key findings were, first, that the MmCSRS is more sensitive to difference between T and R CI profiles on high deposition sites, and second, that a cut-off value for APSD equivalence testing based on the MmCSRS needs to be scaled on the variability of the R product. The former is considered as beneficial for equivalence testing of CI profiles as it decreases the likelihood of failing identical CI profiles by chance, in part, due to increasing analytical variability associated with lower deposition sites. The latter is expected to be important for consistently being able to discriminate equivalent from inequivalent CI profiles.


Aaps Journal | 2017

Development Considerations for Nanocrystal Drug Products

Mei-Ling Chen; Mathew John; Sau L. Lee; Katherine M. Tyner

ABSTRACTNanocrystal technology has emerged as a valuable tool for facilitating the delivery of poorly water-soluble active pharmaceutical ingredients (APIs) and enhancing API bioavailability. To date, the US Food and Drug Administration (FDA) has received over 80 applications for drug products containing nanocrystals. These products can be delivered by different routes of administration and are used in a variety of therapeutic areas. To aid in identifying key developmental considerations for these products, a retrospective analysis was performed on the submissions received by the FDA to date. Over 60% of the submissions were for the oral route of administration. Based on the Biopharmaceutics Classification System (BCS), most nanocrystal drugs submitted to the FDA are class II compounds that possess low aqueous solubility and high intestinal permeability. Impact of food on drug bioavailability was reduced for most nanocrystal formulations as compared with their micronized counterparts. For all routes of administration, dose proportionality was observed for some, but not all, nanocrystal products. Particular emphasis in the development of nanocrystal products was placed on the in-process tests and controls at critical manufacturing steps (such as milling process), mitigation and control of process-related impurities, and the stability of APIs or polymorphic form (s) during manufacturing and upon storage. This emphasis resulted in identifying challenges to the development of these products including accurate determination of particle size (distribution) of drug substance and/or nanocrystal colloidal dispersion, identification of polymorphic form (s), and establishment of drug substance/product specifications.


International Journal of Pharmaceutics | 2017

Building parity between brand and generic peptide products: Regulatory and scientific considerations for quality of synthetic peptides

Larisa C. Wu; Fu Chen; Sau L. Lee; Andre Raw; Lawrence X. Yu

Peptides are a fast growing segment in the pharmaceutical industry. Consequently, the industry and regulatory agencies are increasing their focus on the regulatory path and quality considerations for peptide development and manufacturing. Although most peptides are synthetic, manufactured by solid phase synthesis, nevertheless they are complex molecules with challenging quality and regulatory aspects. This paper provides a structured overview of relevant quality issues for chemically synthesized peptides used as active pharmaceutical ingredients (API) in drug products. It addresses the unique characteristics of peptides pertaining to structural and physicochemical characterization, manufacturing and in process controls, impurities and aggregates arising from manufacturing and storage, along with their potential impact on safety (including immunogenicity) and efficacy of the peptide drug products.


Aaps Journal | 2015

Advancing Product Quality: a Summary of the Inaugural FDA/PQRI Conference

Lawrence X. Yu; Jeffrey Baker; Susan C. Berlam; Ashley Boam; E. J. Brandreth; Lucinda F. Buhse; Thomas Cosgrove; David Doleski; Lynne Ensor; Joseph Famulare; Mohan Ganapathy; Gustavo Grampp; David Hussong; Robert Iser; Gordon Johnston; Filippos Kesisoglou; Mansoor A. Khan; Steven Kozlowski; Emanuela Lacana; Sau L. Lee; Stephen P. F. Miller; Sarah Pope Miksinski; Christine M. V. Moore; Theresa Mullin; G. K. Raju; Andre Raw; Susan Rosencrance; Mark Rosolowsky; Paul Stinavage; Hayden Thomas

On September 16 and 17, 2014, the Food and Drug Administration (FDA) and Product Quality Research Institute (PQRI) inaugurated their Conference on Evolving Product Quality. The Conference is conceived as an annual forum in which scientists from regulatory agencies, industry, and academia may exchange viewpoints and work together to advance pharmaceutical quality. This Conference Summary Report highlights key topics of this conference, including (1) risk-based approaches to pharmaceutical development, manufacturing, regulatory assessment, and post-approval changes; (2) FDA-proposed quality metrics for products, facilities, and quality management systems; (3) performance-based quality assessment and clinically relevant specifications; (4) recent developments and implementation of continuous manufacturing processes, question-based review, and European Medicines Agency (EMA)-FDA pilot for Quality-by-Design (QbD) applications; and (5) breakthrough therapies, biosimilars, and international harmonization, focusing on ICH M7 and Q3D guidelines. The second FDA/PQRI conference on advancing product quality is planned for October 5–7, 2015.


Aaps Journal | 2015

Application of the Modified Chi-Square Ratio Statistic in a Stepwise Procedure for Cascade Impactor Equivalence Testing

Benjamin Weber; Sau L. Lee; Renishkumar Delvadia; Robert Lionberger; Bing V. Li; Yi Tsong; Guenther Hochhaus

Equivalence testing of aerodynamic particle size distribution (APSD) through multi-stage cascade impactors (CIs) is important for establishing bioequivalence of orally inhaled drug products. Recent work demonstrated that the median of the modified chi-square ratio statistic (MmCSRS) is a promising metric for APSD equivalence testing of test (T) and reference (R) products as it can be applied to a reduced number of CI sites that are more relevant for lung deposition. This metric is also less sensitive to the increased variability often observed for low-deposition sites. A method to establish critical values for the MmCSRS is described here. This method considers the variability of the R product by employing a reference variance scaling approach that allows definition of critical values as a function of the observed variability of the R product. A stepwise CI equivalence test is proposed that integrates the MmCSRS as a method for comparing the relative shapes of CI profiles and incorporates statistical tests for assessing equivalence of single actuation content and impactor sized mass. This stepwise CI equivalence test was applied to 55 published CI profile scenarios, which were classified as equivalent or inequivalent by members of the Product Quality Research Institute working group (PQRI WG). The results of the stepwise CI equivalence test using a 25% difference in MmCSRS as an acceptance criterion provided the best matching with those of the PQRI WG as decisions of both methods agreed in 75% of the 55 CI profile scenarios.


Trends in Biotechnology | 2018

The Current Scientific and Regulatory Landscape in Advancing Integrated Continuous Biopharmaceutical Manufacturing

Adam C. Fisher; Mark-Henry Kamga; Cyrus Agarabi; Kurt Brorson; Sau L. Lee; Seongkyu Yoon

There is a trend across the pharmaceutical sector toward process intensification and continuous manufacturing to produce small-molecule drugs or biotechnology products. For biotechnology products, advancing the manufacturing technology behind upstream and downstream processes has the potential to reduce product shortages and variability, allow for production flexibility, simplify scale-up procedures, improve product quality, reduce facility footprints, increase productivity, and reduce production costs. On the upstream side of biotechnology manufacturing, continuous perfusion cell cultures are fairly well established. However, truly integrated continuous biomanufacturing requires the uninterrupted connection of continuous unit operations (upstream and downstream) with no isolated intermediate or hold steps occurring between them. This work examines the current scientific and regulatory landscape surrounding the implementation of integrated continuous biomanufacturing.

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Lawrence X. Yu

Food and Drug Administration

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Robert Lionberger

Food and Drug Administration

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G. K. Raju

Massachusetts Institute of Technology

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Lucinda F. Buhse

Food and Drug Administration

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