1
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Kumari P, Saldanha M, Jain R, Dandekar P. Controlling monoclonal antibody aggregation during cell culture using medium additives facilitated by the monitoring of aggregation in cell culture matrix using size exclusion chromatography. J Pharm Biomed Anal 2023; 234:115575. [PMID: 37467528 DOI: 10.1016/j.jpba.2023.115575] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/09/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023]
Abstract
Controlling monoclonal antibody aggregation at the upstream stage itself can significantly reduce the burden on downstream processing and can improve the process yield. Hence, we have investigated the use of sugar osmolytes (glucose, mannose, sucrose and maltose) and formulation excipients (mannitol, polysorbate 20 and polysorbate 80) as medium additives to reduce protein aggregation during cell culture. Aggregate content in cell culture samples was estimated using a high-resolution size-exclusion chromatography technique, which efficiently resolved the antibody monomer and aggregates in the cell culture matrix i.e., without purification. Glucose, mannose, maltose and the polysorbates effectively reduced the mean aggregate content over the course of the culture. Sugar-based additives exhibited a higher degree of variation during aggregate quantitation as compared to polysorbate additives, rendering the latter a preferred additive. Therefore, this study demonstrated the potential of sugar osmolytes and formulation excipients as media additives during cell culture to reduce aggregate formation, without negatively impacting cell growth and antibody production, facilitated by the monitoring of aggregate content in cell culture samples without purification.
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Affiliation(s)
- Prity Kumari
- Department of Pharmaceutical Science and Technology, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Marianne Saldanha
- Department of Biological Sciences and Biotechnology, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Ratnesh Jain
- Department of Biological Sciences and Biotechnology, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Prajakta Dandekar
- Department of Pharmaceutical Science and Technology, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
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2
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Grossen P, Skaripa Koukelli I, van Haasteren J, H E Machado A, Dürr C. The ice age - A review on formulation of Adeno-associated virus therapeutics. Eur J Pharm Biopharm 2023; 190:1-23. [PMID: 37423416 DOI: 10.1016/j.ejpb.2023.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/30/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Gene therapies offer promising therapeutic alternatives for many disorders that currently lack efficient treatment options. Due to their chemical nature and physico-chemical properties, delivery of polynucleic acids into target cells and subcellular compartments remains a significant challenge. Adeno-associated viruses (AAV) have gained a lot of interest for the efficient delivery of therapeutic single-stranded DNA (ssDNA) genomes over the past decades. More than a hundred products have been tested in clinical settings and three products have received market authorization by the US FDA in recent years. A lot of effort is being made to generate potent recombinant AAV (rAAV) vectors that show favorable safety and immunogenicity profiles for either local or systemic administration. Manufacturing processes are gradually being optimized to deliver a consistently high product quality and to serve potential market needs beyond rare indications. In contrast to protein therapeutics, most rAAV products are still supplied as frozen liquids within rather simple formulation buffers to enable sufficient product shelf life, significantly hampering global distribution and access. In this review, we aim to outline the hurdles of rAAV drug product development and discuss critical formulation and composition aspects of rAAV products under clinical evaluation. Further, we highlight recent development efforts in order to achieve stable liquid or lyophilized products. This review therefore provides a comprehensive overview on current state-of-the-art rAAV formulations and can further serve as a map for rational formulation development activities in the future.
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Affiliation(s)
- Philip Grossen
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland.
| | - Irini Skaripa Koukelli
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Joost van Haasteren
- F.Hoffmann-La Roche AG, Cell and Gene Therapy Unit, Gene Therapy Development Clinical Manufacturing, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Alexandra H E Machado
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Christoph Dürr
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
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3
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Sonje J, Thakral S, Krueger S, Suryanarayanan R. Enabling Efficient Design of Biological Formulations Through Advanced Characterization. Pharm Res 2023; 40:1459-1477. [PMID: 36959413 DOI: 10.1007/s11095-023-03495-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/01/2023] [Indexed: 03/25/2023]
Abstract
The present review summarizes the use of differential scanning calorimetry (DSC) and scattering techniques in the context of protein formulation design and characterization. The scattering techniques include wide angle X-ray diffractometry (XRD), small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS). While DSC is valuable for understanding thermal behavior of the excipients, XRD provides critical information about physical state of solutes during freezing, annealing and in the final lyophile. However, as these techniques lack the sensitivity to detect biomolecule-related transitions, complementary characterization techniques such as small-angle scattering can provide valuable insights.
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Affiliation(s)
- Jayesh Sonje
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN, 55455, USA
- BioTherapeutics, Pharmaceutical Sciences, Pfizer Inc., 1 Burtt Road, Andover, USA
| | - Seema Thakral
- Boehringer Ingelheim Pharmaceuticals, Inc, 900 Ridgebury Road, Ridgefield, CT, 06877, USA
| | - Susan Krueger
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Raj Suryanarayanan
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN, 55455, USA.
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4
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Ghosh I, Gutka H, Krause ME, Clemens R, Kashi RS. A systematic review of commercial high concentration antibody drug products approved in the US: formulation composition, dosage form design and primary packaging considerations. MAbs 2023; 15:2205540. [PMID: 37243580 DOI: 10.1080/19420862.2023.2205540] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 05/29/2023] Open
Abstract
Three critical aspects that define high concentration antibody products (HCAPs) are as follows: 1) formulation composition, 2) dosage form, and 3) primary packaging configuration. HCAPs have become successful in the therapeutic sector due to their unique advantage of allowing subcutaneous self-administration. Technical challenges, such as physical and chemical instability, viscosity, delivery volume limitations, and product immunogenicity, can hinder successful development and commercialization of HCAPs. Such challenges can be overcome by robust formulation and process development strategies, as well as rational selection of excipients and packaging components. We compiled and analyzed data from US Food and Drug Administration-approved and marketed HCAPs that are ≥100 mg/mL to identify trends in formulation composition and quality target product profile. This review presents our findings and discusses novel formulation and processing technologies that enable the development of improved HCAPs at ≥200 mg/mL. The observed trends can be used as a guide for further advancements in the development of HCAPs as more complex antibody-based modalities enter biologics product development.
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Affiliation(s)
- Indrajit Ghosh
- Sterile Product Development, Bristol Myers Squibb, New Brunswick, NJ, USA
| | - Hiten Gutka
- Sterile Product Development, Bristol Myers Squibb, New Brunswick, NJ, USA
| | - Mary E Krause
- Sterile Product Development, Bristol Myers Squibb, New Brunswick, NJ, USA
| | - Ryan Clemens
- College of Pharmacy, University of Illinois at Chicago, Chicago, USA
| | - Ramesh S Kashi
- Sterile Product Development, Bristol Myers Squibb, Summit, NJ, USA
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5
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Sonje J, Thakral S, Mayhugh B, Sacha G, Nail S, Srinivasan J, Suryanarayanan R. Mannitol Hemihydrate in Lyophilized Protein Formulations:Impact of its Dehydration During Storage on Sucrose Crystallinity and Protein Stability. Int J Pharm 2022; 624:121974. [PMID: 35787458 DOI: 10.1016/j.ijpharm.2022.121974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/18/2022] [Accepted: 06/29/2022] [Indexed: 10/17/2022]
Abstract
The high propensity of mannitol to crystallize in frozen solutions along with its high eutectic temperature enabling higher primary drying temperatures makes it a good bulking agent. In protein formulations, addition of a sugar (sucrose) that has the ability to remain amorphous throughout processing as well as storage, it is imperative to retain the protein in its native state. It is well known that in the presence of amorphous excipients and protein, mannitol can crystallize as a mixture of anhydrous polymorphs - α-, β- and δ-forms and a hemihydrate form [mannitol hemihydrate (MHH); C6H14O6·0.5H2O]. The conditions of formation of MHH due to processing and formulation variables are well established in the literature. However, MHH's dehydration kinetics on storage and its impact on the stability of a protein has not been systematically evaluated. The overall objective was to identify conditions (temperature and humidity) at which MHH can dehydrate on storage and the consequences of the release of associated water on sucrose phase behavior and protein stability. In a mannitol-sucrose-protein lyophile, the purpose of this study was (i) to investigate the dehydration behavior of MHH (ii) to determine the influence of dehydration on sucrose crystallization and (iii) the effect of moisture released due to MHH dehydration on model protein (Bovine serum albumin, BSA or Human serum albumin, HSA) aggregation. MHH dehydration and sucrose crystallization was observed in cases where the relative humidity was ≥ 55% (open vials). A relative humidity of ≤ 33% RH prevented MHH dehydration while retaining sucrose amorphous. No protein aggregation was observed irrespective of presence of MHH or its dehydration.
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Affiliation(s)
- Jayesh Sonje
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, United States
| | - Seema Thakral
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, United States
| | - Brendan Mayhugh
- Baxter Global Science and Technology, 927 S. Curry Pike, Bloomington, IN 47403
| | - Gregory Sacha
- Baxter Global Science and Technology, 927 S. Curry Pike, Bloomington, IN 47403
| | - Steve Nail
- Baxter Global Science and Technology, 927 S. Curry Pike, Bloomington, IN 47403
| | - Jayasree Srinivasan
- Baxter Global Science and Technology, 927 S. Curry Pike, Bloomington, IN 47403.
| | - Raj Suryanarayanan
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, United States.
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6
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Xu Y, Jiang B, Samai P, Tank SM, Shameem M, Liu D. Genome DNA leakage of Adeno-Associated virus under freeze-thaw stress. Int J Pharm 2022; 615:121464. [PMID: 35051537 DOI: 10.1016/j.ijpharm.2022.121464] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/25/2022]
Abstract
Adeno-associated virus (AAV) has become an emerging tool for human gene therapies. Currently, AAV gene therapies are subjected to multiple freeze-thaw cycles during manufacturing, storage, transportation, and administration. While studies have shown that multiple freeze-thaw cycles led to a decrease in transduction efficiency, the AAV degradation mechanism during freeze-thaw is not well understood. Here, we have characterized the impact of freeze-thaw on AAV8 by employing a variety of assays, which revealed significant increases in the amount of free single-stranded DNA (ssDNA) in AAV8 formulations after multiple freeze-thaw cycles. Subsequent analysis using Next Generation Sequencing (NGS) revealed that the ssDNA primarily consisted of genome DNA, indicating that the increased ssDNA leaked out from AAV8. Experiments performed using different serotypes of AAV confirmed the pervasiveness of such behavior amongst AAVs. In addition, formulation screening studies were performed to understand the impact on genome DNA leakage from AAV. The formulation screening results showed that the addition of 10% sucrose and 0.1% poloxamer 188 to Dulbecco's phosphate-buffered saline (DPBS) reduced the leakage of ssDNA in AAV samples after freeze-thaw cycles compared to the base formulation of DPBS alone. These findings shed new light on the degradation mechanism of AAVs and stabilization of the AAV-based gene therapies.
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Affiliation(s)
- Yuechuan Xu
- Formulations Development, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Bowen Jiang
- Formulations Development, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA.
| | - Poulami Samai
- Viral Vector Technology, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Sven-Moller Tank
- Viral Vector Technology, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Mohammed Shameem
- Formulations Development, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Dingjiang Liu
- Formulations Development, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA.
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7
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Milewska M, Milewski A, Wandzik I, Stenzel MH. Structurally analogous trehalose and sucrose glycopolymers – comparative characterization and evaluation of their effects on insulin fibrillation. Polym Chem 2022. [DOI: 10.1039/d1py01517f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Comprehensive comparative characterization of highly structurally similar, RAFT-prepared trehalose and sucrose glycopolymers.
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Affiliation(s)
- Małgorzata Milewska
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice, Poland
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland
| | - Andrzej Milewski
- Department of Inorganic Chemistry, Analytical Chemistry and Electrochemistry, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 6, 44-100 Gliwice, Poland
| | - Ilona Wandzik
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice, Poland
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland
| | - Martina H. Stenzel
- Centre for Advanced Macromolecular Design, School of Chemistry, UNSW, Sydney, NSW 2052, Australia
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8
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Hipper E, Blech M, Hinderberger D, Garidel P, Kaiser W. Photo-Oxidation of Therapeutic Protein Formulations: From Radical Formation to Analytical Techniques. Pharmaceutics 2021; 14:72. [PMID: 35056968 PMCID: PMC8779573 DOI: 10.3390/pharmaceutics14010072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 12/25/2022] Open
Abstract
UV and ambient light-induced modifications and related degradation of therapeutic proteins are observed during manufacturing and storage. Therefore, to ensure product quality, protein formulations need to be analyzed with respect to photo-degradation processes and eventually protected from light exposure. This task usually demands the application and combination of various analytical methods. This review addresses analytical aspects of investigating photo-oxidation products and related mediators such as reactive oxygen species generated via UV and ambient light with well-established and novel techniques.
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Affiliation(s)
- Elena Hipper
- Institute of Chemistry, Martin-Luther-Universität Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (E.H.); (D.H.)
| | - Michaela Blech
- Boehringer Ingelheim Pharma GmbH & Co. KG, Innovation Unit, PDB, Birkendorfer Strasse 65, 88397 Biberach an der Riss, Germany;
| | - Dariush Hinderberger
- Institute of Chemistry, Martin-Luther-Universität Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (E.H.); (D.H.)
| | - Patrick Garidel
- Boehringer Ingelheim Pharma GmbH & Co. KG, Innovation Unit, PDB, Birkendorfer Strasse 65, 88397 Biberach an der Riss, Germany;
| | - Wolfgang Kaiser
- Boehringer Ingelheim Pharma GmbH & Co. KG, Innovation Unit, PDB, Birkendorfer Strasse 65, 88397 Biberach an der Riss, Germany;
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9
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Thakral S, Sonje J, Munjal B, Suryanarayanan R. Stabilizers and their interaction with formulation components in frozen and freeze-dried protein formulations. Adv Drug Deliv Rev 2021; 173:1-19. [PMID: 33741437 DOI: 10.1016/j.addr.2021.03.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/06/2021] [Accepted: 03/03/2021] [Indexed: 02/06/2023]
Abstract
This review aims to provide an overview of the current knowledge on protein stabilization during freezing and freeze-drying in relation to stress conditions commonly encountered during these processes. The traditional as well as refined mechanisms by which excipients may stabilize proteins are presented. These stabilizers encompass a wide variety of compounds including sugars, sugar alcohols, amino acids, surfactants, buffers and polymers. The rational selection of excipients for use in frozen and freeze-dried protein formulations is presented. Lyophilized protein formulations are generally multicomponent systems, providing numerous possibilities of excipient-excipient and protein-excipient interactions. The interplay of different formulation components on the protein stability and excipient functionality in the frozen and freeze-dried systems are reviewed, with discussion of representative examples of such interactions.
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10
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Sherman AM, Geiger AC, Smith CJ, Taylor LS, Hinds J, Stroud PA, Simpson GJ. Stochastic Differential Scanning Calorimetry by Nonlinear Optical Microscopy. Anal Chem 2020; 92:1171-1178. [PMID: 31790194 DOI: 10.1021/acs.analchem.9b04300] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stochastic phase transformations within individual crystalline particles were recorded by integration of second harmonic generation (SHG) imaging with differential scanning calorimetry (DSC). The SHG activity of a crystal is highly sensitive to the specific molecular packing arrangement within a noncentrosymmetric lattice, providing access to information otherwise unavailable by conventional imaging approaches. Consequently, lattice transformations associated with dehydration/desolvation events were readily observed by SHG imaging and directly correlated to the phase transformations detected by the DSC measurements. Following studies of a model system (urea), stochastic differential scanning calorimetry (SDSC) was performed on trehalose dihydrate, which has a more complex phase behavior. From these measurements, SDSC revealed a broad diversity of single-particle thermal trajectories and direct evidence of a "cold phase transformation" process not observable by the DSC measurements alone.
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Affiliation(s)
- Alex M Sherman
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , Indiana 47907 , United States
| | - Andreas C Geiger
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , Indiana 47907 , United States
| | - Casey J Smith
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , Indiana 47907 , United States
| | - Lynne S Taylor
- Department of Industrial and Physical Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47907 , United States
| | - Jeremy Hinds
- Eli Lilly & Company , 1200 W. Morris Street , Indianapolis , Indiana 46221 , United States
| | - Paul A Stroud
- Eli Lilly & Company , 1200 W. Morris Street , Indianapolis , Indiana 46221 , United States
| | - Garth J Simpson
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , Indiana 47907 , United States
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11
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Chen Y, Topp EM. Photolytic Labeling To Quantify Peptide-Water Interactions in Lyophilized Solids. Mol Pharm 2019; 16:1053-1064. [PMID: 30721080 DOI: 10.1021/acs.molpharmaceut.8b01031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interactions of a lyophilized peptide with water and excipients in a solid matrix were explored using photolytic labeling. A model peptide "KLQ" (Ac-QELHKLQ-NHCH3) was covalently labeled with NHS-diazirine (succinimidyl 4,4'-azipentanoate), and the labeled peptide (KLQ-SDA) was formulated and exposed to UV light in both solution and lyophilized solids. Solid samples contained the following excipients at a 1:400 molar ratio: sucrose, trehalose, mannitol, histidine, or arginine. Prior to UV exposure, the lyophilized solids were exposed to various relative humidity (RH) environments (8, 13, 33, 45, and 78%), and the resulting solid moisture content (Karl Fischer titration) and glass transition temperature ( Tg; differential scanning calorimetry, DSC) were measured. To initiate photolytic labeling, solution and solid samples were exposed to UV light at 365 nm for 30 min. Photolytic-labeling products were quantified using reversed-phase high-performance liquid chromatography (rp-HPLC) and mass spectrometry (MS). In lyophilized solids, studies excluding oxygen and using H218O confirmed that the source of oxygen in KLQ adducts with a mass increase of 18 amu are attributable to reaction with water, while those with a mass increase of 16 amu are not attributable to reaction with either water or molecular oxygen. In solids containing sucrose or trehalose, peptide-excipient adducts decreased with increasing solid moisture content, while peptide-water adducts increased only at lower RH exposure and then plateaued, in partial agreement with the water replacement hypothesis.
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Affiliation(s)
- Yuan Chen
- Department of Industrial and Physical Pharmacy, College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
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