Simulated Leaching (Migration) Study for a Model Container-Closure System Applicable to Parenteral and Ophthalmic Drug Products.

A simulating leaching (migration) study was performed on a model container-closure system relevant to parenteral and ophthalmic drug products. This container-closure system consisted of a linear low-density polyethylene bottle (primary container), a polypropylene cap and an elastomeric cap liner (closure), an adhesive label (labeling), and a foil overpouch (secondary container). The bottles were filled with simulating solvents (aqueous salt/acid mixture at pH 2.5, aqueous buffer at pH 9.5, and 1/1 v/v isopropanol/water), a label was affixed to the filled and capped bottles, the filled bottles were placed into the foil overpouch, and the filled and pouched units were stored either upright or inverted for up to 6 months at 40 °C. After storage, the leaching solutions were tested for leached substances using multiple complementary analytical techniques to address volatile, semi-volatile, and non-volatile organic and inorganic extractables as potential leachables.The leaching data generated supported several conclusions, including that (1) the extractables (leachables) profile revealed by a simulating leaching study can qualitatively be correlated with compositional information for materials of construction, (2) the chemical nature of both the extracting medium and the individual extractables (leachables) can markedly affect the resulting profile, and (3) while direct contact between a drug product and a system's material of construction may exacerbate the leaching of substances from that material by the drug product, direct contact is not a prerequisite for migration and leaching to occur.LAY ABSTRACT: The migration of container-related extractables from a model pharmaceutical container-closure system and into simulated drug product solutions was studied, focusing on circumstances relevant to parenteral and ophthalmic drug products. The model system was constructed specifically to address the migration of extractables from labels applied to the outside of the primary container. The study demonstrated that (1) the extractables that do migrate can be correlated to the composition of the materials used to construct the container-closure systems, (2) the extent of migration is affected by the chemical nature of the simulating solutions and the extractables themselves, and (3) even though labels may not be in direct contact with a contained solution, label-related extractables can accumulate as leachables in those solutions.

Perspectives on the PQRI Extractables and Leachables "Safety Thresholds and Best Practices" Recommendations for Inhalation Drug Products.

In 2006, the Product Quality Research Institute's (PQRI) Leachables and Extractables Working Group released a comprehensive and detailed recommendation document related to leachables and extractables for inhalation drug products. The document includes best pharmaceutical development practice recommendations regarding container closure/delivery system component composition and selection, controlled extraction studies, drug product leachables studies, and routine extractables testing for component release. Also included in the document are two safety-based thresholds for leachables in inhalation drug products, the qualification threshold (QT) and the safety concern threshold (SCT), the first such safety-based thresholds for leachables in any drug product type. A process was described for converting the SCT into an analytically useful threshold for leachables/extractables characterization, the analytical evaluation threshold (AET), with consideration of individual drug product dosing parameters and container closure system component characteristics. This commentary presents the history and evolution of this recommendation document starting from the propellant changeover (chlorofluorocarbons to hydrofluorocarbons) in metered dose inhaler drug products, which helped prompt interest in inhalation drug product leachables, through the work process of the PQRI group. The overall positive acceptance of the PQRI recommendations is discussed, along with a brief summary of regulatory initiatives influenced by the recommendations. Also presented and discussed are certain key issues and questions that have arisen since the recommendation document was released. The extension and application of best practice recommendations to other high risk drug product types (e.g., large and small volume parenterals, ophthalmics), led by the PQRI Parenteral and Ophthalmic Drug Product Working Group, is introduced and considered. LAY ABSTRACT: The recommendation document released by the Product Quality Research Institute's (PQRI) Leachables and Extractables Working Group in 2006 includes the first safety-based thresholds for leachables in any drug product type, along with comprehensive best practice recommendations for inhalation drug product pharmaceutical development related to extractables and leachables. The best practice recommendations encompass a number of important functional areas, including container closure/delivery system component composition and selection, controlled extraction studies, drug product leachables studies, and routine extractables testing for component release. This commentary presents the history and evolution of this recommendation document starting from the propellant changeover (chlorofluorocarbons to hydrofluorocarbons) in metered dose inhaler drug products, which helped prompt interest in inhalation drug product leachables, through the work process of the PQRI group. The overall positive acceptance of the PQRI recommendations is discussed, along with a brief summary of regulatory initiatives influenced by the recommendations. Also presented and discussed are certain key issues and questions that have arisen since the recommendation document was released. The extension and application of best practice recommendations to other drug product types (e.g., large- and small-volume parenterals, ophthalmics), led by the PQRI Parenteral and Ophthalmic Drug Product Working Group, is introduced and considered.

The Product Quality Research Institute (PQRI) Leachables and Extractables Working Group Initiatives for Parenteral and Ophthalmic Drug Product (PODP).

The Product Quality Research Institute (PQRI) is a non-profit consortium of organizations working together to generate and share timely, relevant, and impactful information that advances drug product quality and development. The collaborative activities of PQRI participants have, in the case of orally inhaled and nasal drug products (OINDPs), resulted in comprehensive and widely-accepted recommendations for leachables assessments to help ensure patient safety with respect to this class of packaged drug products. These recommendations, which include scientifically justified safety thresholds for leachables, represent a significant milestone towards establishing standardized approaches for safety qualification of leachables in OINDP. To build on the success of the OINDP effort, PQRI's Parenteral and Ophthalmic Drug Products (PODP) Leachables and Extractables Working Group was formed to extrapolate the OINDP threshold concepts and best practice recommendations to other dosage forms with high concern for interaction with packaging/delivery systems. This article considers the general aspects of leachables and their safety assessment, introduces the PODP Work Plan and initial study Protocol, discusses the laboratory studies being conducted by the PODP Chemistry Team, outlines the strategy being developed by the PODP Toxicology Team for the safety qualification of PODP leachables, and considers the issues associated with application of the safety thresholds, particularly with respect to large-volume parenterals. Lastly, the unique leachables issues associated with biologics are described. LAY ABSTRACT: The Product Quality Research Institute (PQRI) is a non-profit consortium involving industry organizations, academia, and regulatory agencies that together provide recommendations in support of regulatory guidance to advance drug product quality. The collaborative activities of the PQRI Orally Inhaled and Nasal Drug Products Leachables and Extractables Working Group resulted in a systematic and science-based approach to identify and qualify leachables, including the concept of safety thresholds. Concepts from this widely accepted approach, formally publicized in 2006, are being extrapolated to parenteral and ophthalmic drug products. This article provides an overview of extractables and leachables in drug products and biologics and discusses the PQRI Work Plan and Protocols developed by the PQRI Parenteral and Ophthalmic Drug Products Leachables and Extractables Working Group.

Extractables characterization for five materials of construction representative of packaging systems used for parenteral and ophthalmic drug products.

Polymeric and elastomeric materials are commonly encountered in medical devices and packaging systems used to manufacture, store, deliver, and/or administer drug products. Characterizing extractables from such materials is a necessary step in establishing their suitability for use in these applications. In this study, five individual materials representative of polymers and elastomers commonly used in packaging systems and devices were extracted under conditions and with solvents that are relevant to parenteral and ophthalmic drug products (PODPs). Extraction methods included elevated temperature sealed vessel extraction, sonication, refluxing, and Soxhlet extraction. Extraction solvents included a low-pH (pH = 2.5) salt mixture, a high-pH (pH = 9.5) phosphate buffer, a 1/1 isopropanol/water mixture, isopropanol, and hexane. The resulting extracts were chemically characterized via spectroscopic and chromatographic means to establish the metal/trace element and organic extractables profiles. Additionally, the test articles themselves were tested for volatile organic substances. The results of this testing established the extractables profiles of the test articles, which are reported herein. Trends in the extractables, and their estimated concentrations, as a function of the extraction and testing methodologies are considered in the context of the use of the test article in medical applications and with respect to establishing best demonstrated practices for extractables profiling of materials used in PODP-related packaging systems and devices. LAY ABSTRACT: Plastic and rubber materials are commonly encountered in medical devices and packaging/delivery systems for drug products. Characterizing the extractables from these materials is an important part of determining that they are suitable for use. In this study, five materials representative of plastics and rubbers used in packaging and medical devices were extracted by several means, and the extracts were analytically characterized to establish each material's profile of extracted organic compounds and trace element/metals. This information was utilized to make generalizations about the appropriateness of the test methods and the appropriate use of the test materials.

Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds representing the chemical diversity of extractables. This study demonstrates the complementary nature of SPE-LC/NMR with LC/MS for this particular pharmaceutical application. LAY ABSTRACT: The identification of impurities leached into drugs from the components and materials associated with pharmaceutical containers, packaging components, and materials has historically been done using laboratory techniques based on the combination of chromatography with mass spectrometry. Such analytical techniques are widely recognized as having the selectivity and sensitivity required to separate the complex mixtures of impurities often encountered in such identification studies, including both the identification of leachable impurities as well as potential leachable impurities produced by laboratory extraction of packaging components and materials. However, while mass spectrometry-based analytical techniques have limitations for this application, newer analytical techniques based on the combination of chromatography with nuclear magnetic resonance spectroscopy provide an added dimension of structural definition. This article describes the development, optimization, and application of an analytical technique based on the combination of chromatography and nuclear magnetic resonance spectroscopy to the identification of potential leachable impurities from a pharmaceutical packaging material. The complementary nature of the analytical techniques for this particular pharmaceutical application is demonstrated.

Study and characterization of crystalline hydrate/polymorph forms of 5,11-dihydro-11-ethyl-5-methyl-8-(2-(1-oxido-4-quinolinyl)ethyl-6H-dipyrido(3,2-B:2',3'-E)(1,4)diazepin-6-one by solid-state NMR and solution NMR.

A novel inhibitor of reverse transcriptase was studied by solid-state NMR. Three phases of the compound were examined which included the dihydrate and two anhydrous polymorphs (Form I and Form III). By correlating (1)H and (13)C solution NMR with the solid-state (13)C NMR CP/MAS and CPPI spectral editing experiments, comparative (13)C assignments were made for each phase. Polymorphs of Form I and Form III and the dihydrate were easily distinguished based upon chemical shift patterns of the carbon resonances. The (1)H spin-lattice relaxation times were also measured for each phase which provided information on the mobility and relative crystallinity. The (13)C ssNMR spectrum of Form I showed the presence of a minor component identified as the dihydrate. Weight/percent quantitation of major and minor components in Form I was obtained from integrated intensities of a 50:50 mixture containing weighed amounts of Form I and the pure dihydrate. Comparison of the ssNMR and X-ray powder diffraction techniques is discussed.

(31)P solid state NMR study of structure and chemical stability of dichlorotriphenylphosphorane.

Solid state (31)P NMR spectroscopy was used to examine, monitor and quantify the compound integrity of the chemical reagent dichlorotriphenylphosphorane. Comparison was also made with solution (31)P NMR spectra which showed that this highly reactive species could be observed in dry benzene prior to conversion to the hydrolyzed product. This is the first reported solid state NMR study of the stability and reactivity of dichlorotriphenylphosphorane and the first account of its observation and comparison in the solution state. In the solid state, the ionic and covalent forms for dichlorotriphenylphosphorane were observed along with hydrolyzed products, however, the degree of hydrolysis was dependent upon the rotor packing conditions. Calculation of the relative percent composition of dichlorotriphenylphosphorane with hydrolyzed product was made for samples prepared in air versus under nitrogen atmosphere. This information was critical in adjusting the amount of reagent used in chemical development syntheses and scale up laboratories. All hydrolyzed products were identified, based upon chemical comparisons with spectra of pure materials.

Identification of a process impurity formed during synthesis of a nevirapine analogue HIV NNRT inhibitor using LC/MS and forced degradation studies.

Impurities in pharmaceutical products do not enhance the desired therapeutic effect and may, of course, have adverse effects. Impurities must therefore be limited or controlled for quality and safety considerations. Structural identification of an impurity is the first step in understanding the chemistry of its formation and subsequently controlling the impurity. In this article, the chemical structure of an unknown by-product formed during the synthesis of a nevirapine analogue HIV NNRT inhibitor was identified using a combination of low resolution, high resolution and H/D exchange LC/MS and LC/MS/MS. The origin of the impurity was investigated through a series of photo- and oxidative stress studies. It was concluded that this impurity is formed via a side-reaction of the last intermediate with the oxidant used in the synthesis.

N-nitrosamines as "special case" leachables in a metered dose inhaler drug product.

N-nitrosamines are chemical entities, some of which are considered to be possible human carcinogens, which can be found at trace levels in some types of foods, tobacco smoke, certain cosmetics, and certain types of rubber. N-nitrosamines are of regulatory concern as leachables in inhalation drug products, particularly metered dose inhalers, which incorporate rubber seals into their container closure systems. The United States Food and Drug Administration considers N-nitrosamines (along with polycyclic aromatic hydrocarbons and 2-mercaptobenzothiazole) to be "special case" leachables in inhalation drug products, meaning that there are no recognized safety or analytical thresholds and these compounds must therefore be identified and quantitated at the lowest practical level. This report presents the development of a quantitative analytical method for target volatile N-nitrosamines in a metered dose inhaler drug product, Atrovent HFA. The method incorporates a target analyte recovery procedure from the drug product matrix with analysis by gas chromatography/thermal energy analysis detection. The capability of the method was investigated with respect to specificity, linearity/range, accuracy (linearity of recovery), precision (repeatability, intermediate precision), limits of quantitation, standard/sample stability, and system suitability. Sample analyses showed that Atrovent HFA contains no target N-nitrosamines at the trace level of 1 ng/canister.

Best practices for extractables and leachables in orally inhaled and nasal drug products: an overview of the PQRI recommendations.

The Product Quality Research Institute Leachables and Extractables Working Group includes pharmaceutical development scientists representing industry, government, and academia. The Working Group was created and constituted to address scientific and regulatory questions concerning the pharmaceutical development process for Orally Inhaled and Nasal Drug Products (OINDP) related to organic extractables and leachables. This effort has resulted in the creation of a detailed "Recommendation Document", which was submitted to the U.S. FDA for consideration in September 2006. The recommendations include proposed safety and analytical thresholds for leachables and extractables, as well as detailed "best practice" recommendations for various aspects of the OINDP pharmaceutical development process, including: materials selection for OINDP container closure system components, Controlled Extraction Studies, Leachables Studies, and Routine Extractables Testing. The Working Group's processes and the detailed and comprehensive recommendations that resulted from those processes, demonstrate that the Product Quality Research Institute collaborative process can result in consensus science-based and data driven recommendations that could have a positive effect on patient care. It is anticipated that the Working Group's recommendations will also contribute to the new "Quality by Design" pharmaceutical development paradigm. This commentary summarizes the best practice recommendations within the context of an overall pharmaceutical development process.

Development of safety qualification thresholds and their use in orally inhaled and nasal drug product evaluation.

Safety thresholds for chemical impurities and leachables in consumer products such as foods and drugs have helped to ensure public health while establishing scientifically sound limits for identification and risk assessment of these compounds. The Product Quality Research Institute (PQRI) Leachables and Extractables Working Group, a collaboration of chemists and toxicologists from the U.S. Food and Drug Administration (FDA), industry, and academia, has developed safety thresholds for leachables and extractables in orally inhaled and nasal drug products (OINDP), for application in United States pharmaceutical submissions. The PQRI safety concern threshold (SCT) is 0.15 microg/day, and the qualification threshold is 5 microg/day. OINDP are important in the treatment of lung diseases such as asthma and chronic bronchitis, as well as systemic diseases such as diabetes. Analysis of extractables and minimization of leachables in OINDP are vital to ensuring the quality and safety of the final product. It is expected that the thresholds developed by the PQRI Leachables and Extractables Working Group will be used by both industry and regulators to ensure and assess such quality and safety in OINDP applications. In this article, we describe the importance of the PQRI safety thresholds in the OINDP pharmaceutical development process; the background and context of safety thresholds for consumer products; how these safety thresholds were developed using well-established, robust databases and quantitative risk assessment approaches; and how these thresholds can be applied in a pharmaceutical safety qualification process, including FDA regulatory perspectives on the use of safety thresholds for OINDP.