The Chemical List for Analytical Performance (CLAP) was developed to support the chemical assessment of medical devices. FDA CDRH published the list, along with supporting data and with the intention that the chemicals in the list could be used to perform non-targeted extractable and simulated use extractable studies for devices. The list can be used to establish relative response factors and understand uncertainty in the context of extractable and simulated use extractable studies and can be used to demonstrate system and method suitability. This study utilizes the CLAP list to emphasize the importance of threshold identification, "semi-quantitative" assessment during the non-targeted analysis process of impurities related to Extractable and Leachable (E&L), and biocompatibility testing to ensure meaningful toxicological risk assessments. The current paper also highlights the complexity of the testing process, which involves the use of multiple analytical techniques, addresses challenges associated with screening methods, response factor databases, and the use of internal standards, and highlights a data set based on a modified CLAP list, focusing on volatiles and semivolatiles analyzed by GC-MS. The authors conclude that the CLAP list is a practical tool for establishing a basic database for GC-MS and system suitability evaluation if it has been evaluated at the AET level of the study. It has a reasonable analyte coverage at the highest studied level of 2.5 μg/mL, and the list can be used for evaluating system performance beyond direct injection of liquid extracts. Practical considerations for database generation and response factor applicability at various matrices and concentrations are discussed, with a conclusion that relative responses are generally constant at levels of 2.5 μg/mL or above and are rapidly changing at trace levels.

Chemical safety assessment is one necessary step to demonstrate that the polymer used is free from harmful chemicals. The assessment should start with adequate material characterization using state-of-the-art analytical methods, including various chromatography techniques most often hyphenated with mass-spectrometric detection. Since polymers are usually incompatible with direct analysis using chromatography-based techniques, an extraction step is required prior to analytical testing. This paper provides information for practitioners who need to understand how to develop science-based extraction conditions that enable the determination of the polymer composition with respect to volatile compounds. Analytical data sets for three types of polymers (polypropylene, polycarbonate, polybutylene terephthalate, and a rubber elastomer) are presented using three different solvents and three different extraction techniques. The extracts were collected at different times during extraction and analyzed by GC-MS. The differences observed between extraction techniques, conditions, and solvents are discussed to better understand the impact of these parameters in extractable studies.

Analytical data packages are an essential part of the CMC (Chemistry and Manufacturing Control) section of US FDA (United States Food and Drug Administration) NDA (new drug application) submissions for pharmaceuticals and biologics. In many cases, the biocompatibility assessment for medical devices also requires analytical testing to be performed and reported. Based on the quality of the data presented, the regulatory review team makes an informed decision about the safety of the drug product or the medical device. If the submission is incomplete or does not support the safety assessment of the product, additional data may be required, which often delays product approval. Study sponsors must decide between optimizing the amount and quality of the data in the filing packages to save costs upfront, which may delay the approval process versus taking the more conservative approach of providing detailed information, investing more upfront, and minimizing the risk of delays.

Sample introduction in the GC-MS analysis is a relatively complex, multistep process, where usually a liquid sample is introduced to an injector, evaporated, and transferred to the GC column. To achieve reliable quantitation, the process must be well controlled. In the past decade or so, GC-MS based relative responses were evaluated for hundreds of extractables with the benefit of using those relative response factors for quantitation or to create databases to somewhat bridge the existing gap to estimate the amount of non-identified analytes. No data has yet been published indicating how relative responses are impacted by different injection solvents, or when the evaluation level is addressing the sub µg/mL levels. This paper presents data sets for 74 impurities (0.5-5 µg/mL range), with multiple internal standards, using 8 injection vehicles. Based on the presented data, the injection vehicle has a significant impact on the relative response factors, and therefore the quantitative assignment of the impurities.

Leachable testing for finished pharmaceutical products is an important part of the regulatory filing and is under more regulatory scrutiny than ever before. Leachable testing for multiple finished drug products such as biologics, large volume parenterals, and polymer-based finished products requires analysis at trace levels with a high level of confidence. A high level of analytical expertise and top-of-the-line analytical instrumentation is required for work at trace levels. (The definition of trace level analytical testing has not been accurately defined; however, to have a sense of the “trace-level”-associated testing issues, we are arbitrarily assigning levels below 100 ng/mL as trace level and below 1 ng/mL as ultra-trace level in this paper). Leachable testing ideally should be performed on a targeted list of analytes compiled from an extractable study and an extractable and leachable correlation study, along with a general non-targeted screening evaluation to avoid any undetected leachables. For targeted screening, analytical testing is more straightforward and can typically detect targets at ppb or sub-ppb levels without issue. However, for a general screening method, this can be difficult, and many times requires special sample preparation combined with high-resolution accurate-mass detection. Case studies will be presented to demonstrate the importance of high-performance and highly sensitive screening methods in detecting unexpected leachables, and in supporting related quality investigations. The importance of well-designed and executed system suitability will also be discussed in this paper.

Cannabis industry is a continuously shifting dynamic landscape. According to the United States Federal Law cannabis is still categorized as Schedule I drug, as “substances or chemicals with no currently accepted medical use”. However, at state level the cannabis was recognized and legalized either as recreational or substance of medical use. The legalization of medicinal and recreational marijuana (Cannabis sativa) in North America requires an urgent need for reliable, accurate and economical analytical methods to control the active ingredient and other constituents of the cannabis plant. In addition to the natural constituents of the plants, trace level potentially harmful contaminants also need to be rigorously controlled. This paper is attempting to provide a short overview of solventless extraction techniques, what can be used to analyse the cannabis plant itself, as well as different cannabis originated consumer products. A technical description will be provided of the solventless sample preparation technique discussing the drawback and the benefit of use and the possible hyphenation with mass spectral based detection techniques.

Recently, haloanisoles and halophenols are associated with multiple product recall situations in the pharmaceutical industry. The majority of the recalls are associated with consumer complaints due to the presence of 2,4,6-tribromoanisole, as extremely low levels of this component can be easily detected by the human nose. As part of the root cause analysis to address the cause of the consumer complaints, a GC-MS/MS based analytical method combined with stir bar sorptive extraction (SBSE) sample preparation was developed for determination of halophenols and haloanisoles from various drug product formulations. The method also applies to the analysis of 2,4,6-tribromoanisole analysis in various packaging materials. The optimized MS/MS method is based on component-specific MRM transitions. The detection limit is component dependent and in the range of 1-100 pg/tablet for solid dosage formulations and 0.04-4 ng/L for water based solutions. Deuterated tribromoanisole was used as internal standard for quantitation. The paper also may provide guidance for performing trace level method validation in the regulated Pharmaceutical Industry.

A molecular imaging application was developed to characterize the drug distribution on CYPHER® and NEVO™ Drug-eluting Stents using MALDI Qq-ToF analytical methodology. The coating matrix, laser energy, laser frequency, spatial resolution (related to rastering speed) and mass spectrometer parameters were optimized to analyze drug distribution in both durable and biodegradable polymer matrices. The developed method was extended to generate data from stents explanted from porcine coronary arteries. Due to the method's intrinsic specificity, it offers a significant advantage over other techniques in that it allows low-level detection of the target molecule without biological interferences from the blood or tissue. The method is also capable of detecting drug-related degradation products both from the finished stent product and from explanted stents.

Identification and determination of leachable components are essential for the safety assessment of implantable medical devices. The safety concern threshold (SCT) for leachable components is 0.15 μg/day for genotoxic or carcinogenic compounds and 1.5 μg/day for others. Regulatory agencies require extraction of a whole medical device using an extraction media that simulates in vitro conditions. Large-sized medical devices therefore require large volumes of aqueous media, leading to extracts of very low concentrations of the targeted analytes. Analysis of these dilute solutions is often challenging, and pre-concentration steps are time consuming and can cause significant sample loss. Stir bar sorptive extraction (SBSE) has proven to be a very useful sample preparation technique that is simple and uses no (or minimal (<1 ml)) aqueous or organic solvents. When combined with a highly selective and sensitive GC-MS/MS analysis, volatile and semi-volatile leachable components can be determined at levels below the SCT of 150 ng/device. An SBSE-GC-MS/MS method using multiple reaction monitoring detection was validated for determination of antioxidant related leachable breakdown products from orthopedic knee-inserts made from ultra high molecular weight polyethylene.

Measurements of polar organic marker compounds were performed on aerosols that were collected at a pasture site in the Amazon basin (Rondônia, Brazil) using a high-volume dichotomous sampler (HVDS) and a Micro-Orifice Uniform Deposit Impactor (MOUDI) within the framework of the 2002 LBA-SMOCC (Large-Scale Biosphere Atmosphere Experiment in Amazônia – Smoke Aerosols, Clouds, Rainfall, and Climate: Aerosols From Biomass Burning Perturb Global and Regional Climate) campaign. The campaign spanned the late dry season (biomass burning), a transition period, and the onset of the wet season (clean conditions). In the present study a more detailed discussion is presented compared to previous reports on the behavior of selected polar marker compounds, including levoglucosan, malic acid, isoprene secondary organic aerosol (SOA) tracers and tracers for fungal spores. The tracer data are discussed taking into account new insights that recently became available into their stability and/or aerosol formation processes. During all three periods, levoglucosan was the most dominant identified organic species in the PM2.5 size fraction of the HVDS samples. In the dry period levoglucosan reached concentrations of up to 7.5 μg m−3 and exhibited diel variations with a nighttime prevalence. It was closely associated with the PM mass in the size-segregated samples and was mainly present in the fine mode, except during the wet period where it peaked in the coarse mode. Isoprene SOA tracers showed an average concentration of 250 ng m−3 during the dry period versus 157 ng m−3 during the transition period and 52 ng m−3 during the wet period. Malic acid and the 2-methyltetrols exhibited a different size distribution pattern, which is consistent with different aerosol formation processes (i.e., gas-to-particle partitioning in the case of malic acid and heterogeneous formation from gas-phase precursors in the case of the 2-methyltetrols). The 2-methyltetrols were mainly associated with the fine mode during all periods, while malic acid was prevalent in the fine mode only during the dry and transition periods, and dominant in the coarse mode during the wet period. The sum of the fungal spore tracers arabitol, mannitol, and erythritol in the PM2.5 fraction of the HVDS samples during the dry, transition, and wet periods was, on average, 54 ng m−3, 34 ng m−3, and 27 ng m−3, respectively, and revealed minor day/night variation. The mass size distributions of arabitol and mannitol during all periods showed similar patterns and an association with the coarse mode, consistent with their primary origin. The results show that even under the heavy smoke conditions of the dry period a natural background with contributions from bioaerosols and isoprene SOA can be revealed. The enhancement in isoprene SOA in the dry season is mainly attributed to an increased acidity of the aerosols, increased NOx concentrations and a decreased wet deposition.

Although oxidative stress has been implicated in acute acetaminophen-induced liver failure and in chronic liver cirrhosis and hepatocellular carcinoma (HCC), no common underlying metabolic pathway has been identified. Recent case reports suggest a link between the pentose phosphate pathway (PPP) enzyme transaldolase (TAL; encoded by TALDO1) and liver failure in children. Here, we show that Taldo1(-/-) and Taldo1(+/-) mice spontaneously developed HCC, and Taldo1(-/-) mice had increased susceptibility to acetaminophen-induced liver failure. Oxidative stress in Taldo1(-/-) livers was characterized by the accumulation of sedoheptulose 7-phosphate, failure to recycle ribose 5-phosphate for the oxidative PPP, depleted NADPH and glutathione levels, and increased production of lipid hydroperoxides. Furthermore, we found evidence of hepatic mitochondrial. dysfunction, as indicated by loss of transmembrane potential, diminished mitochondrial mass, and reduced ATP/ADP ratio. Reduced beta-catenin phosphorylation and enhanced c-Jun expression in Taldo1(-/-) livers reflected adaptation to oxidative stress. Taldo1(-/-) hepatocytes were resistant to CD95/Fas-mectiated apoptosis in vitro and in vivo. Remarkably, lifelong administration of the potent antioxidant N-acetylcysteine (NAC) prevented acetaminophen-induced liver failure, restored Fas-dependent hepatocyte apoptosis, and blocked hepatocarcinogenesis in Taldo1(-/-) mice. These data reveal a protective role for the TAL-mediated branch of the PPP against hepatocarcinogenesis and identify NAC as a promising treatment for liver disease in TAL deficiency.

Paclitaxel eluting coronary stents were sterilized by e-beam in a closed system, to investigate sterilization related mass-balance issues and evaluate potential volatile paclitaxel degradation products. A solid-phase microextraction (SPME) method utilizing a polydimethyl-siloxane/divinyl-benzene (PDMS/DVB) fiber was optimized for extracting the volatiles from the head-space of the sterilized stents. GC-MS was used for separation, identification, and quantitation of the components. Benzaldehyde and benzoic acid were identified as paclitaxel related volatile degradation products. Three groups of stents were included in the study, a control group (not exposed to e-beam), a group sterilized at 25 kGy, and a final group sterilized at 75 kGy. The stents sterilized by e-beam at 75 kGy contained significantly higher levels of benzoic acid relative to the controls and the stents at 25 kGy contained intermediate levels of benzoic acid. The benzaldehyde levels increased in the 25 kGy e-beam sterilized stents relative to the control but remained fairly constant in the 75 kGy e-beam sterilized stents relative to the 25 kGy e-beam results. Mechanism for the formation of benzoic acid and benzaldehyde from paclitaxel was proposed. The levels of benzoic acid and benzaldehyde observed on the stents did not resolve the original mass-balance issue, but most likely contribute to the lack of mass balance observed for paclitaxel.

The chemical composition of carbonaceous aerosols collected during the LBA-SMOCC field experiment, conducted in Rondônia, Brazil, in 2002 during the transition from the dry to the wet season, was investigated by a suite of state-of-the-art analytical techniques. The period of most intense biomass burning was characterized by high concentrations of submicron particles rich in carbonaceous material and water-soluble organic compounds (WSOC). At the onset of the rainy period, submicron total carbon (TC) concentrations decreased by about 20 times. In contrast, the concentration of supermicron TC was fairly constant throughout the experiment, pointing to a constant emission of coarse particles from the natural background. About 6–8% of TC (9–11% of WSOC) was speciated at the molecular level by GC-MS and liquid chromatography. Polyhydroxylated compounds, aliphatic and aromatic acids were the main classes of compounds accounted for by individual compound analysis. Functional group analysis by proton NMR and chromatographic separation on ion-exchange columns allowed characterization of ca. 50–90% of WSOC into broad chemical classes (neutral species/light acids/humic-like substances). In spite of the significant change in the chemical composition of tracer compounds from the dry to the wet period, the functional groups and the general chemical classes of WSOC changed only to a small extent. Model compounds representing size-resolved WSOC chemical composition for the different periods of the campaign are then proposed in this paper, based on the chemical characterization by both individual compound analysis and functional group analysis deployed during the LBA-SMOCC experiment. Model compounds reproduce quantitatively the average chemical structure of WSOC and can be used as best-guess surrogates in microphysical models involving organic aerosol particles over tropical areas affected by biomass burning.

Transaldolase (TAL) is a key enzyme of the pentose phosphate pathway (PPP). TAL deficiency is a newly recognized cause of liver cirrhosis. We have developed an ion-pair LC separation combined with negative ion electrospray MS/MS detection method to assess PPP metabolites in urine samples from TAL-deficient mice. Sedoheptulose 7-phosphate (S7P), C5-polyols D-arabitol and D-ribitol, and 6-phosphogluconate (6PG) levels were markedly increased in urine of TAL-deficient mice with respect to those of wild-type and heterozygote littermates. The detection limits of S7P, D-arabitol, and 6PG were 0.15 +/- 0.015 pmol, 3.5 +/- 0.41 pmol, and 0.61 +/- 0.055 pmol, respectively. The limit of quantitation was 0.4 +/- 0.024 nmol/ml for S7P, 1.6 +/- 0.11 nmol/ml for 6PG and 10 +/- 0.7 nmol/ml for D-arabitol. Additional metabolites, hexose 6-phosphates (m/z 259), D-ribose 5-phosphate and D-xylulose 5-phosphate (m/z 229), D-fructose 1,6-diphosphate (m/z 339), C6-polyols (m/z 181) and GSSG (m/z 611), that have been positively identified in mouse urine, showed similar levels in control and TAL-deficient mice.

The diastereoisomeric 2-methyltetrols, 2-methylthreitol and 2-methylerythritol, were recently reported as major secondary aerosol components in natural forest aerosols and proposed as molecular markers for the photooxidation of isoprene. In this study, we examine the complex electron and methane chemical ionization behaviors of their trimethylsilyl ethers. In order to gain insight into their fragmentation behaviors, threitol and erythritol were studied as model compounds, and deuterium labeling of the trimethylsilyl groups and ion trap MS2 experiments were performed.