Relevant Storage Conditions Research Articles

Enhancing Shelf-Life of Electrolytes with LiPF6 By Increasing Stability Under Commercially Relevant Storage Conditions

Lithium hexafluorophosphate (LiPF6) salt is the most commonly used lithium salt in commercial Li-ion batteries due to its high conductivity, passivation of Al current collectors for positive electrodes, and participation in SEI layer formation at graphite anodes.1 However, LiPF6 suffers from poor thermal stability and poor stability toward protic species (like water) leading to decomposition that can significantly reduce Li-ion battery performance especially under the extreme conditions demanded by today’s industrial applications. Specifically, LiPF6 decomposition leads to HF generation, especially in the presence of water2, which results in multiple negative outcomes in Li-ion cells including dissolution of cathode materials and gas generation.3 Conditions during electrolyte blending, transport, and/or storage often exacerbate LiPF6 instability and increase HF generation.To date, efforts to replace LiPF6 have not proven to be commercially successful, therefore strategies to improve the stability of LiPF6 electrolytes under relevant storage conditions are critical to support the deployment of Li-ion batteries. Koura has extensively characterized the degradation of LiPF6 as a function of multiple conditions, including temperature, water content, and electrolyte composition to inform the design of strategies to improve stability.This presentation will summarize Koura’s efforts to understand LiPF6 decomposition under conditions relevant to the Li-ion electrolyte supply chain. Specifically, we will present data showing a series of fluorinated materials that improve the thermal stability of LiPF6 electrolyte through the elimination of existing HF and suppression of additional formation.

Abstract 1906: UNO-A001 (A001), a clinical candidate CD38 x CD3 bispecific with a novel structure, potently kills multiple myeloma cells in vitro and is highly effective in vivo

Abstract CD38 is a validated target for the treatment of multiple myeloma (MM) as evidenced by the important clinical activity of CD38 targeting monoclonal antibodies. Bispecific T Cell Engagers (TCEs) kill cancer cells by distinct mechanisms as compared to standard format antibody therapeutics and several TCEs have demonstrated impressive clinical activity, and have been approved for clinical use, in hematologic malignancies. Here we describe a novel bispecific leveraging the potent killing mechanism of TCEs to target CD38 bearing cancer cells. UNO-A001 is a TCE binding the cell surface receptor CD38 on target human cancer cells and CD3 on T cells. The molecule has a differentiated format, binding CD38 with a high affinity humanized camelid VHH moiety and CD3 on T cells through a unique antibody Fab arm. The affinities of each arm were optimized so that the CD38 arm bound with high affinity and the CD3 arm with much lower relative binding affinity. This configuration was designed to engage CD38 bearing target cells with multiple TCE molecules at lower doses and concentrations while minimizing T cell binding in the periphery, and in the absence of cell surface CD38. A001 potently and specifically killed human CD38 bearing multiple myeloma cell lines in T cell killing assays in vitro with EC50s in the 2.7-6.6 pM range. This potency, despite the designed lower affinity to CD3, may be due to the unique structure of A001 enabling a productive immunologic synapse between T cells and the target cancer cells, and an optimal TAA/CD3 binding affinity ratio. A001 was also highly effective in inhibiting tumor growth in H929 xenograft models. In a flank model of H929 tumor growth A001 dose dependently inhibited tumor growth with complete growth inhibition of established tumors at the highest dose level tested. In a systemic disease model with NCI-H929-luc cells A001 was also highly effective and improved survival relative to control treated animals. In preparation for clinical studies a robust and high yield production cell line was created and characterized. It achieved high expression levels of quality monodisperse UNO-A001 product that was stable in all relevant storage conditions. A001 has similar affinities for human and cynomolgus macaque CD38 and CD3. Dose ranging studies in cynomolgus macaques demonstrated tolerability consistent with clinically approved TCEs, and the expected dose dependent pharmacodynamic effects on CD38 expressing myeloid and lymphoid cell populations. These data support planned clinical testing of A001 in multiple myeloma and other CD38 bearing hematologic malignancies, including mantle cell lymphoma, T cell lymphoma, and acute myelogenous leukemia. Citation Format: Mark Anderson, Yan Ling, Mark L. Chiu, Peter Cheung. UNO-A001 (A001), a clinical candidate CD38 x CD3 bispecific with a novel structure, potently kills multiple myeloma cells in vitro and is highly effective in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1906.

Stability of 10 Beta-Lactam Antibiotics in Human Plasma at Different Storage Conditions.

Recently, several studies have assessed the effects of therapeutic drug monitoring of frequently prescribed beta-lactam antibiotics, for which they were quantified in human plasma samples. Beta-lactams are considered unstable, leading to extra challenges in quantification. Therefore, to ensure sample stability and minimize sample degradation before analysis, stability studies are crucial. This study investigated the stability of 10 frequently used beta-lactam antibiotics in human plasma at relevant storage conditions for clinical use. Amoxicillin, benzylpenicillin, cefotaxime, ceftazidime, ceftriaxone, cefuroxime, flucloxacillin, imipenem, meropenem, and piperacillin were analyzed using ultraperformance convergence chromatography tandem mass spectrometry and liquid chromatography tandem mass spectrometry. Their short-term and long-term stabilities were investigated by measuring quality control samples at low and high concentrations against freshly prepared calibration standards. Measured concentrations at each time point were compared with the concentrations at T = 0. Antibiotics were considered stable if recovery results were between 85% and 115%. Short-term stability results indicated ceftriaxone, cefuroxime, and meropenem to be stable up to 24 hours at room temperature. All evaluated antibiotics, except imipenem, were stable on ice in a cool box for 24 hours. Amoxicillin, benzylpenicillin, and piperacillin were stable for 24 hours at 4-6°C. Cefotaxime, ceftazidime, cefuroxime, and meropenem were stable at 4-6°C up to 72 hours. Ceftriaxone and flucloxacillin were stable for 1 week at 4-6°C. Long-term stability results showed that all antibiotics were stable up to 1 year at -80°C, except imipenem and piperacillin, which were stable for 6 months at -80°C. Plasma samples for amoxicillin, benzylpenicillin, cefotaxime, ceftazidime, flucloxacillin, and piperacillin may be stored for a maximum of 24 hours in a cool box. Refrigeration is suitable for plasma samples of amoxicillin, benzylpenicillin, meropenem, and piperacillin for up to 24 hours and cefotaxime, ceftriaxone, ceftazidime and cefuroxime for 72 hours. Plasma samples for imipenem should be frozen directly at -80°C. For long-term storage, plasma samples can be stored at -80°C for a maximum of 6 months for imipenem and piperacillin and 12 months for all other evaluated antibiotics.

Measurement of hydrogen dispersion in rock cores using benchtop NMR

Electrolysis followed by underground hydrogen storage (UHS) in both salt caverns and depleted oil and gas reservoirs is widely considered as a potential option to overcome fluctuations in energy provision from intermittent renewable sources. Particularly in the case of depleted oil and gas reservoirs, a denser layer of cushion gas (N2, CH4 or CO2) can be accommodated in these storage volumes to allow for sufficient system pressure control as hydrogen is periodically injected and extracted. These gases/fluids are however fully soluble with hydrogen and thus with sufficient mixing can undesirably contaminate the extracted hydrogen product. Fluid mixing in a porous medium is typically characterized by a dispersion coefficient (KL), which is hence a critical input parameter into reservoir simulations of underground hydrogen storage. Such dispersion data is however not readily available in the literature for hydrogen at relevant storage conditions. Here we have developed and demonstrated novel methodology for the measurement of KL between hydrogen and nitrogen in a Berea sandstone at 50 bar as a function of displacement velocity (0.007–0.722 mm/s). This leverages off previous work quantifying KL between carbon dioxide and methane in rock cores relevant to enhanced gas recovery (EGR). This used infrared (IR) spectroscopy to differentiate the two fluids, hydrogen is however IR invisible. Hence the required time-resolved quantification of hydrogen concentration emerging from the rock core is uniquely performed here using bench-top nuclear magnetic resonance (NMR). The resultant hydrogen-nitrogen dispersion data as a function of displacement velocity allows for the determination of dispersivity (α = 0.31 mm). This intrinsic rock property compares favorably with previous CO2 dispersion measurements on similar sandstones, hence validating our methodology to some extent. In addition, at very low velocities, determination of the rock core tortuosity (τ, another intrinsic rock property) produces a value (τ = 10.9) that is similar to that measurement independently using pulsed field gradient NMR methods (τ = 11.3).

Study of Degradation Kinetics and Structural Analysis of Related Substances of Ceftobiprole by HPLC with UV and MS/MS Detection

Ceftobiprole is a novel β-lactam antibiotic, active against methicillin-resistant Staphylococcus aureus, vancomycin-resistant S. aureus and penicillin-resistant Streptococcus pneumoniae. To artificially generate potential degradation products (DPs) of ceftobiprole that may be formed under relevant storage conditions, acidic, alkaline, oxidative, photolytic and thermolytic stress tests were performed in both solution and solid state. A novel selective HPLC method was developed for the separation of ceftobiprole from its DPs and synthesis by-products (SBPs) using Kinetex Biphenyl column, ammonium acetate buffer pH 5.8 and acetonitrile. The kinetic studies demonstrated the low stability of ceftobiprole in alkaline solution, in the presence of an oxidising agent and under irradiation with near UV. In the solid state, ceftobiprole underwent oxidation when the powder was irradiated with visible light and UV. Based on mass spectroscopic analysis, 13 new structural formulas of SBPs and DPs were proposed, along with molecular formulas for three other DPs obtained in solution and four oxidative DPs characteristic of solid-state degradation.

The impact of 1‐MCP treatment and controlled atmosphere storage on the postharvest performance of four ( Chaenomeles japonica (Thunb.) Lindl. ex Spach) fruit cultivars

Japanese quince (JQ) shows climacteric behavior that is respiration takes place during ripening. Phytochemical processes during fruit storage cause changes in quality; thus, relevant storage conditions are to be identified to sustain fruit quality over the storage time. The present work aimed to evaluate the effect of 1-MCP treatment and controlled atmosphere (CA) storage on the quality of JQ fruit. Two experiments during the 2017 and 2018 seasons were carried out with four JQ cultivars. Better maintenance of fresh weight was observed in the case of CA storage, although the degree of effectiveness was cultivar and growing season dependent. The best preservation of JQ fruit phytochemicals, for example, total phenolics, proanthocyanidins, and vitamin C has been reached when the CA system was employed. In turn, no clear effect of either CA or 1-MCP on fruit soluble solids and total acids content was observed for JQ fruit after long-term storage. Practical application In recent years, there have been many studies centered on the evaluation of the chemical composition of Japanese quince (JQ) fruits revealing that these fruits are a good source of valuable compounds for the food and pharmaceutical industries. Currently, the fruit of JQ are processed for many food products, thus leading to the intensive diversification of planting areas. It is expected that the market share of JQ will increase double or triple in the future. To ensure the quality of JQ during storage, proper storage technology needs to be identified. Acquired data in this study are of potential interest to growers and industries dealing with JQ fruit processing and storage.

Hemostatic capacity of canine chilled whole blood over time.

To determine the hemostatic potential of canine chilled whole blood maintained at clinically relevant storage conditions. In vitro experimental study. Government blood and coagulation research laboratory and government referral veterinary hospital. Ten healthy Department of Defense military working dogs. One unit of fresh whole blood was collected from each of 10 military working dogs using aseptic technique. Blood was maintained in a medical-grade refrigerator for 28 days at 4°C (39°F) and analyzed before refrigeration (day 0) and after (days 2, 4, 7, 9, 11, 14, 21, and 28). Ten units of canine blood were analyzed with whole blood platelet aggregation, thromboelastography, CBC, biochemical analysis, blood gas, and prothrombin/activated partial thromboplastin/fibrinogen assay. Clotting strength of chilled blood was maintained up to 21 days despite significant decreases in platelet aggregation to ADP, collagen, or γ-thrombin, significant prolongation of prothrombin and activated partial thromboplastin times, and reduced speed of clot formation (K time, alpha angle). Fibrinogen concentration, WBC, RBC, and platelet counts did not change over time. Chilled canine whole blood loses a small percentage of clot strength through 21 days of refrigerated storage. Further research is needed to determine if this hemostatic potential is clinically relevant in hemorrhaging dogs who require surgical intervention or are exposed to traumatic events.

Suppression of Electrostatic Mediated Antibody Liquid-Liquid Phase Separation by Charged and Noncharged Preferentially Excluded Excipients.

Isotonic concentrations of inert cosolutes or excipients are routinely used in protein therapeutic formulations to minimize physical instabilities including aggregation, particulation, and precipitation that are often manifested during drug substance/product manufacture and long-term storage. Despite their prevalent use within the biopharmaceutical industry, a more detailed understanding for how excipients modulate the specific protein-protein interactions responsible for these instabilities is still needed so that informed formulation decisions can be made at the earliest stages of development when protein supply and time are limited. In the present report, subisotonic concentrations of the five common formulation excipients, sucrose, proline, sorbitol, glycerol, arginine hydrochloride, and the denaturant urea, were studied for their effect on the room temperature liquid-liquid phase separation of a model monoclonal antibody (mAb-B). Although each excipient lowered the onset temperatures of mAb-B liquid-liquid phase separation to different extents, all six were found to be preferentially excluded from the native state monomer by vapor pressure osmometry, and no apparent correlations to the excipient dependence of mAb-B melting temperatures were observed. These results and those of the effects of solution pH, addition of salt, and impact of a small number of charge mutations were most consistent with a mechanism of local excipient accumulation, to an extent dependent on their type, with the specific residues that mediate mAb-B electrostatic protein-protein interactions. These findings suggest that selection of excipients on the basis of their interaction with the solvent exposed residues of the native state may at times be a more effective strategy for limiting protein-protein interactions at pharmaceutically relevant storage conditions than choosing those that are excluded from the residues of the native state interior.

Bioanalytical assay for the novel TRK inhibitor selitrectinib in mouse plasma and tissue homogenates using liquid chromatography-tandem mass spectrometry

Selitrectinib is a next generation tropomyosin receptor kinase (TRK) inhibitor developed to overcome acquired resistance to first generation TRK inhibitors. The drug is a cyclic analogue of larotrectinib. An existing bioanalytical assay for larotrectinib was therefore redesigned for selitrectinib. The assay used liquid chromatography-electrospray tandem mass spectrometry in positive selected reaction monitoring mode. Mouse plasma and tissue homogenates of brain, heart, kidney, liver, lung, small intestine, spleen, and testis were pretreated using acetonitrile protein precipitation with larotrectinib added as internal standard. Successful validation using current guidelines was obtained in the range 0.5–1000 ng/ml. Precision was within 5–12% and accuracy within 91–108% for all matrices investigated. The drug was stable in all matrices under the relevant storage conditions. Pharmacokinetics and tissue distribution of selitrectinib were monitored in a pilot study in mice demonstrating the applicability of the presented assay.

Development and Validation of an Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Method for the Concurrent Measurement of Gabapentin, Lamotrigine, Levetiracetam, Monohydroxy Derivative of Oxcarbazepine, and Zonisamide Concentrations in Serum in a Clinical Setting.

Therapeutic drug monitoring of antiepileptic drugs (AEDs) is often necessary to prevent associated destructive toxicities. Tandem mass spectrometry (MS/MS) with stable-isotope-labeled internal standards is considered the gold standard for the measurement of AEDs. This study presents the development and validation of a clinical ultra-performance liquid chromatography-MS/MS method for the concurrent measurement of gabapentin, lamotrigine, levetiracetam, monohydroxy derivative of oxcarbazepine, and zonisamide in human serum. To determine the optimal assay analyte range, one year of AED therapeutic drug monitoring results (n = 1825) were evaluated. Simple protein precipitation with acetonitrile containing isotopically labeled internal standards was used. Reverse-phase ultra-performance liquid chromatography chromatographic separation was used, having a total run time of 3 minutes. Quantification of analytes was accomplished using electrospray ionization in positive ion mode and collision-induced dissociation MS. Assay parameters were evaluated per Food and Drug Administration bioanalytical guidelines. After evaluating internal patient data, the analytical measuring range (AMR) of the assay was established as 0.1-100 mcg/mL. All AEDs were linear across the AMR, with R values ranging from 0.9988 to 0.9999. Imprecision (% coefficient of variation) and inaccuracy (% difference) were calculated to be <20% for the lower limit of quantitation and <15% for the low, mid, and high levels of quality controls across the AMR. All AEDs demonstrated acceptable assay parameters for carryover, stability under relevant storage conditions, matrix effects, recovery, and extraction and processing efficiency. In addition, the assay displayed acceptable concordance to results obtained from a national reference laboratory, with Deming regression R of 0.99 and slope values ranging from 0.89 to 1.17. A simple, cost-effective, and robust ultra-performance liquid chromatography-tandem mass spectrometry method for monitoring multiple AEDs was developed and validated to address the clinical needs of patients at our institution.

Mechanistic Insight into Caffeine-Oxalic Cocrystal Dissociation in Formulations: Role of Excipients.

Caffeine-oxalic acid cocrystal, widely reported to be stable under high humidity, dissociated in the presence of numerous pharmaceutical excipients. In cocrystal-excipient binary systems, the water mediated dissociation reaction occurred under pharmaceutically relevant storage conditions. Powder X-ray diffractometry was used to identify the dissociated products obtained as a consequence of coformer-excipient interaction. The proposed cocrystal dissociation mechanism involved water sorption, dissolution of cocrystal and excipient in the sorbed water, proton transfer from oxalic acid to the excipient, and formation of metal salts and caffeine hydrate. In compressed tablets with magnesium stearate, the cocrystal dissociation was readily discerned from the appearance of peaks attributable to caffeine hydrate and stearic acid. Neutral excipients provide an avenue to circumvent the risk of water mediated cocrystal dissociation.

A rapid UPLC-MS/MS assay for the simultaneous measurement of fluconazole, voriconazole, posaconazole, itraconazole, and hydroxyitraconazole concentrations in serum.

Triazole antifungals are essential to the treatment and prophylaxis of fungal infections. Significant pharmacokinetic variability combined with a clinical need for faster turnaround times has increased demand for in-house therapeutic drug monitoring of these drugs, which is best performed using mass spectrometry-based platforms. However, technical and logistical obstacles to implementing these platforms in hospital laboratories have limited their widespread utilization. Here, we present the development and validation of a fast and simple ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to measure fluconazole, voriconazole, posaconazole, itraconazole, and hydroxyitraconazole in human serum suitable for incorporation into a hospital clinical laboratory. Serum samples (20 µL) were prepared using protein precipitation in the presence of deuterated internal standards. Chromatographic separation was accomplished using reversed phase UPLC and analysis was performed using positive-mode electrospray ionization and collision-induced dissociation MS. Total analytical run time was 3 min. All analytes demonstrated linearity (r2>0.998) from 0.1 to 10 µg/mL (1-100 µg/mL for fluconazole), acceptable accuracy and precision (%DEV<15% and %CV<15% at all levels tested), suitable stability under relevant storage conditions, and correlated well with reference laboratory results. A simple and rapid UPLC-MS/MS method for monitoring multiple triazole antifungals was developed with a focus on the needs of hospital laboratories. The assay is suitable for clinical utilization and management of patients on these medications.

Highly scalable, closed-loop synthesis of drug-loaded, layer-by-layer nanoparticles.

Layer-by-layer (LbL) self-assembly is a versatile technique from which multicomponent and stimuli-responsive nanoscale drug carriers can be constructed. Despite the benefits of LbL assembly, the conventional synthetic approach for fabricating LbL nanoparticles requires numerous purification steps that limit scale, yield, efficiency, and potential for clinical translation. In this report, we describe a generalizable method for increasing throughput with LbL assembly by using highly scalable, closed-loop diafiltration to manage intermediate purification steps. This method facilitates highly controlled fabrication of diverse nanoscale LbL formulations smaller than 150 nm composed from solid-polymer, mesoporous silica, and liposomal vesicles. The technique allows for the deposition of a broad range of polyelectrolytes that included native polysaccharides, linear polypeptides, and synthetic polymers. We also explore the cytotoxicity, shelf life and long-term storage of LbL nanoparticles produced using this approach. We find that LbL coated systems can be reliably and rapidly produced: specifically, LbL-modified liposomes could be lyophilized, stored at room temperature, and reconstituted without compromising drug encapsulation or particle stability, thereby facilitating large scale applications. Overall, this report describes an accessible approach that significantly improves the throughput of nanoscale LbL drug-carriers that show low toxicity and are amenable to clinically relevant storage conditions.

CIPC vapour for efficient sprout control at low application levels

Isopropyl N-(3-chlorophenyl) carbamate (CIPC) is a growth inhibitor typically applied as a hot fog (spherical particles of about 5μm diameter) on harvested potatoes to prevent sprouting during prolonged storage. Although particularly efficient in sprout control, deposition of solid CIPC particles on the potatoes increases the residue levels of the chemical on the tubers. The potential of CIPC to be used in the vapour phase for efficient sprout control at significantly lower application rates has been evaluated. First, CIPC vapour release rates from different hydrocolloid formulations were evaluated. From the investigated formulations (agar, gellan gum, κ-carrageenan, alginate), 1% gellan gum set with 0.002M calcium ions appeared to result in the fastest vapour releasing formulation. At industrially relevant storage conditions (8°C, 90% relative humidity) CIPC vapour release was significantly reduced. Vapour adsorption by tubers was then investigated and showed maximum of 2.5mgkg−1 (mass of CIPC per mass of tubers) for washed, non-dormant tubers exposed to solid sources for 28d. Efficient sprout control was indicated for tubers exposed to vapour sources and CIPC levels of 0.3mgkg−1. Overall, the work indicates strong potential of CIPC vapour in efficiently preventing sprouting.

Simultaneous determination of azilsartan and chlorthalidone in rat and human plasma by liquid chromatography-electrospray tandem mass spectrometry.

Azilsartan medoxomil (AZM), an ester prodrug of azilsartan (AZ), and chlorthalidone (CLT) have recently been approved as a combination therapy for the management of hypertension. This is the first report which described a selective and sensitive method for the simultaneous quantification of AZ and CLT in rat and human plasma using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). AZ and CLT were extracted from plasma by liquid-liquid extraction technique and separated on a C18 reverse phase column using ammonium acetate (10mM, pH 4)-mixture of methanol and acetonitrile (8:92, v/v) as a mobile phase at a flow rate of 0.7mL/min. Detection was performed by electrospray ionization (ESI) operated in negative multiple reaction monitoring (MRM) mode. The lower limit of quantitation (LLOQ) of this method was 1ng/mL and the calibration curves were linear (r(2)≥0.995) over the concentration range of 1-4000ng/mL for both the analytes. The intra- and inter-day precision and accuracy were well within the acceptable limits. The mean extraction recoveries were found to be about 80% and no matrix effect was observed. AZ and CLT were found to be stable under all relevant storage conditions. The method was successfully applied to the oral pharmacokinetic study of AZM and CLT in rats. Further, the sensitivity of the method enabled the determination of protein binding of AZ and CLT in human plasma.

Liquid chromatography–tandem mass spectrometric assay for the multikinase inhibitor regorafenib in plasma

Regorafenib has recently been approved for the treatment of colorectal cancer. A bioanalytical liquid chromatography-tandem mass spectrometric assay for this multikinase inhibitor was developed and validated in plasma. The concentration range of the assay was 25-25,000 ng/mL. Protein precipitation with acetonitrile was used as sample pre-treatment with sorafenib as internal standard. The extract was diluted with methanol (25%, v/v) and then injected onto the sub-2 µm particle, bridged ethylsilicia hybrid trifunctional bonded C18 column. Isocratic elution using 0.02% (v/v) formic acid in a methanol-water mixture was used. Compounds were monitored by a triple quadrupole mass spectrometer in the selected reaction monitoring mode after positive electrospray ionization. Double logarithmic calibration was used; within-day precisions, between-day precisions, and accuracies were 3.2-9.2, 4.1-12.3 and 94.8-103.0%, respectively. High drug stability was observed under all relevant storage conditions. The assay was used to measure drug concentrations in a pharmacokinetic study in wild-type FVB mice.

Development and validation of a predictive model for the growth of Vibrio parahaemolyticus in post-harvest shellstock oysters

Information is limited about the growth and survival of naturally-occurring Vibrio parahaemolyticus in live oysters under commercially relevant storage conditions harvested from different regions and in different oyster species. This study produced a predictive model for the growth of naturally-occurring V. parahaemolyticus in live Eastern oysters (Crassostrea virginica) harvested from the Chesapeake Bay, MD, USA and stored at 5–30°C until oysters gapped. The model was validated with model-independent data collected from Eastern oysters harvested from the Chesapeake Bay and Mobile Bay, AL, USA and Asian (C. ariakensis) oysters from the Chesapeake Bay, VA, USA. The effect of harvest season, region and water condition on growth rate (GR) was also tested. At each time interval, two samples consisting of six oysters each were analyzed by a direct-plating method for total V. parahaemolyticus. The Baranyi D-model was fitted to the total V. parahaemolyticus growth and survival data. A secondary model was produced using the square root model. V. parahaemolyticus slowly inactivated at 5 and 10°C with average rates of −0.002 and −0.001logcfu/h, respectively. The average GRs at 15, 20, 25, and 30°C were 0.038, 0.082, 0.228, and 0.219logcfu/h, respectively. The bias and accuracy factors of the secondary model for model-independent data were 1.36 and 1.46 for Eastern oysters from Mobile Bay and the Chesapeake Bay, respectively. V. parahaemolyticus GRs were markedly lower in Asian oysters. Harvest temperature, salinity, region and season had no effect on GRs. The observed GRs were less than those predicted by the U.S. Food and Drug Administration's V. parahaemolyticus quantitative risk assessment.

HPLC–MS and HPLC–MS/MS analysis of seven active constituents of Xiao-Xu-Ming decoction and application to a pharmacokinetic study after oral administration to rat

Xiao-xu-ming decoction (XXMD) is a traditional Chinese medicine that has been widely used to treat theoplegia and its sequelae. This paper reports the development of three separate assays based on reversed phase high-performance liquid chromatography–mass spectrometry (HPLC–MS) and HPLC–MS/MS for the determination of seven active constituents of XXMD viz oroxylin A-7-O-glucuronide, wogonoside, liquiritigenin, cimifugin, 5-O-methylvisammiol, glycyrrhizic acid and glycyrrhetinic acid in rat plasma. All calibration curves were linear (r >0.99) with lower limits of quantitation (LLOQs)<12.4ng/mL. Intra- and inter-day precisions (as relative standard deviation) were all <10.7% with recoveries in the range of 88.7–113%. In addition, the seven analytes were shown to be stable in rat plasma samples under relevant storage conditions. The validated methods were successfully applied to a pharmacokinetic study in rat after oral administration of XXMD.

The effect of temperature on the bacterial load and microbial composition in Norway lobster (Nephrops norvegicus) tail meat during storage

The aim of this study was to update and extend our knowledge of the bacterial load and microbial composition in Norway lobster (Nephrops norvegicus) under commercially relevant storage conditions to optimize handling procedures. Total viable counts were performed at different storage temperatures (0, 4, 8, 10, 12 or 16°C) and after different storage times (1-7 days). Storage at 16°C was found to be most detrimental, and storage at 0°C was found to be optimal. 16S-rRNA sequencing was utilized to determine the composition of the bacteria within the microflora. In this way, Photobacterium isolates, especially Photobacterium phosphoreum, were identified as the main specific spoilage organisms. The abilities to reduce trimethylamineoxide (TMAO) and to produce H(2)S were analysed in a selection of bacterial isolates. The higher the incubation temperature during storage, the more isolates were found to reduce TMAO and produce H(2)S. Nephrops norvegicus possesses an unusually high initial microbial load when fresh. Storage temperature is the most crucial factor affecting microbial growth, microbial activity and spoilage potential in N. norvegicus produce. Spoilage can be attributed mainly to P. phosphoreum. This study presents significant new findings with regard to the progression and causative agents of spoilage in N. norvegicus. Based on the results, we can recommend that N. norvegicus tails should be stored in a 0°C environment immediately after catch. Stored this way, the growth and spoilage activity of the microflora may be reduced significantly and an extension of shelf life might be attained.

Tin Whisker Test Development—Temperature and Humidity Effects Part II: Acceleration Model Development

The incubation time for both whisker growth and corrosion in thin Sn platings (3-10 ?m thick) on Cu-based alloys have been found to be well represented by an exponential function of humidity and an Arrhenius function of temperature for both as-deposited and reflowed tin platings. Furthermore, whisker growth was found to follow the same functionality in both corroded and non-corroded regions of the plating. The effective activation energies and humidity coefficients were found to depend upon plating thickness, exposure to reflow, and presence of corrosion. The effective activation energies ranged from 0.23 eV to 0.41 eV and the humidity coefficients ranged from -0.012% to -0.031%. Corrosion enhanced whisker growth occurred by lowering the effective activation energy for whisker growth. A theory based on excess, non-creep relaxed, oxidation induced strain was developed to explain the corrosion induced energy barrier lowering. The data showed that 60°C/87%RH appears to be the optimal high temperature/high humidity test condition at this time for Sn over Cu substrates. Within the limits of the whisker and corrosion (incubation) acceleration functions developed in this study, it is concluded that the JEDEC tests can be used to indicate behavior at other temperature/humidity points that could be relevant storage or service conditions.