Thermal Stress Conditions Research Articles

Thermal Environments and Visitor Attendance in Zoological Parks: Observations in A Humid Continental Climate

This paper reviews associations between weather and visitor attendance at two climatically similar zoological parks. This is achieved by examining weather, climate, and attendance data at the Indianapolis and St. Louis zoological parks over a period of approximately one decade. The methodological approach utilizes tourism climatology as the foundation for information gathering, display, and analysis of results. Peak days of attendance at both zoos coincide with ‘warm’ and ‘slightly’ warm days. Regarding the lowest attendances, visitors at both locations appear to display more aversion to cold thermal stress conditions than hot thermal stress conditions, however visitors at St. Louis Zoo appear to be more averse to cold conditions. Discussions regarding how social calendars and admission pricing may interact with this relationship are introduced.

Forced Degradation Study of Zanubrutinib: An LC-PDA and LC-MS Approach.

Zanubrutinib is an unfamiliar second generation selective Brutson's Tyrosine Kinase inhibitor used to treat mantle cell lymphoma. In the present analysis, a new, stability indicating reverse-phase, high performance liquid chromatography method was developed and validated for the determination of Zanubrutinib succeeding degradation studies as pert the International Conference on Harmonization guidelines. The chromatographic separation of Zanubrutinib was achieved in a C18 column (250 × 4.6mm, 5-μm particle size) using a mobile phase of Acetonitrile: 0.1% Tri Ethyl Amine (65:35v/v) monitored at 219nm. The forced degradation studies were conducted by exposing the analyte to acidic, alkaline and neutral hydrolysis, oxidative, reductive, photolytic, and thermal stress conditions and the degradation behavior was studied. The analyte showed degradation under acidic, alkaline, oxidative and reductive stress conditions with additional peaks but, it was stable under neutral, photolytic and thermal stress conditions. The developed method was extended to triple quadruple mass spectrometry to characterize degradation products and to study the fragmentation pattern. Total four degradants were characterized including DP1 in acid &base hydrolysis, DP2 in oxidative and DP3, DP4 in reductive stress condition. As no substantial method was available for quantification of Zanubrutinib and to characterize zanubrutinib degradants, this method can be used for regular analysis in quality control labs.

A Low-Cost, Easy-to-Assemble Device to Prevent Infant Hyperthermia under Conditions of High Thermal Stress.

High ambient temperature and humidity greatly increase the risk of hyperthermia and mortality, particularly in infants, who are especially prone to dehydration. World areas at high risk of heat stress include many of the low- and middle-income countries (LMICs) where most of their inhabitants have no access to air conditioning. This study aimed to design, evaluate, and test a novel low-cost and easy-to-assemble device aimed at preventing the risk of infant hyperthermia in LMICs. The device is based on optimizing negative heat transfer from a small amount of ice and transferring it directly to the infant by airflow of refrigerated air. As a proof of concept, a device was assembled mainly using recycled materials, and its performance was assessed under laboratory-controlled conditions in a climatic chamber mimicking realistic stress conditions of high temperature and humidity. The device, which can be assembled by any layperson using easily available materials, provided sufficient refrigerating capacity for several hours from just 1–2 kg of ice obtained from a domestic freezer. Thus, application of this novel device may serve to attenuate the adverse effects of heat stress in infants, particularly in the context of the evolving climatic change trends.

Efficacy and Function of Feathers, Hair, and Glabrous Skin in the Thermoregulation Strategies of Domestic Animals

Simple SummaryAnimals adopt several strategies to regulate their body temperature by promoting heat loss or gain in hot and cold environments, respectively. This mechanism of heat loss or production is performed in thermal windows. A thermal window is a structure where many blood capillaries facilitate thermal exchange in this region. The presence of feathers, hair, or glabrous (hairless) skin and their structural characteristics greatly influence each species’ capacity to maintain thermal comfort. This factor needs to be considered when implementing new monitoring or measuring techniques such as infrared thermography since interpretations may vary due to the presence or absence of these structures. It is essential to recognize the effects of glabrous skin, hair, and feathers on thermoregulation to identify species-specific thermal windows that allow accurate evaluations of the thermal state of domestic animals.The objective of this review is to describe and analyze the effect of feathers, hair, and glabrous (hairless) skin on the thermoregulation of domestic and endotherm animals, especially concerning the uses and scope of infrared thermography (IRT), scientific findings on heat and cold stress, and differences among species of domestic animals. Clinical medicine considers thermoregulation a mechanism that allows animals to adapt to varying thermal environmental conditions, a process in which the presence of feathers, hair, or glabrous skin influences heat loss or heat retention, respectively, under hot and cold environmental conditions. Evaluating body temperature provides vital information on an individual’s physiological state and health status since variations in euthermia maintenance in vertebrates reflect a significant cellular metabolism deviation that needs to be assessed and quantified. IRT is a non-invasive tool for evaluating thermal responses under thermal stress conditions in animals, where the presence or absence of feathers, hair, and glabrous skin can affect readings and the differences detected. Therefore, anatomical regions, the characteristics of feathers, hair, glabrous skin such as structure, length, color, and extension, and strategies for dissipating or retaining heat together constitute a broad area of opportunity for future research into the phenomena of dermal thermoregulation in domestic species.

Aging Status Prediction of Oil Impregnated Insulating Kraft Paper Using GLCM Based Textural Features

This paper presents the prediction of aging state of oil impregnated insulating Kraft paper using textural properties. Under conditions of prolonged thermal stress, the insulating capacity of Kraft paper decreases due to carbonization and degradation of cellulose. To analyze these effects, a new accelerated aging kit is developed for the experiments. Four groups of samples are collected, and the morphology is examined. Texture feature is extracted for the samples using normalization and Gray-Level Co-occurrence Matrix (GLCM). Supervised (Support Vector Machine (SVM)) and unsupervised (K-means) machine intelligence methods are trained to classify images based on the feature. In addition, new samples are checked for feasibility of the prediction of aging state. The calculated training accuracy of SVM is 92.67%, and for k-means is 95.0%, on the other hand, the testing accuracy of SVM is 91.0%, and for k-means is 92.6%. Therefore, this machine intelligence-based methodology using image features is effective in classifying the aging state of the Kraft Insulating Paper.

Effects of Local Cold and Heat Stimuli on Cutaneous Thermal Sensitivity and Inter-Threshold Zone at Rest and During Exercise

PURPOSE: The primary objective of this study was to investigate the effects of local cold and heat stimuli on cutaneous thermal sensitivity and inter-threshold zone at rest and during exercise.METHODS: Cutaneous warm and cold thresholds were measured on two body regions (forehead and hand) in three types of local thermal stress environments (neutral, heat, cold) using a method of limit in sixteen young, healthy male subjects (25.44±2.28 years) at rest and during exercise.RESULTS: The results showed that the thermal inter-threshold zone was wider on the hand than on the forehead under thermal stress conditions at rest and during exercise. The thermal inter-threshold zone on both body regions widened with exercise (p<.05). Exercise significantly blunted both the warm and cold sensitivity in the forehead (p<.05), but only cold sensitivity in the hand (p<.05). Moreover, the thermal inter-threshold zone on both the forehead and hand became significantly wider when heat or cold stress was applied to the local body region (p<.001). In the forehead, warm and cold sensitivity were significantly blunted in both heat and cold stress environments (p<.05), whereas in the hard they were significantly blunted only in the heat stress environment (p<.01).CONCLUSIONS: In conclusion, the present study showed that the forehead is more sensitive to both warm and cold stimuli than the hand, regardless of thermal stress or exercise. Furthermore, the thermal inter-threshold zone on both the forehead and the hand widened with exercise and local thermal stimuli.

RWLMod-Potential Model to Study Plant Tolerance in Drought Stress Conditions.

Rationale: Water loss by evaporation is a normal physiological process, in order to regulate plant temperature. Under conditions of thermal and water stress, water loss is accelerated compared to normal conditions, and the response of plants is variable. In extreme cases, it can lead to wilting and death of plants. It was found that the phenomenon of water loss behaved as a pattern in different plant species, given by two functions, logistics (first part of water loss) and hyperbola (second part of water loss) in relation to a moment m, at which the rate of water loss (RWL) has reached its maximum value. Method: We studied the water loss process for a series of plant samples on different plant species (Picea abies L., H. Karst; Juniperus communis L.; Pinus silvestris L.; Thuja occidentalis L.; Lamium purpureum L.; Veronica hederifolia L.), measuring the rate of weight loss (RWL) in controlled conditions. The drying of the samples was done in identical conditions (thermo-balance, 100 °C, standard temperature for drying the plant samples) with the real-time recording of the drying time simultaneously with the water loss rate (RWL) from the plant samples. The exposure time varied, depending on each species sample, and was approximately 1000 s. Results: The experimental data was recorded at intervals of every 10 s, during the entire drying period. RWL values varied from 0.024 to 0.054 g/min at the beginning of the drying process and reached maximum values after 70–100 s, having values between 0.258 g/min and 0.498 g/min. During the drying period, this indicator presented different graphic evolutions, difficult to be described with a single function. The first segment was described by a logistic function, and the second was described by a hyperbola, resulting in a model (RWLMod) which described the real phenomenon. This model and theoretical calculation were used to quantify the water loss in a time interval and, compared with empirical dates, no significant differences were observed, which indicated an increased degree of accuracy regarding the use of this model. Recommendation and novelty of work: The novelty of the work is given by the obtained model (RWLMod), which makes possible the description of RWL over the entire time interval, and ensures a good fit with the real data. It recommends the method and model in studies of plant behaviour under stress in relation to different influencing factors.

Stability-Indicating Reverse-Phase High-Performance Liquid Chromatographic Method Development and Validation of Lamotrigine in Bulk and Pharmaceutical Dosage Form

In the current study, analytical method has been validated by system suitability parameters, linearity, accuracy and percent recovery, precision, ruggedness, robustness, limit of detection, and limit of quantification. The present study of lamotrigine was achieved using Cosmosil C18 (250 nm×4.6 ID, particle size: 5 Micron) Column with mobile phase methanol: water (60:40) pH: 3 at a flow rate 0.8 ml/min with UV detection at 308 nm. The retention time for lamotrigine was found to be 4.979 min. In linearity, the correlation coefficient (R2) for lamotrigine was found to be 0.999, slope is 39,801, and intercept was found to be 51,862 which are well within the acceptance criteria. The mean percent recovery for lamotrigine at three different levels for 50%, 100%, and 150% was found to be 99.28%, 99.30%, and 100.40%. The % RSD should not more than 2%. In precision study, interday (RSD is 0.41%) and intraday (RSD is 0.26%) are found. Forced degradation experiments were carried out by exposing standard form of lamotrigine for acid-base, oxidative, photolytic, and thermal stress conditions. Hence, the developed method is accurate, precise, repeatable, and reproducible and can be used for routine analysis of lamotrigine.

Multi-omic characterization of the thermal stress phenome in the stony coral Montipora capitata.

BackgroundCorals, which form the foundation of biodiverse reef ecosystems, are under threat from warming oceans. Reefs provide essential ecological services, including food, income from tourism, nutrient cycling, waste removal, and the absorption of wave energy to mitigate erosion. Here, we studied the coral thermal stress response using network methods to analyze transcriptomic and polar metabolomic data generated from the Hawaiian rice coral Montipora capitata. Coral nubbins were exposed to ambient or thermal stress conditions over a 5-week period, coinciding with a mass spawning event of this species. The major goal of our study was to expand the inventory of thermal stress-related genes and metabolites present in M. capitata and to study gene-metabolite interactions. These interactions provide the foundation for functional or genetic analysis of key coral genes as well as provide potentially diagnostic markers of pre-bleaching stress. A secondary goal of our study was to analyze the accumulation of sex hormones prior to and during mass spawning to understand how thermal stress may impact reproductive success in M. capitata.MethodsM. capitata was exposed to thermal stress during its spawning cycle over the course of 5 weeks, during which time transcriptomic and polar metabolomic data were collected. We analyzed these data streams individually, and then integrated both data sets using MAGI (Metabolite Annotation and Gene Integration) to investigate molecular transitions and biochemical reactions.ResultsOur results reveal the complexity of the thermal stress phenome in M. capitata, which includes many genes involved in redox regulation, biomineralization, and reproduction. The size and number of modules in the gene co-expression networks expanded from the initial stress response to the onset of bleaching. The later stages involved the suppression of metabolite transport by the coral host, including a variety of sodium-coupled transporters and a putative ammonium transporter, possibly as a response to reduction in algal productivity. The gene-metabolite integration data suggest that thermal treatment results in the activation of animal redox stress pathways involved in quenching molecular oxygen to prevent an overabundance of reactive oxygen species. Lastly, evidence that thermal stress affects reproductive activity was provided by the downregulation of CYP-like genes and the irregular production of sex hormones during the mass spawning cycle. Overall, redox regulation and metabolite transport are key components of the coral animal thermal stress phenome. Mass spawning was highly attenuated under thermal stress, suggesting that global climate change may negatively impact reproductive behavior in this species.

Role of integrated crop-livestock system on amelioration of heat stress on crossbred Brazilian sheep in semiarid region of northeastern Brazil

• Physiological parameters were lower in the animals under ICL system. • ICL did not promote heat stress in the morning. • The presence of trees in the ICL system promoted thermal comfort to the animals. • Greater sheep ability to dissipate the heat under ICL. • Sustainable sheep production. The aim of this study was to evaluate the effect of livestock rearing system, sheepfold vs . integrated crop-livestock system, on heat tolerance and physiological traits of crossbred sheep (Santa Ines x Dorper) in the semiarid region of Brazilian Northeastern. Forty crossbred hair ewes (Santa Ines x Dorper), 15–48 months old, were assigned to two treatments: 20 in treatment I (SF – Sheepfold) and 20 in treatment II (ICL - integrated crop-livestock system with tall coconut palm trees). Physiological and environmental evaluations were conducted on 21 consecutive days. Respiratory rate (RR), rectal temperature (RT) and heart rate (HR) were recorded at 06:00 am and 05:00 pm, while air temperature and relative humidity were recorded from 06:00 am to 05:00 pm. Temperature and Humidity Index (THI) in the SF and ILC indicated severe stress for sheep regardless of the period of the day, and although THI in integrated crop-livestock system was 1% lower than in the sheepfold, there was no statistical differences between the treatments. Ewes from integrated crop-livestock system had lower RR and HR than sheepfold ewes at 06:00 am and 05:00 pm. The afternoon period led the animals to more dangerous situation of thermal stress condition in both treatments, however we suggest that the presence of trees in the ICL system promoted an amelioration of heat stress on grazing ewes.

Development and Validation of a Stability-Indicating UPLC Method for the Determination of Hexoprenaline in Injectable Dosage Form Using AQbD Principles.

A novel and efficient stability-indicating, reverse phase ultra-performance liquid chromatographic (UPLC®) analytical method was developed and validated for the determination of hexoprenaline in an injectable dosage form. The development of the method was performed using analytical quality by design (AQbD) principles, which are aligned with the future requirements from the regulatory agencies using AQbD principles. The method was developed by assessing the impact of ion pairing, the chromatographic column, pH and gradient elution. The development was achieved with a Waters Acquity HSS T3 (50 × 2.1 mm i.d., 1.8 µm) column at ambient temperature, using sodium dihydrogen phosphate 5 mM + octane-1-sulphonic acid sodium salt 10 mM buffer pH 3.0 (Solution A) and acetonitrile (Solution B) as mobile phases in gradient elution (t = 0 min, 5% B; t = 1 min, 5% B; t = 5 min, 50% B; t = 7 min, 5% B; t = 10 min, 5% B) at a flow rate of 0.5 mL/min and UV detection of 280 nm. The linearity was proven for hexoprenaline over a concentration range of 3.50–6.50 µg/mL (R2 = 0.9998). Forced degradation studies were performed by subjecting the samples to hydrolytic (acid and base), oxidative, and thermal stress conditions. Standard solution stability was also performed. The proposed validated method was successfully used for the quantitative analysis of bulk, stability and injectable dosage form samples of the desired drug product. Using the AQbD principles, it is possible to generate methodologies with enhanced knowledge, which can eventually lead to a reduced regulatory risk, high quality data and lower operational costs.

In Situ Perovskitoid Engineering at SnO2 Interface toward Highly Efficient and Stable Formamidinium Lead Triiodide Perovskite Solar Cells.

The black-phase formamidinium lead triiodide (α-FAPbI3) perovskite has turned out to be one of the most efficient light harvesting materials. However, the phase stability of FAPbI3 is a long-standing issue. Herein, we introduce a layer of tetrabutylammonium fluoride (TBAF) on SnO2, which would form an in situ layer of TBAPbI3 perovskitoid at the SnO2/FAPbI3 interface by interacting with PbI2. The results show that this strategy could improve the conductivity of SnO2, passivate the defects in perovskite, improve the phase stability of α-FAPbI3, and retard the nonradiative recombination in the device. As a result, we obtain a champion device with a power conversion efficiency of 23.1% under AM 1.5 G illumination of 100 mW/cm2. The unencapsulated devices can maintain excellent stability under illumination, thermal stress, and humidity conditions, respectively.

PSXIV-2 Influences of glycerol and bypass fat supplementation on performance of early fattening Hanwoo steers under heat stress

Abstract This study was conducted to determine the influence of glycerol and bypass fat supplementation on growth performance of early fattening Hanwoo steers under heat stress. Thirty-six Hanwoo steers were randomly allocated into 4 treatments based on BW and age for 112 days from the beginning of July to the end of October 2020. Experimental treatments were divided into four by the type of energy supplements: Control (CP, 14%; TDN 71.9), glycerol addition (GL; CP, 14%; TDN 74.9), bypass fat addition (BF; CP, 14%; TDN 74.9), and glycerol plus bypass fat additive (GL+BF; CP, 14%; TDN 74.9). During the experimental period, automatic temperature-humidity recorders were used for measuring every 10 minutes in the pen. The temperature-humidity index (THI) range of the 1st and 2nd periods was recorded above the threshold (THI 75~77) level based on the Korean beef heat stress index, and the average THI of the 2nd period was 79.91, being the mild-moderate (THI 78~81) level. The dry matter intake (DMI) and average daily gain (ADG) did not show significant differences in all treatments during the whole period. The feed conversion ratio (FCR) during 1st and 2nd periods showed the same pattern because FCR is related to DMI and ADG. Additionally, the rectal temperature showed no significant difference in all treatments, but a significant difference in each period (P < 0.05). The results demonstrated that early fattening Hanwoo steers under mild-moderate stress did not affect DMI and productivity but 9.8% of GL or 1.9% BF in a concentrate only could be included in Hanwoo steers diets without decreasing palatability. In addition, increasing the energy content in the feed by 5% did not lead to a difference in productivity. Further studies would be needed on the effect of increasing the energy density on productivity under more severe thermal stress conditions.

Assessing the influence of street configurations on human thermal conditions in open balconies in the Mediterranean climate

Heat stress in the built environment has become a serious health and comfort issue, given the increases in Urban Heat Island effects, and augmenting impacts associated to climate change. This study deals with the potential correlations between human thermal conditions, the encircling microclimate, and the physical structure of the city. Through long-term numerical simulations, the disclosed study analyses the influence of the urban street configurations on the thermal bioclimate within urban canyons, specifically upon open balconies in the most populated district of Barcelona: The Eixample. The simulated thermal conditions were carried out in the human biometeorological RayMan Pro model using local climatic data, to determine the Physiologically Equivalent Temperature (PET) within four generated scenarios, with similar morphological properties of the Eixample district.The findings reveal that streets with axes oriented NS and SE-NW provide the best thermal conditions for balconies, achieving acceptable PET values (18 °C < PET <29 °C) on both façades. On the other hand, EW streets presented high thermal stress conditions (over 43,4% of the time) for those balconies located in the north side of the canyon. Open balconies at heights below 12 metres are the most comfortable ones during summer daytime, with acceptable thermal conditions that range between 50,4% and 82,5% of the time. The highest frequencies of acceptable thermal conditions were found on balconies located at 6 metres and 9 metres high on the east, south and southeast façades of the NS, EW and NE-SW oriented streets respectively (from 77% to 83% of the time). These configurations provide the most suitable thermal conditions during the studied summer periods by having frequencies of heat stress below 20%.Our results and recommendations contribute to bridge the gap between human biometeorology, public health, and architectural and urban planning. Some areas of its direct application are the use of balconies in periods of confinement; decision-making on the sale or rental of apartments; and the promotion of bioclimatic retrofit projects at an urban and architectural scale supported by local governments.

Adaptive assessment of small ruminants in arid and semi-arid regions

• This manuscript provides deep understanding of the various impacts of heat stress on small ruminant production and climate adaptation. • The review presented possible phenotypic markers for the inclusion on evaluation of more adapted animals. • We suggest the inclusion of immediate and subsequent responses on the adaptive assessment of animals. Breeding small ruminants is an important economic activity in arid and semi-arid regions. This activity has gained more prominence in the present climatic scenario. With increasing global warming, many researchers are analysing how locally adaptive animals maintain homeostasis in regions characterized by high air temperatures. However, there has been no standardization regarding which characteristics should be assessed to determine the adaptive capacity of these animals or included in breeding programmes to improve thermal resistance. Thus, the objectives of this review are: (1) to present an overview of characteristics involved in heat adaptation of highly adapted small ruminants and (2) highlight the characteristics that could be included in breeding programmes to increase the adaptability of herds. Much research has evaluated the immediate response of animals to thermal stress conditions, such as increases in rectal temperature, respiratory rate, and sweating. However, considering that homeostasis represents a condition of balance in a biological system and that animals adapted to the environment are in homeostasis, this review proposes to address the adaptive characteristics acquired over years of exposure to stressful conditions in arid and semiarid regions. These include morphological changes such as coat characteristics, alterations in blood constituents, acid-base balance, such as hormones, haematological and biochemical profiles, as well as advances in genetic assessments.

System for assessing broilers thermal comfort

One of the ways to optimize animal production environments is through the understanding of the bioclimatic factors that are harmful to the animals. Among the techniques currently applied for measuring and analyzing bioclimatic factors, the vast majority demand that the producers and researchers have high level of technical skills, those techniques (e.g. using maps of spatial variability) hinder the rapid evaluation of certain environments. It is important to note that there is currently no software and hardware tool that allows for an on-site bioclimatic analysis, for example using an Android or iOS app. Thus, the present study was conducted with the objective of developing a system capable of collecting air temperature measurements (Ta), black globe temperature (Tg) and relative humidity (RH), to interact with Aurora mobile app, enabling the on-site development of maps with spatial variability of the air temperature and indices of thermal broilers comfort, using data interpolation. The system was developed through the creation of six transmitters and one receiver. The results obtained indicate that the system operated correctly and allows on-site analysis of thermal animal comfort. During the validation period a total of 48 maps were developed, considering the periods of morning and afternoon, and using the Ta, BGHI and THI measurements. The maps allowed the on-site identification of regions with conditions of comfort, discomfort and thermal stress (both by heat and cold). According to the maps of thermal comfort indices, the afternoon period presented conditions that were often heat stress. The maps of air temperature and thermal comfort indices allow the producers and researchers to have, at hand, a highly portable tool for evaluating the broilers welfare.

Enzymatic synthesis of an homologous series of long- and very long-chain sucrose esters and evaluation of their emulsifying and biological properties

Certain sucrose mono-esters display excellent emulsifying properties as well as a range of other useful physicochemical characteristics that follow from their amphipathic nature. Accordingly, they are playing increasingly important roles in various food manufacturing industries. In this study, an homologous series of 6-O-acylsucrose mono-esters with long and very long fatty acid-derived acyl side-chains has been prepared via enzymatic transesterification. The surface-active properties as well as the antibacterial and antitumor activities of these esters have been studied. Their HLB values were 10.3–15.7 while the mean droplet sizes of the emulsions formed with soybean, colza and olive oils were 380–563 nm. Oil-water emulsions incorporating some of them are more stable, even under conditions of thermal and ionic stress, than those prepared using commercial sucrose esters. Additionally, these esters display activities against Gram-positive bacteria and certain fungi as well as exerting antiproliferative effects on six tumor cell lines. Taken together, these results suggest that the title esters could have considerable utility in the food industry by serving as emulsifiers, as preservatives and even as functional foods.

VALIDATED AND QUANTIFIED STABILITY INDICATING STRESS DEGRADATION STUDY OF ORAL ANTI-DIABETIC AGENT CANAGLIFLOZIN BY RP-HPLC METHOD

Objective: The present investigation is aimed to develop and validate, a simple, consistent and sensitive stability-indicating reverse phase-high performance liquid chromatography (RP-HPLC) method for the determination of oral anti-diabetic drug Canagliflozin in bulk and pharmaceutical dosage form as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH-Q2 (R1)). Methods: The chromatographic separation was achieved by using Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) ZORBAX C18 (250 mm x 4.6 mm, 5μm particle size) with a mobile phase consisting of Acetonitrile: Water in a ratio of 53:47% v/v at a flow rate of 1 ml/min with an injection volume of 20 μl. Results: The Retention time of the drug Canagliflozin was found to be 2.36±0.05 min and detected at 214 nm UV wavelength. The linear regression equation was found to be y = 60702x–2156.2 with a correlation coefficient 0.9999. Stress degradation studies were performed by exposing the Canagliflozin into acidic, alkaline, oxidative, thermal and photolytic stress conditions with active samples withdrawn at different time intervals as per ICH guidelines. Conclusion: The proposed Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method was found to be robust, precise and specific for estimation of Canagliflozin in pharmaceutical dosage forms.

A Stability-Indicating Ultra Performance Liquid Chromato-Graphic (UPLC) Method for the Determination of a Mycophenolic Acid-Curcumin Conjugate and Its Applications to Chemical Kinetic Studies.

A simple, precise, and accurate reversed-phase ultra-performance liquid chromatographic (UPLC) method was developed and validated for the determination of a mycophenolic acid-curcumin (MPA-CUR) conjugate in buffer solutions. Chromatographic separation was performed on a C18 column (2.1 × 50 mm id, 1.7 µm) with a gradient elution system of water and acetonitrile, each containing 0.1% formic acid, at a flow rate of 0.6 mL/min. The column temperature was controlled at 33 °C. The compounds were detected simultaneously at the maximum wavelengths of mycophenolic acid (MPA), 254 nm, and curcumin (CUR), or MPA-CUR, at 420 nm. The developed method was validated according to the ICH Q2(R1) guidelines. The linear calibration curves of the assay ranged from 0.10 to 25 μg/mL (r2 ≥ 0.995, 1/x2 weighting factor), with a limit of detection and a limit of quantitation of 0.04 and 0.10 μg/mL, respectively. The accuracy and precision of the developed method were 98.4–101.6%, with %CV < 2.53%. The main impurities from the specificity test were found to be MPA and CUR. Other validation parameters, including robustness and solution stability, were acceptable under the validation criteria. Forced degradation studies were conducted under hydrolytic (acidic and alkaline), oxidative, thermal, and photolytic stress conditions. MPA-CUR was well separated from MPA, CUR, and other unknown degradation products. The validated method was successfully applied in chemical kinetic studies of MPA-CUR in different buffer solutions.

Xylooligosaccharides and their chemical stability under high-pressure processing combined with heat treatment

Xylooligosaccharides (XOS) are emerging prebiotic ingredients used for enriching food products due to their health-promoting properties. This study investigated XOS chemical stability after high-pressure processing (HPP) combined with heat treatment. First, orange juice was enriched with XOS (xylobiose, xylotriose, xylotetraose, xylopentaose, and xylohexaose), and then HPP-treated at 100, 300, and 600 MPa applying non-thermal (30 °C) and thermal (100 °C) conditions. Ascorbic acid (vitamin C) degradation was monitored to evaluate the extend of the severity of the treatments due to its low stability under high-energy process conditions. Also, quality attributes associated with fruit juices such as physicochemical properties (pH, soluble solid content, and ζ-potential), organic acid content (malic and citric acids), total phenolic content, antioxidant activity, and sugar content (glucose, fructose, and sucrose) were determined. The use of HPP combined with heat treatment degraded ascorbic acid up to 37% and promoted sucrose hydrolysis into glucose and fructose. However, our findings demonstrated that the XOS were chemically stable to HPP in the range of 100–600 MPa even applying thermal treatment. Therefore, XOS are promising ingredients for the formulation of functional plant-based beverages since their integrity was preserved under high mechanical and thermal stress conditions of 600 MPa and 100 °C.