Risk assessment based on spectrophotometric signals used in eco-friendly analytical scenarios for estimation of carvedilol and hydrochlorothiazide in pharmaceutical formulation.

Special attention is given to the pharmacological treatment of combined medication of Carvedilol and hydrochlorothiazide which is the most effective and the most beneficial therapy for hypertensive patients with diabetes and various metabolic comorbidities. This work represents spectrophotometric platform scenarios based on factorized spectrum (FS) using interpoint data difference resolution scenarios (IDDRS) coupled with spectrum subtraction method (SS) for the concurrent quantification of carvedilol (CAR) and hydrochlorothiazide (HCT) when present together in a combination without the need for any initial physical separation steps. This IDD resolution scenario based on manipulating the zero-order spectra (D0) of both drugs in the mixture with various spectral features at different wavelength regions (200-400 nm), region I (220-250 nm), region II (240-300 nm) and region III (270-320 nm) via absorbance resolution (AR) and induced absorbance resolution (IAR) methods coupled with corresponding spectrum subtraction (SS). The calibration curves were established across the linearity ranges of 2.0-12.0 µg/mL at 242.50 nm and 4.0-40.0 µg/mL at 285.5 nm for CAR and 1.0-11.0 µg/mL at 226.10 nm and 2.0-20.0 µg/mL at 270.5 nm for HCT. Moreover, methods' validation was confirmed via ICH guidelines. A Multicenter comparison between sensitivity, specificity in respect resolution sequence were applied using different wavelength regions with various concentration ranges was applied and finally spectral resolution recommendation is issued and cumulative validation score (CVS) is calculated as an indicator in the risk analysis. In quality control laboratories, the studied approaches are applicable for conducting analysis on the mentioned drugs. In addition, the selection of spectrophotometry aligns with the principles of green analytical chemistry, an approach that resonates with the overarching theme of minimizing environmental impact. Via four metric tools named: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), methods' greenness profile was guaranteed.

Zinc Oxide Nanoparticles Induced Testicular Toxicity Through Inflammation and Reducing Testosterone and Cell Viability in Adult Male Rats.

Zinc oxide nanoparticles (ZnO NPs) have wide applications in daily life. Therefore, there is growing interest in the potential harmful impacts of these particles on human health. The present study was conducted to investigate the potential toxic effects of ZnO NPs (40 and 70 nm) compared to ZnO on the testes of rats. ZnO NPs were synthesized and characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Adult male rats were randomly divided into four groups (n = 8): Group I (control), Group II (ZnO) received daily oral administration of ZnO (50 mg/kg), and Groups III and IV received daily oral administration of ZnO NPs of 40 nm or 70 nm at 50 mg/kg, respectively. All treatments continued for 50 consecutive days. ZnO and ZnO NPs reduced body and testis weights, sperm count and motility, serum luteinizing hormone (LH) and testosterone levels, testicular cytochrome p450 17A1 (CYP17A1) and cytochrome p450 1B1 (CYP1B1) concentrations, and the expression of p53 and cdk1. These treatments elevated testicular myeloperoxidase and serum acid phosphatase activities as well as sperm abnormalities. ZnO NPs reduced LH levels, which decreased CYP17A1 and CYP1B1, resulting in reduced synthesis of testosterone. ZnO NPs enhanced testicular inflammation and reduced cell viability. All these effects were manifested as reduced sperm motility and increased sperm deformities. Compared to macromolecules, nanoparticles exhibited significantly higher toxicity. The larger diameter ZnO NPs had more profound toxicity than the smaller-sized particles.

Correlation between cone-beam computed tomographic findings and the apnea-hypopnea index in obstructive sleep apnea patients: A cross-sectional study.

Purpose: The aim of this study was to explore the correlations of cone-beam computed tomographic findings with the apnea-hypopnea index in patients with obstructive sleep apnea. Materials and Methods: Forty patients with obstructive sleep apnea were selected from the ear-nose-throat (ENT) outpatient clinic, Faculty of Medicine, Mansoura University. Cone-beam computed tomography was performed for each patient at the end of both inspiration and expiration. Polysomnography was carried out, and the apnea-hypopnea index was obtained. Linear measurements, including cross-sectional area and the SNA and SNB angles, were obtained. Four oral and maxillofacial radiologists categorized pharyngeal and retropalatal airway morphology and calculated the airway length and volume. Continuous data were tested for normality using the Kolmogorov-Smirnov test and reported as the mean and standard deviation or as the median and range. Categorical data were presented as numbers and percentages, and the significance level was set at P<0.05. Results: The minimal value of the cross-sectional area, SNB angle, and airway morphology at the end of inspiration demonstrated a statistically significant association (P<0.05) with the apnea-hypopnea index, with excellent agreement. No statistically significant difference was found in the airway volume, other linear measurements, or retropalatal airway morphology. Conclusion: Cone-beam computed tomographic measurements in obstructive sleep apnea patients may be used as a supplement to a novel radiographic classification corresponding to the established clinical apnea-hypopnea index classification.

A Study on Semaphorin 3A Level in Juvenile-onset Systemic Lupus Erythematosus Patients.

BACKGROUND: Juvenile-onset systemic lupus erythematosus (jSLE) is an uncommon yet severe autoimmune/inflammatory condition affecting multiple bodily systems, typically manifest-ing before the age of 18. This disease exhibits significant complexity, displaying considerable variation among patients. Its effects can range in severity from minor to fatal, characterized by a pattern of recurring flare-ups and periods of remission, making its natural progression difficult to predict. AIM OF THE WORK: The aim of this work is to investigate the correlation between semaphorin 3A and systemic lupus erythematosus patients who follow up at Pediatric Rheumatology Unit Chil-dren's Hospital at Cairo University. PATIENTS & METHODS: This cross-sectional research was performed at the Pediatric Rheumatology Unit Cairo University Children's Hospital and included cases with jSLE under treatment and fol-low-up from the period of August 2021 to August 2022. RESULTS: Regarding demographic data of the studied subjects, highly significant variances were noted among the patient group & control group regarding age (years) & sex. However, there were non-significant variances among the patient group and control group concerning weight. In the current research, median (IQR) onset of disease was 2 (1 3) years, mean ± SD age at dis-ease diagnosis was 8.98 ± 2.13 years, median (IQR) disease duration 2 (1 3) years, family history was negative in 36 (90.0%) patients and consanguinity was negative in 28 (70.0%). The distribution of the manifestations within the patients group was as follow 7 (17.5%) with mu-cocutaneous, 7 (17.5%) with vasculitis, 4 (10.0%) with serositis, 11 (27.5%) with cardiac, 17 (42.5%) with renal, 11 (27.5%) with GIT, 5 (12.5%) with hematological, and 4 (10.0%) with neu-rological manifestations. In addition, there were 2 (5.0%) with arthritis, 31 (77.5%) with arthral-gia, and 2 (5.0%) with fever mean ± SD systolic BP was 115.95 ± 8.38 & mean ± SD diastolic BP was 75.60 ± 6.11. Regarding treatments in the patients' group, the median steroid dose was 15mg (5-25) with medi-an duration of 2 (1 3), 38 (95.0%) patients received hydroxychloroquine with mean ± SD hy-droxychloroquine dose of 205.26 mg ± 51.71. 23 (57.5%) patients received cyclophosphamide with mean ± SD number of cyclophosphamide doses 7.17 mg ± 2.42. Mycophenolate was re-ceived in 27 (67.5%) with mean ± SD dose of 614.07 mg ± 225.85. There were highly statistically significant differences between control group and patients' group concerning TLC, creatinine, & ESR. Highly statistically significant variance was noted among the control group and patients group concerning CRP. Regarding the patients' group, the mean ± SD serum C3 was 99.89 mg/dl ± 28.45, median (IQR) serum C4 was 14.5 mg/dl (8.8 25.5), and median (IQR) albumin creatinine ratio was 27 IU/ML (16 186). There was positive ANA with titre and pattern in 34 patients (85.0%), positive antids-DNA in 25 patients (62.5%), and positive anticardiolipin IgM and IgG in 5 patients (12.5%). Renal biopsy was found to be normal in 23 (57.5 percent), lupus nephritis class II, III in 3 (7.5 percent), lupus nephritis class III in 10 (25.0%), and lupus nephritis class IV in 4 (10.0%). Urine analysis results showed the following: normal in 28 (70.0%), albumin in 2 (5.0%), casts in 2 (5.0%), pus cell in 4 (10.0%), albumin + casts in 2 (5.0%) and albumin + pus cell in 2 (5.0%). Regarding semaphorin 3A level, a highly statistically significant variance was noted among the control & patients group concerning semaphorin 3A level found to be lower in cases than control with a p-value below 0.001. In patients' group, a negative correlation for semaphorin 3A with SBP, DBP, AST and ESR and also a positive correlation with steroid duration in the studied pa-tients. In addition, highly significant association between semaphorin 3A & positive CRP. How-ever, no significant relationship between semaphorin 3A & SLE manifestations except arthritis was found related to semaphorin 3A level. ROC curve shows that the semaphorin 3A cut-off point to predict SLE ≤ 3 with sensitivity = 47.50, specificity=92.50, PPV=86.4, and NPV=63.8. CONCLUSION: Reduced plasma Semaphorin 3A levels were found in this study; furthermore, their clinical relationship in SLE proposes their significant job in this illness. Furthermore, the ROC results demonstrated that Semaphorin 3A could be a new symptomatic biomarker in SLE with very high sensitivity for the determination of SLE, demonstrating that they might be helpful bi-omarkers for the evaluation of SLE. However, extra studies that focus on the potential role of Semaphorin 3A in SLE are needed.

Protective effect of astaxanthin on indomethacin-induced gastric ulcerations in mice.

Gastric ulcer disease remains one of the common medical burdens affecting millions worldwide due to its prevalent risk factors with the chronic usage of non-steroidal anti-inflammatory drugs at the top, reportedly through the stimulation of oxidative stress and triggering of inflammatory and apoptotic cascades in the gastric mucosa. Astaxanthin, a dietary keto-carotenoid derived from marine organisms is gaining a wide interest as a nutraceutical for its pronounced antioxidant properties. Here, we aim to examine the potential modulatory role of astaxanthin on indomethacin-induced gastric ulceration in experimental mice. Twenty-four Swiss albino mice were randomly distributed into four groups: a control group, an indomethacin group, and two groups pre-treated with either omeprazole or astaxanthin. The gastric tissues were assessed using gross morphology, ulcer scoring, gastric juice acidity, as well as reduced glutathione (GSH) and malondialdehyde (MDA) levels. Histopathological examination and immunostaining for nuclear factor-kappa B (NF-κB) and caspase-3 levels were also employed. Indomethacin group tended to show a higher number of mucosal ulcerations relative to control and pre-treated groups. The indomethacin group also showed significantly lower GSH levels and higher MDA levels relative to control. Immunostaining of gastric tissue sections showed a higher reactivity to NF-κB and caspase-3 in indomethacin group. Astaxanthin pre-treatment significantly elevated gastric juice pH, normalized GSH levels, and lowered the indomethacin-induced elevations in MDA, NF-κB, and caspase-3 levels. These results indicate that astaxanthin exhibits a comparable protective effect to omeprazole, against indomethacin-induced gastric ulceration. This anti-ulcerogenic effect could be mediated through its antioxidant, anti-inflammatory, and anti-apoptotic modulatory activities.

A novel green spectrofluorimetric method for simultaneous determination of antazoline and tetryzoline in their ophthalmic formulation.

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 µg/mL for ANT and 0.5-10.0 µg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

A Novel Spectrofluorimetric Determination of Antazoline and Xylometazoline in their Ophthalmic Formulation; Green Approach and Evaluation.

A green developed spectrofluorimetric method has been applied for Antazoline (ANT) and Xylometazoline (XLO) determination in both pharmaceutical formulation and pure form. The developed method is synchronous spectrofluorimetry coupled with the second derivative mathematical tool for the determination of antazoline and xylometazoline in their dosage form. The developed method depends on reacting the cited drugs with dansyl chloride, a suitable derivatizing agent, to generate highly fluorescent derivatives. The products formed were measured at emission wavelengths; 703.0 and 712.0 nm after being excited at wavelengths; 350.0 and 355.0 nm for antazoline and xylometazoline, respectively. Synchronous spectrofluorimetry coupled with second derivative mathematical tool was developed and optimized using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for antazoline and 598.0 nm for xylometazoline. Linear responses have been represented over a wide range of concentration 0.5-12.0 µg/mL for antazoline and 0.1-10.0 µg/mL for xylometazoline, correspondingly. Method validation was successfully applied. Additionally, statistical comparison of developed method with official ones has been carried out where no significant difference was found. Evaluation of the method's greenness was proven using several assessment tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

Pendant Modification of Poly(methyl methacrylate) to Enhance Its Stability against Photoirradiation.

Photostabilization of functional polymeric materials is important for protection against aging and ultraviolet (UV) irradiation. There is, therefore, the impetus to modify polymers to increase their resistance to photodegradation and photooxidation on extended exposure to UV light in harsh conditions. Various polymeric additives have been designed and synthesized in recent years, and their potential as photostabilizers has been explored. Reported here is the effect of pendant functionalization of poly(methyl methacrylate) (PMMA) through organometallic moiety incorporation into the polymer's backbone. The reaction of PMMA with ethylenediamine leads to the formation of an amino residue that can react with salicylaldehyde to produce the corresponding Schiff base. Adding metal chlorides (zinc, copper, nickel, and cobalt) led to the formation of organometallic residues on the polymeric chains. Thin films of modified and unmodified PMMA were produced and irradiated with UV light to determine the effect of pendant modification on photostability. The photostabilization of PMMA was assessed using a range of methods, including infrared spectroscopy, weight loss, decomposition rate constant, and surface morphology. The modified PMMA incorporating organic Schiff base metal complexes showed less photodecomposition than the unmodified polymer or one containing the Schiff base only. Thus, the metals significantly reduced the photodegradation of polymeric materials. The polymer containing the Schiff base-cobalt unit showed the least damage in the PMMA surface due to photoirradiation, followed by those containing nickel, zinc, and copper, in that order.

Exquisite integration of quality-by-design and green analytical approaches for simultaneous determination of xylometazoline and antazoline in eye drops and rabbit aqueous humor, application to stability study.

This work implements a stability indicating HPLC method developed to simultaneously determine xylometazoline (XYLO) and antazoline (ANT) in their binary mixture, rabbit aqueous humor and cited drug's degradates by applying analytical quality-by-design (AQbD) combined with green analytical chemistry (GAC) experiment for the first time. This integration was designed to maximize efficiency and minimize environmental impacts, as well as energy and solvent consumption. Analytical quality-by-design was applied to achieve our aim starting with evaluation of quality risk and scouting analysis, tracked via five parameters chromatographic screening using Placket-Burman design namely: pH, temperature, organic solvent percentage, flow rate, and wavelength detection. Recognizing the critical method parameters was done followed by optimization employing central composite design and Derringer's desirability toward assess optimum conditions that attained best resolution with satisfactory peak symmetry with short run time. Optimal chromatographic separation was attained by means of an XBridge® C18 (4.6 × 250 mm, 5 µm) column through isocratic elution using a mobile phase consists of phosphate buffer (pH 3.0): ethanol (60:40, by volume) at a 1.6 mL/min flow rate and 230.0 nm UV detection. Linearity acquired over a concentration range of 1.0-100.0 µg/mL and 0.5-100.0 µg/mL for XYLO and ANT, respectively. Furthermore, imperiling cited drugs' stock solutions to stress various conditions and satisfactory peaks of degradation products were obtained indicating that cited drugs are vulnerable to oxidative degradation and basic hydrolysis. Degradates' structures were elucidated using mass spectrometry. Applying various assessment tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), Greenness method's evaluation was applied and proved to be green. In fact, the developed method is established to be perceptive, accurate, and selective to assess cited drugs for routine analysis.

Green TLC-Densitometric Method for Simultaneous Determination of Antazoline and Tetryzoline: Application to Pharmaceutical Formulation and Rabbit Aqueous Humor.

Ophthalmic pharmaceutical preparation containing antazoline (ANT) and tetryzoline (TET) is prescribed widely as an over the counter medication for allergic conjunctivitis treatment. Development of a selective, simple and environmentally friendly thin-layer chromatographic method established to determine both ANT and TET in their pure forms, pharmaceutical formulation and spiked aqueous humor samples. By using silica gel plates and means of a developing system consists of ethyl acetate:ethanol (5:5, by volume), the studied drugs separation was achieved, and scanning was carried out at 220.0 nm for the separated bands with a 0.2-18.0 µg/band concentration range for each of ANT and TET. Standard addition technique application was carried out to determine the proposed method validity. Statistical comparison was made between the proposed method and the official methods ANT and TET showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools, namely, analytical greenness, green analytical procedure index, analytical eco-scale and national environmental method index.Highlights.

Spectrophotometric platform windows' exploitation for the green determination of Alcaftadine in presence of its oxidative degradation product.

This study presents the determination of Alcaftadine (ALF) in its oxidative degradation product presence by applying comprehensive study comparative of four different green stability indicating spectrophotometric approaches through successful exploitation of different spectrophotometric platform windows. Window I; based on absorption spectrum zero order data manipulation using the newly developed extended absorbance difference (EAD). Window II; based on derivative spectra by second order derivative (D2) data manipulation. Window III; based on ratio spectra applying constant multiplication (CM) and absorptivity centering via factorized ratio difference spectrum (ACT-FSRΔP) methods data manipulation. Finally, window IV; based on derivative of ratio spectrum by virtue of first derivative of ratio spectral (DD1) method data manipulation. Calibration curves construction were over linearity range; 1.0-14.0 µg/mL for ALF. The proposed methods accuracy, precision, and linearity range were determined and validated as per ICH guidelines. Moreover, they were able to analyze ALF in raw form, dosage form and in existence of its oxidative degradation product. Statistical comparisons were done between the proposed methods and the reported one showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI).

Novel solid-contact ion-selective electrode based on a polyaniline transducer layer for determination of alcaftadine in biological fluid.

Fabrication of a novel ion selective electrode for determining alcaftadine was achieved. The glassy carbon electrode (GCE) was utilized as a substrate in fabrication of an electrochemical sensor containing polyaniline (PANI) as an ion-to-electron transducer layer. A PVC polymeric matrix and nitrophenyl-octyl-ether were employed in designing the ion-sensing membrane (ISM). Potential stability was improved and minimization of electrical signal drift was achieved for inhibition of water layer formation at the electrode interface. Potential stability was achieved by inclusion of PANI between the electronic substrate and the ion-sensing membrane. The sensor's performance was evaluated following IUPAC recommendations. The sensor dynamic linear range was from 1.0 × 10-2 to 1.0 × 10-6 mol L-1 and it had a 6.3 × 10-7 mol L-1 detection limit. The selectivity and capabilities of the formed alcaftadine sensor were tested in the presence of its pharmaceutical formulation excipients as well as its degradation products. Additionally, the sensor was capable of quantifying the studied drug in a rabbit aqueous humor. Method's greenness profile was evaluated by the means of Analytical Greenness (AGREE) metric assessment tool.

Enhancement of Photostabilization of Poly(Vinyl Chloride) in the Presence of Tin-Cephalexin Complexes.

Poly(vinyl chloride), PVC, has many attractive properties, including low cost of manufacture, resistance to acid and alkali corrosion, and ease of molding. However, PVC suffers from aging in harsh conditions, leading to the shortening of its useful life. Stability to irradiation, for example, can be improved through the incorporation of additives to PVC. The design, synthesis, and application of new stabilizers continue to attract attention. The current work investigates the effect of three tin-cephalexin complexes on the stability of PVC on irradiation with ultraviolet (UV) light (λ = 313 nm) at 25 °C for a long duration. The PVC was blended with tin-cephalexin complexes at low concentrations (0.5% by weight), and thin films (around 40 µm) were made from the mixed materials. Various methods, including weight loss, infrared spectroscopy, and surface inspection of irradiated films were used to investigate the role played by these additives in the inhibition of PVC photodecomposition. The results confirmed that the additives led to a significant reduction in the rate of photodecomposition of the PVC blends. Tin-cephalexin complexes can absorb harmful radiation, deactivate hydrogen chloride, and scavenge high-energy species such as peroxides, therefore acting as stabilizers for PVC.

Early predictors of colchicine resistance in familial Mediterranean fever.

OBJECTIVE: To explore early features that can predict colchicine resistance in familial Mediterranean fever (FMF) patients. METHODS: It included FMF cases who fulfilled the Yalcinkaya-Ozen criterion and were on colchicine for at least 6 months. Data were collected from medical files and interpreted with respect to clinical parameters, incluing the auto-inflammatory diseases activity index (AIDAI) and FMF severity score. FMF50 score assessed the treatment response. Laboratory findings and genetic analysis of Mediterranean fever (MEFV) mutations were evaluated according to the standard technique. Patients were classified into two groups according to their response to colchicine. Both groups were compared, and significant variables were entered into a logistic regression model to detect independent predictors. The diagnostic accuracy of these predictors was assessed using the receiver operating characteristic curve. RESULTS: In all, 120 FMF children were included. After the exclusion of 16 non-compliant patients (13.3%), colchicine responders were 66 (63.4%) (group I) and colchicine-resistant cases (group II) were 38 (36.5%). The fever duration after colchicine, number of attacks before/after colchicine, skin rash/erysipelas-like erythema, myalgia/protracted febrile myalgia, AIDAI before/after treatment, FMF severity score, and the maximum colchicine dose were higher in group II. Furthermore, high C-reactive protein and neutropenia were frequent in group II. However, different MEFV mutations, including M694V were similar between the two groups. Eight variables were detected in the regression analysis model, and independent predictors were utilized to generate a scoring model. CONCLUSION: This study constructed a prediction model for colchicine nonresponse based on clinical and laboratory profiles. This model will be valuable for the treatment decisions of FMF children.

The role of cone-beam computed tomography in the radiographic evaluation of obstructive sleep apnea: A review article.

The apnea-hypopnea index is widely regarded as a measure of the severity of obstructive sleep apnea (OSA), a condition characterized by recurrent episodes of apnea or hypopnea during sleep that induce airway collapse. OSA is a catastrophic problem due to the wide range of health issues it can cause, including cardiovascular disease and memory loss. This review was conducted to clarify the roles of various imaging modalities, particularly cone-beam computed tomography (CBCT), in the diagnosis of and preoperative planning for OSA. Unfortunately, 2-dimensional imaging techniques yield insufficient data for a comprehensive diagnosis, given the complex anatomy of the airway. Three-dimensional (3D) imaging is favored as it more accurately represents the patient's airway structure. Although computed tomography and magnetic resonance imaging can depict the actual 3D airway architecture, their use is limited by factors such as high radiation dose and noise associated with the scans. This review indicates that CBCT is a low-radiation imaging technique that can be used to incidentally identify patients with OSA, thereby facilitating early referral and ultimately enhancing the accuracy of surgical outcome predictions.

Synthesis of Methyldopa-Tin Complexes and Their Applicability as Photostabilizers for the Protection of Polyvinyl Chloride against Photolysis.

Polyvinyl chloride (PVC) is a ubiquitous thermoplastic that is produced on an enormous industrial scale to meet growing global demand. PVC has many favorable properties and is used in various applications. However, photodecomposition occurs when harsh conditions, such as high temperatures in the presence of oxygen and moisture, are encountered. Thus, PVC is blended with additives to increase its resistance to deterioration caused by exposure to ultraviolet light. In the current research, five methyldopa-tin complexes were synthesized and characterized. The methyldopa-tin complexes were mixed with PVC at a concentration of 0.5% by weight, and thin films were produced. The capability of the complexes to protect PVC from irradiation was shown by a reduction in the formation of small residues containing alcohols, ketones, and alkenes, as well as in weight loss and in the molecular weight of irradiated polymeric blends. In addition, the use of the new additives significantly reduced the roughness factor of the irradiated films. The additives containing aromatic substituents (phenyl rings) were more effective compared to those comprising aliphatic substituents (butyl and methyl groups). Methyldopa-tin complexes have the ability to absorb radiation, coordinate with polymeric chains, and act as radical, peroxide, and hydrogen chloride scavengers.

Smartphone-Based Localization for Passengers Commuting in Traffic Hubs.

Passengers commute between different modes of transportation in traffic hubs, and passenger localization is a key component for the effective functioning of these spaces. The smartphone-based localization system presented in this work is based on the 3D step and heading approach, which is adapted depending on the position of the smartphone, i.e., held in the hand or in the front pocket of the trousers. We use the accelerometer, gyroscope and barometer embedded in the smartphone to detect the steps and the direction of movement of the passenger. To correct the accumulated error, we detect landmarks, particularly staircases and elevators. To test our localization algorithm, we have recorded real-world mobility data in a test station in Munich city center where we have ground truth points. We achieve a 3D position accuracy of 12 m for a smartphone held in the hand and 10 m when the phone is placed in the front pocket of the trousers.

Synthesis and Application of Levofloxacin-Tin Complexes as New Photostabilizers for Polyvinyl Chloride.

Polyvinyl chloride (PVC) is a synthetic polymer with a wide range of applications with impact on our daily life. It can undergo photodegradation with toxic products that are hazardous to both human health and the environment. In addition, photodegradation shortens the useful lifetime of the material. Elongation of the effective lifespan of PVC is, therefore, a salient area of research. Recently, a lot of attention has been directed toward the design, preparation, and usage of new additives that are capable of reducing the photodecomposition of PVC. This work investigates the synthesis of new levofloxacin-tin complexes and their potential exploitation against the photodecomposition of PVC. Several levofloxacin-tin complexes have been synthesized, in high yields, by a simple procedure and characterized. The potential use of the additives as photostabilizers for PVC has been investigated through the determination of weight loss, molecular weight depression, formation of fragments containing carbonyl and alkene groups, and surface morphology of irradiated PVC films. The results show that the new additives are effective in reducing the photodegradation of PVC. The new levofloxacin-tin complexes act as absorbers of ultraviolet light and quenchers of highly reactive species such as free radicals produced during photodegradation. They are more effective photostabilizers compared with organotin complexes previously reported. The complexes containing aromatic substituents were more effective than those counterparts having aliphatic residues.

Forced Degradation Studies and Development and Validation of HPLC-UV Method for the Analysis of Velpatasvir Copovidone Solid Dispersion.

Analytical methods for the drug substance and degradation products (DPs) are validated by performing forced degradation studies. Forced degradation studies of Velpatasvir (VEL) drug substance and Velpatasvir copovidone solid dispersion (VEL-CSD) were performed under the stressed alkaline, acidic, oxidative and thermal conditions according to ICH guidelines ICH Q1A (R2). VEL is labile to degrade in stressed alkaline, acidic, and oxidative conditions. It is also photolabile and degraded during photostability studies as described by ICH Q1B, and showed no degradation on exposure to extreme temperature when protected from light. A sensitive stability indicating HPLC-UV method was developed and validated for the separation of VEL and eight DPs. The DPs of VEL are separated using gradient elution of mobile phase containing 0.05% Trifluoroacetic acid (TFA) and methanol over symmetry analytical column C18 (250 mm × 4.6 mm, 5 µm) with a flow rate of 0.8 mL min-1. Simultaneous detection of all DPs and VEL was performed on UV detector at 305 nm. The performance parameters like precision, specificity and linearity of the method were validated using reference standards as prescribed by ICHQ2 (R1). Limits of quantification and limits of detection were determined from calibration curve using the expression 10δ/slope and 3δ/slope respectively. The proposed method is stability-indicating and effectively applied to the analysis of process impurities and DPs in VEL drug substance and VEL-CSD.

Synthesis of New Norfloxacin-Tin Complexes to Mitigate the Effect of Ultraviolet-Visible Irradiation in Polyvinyl Chloride Films.

Polyvinyl chloride is used in the manufacturing of a wide range of products, but it is susceptible to degradation if exposed to high temperatures and sunlight. There is therefore a need to continuously explore the design, synthesis, and application of new and improved additives to reduce the photodegradation of polyvinyl chloride in harsh environments and for outdoor applications. This research investigates the use of new norfloxacin-tin complexes as additives to inhibit the photodegradation of polyvinyl chloride to make it last longer. Reactions between norfloxacin and substituted tin chlorides, in different molar ratios and in methanol under reflux conditions, gave the corresponding organotin complexes in high yields. The chemical structures of the synthesized complexes were established, and their effect on the photodegradation of polyvinyl chloride due to ultraviolet-visible irradiation was investigated. Norfloxacin-tin complexes were added to polyvinyl chloride at very low concentrations and homogenous thin films were made. The films were irradiated for a period of up to 300 h, and the damage that occurred was assessed using infrared spectroscopy, polymeric materials weight loss, depression in molecular weight, and surface inspection. The degree of photodegradation in the polymeric materials was much less in the blends containing norfloxacin-tin complexes compared to the case where no additives were used. The use of the additives leads to a reduction in photodegradation (e.g., a reduction in the formation of short-chain polymeric fragments, weight loss, average molecular weight depletion, and roughness factor) of irradiated polyvinyl chloride. The norfloxacin-tin complexes contain aromatic moieties (aryl and heterocycle), heteroatoms (nitrogen, oxygen, and fluorine), and an acidic center (tin atom). Therefore, they act as efficient photostabilizers by absorbing the ultraviolet radiation and scavenging hydrogen chloride, peroxides, and radical species, thereby slowing the photodegradation of polyvinyl chloride.