A Novel Process for Manufacturing High-Friction Rings with a Closely Defined Coefficient of Static Friction (Relative Standard Deviation 3.5%) for Application in Ship Engine Components

In recent years, there has been an increased uptake for surface functionalization through the means of laser surface processing. The constant evolution of low-cost, easily automatable, and highly repeatable nanosecond fibre lasers has significantly aided this. In this paper, we present a laser surface-texturing technique to manufacture a surface with a tailored high static friction coefficient for application within driveshafts of large marine engines. The requirement in this application is not only a high friction coefficient, but a friction coefficient kept within a narrow range. This is obtained by using nanosecond-pulsed fibre lasers to generate a hexagonal pattern of craters on the surface. To provide a suitable friction coefficient, after laser processing the surface was hardened using a chromium-based hardening process, so that the textured surface would embed into its counterpart when the normal force was applied in the engine application. Using the combination of the laser texturing and surface hardening, it is possible to tailor the surface properties to achieve a static friction coefficient of ≥0.7 with ~3–4% relative standard deviation. The laser-textured and hardened parts were installed in driveshafts for ship testing. After successfully performing in 1500 h of operation, it is planned to adopt the solution into production.

Pharmacokinetics, Bioavailability and Tissue Distribution of Chitobiose and Chitotriose in Rats

Chitooligosaccharides (COSs) have various physiological activities and broad application prospects; however, their pharmacokinetics and tissue distribution remain unclear. In this study, a sensitive and selective ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method for determining chitobiose (COS 2) and chitotriose (COS 3) in rat serum and tissues was developed. This method was successfully validated based on FDA guidelines in terms of selectivity, calibration curves (lower limit of quantification was 0.002 µg/mL for COS 2 and 0.02 µg/mL for COS 3), precision (intra-day relative standard deviation of 0.04–3.55% and inter-day relative standard deviation of 1.94–11.63%), accuracy (intra-day relative error of -1.81–11.06% and inter-day relative error of -9.41–8.63%), matrix effects, recovery (97.10–101.29%), stability, dilution integrity, and carry-over effects. Then, the method was successfully applied to the pharmacokinetics and tissue distribution study of COS 2 and COS 3 after intragastric and intravenous administration. After intragastric administration, COS 2 and COS 3 were rapidly absorbed, reached peak concentrations in the serum after approximately 0.45 h, and showed rapid elimination with clearances greater than 18.82 L/h/kg and half-lives lower than 6 h. The absolute oral bioavailability of COS 2 and COS 3 was 0.32–0.52%. COS 2 and COS 3 were widely distributed in Wistar rat tissues and could penetrated the blood-brain barrier without tissue accumulation.

Multielemental Screening and Analytical Method Validation for Determination of Elemental Impurity in Sucroferric Oxyhydroxide by Using (ICP-MS)

A highly selective, specific, precise sensitive and reliable ICPMS method has been developed and validated by using ICP-MS for the determination of multielement in Sucroferric oxyhydroxide. The described ICP-MS method provides specific detection and quantification of minor and trace elements from 0.3J(30%) to 2J(200%) of its individual specification of each element i.e Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl, and V.The analytical method found to be Linear for each individual element with working concentration range from 30%, 50%, 100%, 150% and 200% i.e 0.3J, 0.5J, 1J, 1.5J and 2J with correlation coefficient not less than 0.990.The % recoveries of elemental impurities of each individual elements at three different concentrations with spiking in samples were found to be an acceptable range as 70% to 150%.The method was found to be precise and robust and its relative standard deviation was below 20%.The actual observed relative standard deviation in Precision was found to be in an acceptable range. Therefore developed method can be use for routine quantitative analysis of elemental impurities like Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl, and V to ensure the quality of drug product.

Innovative NSAID dosage forms: lornoxicam suppositories and their standardization

The article presents the studies on the development of a method for the quantitative determination of lornoxime in suppositories using UV spectrophotometry. The optical densities of the test solutions were recorded at a wavelength of 375 nm. The absorption spectra of standard solutions of lornoxicam, as well as of tested solutions of suppositories were obtained. The relative standard deviation was 2.31%.

Development and Validation of an HPLC Method for the Analysis of Flowers of Wild-Growing Primula veris from Epirus, Greece

An HPLC-PDA method was developed for the determination of the flavonoids in the flowers of Primula veris from Epirus, Greece. The aim was to investigate the chemical content of the over-harvested P. veris populations of Epirus and to develop and optimize an extraction protocol to allow fast, exhaustive, and repeatable extraction. Qualitative analysis revealed that the P. veris flowers from Epirus were particularly rich in flavonoids, especially flavonol triglycosides including derivatives of quercetin, isorhamnetin, and kaempferol. A phytochemical investigation of a 70% hydromethanolic extract from the flowers afforded a new flavonoid, namely, isorhamnetin-3-Ο-β-glucopyranosyl-(1 → 2)-β-glucopyranosyl-(1 → 6)-β-glucopyranoside, which is also the main constituent of the flower extracts. Its structure elucidation was carried out by means of 1D and 2D NMR and mass spectrometry analyses. The HPLC-PDA method was developed and validated according to the International Council for Harmonisation guidelines. Since the main flavonol glycoside of the plant is not commercially available, rutin was used as a secondary standard and the response correction factor was determined. Finally, the overall method was validated for precision (% relative standard deviation ranging between 1.58 and 4.85) and accuracy at three concentration levels. The recovery ranged between 93.5 and 102.1% with relative standard deviation values < 5%, within the acceptable limits. The developed assay is fast and simple and will allow for the quality control of the herbal drug.

Optimasi dan Validasi Metode KCKT untuk Identifikasi dan Penetapan Kadar Metabolit Nitrofuran dalam Bakso Udang

Pendahuluan: Dikarenakan sifat dari Furazolidon, furaltadon, dan nitrofurantoin yang karsinogenik, perlu dilakukan pengawasan terhadap cemaran metabolit nitrofuran dalam produk berbahan dasar udang. Nitrofuran dimetabolisme secara cepat dalam jaringan tubuh hewan. Tujuan: Penelitian ini bertujuan melakukan validasi metode KCKT untuk penetapan kadar metabolit nitrofuran dalam bakso udang. Metode: Metabolit furazolidone, furaltadone dan nitrofurantoin yaitu 3-amino-2-oxazolidinone (AOZ), 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ), dan 1-aminohydantoin (AHD) diderivatisasi menggunakan 2-nitrobenzaldehida, diekstraksi dalam etil asetat dan dicuci dengan n-heksana, kemudian disuntikkan ke dalam system KCKT dengan detektor UV-PDA. Pemisahan dilakukan dengan kolom C-18 46 x 250 mm, 5 mm. Sebagai fase gerak adalah ammonium asetat 20 mM : asetonitril (70:30), dengan laju alir 0.5 mL/menit, suhu kolom 40oC, dan volume injeksi 100 µL. Hasil: Metode yang digunakan dapat memisahkan semua metabolit dari senyawa pengotor dengan waktu analisis 40 menit, dan menghasilkan linieritas yang baik dalam rentang konsentrasi 51,90 – 103,79 ng/mL (AOZ); 56,63 - 101,39 ng/mL (AMOZ); dan 49,92 - 89,86 ng/mL (AHD). Akurasi metode dipresentasikan sebagai rekoveri dengan hasil sebesar 78,50 - 102,29% untuk AOZ; 77,02 - 99,87% untuk AMOZ; and 85,54 - 99,77% untuk AHD. Presisi metode dinyatakan dalam simpangan baku relatif (relative standard deviation, RSD) dengan hasil masing-masing adalah 6,10 - 19,90%; 3,68 - 17,75%; and 2,75 - 12,58% untuk AOZ, AMOZ, dan AHD. LOD dan LOQ sebesar 3,09 ng/mL dan 10,29 ng/mL (AOZ); 6,84 ng/mL dan 22,82 ng/mL (AMOZ); serta 4,61 ng/mL dan 15,36 ng/mL (AHD). Kesimpulan: Metode uji dapat digunakan untuk skrining awal untuk mendeteksi dan penetapan kadar cemaran metabolit nitrofuran pada bakso udang.

A New Method for Determination of Pectin Content Using Spectrophotometry

The study aimed at developing a new spectrophotometric method for determining the pectin content. Take commercial pectin as an example, and the method is based on the reaction of copper ions with pectin to produce copper pectate. The spectrophotometer was used to measure the remaining content of copper ions so as to calculate the pectin content. This method eliminated the weight step and avoided the error associated with it. Effects of reaction time, temperature, and pH on absorbance were also studied. Additionally, the accuracy of this method was verified. It indicated excellent repeatability and accuracy with the relative standard deviation of 2.09%. In addition, three different plant types were used to demonstrate the reliability of the method. To summarize, this method can be widely used for the determination of pectin content in many materials.

Comprehensive quantification of height dependence of entrainment mixing between stratiform cloud top and environment

Different entrainment-mixing processes of turbulence are crucial to processes related to clouds; however, only a few qualitative studies have been concentrated on the vertical distributions of entrainment-mixing mechanisms with low vertical resolutions. To quantitatively study vertical profiles of entrainment-mixing mechanisms with a high resolution, the stratiform clouds observed in the Physics of Stratocumulus Top (POST) project are examined. The unique sawtooth flight pattern allows for an examination of the vertical distributions of entrainment-mixing mechanisms with a 5 m vertical resolution. Relative standard deviation of volume mean radius divided by relative standard deviation of liquid water content is introduced to be a new estimation of microphysical homogeneous mixing degree, to overcome difficulties of determining the adiabatic microphysical properties required in existing measures. The vertical profile of this new measure indicates that entrainment-mixing mechanisms become more homogeneous with decreasing altitudes and are consistent with the dynamical measures of Damköhler number and transition scale number. Further analysis shows that the vertical variation of entrainment-mixing mechanisms with decreasing altitudes is due to the increases of turbulent dissipation rate in cloud and relative humidity in droplet-free air and the decrease of size of droplet-free air. The results offer insights into the theoretical understanding and parameterizations of vertical variation of entrainment-mixing mechanisms.

ULTRAVIOLET SPECTROPHOTOMETRIC METHOD DEVELOPMENT FOR ESTIMATION OF NEW ANTIVIRAL REPURPOSING DRUG FAVIPIRAVIR

Objective: A new, economical, precise, linear, sensitive, accurate, ultraviolet (UV) spectrophotometric method for the estimation of new antiviral repurposing drug favipiravir as there is no reported simple UV spectrophotometric method for estimation. The efforts were made for development and validation of favipiravir as per ICH guidelines, because drug has a wide scope for formulations to be developed for treating different viruses. Methods: This method was developed using ethanol and water as a solvent. Favipiravir showed the absorption maxima at 234 nm. A Shimadzu UV–visible spectrophotometer (UV JAPAN 1801) was used to carry out spectral analysis. Results: The developed method was linear for a range of 0–10 μg/ml and displayed a good correlation coefficient of 0.9995. Accuracy of the method was estimated using a recovery study. The amount of drug recovered was found to be in the range of 99.30–99.91%. The % relative standard deviation value of intraday precision was found to be 0.408% and interday precision was found to be in the range of 0.348–0.693%. The % relative standard deviation found to be <2 which are indicative of the precision and reproducibility of the method. Detection limit and quantitation limit were noticed as 0.095 and 0.290, respectively. Conclusion: The developed UV spectrophotometric method was validated statistically for linearity, accuracy, precision, and sensitivity and results proved that the method can be employed for routine analysis of favipiravir.