Kinetic Assessment of Mechanical Properties of a Cellulose Board Aged in Mineral Oil and Synthetic Ester

In oil-immersed power transformers, the insulation system is constituted of a dielectric oil–solid combination. The insulation oil generally used is mineral oil; however, this fluid has started to be substituted by natural and synthetic esters due to their higher biodegradability and flash point. The introduction of a new fluid in the insulation system of power transformers requires kinetic models that can estimate the degradation rate of insulation solids. The aim of this work was to go further in quantifying through different kinetic models the deterioration suffered by a commercial cellulose board (PSP 3055), which is one of the solid materials used in the insulation system of oil-filled transformers. The aging study was extended to cellulose board specimens immersed in two different oils (mineral and synthetic ester). It was obtained that there is a lower degradation when synthetic ester is used in the insulation system. Additionally, it can be concluded that the use of mechanical properties to quantify the degradation of the cellulose board through kinetic models provides information about the different behavior shown by PSP 3055 when different fiber direction angles are considered.

PHARMACEUTICAL QUALITY ASSESSMENT OF GLIMEPIRIDE TABLETS – COMPARISON OF BRANDS AND NEWLY FORMULATED TABLETS WITH INNOVATOR

Objective: The main objective of the study was to assess the quality attribute of generic brands and newly formulated tablet of glimepiride and compare their drug release profile with innovator brand. Methods: Different brands were purchased from different markets of UAE. The validated high-performance liquid chromatography method was used to assess the quantitative analysis of glimepiride. The linearity of curve (r² = 0.9999) indicated the accuracy and precision of the analytical method. Comparative dissolution of newly formulated and generic tablets was carried out using USP dissolution apparatus II. Study was accomplished in phosphate buffer (pH = 7.8), the paddle speed was adjusted at 75 rpm. F1 and F2 factor among the brands and kinetic assessment were done to obtain the order of release. Results: Dissolution profiles of formulated tablets were almost same as that of innovator, 91.53 and 94.9, respectively, in 15 min. The statistical value between the different brands (F = 3.698) indicated that there were some differences among the few groups of tablets and p-value (0.002154) indicated that it supported H1 hypothesis. First-order and Weibull models described the drug release with r2 value of 0.9981–0.927210 and 0.9992– 0.9835, respectively. Stability of optimized formulated batch was also examined. Conclusion: It was concluded that the formulated tablets are stable and pharmaceutically as good as the innovators; however, all the selected brands could not be used interchangeably in the clinical practice. It was also concluded that the scrutiny and screening of the drug products, available in the markets, can help to build a better health-care setup.