Determination of Vacant Lattice Sites in Aluminium Alloys by X-ray Diffraction Technique

THE study of the structure of metals and alloys is very important because this affords the possibility of developing new alloys with improved properties to be useful for meeting service requirements. Theories based on ideal crystals fail miserably when applied to real crystals of the metals and alloys, for example the calculated Yield strength and breaking strength of ideal crystals are 100 to 10,000 times more than the observed strength of real crystals. The reason is that the crystals contain many haws and irregularities, so it is felt that a detailed knowledge of vacant lattice sites in alloys will be useful, because of their effects on physical and mechanical properties. The object of this investigation is to find out the effect of copper on the lattice parameter and vacant lattice sites in aluminium

Stability-Indicating High-Performance Liquid Chromatographic Determination of Apixaban in the Presence of Degradation Products

A simple, robust, and stability-indicating reversed-phase high-performance liquid chromatographic (HPLC) method for the analysis of apixaban and its related substances has been successfully developed. Chromatography was performed on a 250 mm × 4.6 mm, 5 μm C18 column with a gradient mixture of a phosphate buffer–methanol 60:40 (v/v) at 1.0 mL min−1. Ultraviolet detection of apixaban was at 220 nm. The method was validated for linearity, precision, repeatability, sensitivity, and selectivity. Selectivity was validated by subjecting apixaban solution to photolytic, acidic, basic, oxidative, and thermal degra-dation. The peaks from the degradation products did not interfere with that from apixaban. The method was used to quantify the related substances in apixaban in the bulk drug and can be used for routine quality control purposes