Quantitative Phase Analysis: Method Developments

During the years several methods have been developed to identify and quantify the phases in our samples. The newly developed methods respond to precise needs like increasing accuracy, lowering detection limits, automatize and speed-up the process or overcome errors and limitations. Most of the last developments are based on the use of large set of data and full pattern analyses like the Rietveld method. The progresses have been stimulated by the need to analyze new and complex materials with the help of advanced hardware to collect quickly and reliably our data. Refinement of old and new methods will be presented for the quantification of phases as well as some examples. Particular cases will be treated for layered materials and thin films, bulk amorphous, textured samples and clay materials. The last frontier appears to be the combination of the diffraction with other techniques to improve the final analysis.

A rapid, specific, and sensitive ultra-performance liquid chromatographic (UPLC) method for quantitative analysis of raloxifene in bulk drug and pharmaceutical formulations has been developed and validated as per the guidelines laid by ICH. The chromatographic separation of raloxifene was achieved on a Waters Acquity BEH C-18, 50 x 2.1 mm, 1.7 mu m column with mobile phase containing a gradient mixture of solvent A (0.1% of Formic acid in water) and solvent B (acetonitrile). The method was linear in the range of 0.1-50 mu g/mL (r(2) = 0.9998) and having a run time of 6 min, which allows for a large number of samples to be analyzed in less time. The analyte was monitored at 287 nm. The method was validated according to the ICH guidelines with respect to linearity, precision, accuracy, limit of detection (LOD), lower limit of quantification (LLOQ), specificity, and robustness. Forced degradation studies were also performed for raloxifene bulk drug samples to demonstrate the stability-indicating aspect of the UPLC method. Degradation was found to occur in reductive condition only while the drug was stable to oxidation, alkaline, acidic, photolytic, and hydrolytic stress conditions. The developed method was applied for the assay of raloxifene formulations like tablets and nanoparticulate formulation.