A stability-indicating ultra high performance liquid chromatographic (UHPLC) method has been developed for purity testing of ebastine and its pharmaceutical formulations. Successful chromatographic separation of the API from impurities was achieved on a Waters Acquity UPLC BEH C18, 50mm×2.1mm, 1.7 µm particle size column with gradient elution of 10mM acetate buffer pH 6.2 and a mixture of acetonitrile/2-propanol(1:1) as the mobile phase. Incorporating Quality by Design (QbD) principles to the method development approach by using the chromatography modeling software DryLab allows the visualization of a “Design Space”, a region in which changes to method parameters will not significantly affect the results as defined in the ICH guideline Q8 (R2). A verification study demonstrated that the established model for Design Space is accurate with a relative error of prediction of only 0.6%.

The method was fully validated for specificity, linearity, accuracy and precision, and robustness in compliance to the ICH guideline Q2 (R1). The method was found to be linear in the concentration range from the quantification limit(LOQ) to 125 of the specification limit for ebastine and each of the impurities with correlation coefficients of not less than 0.999. The recovery rate was between 98.15 and 100.30% for each impurity. The repeatability and intermediate precision (RSD) were less than 3.2% for ebastine and each of the impurities. The robustness of the developed method was studied by varying the six parameters: gradient time, temperature, ternary composition of the eluent, flow rate and start and end concentration of the gradient at 3 levels (+1, 0, −1). The resulting 729 experiments were performed in silico from the previously constructed model for Design Space and showed that the required resolution of 2.0 can be reached in all experiments. To prove the stability-indicating performance of the method, forced degradation (acid and base hydrolysis, oxidation, photolytic and thermal stress conditions) of ebastine was carried out. Baseline separation could be achieved for all peaks of the impurities, the degradation products and the API. Total runtime was only 4 min,which is an impressive 40-fold increase in productivity in comparison to themethod published in the Ph. Eur.monograph and allowed purity testing of more than 360 samples per day.

This article discusses the development of chromatography modelling of the last 30 years from the first software package for calculating resolution and capacity factors to the visual modelling of chromatograms for testing peak movements with altering elution conditions. Different approaches are discussed, such as retention modelling based on measurements, others based on molecular structure or on statistical considerations. The state-of-the-art will be demonstrated using DryLab with a few applications of industrial importance.

This article aims to investigate the predictability of chromatographic behavior of enantiomers using DryLab to predict the effect of changing various chromatographic parameters on resolution in the reversed phase mode. Three different types of chiral stationary phases were tested for predictability.High rates of accuracy allow for the conclusion that Chirobiotic V reversed phase retention mechanism follows the solvophobic theory.

In the pharmaceutical field, there is considerable interest in the use of peptides and proteins for therapeutic purposes. There are various ways to characterize such complex samples, but during the last few years, a significant number of technological developments have been brought to the field of RPLC and RPLC-MS. Thus, the present review focuses first on the basics of RPLC for peptides and proteins, including the inherent problems, some possible solutions and some directions for developing a new RPLC method that is dedicated to biomolecules. Then the latest advances in RPLC, such as wide-pore core-shell particles, fully porous sub-2 μm particles, organic monoliths, porous layer open tubular columns and elevated temperature, are described and critically discussed in terms of both kinetic efficiency and selectivity using DryLab. Numerous applications with real samples are presented that confirm the relevance of these different strategies. Finally, one of the key advantages of RPLC for peptides and proteins over other historical approaches is its inherent compatibility with MS using both MALDI and ESI sources.

The application of factor analysis (FA) method in classification of the antitumor acridinones based on high-performance liquid chromatography (HPLC) retention data and calculated parameters of lipophilicity as well as some nonempirical structural parameters was studied. First, a group of 19 acridinone (imidazoacridinone and triazoloacridinone) derivatives was chromatographed in six RP-HPLC systems, and the values of their HPLC retention data as retention times determined in both 10 min and 30 min gradient times were obtained as well as log kw (retention factor log k extrapolated to 0% organic modifier) parameters using DryLab 4 program were calculated. 

A new, simple, rapid, sensitive and economical spectrophotometric method has been developed and validated for estimation of lercanidipine in pure and its pharmaceutical formulation like tablet. During the development of formulations containing lercanidipine in its solid dosage form, analytical methods will serve as assay method for quantitation of the lercanidipine during product developmental stages. The present work consist of estimation of lercanidipine by difference spectrophotometry which is based on shifting of λ max by changing the pH of the solution by adding 0.1M HCl and 0.1M NaOH the absorption maximum was obtained. Linearity of the response was demonstrated for the drug for a range fulfilling Beer’s law, which is 5-25 μg/ml. The absorption maxima of lercanidipine were obtained at 260 nm in 0.1M NaOH, and 240 nm in 0.1M HCl. The results of analysis have been validated statistically and by recovery studies. The method was extended to pharmaceutical formulation and there were no interferences from any excipients and diluents. The full analytical validation was performed according to International Conference on Harmonization Q2R1 guidelines for validation of analytical procedures, supported by DryLab-models.