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 validity of the extended Tanaka column characterization procedure against the retention behavior of 101 analytes of widely differing properties chromatographed on five differing stationary phase chemistries has been established using a chemometric technique called principal component analysis (PCA). It was concluded that the simple and conveniently determined column characterization parameters covered the same space in the PCA loading plot as the retention times for the 101 differing analytes. This confirms that the ten column characterization parameters of the extended Tanaka protocol encode the same information as the retention times of the 101 analytes. Significant selectivity differences were observed between stationary phases and the mobile-phase modifiers – MeOH and MeCN. PCA contribution plots served as a convenient way to highlight specific selectivity differences between stationary phases. logD values exhibited a poor correlation with retention indicating that retention in RP-LC is not solely dictated by the analytes hydrophobicity. The use of MeOH was found to generate greater selectivity differences with the five stationary phases than when MeCN is used.

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. 

Following administration of the acidic drug tolmetin (TOL) anaphylactic reactions occurred, which have been hypothesized to be related to the formation of reactive acyl glucuronides. Recently, glutathione adducts have been detected upon incubation of TOL with human liver microsomal preparations, which proved that oxidative activation might also be a pathway of formation of reactive—possibly toxic—glutathione metabolites of TOL. The aim of this work was to develop a new and robust HPLC method to investigate the in vivo effect of 2 coadministered drugs/nutritional supplements on the kinetics of TOL in rats (cimetidine, CIM) known to be a potent inhibitor of CYP3A4, an enzyme that catalyzes the oxidative metabolism and Quercetin, and QUE which induces UGT1A6, an enzyme involved in glucuronidation of acidic drugs. DryLab, a computer modeling software package, was used to assist in the development and optimization of the HPLC method used for separation of TOL and the two potential kinetic modulators together with three potential internal standards (zomepirac, carvedilol and fexofenadine). The method was validated in biological samples obtained from rats.