Beta-blockers are a class of medications predominantly used to manage abnormal heart rhythms. They are also widely used to treat high blood pressure. From the liquid chromatography separation point ...of view, beta-blockers are interesting molecules due to their hydrophobic-hydrophilic properties. Thus, the study aimed to investigate the beta-blocker separation selectivity on four phosphodiester stationary phases in reversed-phase liquid chromatography (RP LC) and hydrophilic interactions liquid chromatography (HILIC). On tested stationary phases, beta-blockers provide retention in both chromatographic systems, RP LC and HILIC. Additionally, it was found that cation-exchange mechanisms have a significant contribution to retention. Separations were enhanced by applying ChromSword software for gradient optimization and Intelligent Peak Deconvolution Analysis to separate unseparated peaks digitally.
A comprehensive, fully automated strategy is demonstrated for HPLC-UV chromatographic method development using ChromSword
® optimization software. The strategy involves: (1) the automated screening ...of various column and mobile phase combinations, (2) rational selection of the best starting conditions; and (3) subsequent automated method development to generate optimized separation methods. Pharmaceutical compounds were applied to solve problematic drug impurity separations. ChromSword
® software automates the screening, optimization, and documentation steps thus reducing the method development time. The strategy was compared to a manual method development approach showing the automated method strategy affords better selectivity in a shorter time.
Diprosalic Lotion
® is an anti-inflammatory drug product that contains salicylic acid and betamethasone dipropionate as active pharmaceutical ingredients (APIs). A reversed-phase high performance ...liquid chromatography (RP-HPLC) method was developed for simultaneous determination of salicylic acid, betamethasone dipropionate, and their related compounds in Diprosalic Lotion
®. A 150
mm
×
4.6
mm I.D. YMC J'sphere ODS-H80 column at 35
°C and UV detection at 240
nm was used. A gradient elution was employed using 0.05% (v/v) methanesulfonic acid solution and acetonitrile as mobile phases. A total of thirty three compounds from Diprosalic Lotion
® samples were separated in 38
min. The stability-indicating capability of this method has been demonstrated by the adequate separation of all the impurities and degradation products in expired stability samples of Diprosalic Lotion
®. The method was validated as per the current ICH guidelines.
Application of the solvatic retention model of reversed-phase liquid chromatography was studied to predict retention of phenylisothiocyanate derivatives of amino acids from structural formulae and ...stationary and mobile phase properties. The gradient elution mode with methanol and acetonitrile aqueous mobile phases was used. It was shown that practically acceptable prediction or retention time values can be achieved after the first approximation step when experimental data of one run are used. The zero approximation level predictions—from structural formulae, column and mobile phase properties can be used as a “first guess” method from which further optimization can begin.
In this paper, we describe a strategy that can be used to efficiently develop a high-performance liquid chromatography (HPLC) separation of challenging pharmaceutical molecules. This strategy ...involves use of advanced chromatographic technologies, such as a computer-assisted chromatographic method development tool (ChromSword) and an automated column switching system (LC Spiderling). This process significantly enhances the probability of achieving adequate separations and can be a large time saver for bench analytical scientists. In our study, the ChromSword was used for mobile phase screening and separation optimization, and the LC Spiderling was used to identify the most appropriate HPLC columns. For proof of concept, the analytes employed in this study are the structural epimers betamethylepoxide and alphamethylepoxide (also known as 16-beta methyl epoxide and 16-alpha methyl epoxide). Both of these compounds are used in the synthesis of various active pharmaceutical ingredients that are part of the steroid pharmaceutical products. While these molecules are relatively large in size and contain various polar functional groups and non-polar cyclic carbon chains, their structures differ only in the orientation of one methyl group. To our knowledge, there is no reported HPLC separation of these two molecules. A simple gradient method was quickly developed on a 5
cm YMC Hydrosphere C
18 column that separated betamethylepoxide and alphamethylepoxide in 10
min with a resolution factor of 3.0. This high resolution provided a true baseline separation even when the concentration ratio between these two epimers was 10,000:1. Although outside of the scope of this paper, stability-indicating assay and impurity profile methods for betamethylepoxide and for alphamethylepoxide have also been developed by our group based on a similar method development strategy.
We reported the development of an ion-pair chromatographic method to separate desloratadine and all known related compounds in Clarinex Tablets, which use desloratadine as active pharmaceutical ...ingredient (API). For the first time, baseline separation for desloratadine and all known related compounds was achieved by utilizing a YMC-Pack Pro C
18 column (150
mm
×
4.6
mm I.D., 3
μm particle size, 120
Å pore size) and a gradient elution method. The mobile phase A contains 3
mM sodium dodecylsulfate (SDS), 15
mM sodium citrate buffer at pH 6.2, and 40
mM sodium sulfate, while the mobile phase B is acetonitrile. Chromsword
®, an artificial intelligence method development tool, was used to optimize several key chromatographic parameters simultaneously including buffer pH/solvent strength, and temperature/gradient profile. The resolution of desloratadine and desloratadine 3,4-dehydropiperidine derivative, one of the critical pairs was improved by adding 40
mM sodium sulfate. Ultraviolet detection at 267
nm was used to achieve the detection for desloratadine and all compounds. This method has been successfully validated according to ICH guidelines in terms of linearity, accuracy, quantitation limit/detection limit, precision, specificity and robustness. It could be used as a stability indicating method for desloratadine drug substances or drug products that use desloratadine as active pharmaceutical ingredient.
Currently, several different approaches are used for speed-up and cost reduction for new method development in reversed-phase high-performance liquid chromatography. During this research, application ...of a solvatic retention model of reversed-phase high-performance liquid chromatography was studied to predict the retention of phenylisothiocyanate derivatives of 25 natural amino acids, working with different stationary phases. The gradient elution mode was used, with methanol and acetonitrile as the aqueous mobile phases. Retention factors were calculated from the molecular parameters of the structures of the analytes and stationary and mobile phase properties. Such step-by-step methods, which include the first-guess prediction of initial conditions from structural formulae and fine tuning parameters of the retention model using data from successive runs, can save time and consequently will reduce the cost of method development and optimization.
The objective of the work was continuation of our study on identification of target coumarins in extracts from Peucedanum alsaticum L. and Peucedanum cervaria (L.) Lap., by use of ChromSword, on the ...basis of relationships between retention data and descriptors such as partial molecular volume of structural fragments in water and energies of electrostatic interactions of bond dipoles with water (QSRR). The coumarins were mainly identified by comparing UV spectra from gradient runs with spectra from the literature. The presence of columbianadin, ostruthin, and 8-methoxypeucedanin in the fruits of P. cervaria (L.) Lap. and oxypeucedanin and isoimperatorin in the fruits of P. alsaticum was confirmed. The optimum conditions obtained from DryLab simulation were used for both RP-HPLC and RP-UPLC.
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