Implementation of a design space approach for enantiomeric separations in polar organic solvent chromatography

Structural analysis of some bis-(8-isopropyl-isoquinolinium) derivatives reveals a preferential folded conformation leading to a stereoselective attack by sodium borohydride

“…Separation of propyl THIQ sample was made according to previously described protocol with some modifications [7]. On the one hand, the volume of injection was 30 lL to get enough resolution for collecting both peak samples, and on the other hand, the chromatographic system consisted of a Waters (Milford, MA, USA) 2535 pump quaternary gradient module associated with a Waters Prep Degasser with a Waters 2707 Autosampler for injection.…”

“…Subsequently, we initiated a chiral separation program by assessing different HPLC conditions such as chiral stationary phases, solvent systems, temperature or pressure. Our efforts conducted to the resolution of several diastereoisomeric mixtures for compounds that incorporate a butyl, a pentyl and a p-xylyl linker between the isoquinolinium moieties [7]. Three peaks corresponding to both enantiomers (R,R and S,S) and the meso derivative (R,S or S,R) were effectively detected in a normal ratio of 1:1:2.…”

QbD Approach Method Development for Estimation of Dabigatran Etexilate along with Its Impurities and Identification of Degradants in Capsule Dosage Form

“…Publications on the DoE and adopting QbD approach are available on internet to obtain the multidimensional robust design space [21] [22]. Experimental design and measurement system analysis are structured risk assessment tools for the evaluation of method robustness and ruggedness.…”

Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles

“…The robust optimization approach provides the assurance of the method quality represented by such DS which can be considered a "safe zone" where no significant changes of the CQAs levels should be observed as a consequence of small, deliberate changes of method parameters. In the literature several examples of the QbD approach in the development of liquid chromatographic methods could be found [4][5][6][7][8][9].…”