Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities

Development and Validation of a Robust and Efficient HPLC Method for the Simultaneous Quantification of Levodopa, Carbidopa, Benserazide and Entacapone in Complex Matrices

“…Selective and reliable HPLC methods for detecting more than two of the compounds within a single run were published by Ribeiro et al (9) and Vemic et al (10). However, the cited methods did not cover the complete range of APIs studied in our experiments and the overall run times of the methods were quite long.…”

“…However, the cited methods did not cover the complete range of APIs studied in our experiments and the overall run times of the methods were quite long. The method for the simultaneous analysis of levodopa, carbidopa and entacapone published by Vemic et al (10) had for instance a total run time of 40 min, even though a relatively short 150 mm C-18 column was applied and thus was not regarded as efficient.…”

“…A couple of methods enabling the detection of levodopa, carbidopa and entacapone in a single HPLC run have been described in the recent past (9-11) and were investigated for our purpose. However, it turned out that without modification the respective methods were not applicable for also properly detecting benserazide (9)(10). Moreover, one of the methods turned out to not even being applicable for the detecting the drug combination given in the title of the manuscript (11).…”

Liquid chromatographic method for toxic biogenic amines in foods using a chaotropic salt

“…stationary phase, leading to slow column-equilibration and difficulty in recovering the initial column properties [10][11][12][13]. Nowadays, chaotropic salts are usually used in the analysis of active ingredients and impurities in pharmaceutical formulations [11,[14][15][16]. In the meanwhile, attempts to understand the fundamentals behind the applications are still ongoing (see Ref.…”

Stability Indicating HPLC Method for Simultaneous Estimation of Entacapone, Levodopa and Carbidopa in Pharmaceutical Formulation

“…A method for in-vitro release of drugs is also found [3][4][5]. Publications were found on LC method for estimation using electrochemical detector [6] and LC method for estimation of levodopa and carbidopa using fluorescence detector [7][8][9][10][11][12][13][14][15][16][17][18]. Few official pharmacopial monographs for single and dual drug combinations [19][20][21][22][23][24] were also found.…”