High-performance liquid chromatographic control of drugs containing caffeine was written by Alary, J.;Vergnes, M. F.. And the article was included in Annales Pharmaceutiques Francaises in 1984.Category: amides-buliding-blocks This article mentions the following:
Pharmaceutical dosage forms containing caffeine (I) [58-08-2] and other drugs were analyzed by reversed-phase HPLC. All the dosage forms except the oral solutions were extracted with CHCl3 or water and I was determined at 273 nm. The mobile phase was a mixture of MeCN-HOAc (either 10:90 or 50:50). The other drugs were detected either at 273 nm or other wavelengths. The oral solutions were measured directly. The recovery was 98-100%. The method is applicable to various pharmaceutical forms. In the experiment, the researchers used many compounds, for example, N,N-Diethylsalicylamide (cas: 19311-91-2Category: amides-buliding-blocks).
N,N-Diethylsalicylamide (cas: 19311-91-2) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Category: amides-buliding-blocks
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics