Metoprolol
Metoprolol or Toprol XL is a beta-selective (cardioselective) adrenoceptor or blocking agent lacking intrinsic sympathomimetic activity. It is employed as a antihypertensive and antianginal agent and used in the treatment of myocardial infarction.. Its chemical name is 1-[4-(2-Methoxyethyl)phenoxyl]-3-[(1-metylethyl)amino]-2-propanol, it has a molecular weight of 267.38 and elemental analysis shows it contains 63.56% carbon, 6.00% hydrogen, 9.27% nitrogen and 21.17% oxygen. It is often prescribed as the succinate which is a white powder, molecular weight 652.8. Metapropol reacts directly with the fluorescence agent 4(N-chloroformethyl-N-methylamino-7-N-N-dimethylamino sulphonyl-2,1,2-benzoxydazole to form a fluorescent derivative as a 1-1 aduct with the secondary amino group of the B blocker. The reaction proceeds readily with no catalyst. The derivatives can be separated on a reversed phase column 15 cm long and 4.6 mm in diameter packed with 5 micron particles using an appropriate aqueous/solvent mixture as the mobile phase
Author: RPW Scott
Book:Principles and Practice of Chromatography
Section:Principles Applications Liquid-Chromatography b--blockers
of the solutes with the stationary phase would become
almost exclusively dispersive. This is an example where the phase
system is complex and is required to be so, because limited column
efficiency demanded clever phase selection to obtain the necessary
differential retention.
Analysis of b -blockers
Another liquid
chromatography application that involves some novel derivatization
is the separation of some 'b
blockers', the enantiomers of propranolol, metroprolol and atenalol
as fluorescent enhanced derivatives on cellulose
tris(3,5dimethylphenylcarbamate) coated on silica gel. This
technique was developed by Yang et al. [14] developed and
involved the synthesis of their fluorescent derivatives, which were
formed by reacting them with an electrophilic fluorogenic reagent,
4-(N-chloroformethyl-N-
methylamino-7-N-
Ndimethylaminosulfonyl-2, 1, 2benzoxydiazole (DBD-
COCl). These derivatives show intense fluorescence at
Principles Applications Liquid-Chromatography b--blockers
Author: RPW Scott
Book:Principles and Practice of Chromatography
Section:Principles Applications Liquid-Chromatography b--blockers
nbsp;
Courtesy of
the Royal Society of Chemistry, Ref. [14]
Figure 48 The Separation of
Derivatized Propranolol (Pro) Metroprolol (Met) and Atenolol
(Ate
Principles Applications Liquid-Chromatography b--blockers
Author: RPW Scott
Book:Principles and Practice of Chromatography
Section:Principles Applications Liquid-Chromatography b--blockers
nbsp;
The detection limits at a signal-to-noise
ratio of 3 were 50 fmol for both (S)- and (R)-Propanolol, 12 and 17
fmol for (S)- and (R)-Metroprolol respectively and 15 and 20 fm for
(S)- and (R)-Atenolol respectively.
The
cyclodextrin based stationary phases are some of the more popular and effective
chiral stationary phases presently available. One of their distinct advantages
lies in their unrestricted and successful use with all types of solvent. In
particular, they can be used very effectively in the reversed phase mode (a
method of development that is not possible with some other chiral stationary
Principles Applications Liquid-Chromatography b--blockers
