Nonsteroidal anti-inflammatory drugs propionic acid derivatives

For therapeutical purposes, a likewise frequently used group of drug compounds are the nonsteroidal anti-inflammatory drugs (NSAID). Among the best known representatives of the aryl acetic acid derivatives is diclofenac as well as ibuprofen, an aryl propionic acid derivative. As both have acidic properties, they dissociate while being dissolved and may form salts with amphiphilic properties. Together with appropriate counterions these amphiphilic organic acids may form lyotropic mesophases with water even at room or body temperature, for example, diclofenac diethylamine... 

The eight groups of nonsteroidal anti-inflammatory drugs are salicylates, parachlorobenzoic acid derivatives, pyrazolone derivatives, propionic acid derivatives, fenamates, oxicams, phenylacetic acid, and selective COX-2 inhibitors. 

Naproxen is one of many drugs in the group classified as nonsteroidal anti-inflammatory drugs (NSAIDs). Naproxen is in the chemical class of propionic acid derivatives and possesses analgesic, antipyretic, and anti-inflammatory properties. It was first introduced in 1976 under the trade name Naprosyn by Roche Pharmaceuticals. Both the acid and salt formulations are currently used, with the salt form having a slightly more rapid absorption rate. Reduced-dose naproxen sodium was approved as an over-the-coimter (OTC) pain reliever in the USA in 1994 and entered the market under the trade name of Afleve [1,2]. 

As an example, let us have a look at some derivatives of propionic acid, such as ketoprofen, ibuprofen, and naproxen, that are commonly used as nonsteroidal anti-inflammatory drugs (NSAIDs) and, hence, frequently subjected to chromatographic studies. These compounds, the formulas of which are shown in Figure 2.4, have one asymmetrical carbon atom in the molecule. It has been known that only 5-isomers of all three compounds have therapeutic utility, whereas from among I -enantiomers only ketoprofen of such conflguration finds specific application [10], It is not, however, the same as application as that of the 5-enantiomer. 

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