Ibuprofen Advil Motrin enantiomers

Ibuprofen is an analgesic sold under various names including Advil, Motrin, and Nuprin. The material is sole as a racemic mixture, but only one enantiomer acts as ar analgesic. The other enantiomer is inactive. Assign R oi S forms to the two enantiomers of ibuprofen. 

In some cases, a choice is made based on the biochemical activity of the enantiomers. For example, ibuprofen, the pain reliever contained in Advil, Motrin, and Nuprin, is sold as a racemic mixture. The D-isomer of ibuprofen is the... 

The active enantiomer of the popular analgesic ibuprofen used in Advil, Motrin, and Nuprin has been produced. However, recent research shows that humans have an enzyme called isomerase that converts the inactive enantiomer of ibuprofen to its active form. Due to the lower cost of preparation, most manufacturers prepare ibuprofen as a mixture of inactive and active forms. 

Ibuprofen is a popular analgesic and anti-inflammatory drug. There are two stereoisomeric forms of ibuprofen. This drug can exist as (S)- and (/ )-stereoisomers (enantiomers). Only the (5)-form is active. The (/ )-form is completely inactive, although it is slowly converted in the body to the active (5)-form. The drug marketed under the trade names, commercially known as Advil , Anadin , Arthrofen , Brufen , Nurofen , Nuprin , Motrin etc., is a racemic mixture of (/ )- and (5)-ibuprofen. 

In contrast to drugs from natural sources, those drugs that are made entirely in the laboratory are either achiral or, if cliiial, are often produced and sold as racemic mixtures. Ibuprofen, for example, has one chirality center and is sold commercially under such trade names as Advil, Nuprin, and Motrin as a racemic mixture of R and 5. It turns out, however, that only the 5 enantiomer is active as an analgesic and anti-inflammatory agent. The R enantiomer of ibuprofen is inactive, although it is slowly converted in the body to the active S form. 

For example, the drugs ibuprofen and fluoxetine each contain one stereogenic center, and thus exist as a pair of enantiomers, only one of which exhibits biological activity. (S)-IbupFofen is the active component of the anti-inflammatory agents Motrin and Advil, and (fi)-fluoxetine is the active component in the antidepressant Prozac. 

Ibuprofen is an analgesic (painkiller) with anti-inflammatory properties. The S enantiomer is the active agent, while the R enantiomer is inactive. Nevertheless, ibuprofen is sold as a mixture of both enantiomers (under the trade names Advil and Motrin ), because the benefit of separating the enantiomers is not clear. In fact, there is evidence that the human body is capable of slowly converting the R enantiomer into the desired S enantiomer. Many synthetic drugs are sold as a mixture of enantiomers, because of the high cost and difficulty associated with separating enantiomers. 

The painkiller ibuprofen, commonly available under the names Advil and Motrin, is sold as a racemate. Even though the active ingredient is the (5)-(+) enantiomer ( dexibuprofen ), the racemate is almost as active as the (S) form. As luck (for the discoverers) would have it (see also Problem 64), an enzyme in the body, a-methylacyl-CoA racemase, converts the inactive (R) to the (S) isomer to the tune of 63%, thus adding value to the racemic mixture. 

FIGURE 5.7. Molecular structure of ibuprofen enantiomers. (Advil is a registered trademark of Wyeth Consumer Healthcare, and Motrin is a registered trademark of McNeill-PPC Inc.)... 

Chirality plays a major role in the development of drugs. A chiral molecule is defined as nonsuperimposable on its mirror image. Two chiral molecules commonly called enantiomers are often compared to the right and left hands. The same type and number of atoms are in the two enantiomers but the spatial arrangement of atoms is different Usually one enantiomer is preferred over the other. In the pharmaceutical industry chiral molecules constitute a large portion of pharmaceutical sales. More than half the drugs approved worldwide are chiral. Examples include Lipitor and Zocor , as well as ibuprofen sold under the common brand names Motrin and Advil . 

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