Propanolol, racemate

Propanolol Racemic compound is used as drug however, only the (SFf-I-isomer has the desired P-adrenergic blocking activity... 

Propanolol (14) is a broadly used j8-adren-ergic receptor blocking agent that is sold as the racemate. However, the majority of the activity is associated with the S-enantiomer (74) (see Section 2) (122). The asymmetric... 

Several clinically used drugs, e.g. salbutamol (a 13-adrenoceptor agonist), propanolol (a (3-adrenoceptor antagonist) and the 2-arylpropionic acids (NSAIDs) are employed in the racemic form. In the... 

A number of recent studies extend the observation of stereoselectivity of drug metabolism. The inactive d-isomer of propanolol was metabolized in rats with a two-fold shorter plasma half-life than l-propanolol . The anti-inflammatory agent l-a-methylfluorene-2-acetic acid was isomerized in dogs to the d-enantiomer , thus being another example of stereospecific metabolic inversion. Whereas the individual R and S enantiomers of 15 were metabolized at similar rates, the half-life of the more active R isomer was prolonged in the racemic mixture, perhaps due to inhibition of metabolism of the R isomer by the S isomer. A similar effect was observed with the R and S enantiomers of amphetamines , which further illustrates that racemates may exhibit a biological profile different from that anticipated on the basis of the activity of the component enantiomers. 

A NMR study on the formation of diastereoisomeric inclusion complexes between fluorinated amino acid derivatives and a-CD in 10% D2O solution shows that the chemical shifts of the D-amino acid derivatives included by a-CD are upheld from those of their L analogues [77]. The shift difference between the diastereoisomers formed with D and L enantiomers can be used for chiral analysis and optical purity determinations. For example, the interaction of -CD with propanolol hydrochloride produces diastereomeric pairs. The protons of the antipode give NMR signals which differ in chemical shifts in D2O solution at 400 MHz. The intensity of the resonance signals for each diastereoisomer has been used for optical purity determination. By adding racemate to pure (—) isomer, this technique is able to measure optical purity of propanolol hydrochloride in water down to the level of 1%. 

Gattuso et al. [32, 33] illustrate the specific separation costs and their change by the influence of the production size for the separations of the racemic mixtures of propanolol and fluoxetin. For propanolol the separations costs are stated to be 450 US at 2 tons/year. The increase of the production size by a factor of 20 would lead to a bisection of the specific separation costs. Also given are the specific separation costs of the SMB technique for petrochemical applications. These are in the range from 0.08 to 0.14 US per kg product, at a plant capacity of 15000 to 100000 tons/year. 

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