Stereochemistry - Racemic Modification, Resolution, and Its Importance With Recently Used Optically Active Drugs.

Abstract

Stereochemistry involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. An important branch of stereochemistry is the study of chiral molecules. Optical activity is the ability of a chiral molecule to rotate the plane of planepolarized light, measured using a polarimeter. Racemic modification and resolution, both processes are very important in stereochemistry. A mixture of equal parts of enantiomers is called a racemic modification. The process of separating a racemate into pure enantiomers is known as resolution. Recently, various optically active drugs are used for the treatment for various diseases. In these drugs, some are used as mixture of enantiomers and some used as single enantiomer. For preparation of optically active drugs, racemic modification and resolution processes are generally used. Hence, this is very important to know about various steps and types of processes used for the same. Racemic modification is advantageous where racemates have more therapeutic advantages than single isomers. Resolution is advantageous where single entiomer is used for treatment because single enantiomers have less complex and more selective pharmacodynamic profile as compared to racemic mixture so have lesser adverse drug reactions, improved therapeutic profile, less chances of drug interactions than racemic mixtures. Recently used optically active drugs are amlodipine,

Tailoring of Solubility of Ibuprofen in the Presence of Hydrophilic Excipients in Water-Ethanol Mixtures by Crystallization Method

“…log10(sol)= a+(b+e*t-25)(1+exp[-Xe-c+f*t-25)/d])………… [1] Where sol = Ibuprofen solubility as I*/(E+W) in ppm, t = temperature in °C and Xe = E/(E+W) as mass fraction. The four parameters of the sigmoid (a-d) were taken to be linear functions of temperature but only the two showed as functions of temperature were significant.…”

“…Racemic Ibuprofen, which contains equal quantities of R(-)Ibuprofen and S(+)Ibuprofen, has been used as an anti-inflammatory and analgesic agent for over 30 y [1]. Racemic ibuprofen is known as Ibuprofen (Ibu) is a water insoluble non-steroidal anti-inflammatory drug commonly used in the treatment of arthritis, fever, and analgesia.…”