Structural and spectroscopic investigation of some drug crystals and its complexes using experimental and theoretical perspectives

Abstract

Xanthines are compounds obtained from plants and it is included in daily life products such as coffee, energetic drinks, tea and chocolate. Methylated xanthines known to be methylxanthines which includes Theophylline, Caffeine and Theobromine. Both Theophylline and Caffeine have pharmacologic mechanism of action. Caffeine plays its role in central nervous stimulant while theophylline in airway borne diseases. Theophylline, most commonly used methylxanthine was first extracted from tea leaves and it has been pharmaceutical use since 1902. Initially, it is used as diuretic and the bronchodilator property was identified later. It becomes the most widely prescribed drugs used as bronchodilator. It is used to treat bronchial asthma and Chronic Obstructive Pulmonary Disease (COPD). Also, theophylline possesses a pyrimidine and an imidazole ring structure which is a five-membered nitrogen containing heterocyclic structure. Literature survey shows imidazole derivatives have several pharmacological activities such as antifungal, antibacterial, antiviral, anti- inflammatory and antimalarial activity. The first chapter explains the fundamentals of crystal growth and characterization of pharmaceutical drug and its pharmacological importance. By crystal engineering technique the therapeutic effectiveness of the drug can be improved. Further, the literature survey of theophylline and its related moieties was done with the help of Cambridge Structural Database (CSD ver 5.35). The crystal structures of the grown crystals are obtained through single crystal XRD. The structure determination and refinement method has been discussed. Likewise, vibrational spectroscopy gives data about atomic structure and intermolecular interactions newline