Excimer formation in inclusion complexes of β-cyclodextrin with salbutamol, sotalol and atenolol: spectral and molecular modeling studies.
The inclusion complexation behavior of salbutamol, sotalol and atenolol drugs with β-cyclodextrin (β-CD) were investigated by UV-visible, fluorometry, time resolved fluorescence, FT-IR, (1)H NMR, SEM and PM3 methods. The above drugs gave a single emission maximum in water where as dual emission in β-CD. In β-CD solutions the shorter wavelength fluorescence intensity was regularly decreased and longer wavelength fluorescence intensity increased. Addition of β-CD to aqueous solutions of drugs resulted into excimer emission. The excimer emission is concluded to be due to a 1:2 inclusion complex between β-CD and drug. Nanosecond time-resolved studies indicated that all drugs exhibited biexponential decay in solvents and triexponential decay in CD. Investigations of thermodynamic and electronic properties confirmed the stability of the inclusion complex.
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India.
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Antony Muthu Prabhu
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Subramanian
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Rajendiran
D000042:Absorption; D000097:Acetonitriles / Q000737:chemistry; D000420:Albuterol / Q000737:chemistry*; D001262:Atenolol / Q000737:chemistry*; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000648:ultrastructure; D011522:Protons; D012997:Solvents / Q000737:chemistry; D013015:Sotalol / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D013997:Time Factors; D014867:Water / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
D000097:Acetonitriles; D011522:Protons; D012997:Solvents; D047392:beta-Cyclodextrins; D014867:Water; D001262:Atenolol; D013015:Sotalol; C031215:betadex; D000420:Albuterol; C032159:acetonitrile