Complexation of sulphonamides with beta-ciclodextryn studied by experimental and theoretical methods

ZOPPI, A.; QUEVEDO, M.A.; DELRIVO, A.; LONGHI, M.R.

JOURNAL OF PHARMACEUTICAL SCIENCES

JOHN WILEY & SONS INC

Año: 2010 vol. 99 p. 3166 - 3176

0022-3549

The complex formation between three structurally related sulfonamides (sulfadiazine (SDZ), sulfamerazine (SMR), and sulfamethazine (SMT)) and -cyclodextrin (-CD) was studied, by exploring its structure affinity relationship. In all the cases, 1:1 stoichiometries were determined with different relative affinities found by phase solubility (SDZ:-CD > SMR:-CD > SMT:-CD) and nuclear magnetic resonance (NMR) (SMT:-CD > SMR:-CD > SDZ:-CD) studies. The spatial configurations determined by NMR were in agreement with those obtained by molecular modeling, showing that SDZ included its aniline ring into -CD, while SMR and SMT included the substituted pyrimidine ring. Energetic analyses demonstrated that hydrophobicity is the main driving force to complex formation. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci