Mechanistic Investigation of Inclusion Complexes of a Sulfa Drug with α- and β‑Cyclodextrins

Molecular encapsulation is extremely important in pharmaceutical and drug delivery science. In this article, one of the most important sulfa drugs, namely, sulfacetamide sodium, has been probed in the solution and solid phases for encapsulation within the cavities of α- and β-cyclodextrins. Various physicochemical techniques were employed to establish the outcome of the work. The isothermal titration calorimetric method was used to evaluate the stoichiometry, association constant, and thermodynamic parameters with high accuracy. The solid inclusion complexes were analyzed by spectroscopic techniques to ascertain the encapsulation of the investigated drug within the cavities of α- and β-cyclodextrins. This phenomenon of drug inclusion is exceedingly significant for its stabilization against external hazards, such as oxidation, sensitization, and photolytic cleavage, for the proficient and accurate regulatory release of an essential amount of drug at the targeted site for a period of time and for the prevention of overdose when applied as an ophthalmic solution and ointment.