Studies on Diclofenac -β- Cyclodextrin Inclusion Complexes

This work was aimed at investigating diclofenac-β-cyclodextrin inclusion complexes in aqueous medium. Applying the method of phase solubility analysis, β-cyclodextrin formed a complex in 1:1 stoichiometry with diclofenac. The complex obeyed Beer's law. The stability constant, partition coefficient and solubility values were evaluated. The effect of pH on the stability of the complex was studied. The results indicated an increased aqueous solubility of diclofenac when complexed with β-cyclodextrin. Maximum stability of the complex was at pH value of 4.0. This makes it possible for aqueous oral solution of diclofenac to be formulated.