Sulphamethizole-Cyclodextrin-Hydroxy Propylmethyl Cellulose Multicomponent Complexes

The effect of cyclodextrin complexation of sulphamethizole (SM) was studied. Two systems were prepared with two cyclodextrin derivatives, β-cyclodextrin (BCD) and hydroxypropyl-β-cyclodextrin (HPBCD): binary complexes and multicomponent systems (cyclodextrins and a hydroxylpropylmethyl cellulose K4M). Inclusion complexes were prepared by freeze-drying and characterized by thermal analysis (DSC) and X-ray diffractometry. The presence of the polymer in the solution increases the effect of cyclodextrins – specially BCD – on the solubility of SM. In solid state, binary inclusion complexes enhance the dissolution behaviour of SM but, from the multi-component complexes, the polymer controls the release of the drug. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of hydroxypropylmethyl cellulose on the complexation of diclofenac with cyclodextrins

The effect of a hydrophilic polymer, hydroxypropylmethyl cellulose K4M, on the complexation of diclofenac sodium with b- and hydroxypropyl-b-cyclodextrins has been studied. Multicomponent systems were prepared with the drug, both cyclodextrin and the polymer. Phase solubility diagrams revealed the positive effect of the polymer on the complexation of the drug but this effect was found after autoclaving the solutions. Solid inclusion complexes were prepared by freeze-drying and characterized by thermal analysis (DSC) and X-ray diffractometry. In solid state, binary inclusion complexes enhance the dissolution behaviour of diclofenac but, from the b-cyclodextrin multicomponent complex, the polymer controls the release of the drug. In the case of hydroxy- propyl-b-cyclodextrin multicomponent system, the solubility of the drugs increases significantly compared with the binary complex. This revised version was published online in July 2006 with corrections to the Cover Date.