Inclusion Complexation and Dissolution Properties of Nimesulide and Meloxicam–hydroxypropyl-β-cyclodextrin Binary Systems

The purpose of the work is physicochemical characterization of nimesulide (NI) and meloxicam (ME)–hydroxypropyl-β-cyclodextrin (HP-β-CD) binary systems both in solution and solid states and to improve the pharmaceutical properties of NI and ME via inclusion complexation with HP-β-CD. Binary systems of NI and ME with HP-β-CD have been characterized both in solution and solid state by different physicochemical methods. Three types of drug–HP-β-CD binary systems, namely physical mixtures (PM), kneaded systems (KS) and co evaporated systems (CS) in 1:1 and 1:2 molar ratios (1:1 and 1:2 M) were prepared. Phase solubility and 1H-NMR spectroscopic studies in solution state revealed 1:1 M complexation of NI and ME with HP-β-CD. A partial inclusion of NI with HP-β-CD at both molar ratios of kneaded and co evaporated systems and a true inclusion of ME with HP-β-CD at both molar ratios of co evaporated systems in solid state was confirmed by differential scanning calorimetry (DSC), powder X-ray diffractometry (powder X-RD) and scanning electron microscopy (SEM) studies. Dissolution properties of NI and ME–HP-β-CD binary systems were superior when compared to corresponding pure drugs. The aqueous solubility and dissolution properties of NI and ME can be improved by inclusion complexation with HP-β-CD.