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The aim of this study was to prepare and characterise inclusion complexes of a low water-soluble drug, mefenamic acid (MA), with b-cyclodextrin (b-CD). First, the phase solubility diagram of MA in b-CD was drawn from 0 to 21 Â 10 À3 M of b-CD concentration. A job's plot experiment was used to determine the stoichiometry of the MA:b-CD complex (2:1). The stability of this complex was confirmed by molecular modelling simulation. Three methods, namely solvent co-evaporation (CE), kneading (KN), and physical mixture (PM), were used to prepare the (2:1) MA:b-CD complexes. All complexes were fully characterised. The drug dissolution tests were established in simulated liquid gastric and the MA water solubility at pH 1.2 from complexes was significantly improved. The mechanism of MA released from the b-CD complexes was illustrated through a mathematical treatment. Finally, two in vitro experiments confirmed the interest to use a (2:1) MA:b-CD complex.

Microparticles charged by niflumic acid and based on cellulose derivatives as polymeric matrices, that is, ethylcellulose (EC) and mixtures of EC and hydroxypropylmethylcellulose (HPMC), were elaborated using microencapsulation by emulsion-solvent evaporation technique. The niflumic acid is considered as a poorly water soluble drug, so the main objective of the paper is to use designs of experiment in order to prepare new solid formulations with a large range of size for the drug dissolution enhancement. The possible drug-polymer interaction was investigated by Fourier transform-infrared spectroscopy, X-ray diffraction, and differential scanning calorimetric analysis. Some of the process variables, namely, the stirring speed of emulsion, the emulsifier concentration, and the EC:HPMC ratio, were selected and varied. Their main and interactive effects on the microparticles' characteristics were obviously evaluated and discussed using Minitab software 16.1. The obtained microparticles' size (d 10 ) ranged from 196 to 796 μm, and the drug entrapment reached 45% in some formulations. The drug dissolution results showed that the Higuchi's release constant varied from 0.011 to 0.067 min −1/2 and was enhanced especially when the HPMC concentration was increased.

The aim of this work is the enhancement of the hydrosolubility behaviour of a poorly soluble, weakly basic drug, using itraconazole (ITZ) as a case example. Binary inclusion complexes of ITZ with β-cyclodextrin (β-CD) are prepared in 1:2 molar ratios of ITZ to β-CD by co-evaporation method. Both solubility and dissolution behaviour are compared with that of the pure drug. Ternary complexes can be obtained by adding the polyvinylpirrolidone (PVP) which is a highly water soluble polymer, in the ITZ/ β-CD complex formation. Actually, Solid state analysis is performed for all formulations and for pure ITZ applying the Fourier transforms infrared (FT-IR) spectroscopy, powder X-ray diffraction (pX-RD) and differential scanning calorimetry (DSC). Solubility tests indicate that with all formulation, the solubility of ITZ formed with β-CD or β-CD and PVP proved to be increased. The obtained results show that the pure drug has a poor dissolution property, and the ternary inclusion complexes resulted in fast and extensive release of ITZ. Keywords: Itraconazole, β-cyclodextrin, polyvinylpyrrolidone.

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