Oral use remains preferable due to ease of use and patient compliance. However, development of oral formulations often presents a challenge, since approximately 40% of newly discovered active pharmaceutical ingredients are poorly water-soluble. To improve solubility and thereby bioavailability of such drugs, a great option remains formulation of amorphous solid disperisons. This approach is also suitable for the poorly soluble fenofibrate, which is used to lower the amount of fatty substances in blood. The aim of our research was to improve dissolution of fenofibrate by making solid dispersions with coprocessed excipient, which consisted of mesoporous silica, granulated with isomalt. Co-processing significantly improved compressibility and flowability of pure silica, which made it easier to produce final dosage form, orodispersible tablets. Solvent evaporation method was used to produce solid dispersions, which differed in the use of the solvent (acetone or isopropanol) and the solvent evaporation temperature (40 °C or 70 °C). We also varied the content of active ingredient in solid dispersions with 50%, 40%, 30% or 20% of fenofibrate. Solid dispersions were evaluated by thermic analysis and dissolution tests in buffer of pH 1.2 as the dissolution medium. Drug amorphisation as well as improved dissolution was achieved compared to dissolution of pure fenofibrate and physical mixtures. Based on results of dissolution testing and results of thermic analysis, solid dispersion containing 30% of fenofibrate prepared with acetone at 70 °C was chosen to formulate orodispersible tablets with direct compression. By adding 10% of superdisintegrant sodium croscarmellose, 10% of mannitol and 1% of magnesium stearate to formulation, the dissolution profile of tablets came close to the dissolution profiles of pure solid dispersion. After 5 weeks of storage in refrigerator and at 40 °C and 75% relative humidity, stability of prepared solid dispersions was evaluated as well. Elevated temperature and relative humidity significantly affected stability, while the samples stored in a refrigerator had comparable characteristics as freshly prepared samples. The solvent used and the solvent evaporation temperature did not significantly affect the results of dissolution testing and of thermic analysis.
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