Modification of mannitol compressibility via quasi emulsion solvent diffusion

One of the modification methods of flowability and compressibility of excipients for using in direct compression is changing in particles shape with crystallization using quasi-emulsion solvent diffusion. The aim of this research is to identify of effectiveness of quasi emulsion solvent diffusion (QESD) method in modification of mannitol compressibility. Firstly, mannitol was dissolved in distilled water at 80°C. The solution was then kept cool until 55°C. After that, ethanol was gradually added to the solution. The precipitated crystals were collected by drying. Floweability, SEM, DSC and X-ray powder diffraction of precipitated crystals was measured. Finally an equal amount of naproxen and excipients was prepared as direct compression tablets and then hardness, tensile strength and friability of tablets were measured. Flowability of mannitol was almost treated by QESD method. Bulk and tapped density of mannitol decreased; meanwhile increase in particle size was observed. The results of SEM demonstrated that primary particles of mannitol were broken in this method and were stuck together to produce very big particles that are not spherical. Tablets produced from treated mannitol had higher hardness and tensile strength than primary mannitol and they were measured 5.1 Kg± 0.72 and 0.16 Kg/mm2 ±0.0001, respectively. Spherical crystallization via QESD was useful method for changing compressibility mannitol characteristics so that tablets had suitable tensile strength. However this method had a few effect on flowability.