Investigation of the Parameters Influencing the Drug Release from Lipid Microspheres Prepared by Congealable Hydrophobic Disperse Phase Encapsulation Method
 Eda GÖKBULUT*, Nurten ÖZDEMIR*^,°
 * Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Turkey

 ° Corresponding Author E-mail: nozdemir@pharmacy.ankara.edu.tr

Summary

The aim of this study was to prepare ibuprofen microspheres by congealable hydrophobic disperse phase encapsulation method using hydrogenated cotton seed oil (HCSO) as the lipid material. With in vitro dissolution studies, the drug release influenced by the amount of lipid material, the amount and types of dispersing agents, water and oil soluble auxiliary substances were investigated. Static dissolution method was applied by using pH 7.2 phosphate buffer as medium. Different dissolution models were applied to drug release data in order to evaluate release mechanisms and kinetics. According to in vitro dissolution studies, using different molecular weights of polyvinyl alcohol (PVA) as dispersing agent had no significant effect on the drug release, besides, using polyethylene glycoles (PEGs) as water soluble, glyceryl monostearate (GMS), stearyl alcohol (SAL) and stearic acid (SAS) as oil soluble auxiliary substances increased drug release. In order to enhance the solubility and drug release, solid dispersions of β-cyclodextrin (1:1) were prepared but contrarily the drug release decreased.
 
Key Words : Lipid microsphere, Ibuprofen, Controlled release,Congealable hydrophobic disperse phase encapsulation