Phenylbutazone(PBZ) is a Non Steroid Anti Inflammatory Drug (NSAID). It is practically insoluble in water. The objective of this study was to find out the millinginfluence on PBZ prior to inclusion complex with β-cyclodextrin (β- CD). The milling process of intact PBZ was carried out in a ball mill with time variation 1 and 4 hours. Preparation of inclusion complex was done by kneading method with molar ratio of milled PBZ and β-CD was 2:1. Physical mixture and PBZ without milling process were also prepared with the same ratio of PBZ and β-CD as comparisons. The characterization of intact PBZ, physical mixture and PBZ-β-CD inclusion complexes were done by Infra-Red spectroscopy, Scanning Microscopy electron (SEM), Differential Thermal Analyzer (DTA), X-ray Powder Diffraction (XRPD). Dissolution test was done using basket method in a 900 ml phosphate buffer as medium at speed 100 rpm and temperature 37°C ± 0.5 for 60 minutes. X-Ray spectrum showed a decrease of peak intensity of inclusion complexes. SEM depicted the aggregation of PBZ. Meanwhile, the dissolution showed a decreasing on milled PBZ after inclusion complex withβ-CD compared to PBZ without milling. In conclusion, milling process on PBZ created aggregation which decreased the dissolution of inclusion complex of PBZ - β-CD
