Patent ID: 7700579

Claim:
A process of lyophilization for the preparation of a piroxicam:β-cyclodextrin inclusion compound in a 1:2.5 molar ratio conducted on a kilogram scale, comprising: (a) dissolving piroxicam and β-cyclodextrin in the molar ratio of 1 to 2.5 and ammonium hydroxide in water brought to a temperature of at least 60° C.; (b) pouring the piroxicam and β-cyclodextrin dissolved in water from (a) on temperature-controlled shelves of a freeze-dryer pre-cooled to a temperature of at least −30° C. to lower the temperature of the solution to −10° C. at a cooling rate equal to or higher than 1° C./min, to produce a frozen solution; (c) further lowering the temperature of the frozen solution to at least −20° C.; and (d) drying the frozen solution under vacuum, wherein the inclusion reaction is complete with complete amorphization of the inclusion compound and complete conversion of the piroxicam to the zwitter-ionic form.