Co-microprecipitation of nanoparticulate pharmaceutical agents with

Abstract

This invention describes the coprecipitation of nanoparticulate pharmaceutical agent dispersion via a process that comprises the dissolution of the said pharmaceutical agent in combination with a crystal growth modifier (CGM) in an alkaline solution and then neutralizing the said solution with an acid in the presence of suitable surface-modifying surface-active agent or agents to form a fine particle dispersion of the said pharmaceutical agent, followed by steps of diafiltration clean-up of the dispersion and then concentration of it to a desired level. This process of dispersion preparation leads to microcrystalline particles of Z-average diameters smaller than 400 nm as measured by photon correlation spectroscopy. Various modification of precipitation schemes are described, many of which are suitable for large-scale manufacture of these agent dispersions. It has been discovered that coprecipitation with CGM leads to smaller particle size compared to a case where precipitation is carried out using the pharmaceutical agent alone. Thus, this dispersion of instant invention is expected to have greater bioavailability. The CGM compound is a compound that has at least about 75% of its chemical structure identical to that of the pharmaceutical agent.