Aqueous suspension with good redispersibility

Abstract

The aqueous suspension can be prepared by incorporating, in an aqueous suspension of a hardly soluble drug, a water-soluble polymer within the concentration range from the concentration at which the surface tension of the aqueous suspension of the drug begins to decrease up to the concentration at which the reduction in surface tension ceases. The resulting aqueous suspension shows ready redispersibility and will not undergo aggregation of dispersed particles or caking. Because of its good redispersibility, the suspension is useful as a parenteral preparation, eye drops, nasal drops, a preparation for oral administration, a lotion or the like.

Description

[0001] The present invention relates to an aqueous suspension with good redispersibility.

[0002] In preparing, for instance, an ophthalmic preparation, nasal preparation or parenteral preparation containing a medicinal compound hardly soluble in water, it is presumable that the drug be suspended in an aqueous medium to give an aqueous suspension. When such aqueous suspension is stored for a long period, the drug occurring as dispersed particles (hereinafter sometimes referred to merely as dispersed particles) tends to undergo aggregation, resulting in increases in size of dispersed particles or sedimentation of dispersed particles and further in secondary aggregation of the dispersed particles that have settled, for example caking. Therefore, efforts have been devoted to prevent the aggregation or sedimentation of dispersed particles as far as possible or, when such aggregation or sedimentation cannot be prevented, to obtain suspensions capable of readily regaining their original sta...

Images