Abstract: An effective and simple process for producing a fine dispersion of a poorly soluble drug; and a fine sparingly-soluble-drug dispersion having excellent dispersion stability. In a first step, a poorly soluble drug is suspended in a liquid containing no deflocculant and the suspension is subjected to a high-pressure treatment with a high-pressure homogenizer. In a second step, a deflocculant is added to the dispersion obtained in the first step and this dispersion is subjected to a deagglomeration treatment such as a high-pressure treatment with a high-pressure homogenizer or an ultrasonic treatment. Thus, a fine dispersion of the poorly soluble drug is effectively and simply produced in which the size of the particles dispersed is on the order of nanometer. The fine sparingly-soluble-drug dispersion produced has excellent dispersion stability and the fine particles of the poorly soluble drug do not suffer aggregation/sedimentation even upon standing.

Abstract: Novel quinolonecarboxylic acid derivatives of general formula (1) or salts thereof which have potent antibacterial effects on gram-positive bacteria in particular Propionibacterium acnes (wherein R1 represents a hydrogen atom or a carboxyl-protective group; R2 represents an optionally substituted cycloalkyl group; R3 represents a hydrogen atom, a halogen atom, an optionally substituted alkyl, alkoxy or alkylthio group, an optionally protected hydroxyl or amino group, or a nitro group; R4 represents an optionally substituted alkyl or alkoxy group; and Z represents a pyridin-4-yl or pyridin-3-yl group which is optionally substituted with at least one group selected from a halogen atom, an optionally substituted alkyl, alkenyl, cycloalkyl, alkoxy, alkylthio or amino group and an optionally protected hydroxyl or amino group).