Abstract: A liver-targeting active compound has the general formula (I):- wherein A is &agr;-OH or &bgr;-OH, B is &agr;-H or &bgr;-H, C is —H, &agr;-OH or &bgr;-OH, or B and C together form a double bond, D is —H, &agr;-OH or &bgr;-OH, E is —H, &agr;-OH or &bgr;-OH, —G-is a side chain moiety, —NH—J is selected from (i) a residue of an amino group-containing active compound wherein said —NH— group is provided by said amino group of the active compound, and (ii) a residue of an active compound to which an amino group has been added wherein said —NH— group is provided by said added amino group; each of X and Y independently represents a single bond, —(CH2)z— (where z is 1 to 8), —O— or —S—; n is 0 or 1; m is 0 or 1; and p is 0 or 1; provided that, when —NH—J is (i), m is 1. A method of producing such as compound is also disclosed.

Abstract: A method for the determination of liver function, comprises the steps of:(i)introducing an effective amount of a coloured or fluorescent bile acid derivative intravenously into a patient,(ii)collecting samples of blood which has passed through the liver of the patient at timed intervals after step (i), and(iii)assessing the colour or fluorescence of bile acid derivative in each sample.