Barium sulphate X=ray contrast agent suspensions - with defined properties produced from barium sulphate with defined parameters such as bulk density and particle size

摘要

New use of barium sulphate is in the prodn. of X-ray contrast agent suspensions consisting essentially exclusively of barium sulphate. The barium sulphate dry substance has a bulk density of =1.20g/ml. (DIM 53912); a specific surface of =5.00m2/g. (DIN 66132); a density of =4.00g/ml. (DIN 51057); an ignition residue of is not 6.00g% (DIN 51070/9); and particle sizes of 400-1500 angstroms (DIN 51033). The aq. suspension has a viscosity of is not 15cP (DIN 51550/53788); a surface tension has of 35-55 dyn/cm (DIN 53914); an interface tension w.r.t. gastric juice of is not 10dyn/cm; and a pH of 7-8 (DIN 19261/19266). The suspensions combine max. absorption of radiation with minimal viscosity, and their surface tension corresponds closely to that of gastric juice, so that they penetrate deeply into the folds of mucous membranes. Because the desirable properties of the suspensions are defined by specific parameters, X-ray contrast agents for gastrointestinal use can be obtd. with reproducible properties. The suspensions are produced by mixing dry substance consisting of polydisperse aggregation of different forms and sizes, pref. by a combined stirring and grinding process.