RESUMEN
Gadolinium-based contrast agents (GBCAs) are widely used in magnetic resonance imaging. Recently, a large amount of evidence indicates that change of magnetic resonance signal in deep brain nuclei is related to repeated injection of GBCAs. Especially in the dentatum and pallidum the gadolinium deposition is most obvious. This paper reviews the research status and policy progress of brain deposition of GBCAs, and introduces the relationship between gadolinium deposition in the brain and the type of GBCAs.
RESUMEN
Using the weight-average molecular weight 50 000 polylactic acid (PLA) as a carrier, and a certain proportion of erythromycin (EM) and prednisone acetate (PNA) to mixed prepare the compound erythromycin sustained release preparation (sustained-release tablets). Using ultraviolet spectrophotometry and high performance liquid chromatography (HPLC) to detect separately the release amount of EM and PNA in vitro medium. The sustained-release tablets release for about 21 days, the average content of EM is 99.7 mg/table, RSD = 0.82%; and the average content of PNA is 10.03 mg/table, RSD = 0.93%. Within 21 days, the cumulative releases of EM and PNA are 86.1% and 78.3%, respectively. The drug release is steady and slow after 5 days, the burst release phenomenon in early stage is more significant. The results showed that the sustained-release tablet preparation method is feasible, the release performance is good and the clinical efficacy is significant.