Валсподар

PSC 833 is a non-immunosuppressant derivative of cyclosporine and potent multidrug-resistance (MDR) modulator. It restores sensitivity of MDR-P388 murine leukemia cells to cytostatic agents when used at concentrations of 70, 33, 45, 34, and 26 nM in combination with colchicine, vincristine , daunorubicin , doxorubicin , and etoposide , respectively. PSC 833 inhibits basal-to-apical transport and increases apical-to-basal transport of [¹⁴C]docetaxel in LLC-GA5-COLO150 cells that overexpress human P-glycoprotein (P-gp). In vivo, PSC 833 increases survival time in MDR-P388 tumor-bearing mice and in an MDR-L1210 leukemia mouse xenograft model when administered in combination with doxorubicin. PSC 833 also prolongs the anti-hyperalgesic effects of intraperitoneally administered pregabalin in a mouse model of cold stress-induced central pain.

White Solid

Valspodar/ PSC-833 has been used as a ABCB1 (P-glycoprotein) inhibitor.

Cells treated with increasing concentrations of valspodar over a 9-day period show minimal cytotoxicity. It appears to be neither immunosuppressive nor nephrotoxic with the ability to achieve levels in the blood (1 μm) capable of reversing drug resistance without excessive toxicity[1].