Unbound drug concentrations in plasma (dotted) and brain ISF (solid, calculated from recovery and dialysate concentration) following repeated subcutaneous administration in rats, every 2 hours. Unbound drug concentrations in plasma (dotted) and brain ISF (solid, calculated from recovery and dialysate concentration) following repeated subcutaneous administration in rats, every 2 hours. Data are mean ± S.D., n = 3. For quinidine and desmethylclozapine, dialysate concentrations were measurable in only one of the three rats and therefore the S.D. values were not reported and brain:plasma ratios were not calculated. Matthew R. Durk et al. Drug Metab Dispos 2018;46:964-969 Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics