TABLE 2

Physicochemical properties of HCQ and lysosomal properties

Drug ConstantsSymbolValueReference
Molecular weightMol. wt.335.872
LipophilicityLog10 (Kow)3.84Warhurst et al. (2003)
First dissociation constantpKa19.67
Second dissociation constantpKa28.27
Lysosomal parameters
 Lysosomal lipid fractionL0.05Trapp et al. (2008)
 Lysosomal water fractionW0.95Trapp et al. (2008)
 Neutral activity coefficientγN1.23Trapp et al. (2008)
 First activity coefficientγ10.74Trapp et al. (2008)
 Second activity coefficientγ20.3Trapp et al. (2008)
 Lysosomal radiusrlys (μm)0.275Kawashima et al. (1998)
 Lysosomal buffering capacityβ (mM)46Ishizaki et al. (2000)
 Lysosomal pHpHlys5.0Trapp et al. (2008)
 Cytosolic pHpHcyt7.2Trapp et al. (2008)
Lysosome contenta
 Kidney% Tissue volume0.05
 Heart0.1
 Eye0.015
 Skin0.1
 Gut0.1
 Liver0.05
 Slowly perfused0.1
 Rapidly perfused0.2
  • a Starting values from Sewell et al. (1986) and Kawashima et al. (1998). Final values determined from acid phosphatase and optimization.