Table 2. Concentration Values of DOX⁺, DOX⁰, DOX^–, and DOX^2– Calculated for Experimental Conditions (pH 7.6 and 6.3) for 25, 37, and 50 °C.

cell line	pH	pK1	pK2	pK3	total DOX [μM]	DOX+ [μM]	DOX0 [μM]	DOX– [μM]	DOX2–	[%] DOX+	[%] DOX0
HeLa 50 °C	7.6	7.530	9.430	1030	5	2.18	2.78	4.4 × 10–2	1,8 × 10–4	43.6	55.5
	6.3				5	4.70	0.30	2.4 × 10–4	4.8 × 10–8	94.0	6.0
A498 50 °C	7.6				25	10.9	13.9	2.2 × 10–1	8.8 × 10–4	43.6	55.5
	6.3				25	23.5	1,50	1.2 × 10–1	2.5 × 10–7	94.0	6.0
HeLa 25 °C	7.6	7.8431	9.534	10.133	5	3.16–4.08	0.91–1.82	1.2 × 10–2–2.3 × 10–2	3.4 × 10–5–7.2 × 10–5	63.2–81.5	18.3–36.4
	6.3	8.232	1030		5	4.86–4.94	0.14–0.055	3.5 × 10–5–8.8 × 10–5	5.5 × 10–9–1.4 × 10–8	97.2–98.9	1.11–2.80
A498 25 °C	7.6	8.2533	10.231		25	15.8–20.0	4.56–9.09	5.7 × 10–2–1.1 × 10–1	1.8 × 10–4–3.6 × 10–4	63.2–81.5	18.3–36.4
	6.3				25	24.3–24.7	0.27–0.70	1.8 × 10–4–4.4 × 10–4	2.8 × 10–8–7.0 × 10–8	97.2–98.9	1.11–2.80
HeLa 37 °C	7.6	7.8a	9.65a	10.05a	5	3.05	1.93	1.7 × 10–2	6.2 × 10–5	61.0	39.0
	6.3				5	4.85	0.15	6.9 × 10–5	1.2 × 10–8	96.9	3.08
A498 37 °C	7.6				25	15.2	9.67	8.7 × 10–2	3.1 × 10–4	61.0	39.0
	6.3				25	24.2	0.77	3.5 × 10–4	6.2 × 10–8	96.9	3.08

^aBased on eq 12, the mean values of reported pK₁ and pK₂ at 25 °C were taken to calculate the values at 37 °C.