. 2020 Jan 16;10:458. doi: 10.1038/s41598-019-56872-3

Table 3.

Pulmonary dissolution rates and associated half-times for BaSO₄ derived from acute and repeated rat exposure studies.

Exposure duration	Particle type and method of delivery	Total Retention t_1/2 (d)	$b_{t o t}$ (d⁻¹)	Dissolution Retention t_1/2 (d)	$b_{d i s s}$ (d⁻¹)
---- ⁽³⁾	¹³¹BaSO₄ NM-220 intratracheal instillation	9.6	7.23%	11.1	6.23%
90 days ⁽⁴⁾	BaSO₄ NM-220 nose-only inhalation	56	1.24%	289	0.24%
2 years ⁽⁵⁾	BaSO₄ NM-220 head-nose inhalation	45*	1.54%	128	0.54%

Exposure duration

Particle type and
method of delivery

Total Retention t_1/2 (d)

b_{t o t}

(d⁻¹)

Dissolution Retention t_1/2 (d)

b_{d i s s}

(d⁻¹)

---- ⁽³⁾

¹³¹BaSO₄ NM-220

intratracheal instillation

9.6

7.23%

11.1

6.23%

90 days ⁽⁴⁾

BaSO₄ NM-220

nose-only inhalation

1.24%

289

0.24%

2 years ⁽⁵⁾

BaSO₄ NM-220

head-nose inhalation

45*

1.54%

128

0.54%

^*At steady-state.