Reproducibility of GMP-compliant production of therapeutic stressed peripheral blood mononuclear cell-derived secretomes, a novel class of biological medicinal products

Table 7 Physicochemical properties of PBMC^sec 1 and 2 after 3 months of storage at various temperatures

Test	− 20 °C	+ 5 °C	+ 25 °C	+ 40 °C
Appearance of lyophilisate	White, no color deviations or discolorations, amorphous, homogenous	White, no color deviations or discolorations, amorphous, homogenous	White, no color deviations or discolorations, amorphous, homogenous	Orange, stained in different shades of orange, several small red spots, amorphous, not homogenous
Dissolution time	53.5 ± 1.5 s	50 ± 5 s	51 ± 8 s	Could not be completely dissolved within 15 min
Color of reconstituted solution	Equivalent to reference solution GY5	Equivalent to reference solution GY5	Equivalent to reference solution GY5	Not equivalent to any of the reference solutions GY1–GY7, color was estimated to be in the range of dark orange
Clarity and degree of opalescence	Clear, equivalent to reference suspension 1 (3 NTU)	Clear, equivalent to reference suspension 1 (3 NTU)	Clear, less than reference suspension 1 (3 NTU)	Between reference suspension 2 (6 NTU) and reference suspension 4 (30 NTU)
Water content	2.65 ± 0.15%	3.1 ± 0.1%	3.7 ± 0.2%	6.15 ± 0.25%⁽¹⁾
pH	8.01 ± 0.51	8.7 ± 0	8.85 ± 0.05	7.95 ± 0.55⁽¹⁾
Osmolality	1.4 ± 0 osmol/kg	1.4 ± 0 osmol/kg	1.4 ± 0 osmol/kg	1.3 ± 0 osmol/kg⁽¹⁾
Visible particles	0 against white background, 0 against black background	0 against white background, 0 against black background	0 against white background, 0 against black background	Visible particles could not be evaluated due to large residues of undissolved sample material

⁽¹⁾As the samples could not be dissolved completely, the validity of these results is compromised

ISSN: 1757-6512