Objective To analyze the key quality indices of BCG for intradermal injection (BCG), in order to provide some basis for process control.
Methods The key quality indices such as BCG passage, sedimentation rate of final bulk, culturable particle count of final bulk, efficacy of final product and osmolarity of final product of 211 batches of BCG were statistically analyzed, and the correlation between key indices was found using statistical softwares (Minitab 17 and SPSSAU).
Results The average culturable particle counts of final product produced by the 6th, 9th and 12th passage BCGs were 5.07×10
6, 5.49×10
6 and 6.02×10
6 colony-forming unit (CFU)/mg, respectively, the Pearson correlation coefficient was 0.200 (
P<0.05). The culturable particle count of final product increased slightly with the increase of BCG passage. The average culturable particle counts of final product for the final bulk sedimentation rates at (0.00-7.99) %, (8.00-11.99) % and (12.00-20.00) % were 5.57×10
6, 5.52×10
6 and 5.06×10
6 CFU/mg, respectively, the Pearson correlation coefficient was -0.182 (
P<0.05). The culturable particle count of final product decreased slightly with the increase of sedimentation rate of final bulk. The average culturable particle counts of final product for the final bulk culturable particle counts at (1.00-1.99)×10
7, (2.00-2.99)×10
7 and (3.00-4.00)×10
7 CFU/mg were 4.61×10
6, 5.69×10
6 and 6.53×10
6 CFU/mg, respectively, the Pearson correlation coefficient was 0.537 (
P<0.05). The culturable particle count of final product significant increased with the increase of the culturable particle count of final bulk. The average efficacy of final product for the final product culturable particle counts at (1.00-3.99)×10
6, (4.00-5.99)×10
6 and (6.00-8.00)×10
6 CFU/mg were 17.61, 16.51 and 16.55 mm, respectively, the Pearson correlation coefficient was -0.187 (
P<0.05). The efficacy of final product decreased at first and then stabilized with the increase of the culturable particle count of final product. The average osmolarity of final product for the final product culturable particle counts at (1.00-3.99)×10
6, (4.00-5.99)×10
6 and (6.00-8.00)×10
6 CFU/mg were 363.61, 363.21 and 368.68 mOsmol/kg, respectively, the Pearson correlation coefficient was 0.210 (
P<0.05). The osmolarity of final product increased slightly with the increase of the culturable particle count of final product. Conclusions At the enterprise standard level, culturable particle count of final product is significantly affected by culturable particle count of final bulk, and slightly affected by BCG passage, sedimentation rate of final bulk. Also, culturable particle count of final product has small effect on the efficacy of final product and the osmolarity of final product.