. 2020 Oct 22;8(6):e00668. doi: 10.1002/prp2.668

Table 1.

Benzathine penicillin G (BPG) content, melting point, and particle size analysis of commercial BPG injection powder sourced from international clinical settings

Code	Number of Vials Tested	BPG content (%) ^a (Mean ± SD)	Melting Point ^b (°C)	Specific surface area (m²/g)	Average particle size; D50 ^c (µm)	D10‐D90 ^c (µm)
1	3	106.1 ± 0.7	126	0.94	15	3‐48
2	6	98.4 ± 2.5	124	0.55	33	5‐86
3	3	97.5 ± 0.4	124	0.48	23	6‐71
4	1	105.6	129	0.45	25	6‐90
5	3	106.4 ± 3.3	125	0.39	32	8‐89
6	3	105.8 ± 1.8	131	0.51	22	6‐62
7	6	107.0 ± 1.4	129	0.52	37	5‐95
8	6	106.6 ± 2.7	129	0.54	22	6‐63
9	6	106.3 ± 2.6	133	0.45	27	7‐71
10	3	99.0 ± 1.3	124	1.33	8	2‐34
11	6	97.2 ± 1.6	123	0.37	33	11‐91
12	3	104.6 ± 2.4	127	0.39	30	8‐90
13	1	105.3	128	0.37	33	8‐99
14	3	106.9 ± 2.1	128	0.55	20	6‐55
15	3	106.8 ± 1.8	126	0.94	18	3‐50
16	3	106.1 ± 0.8	132	1.07	18	2‐59
17	3	103.4 ± 2.5	132	0.92	11	3‐34
18	3	98.3 ± 1.1	124	1.11	10	3‐34
19	3	98.1 ± 0.4	124	1.03	11	3‐35
20	6	98.0 ± 1.0	126	1.01	11	3‐36
21	6	91.5 ± 1.1	127
22	6	97.3 ± 1.2	126
23	3	100.2 ± 0.4	126
24	3	101.9 ± 2.4	128
25	3	101.9 ± 2.4	127
26 ^d	3	98.5 ± 1.0	127
27 ^d	3	99.9 ± 3.4	128
28	6	102.7 ± 5.0	127
29	1	100.8	128
30	6	108.1 ± 7.4	126
31	6	98.5 ± 0.9	124
32	1	102.6	127
33	1	101.4	129
34	1	101.6	128
35 ^e	6	95.8 ± 5.1 ^e	126

^{^a}

Pharmacopeial requirements are 90%‐115% BPG content for the injectable suspension in the United States Pharmacopeia and 94.5%‐102% for the active pharmaceutical ingredient (API) in the British Pharmacopoeia. The BPG content in the powder for injection is expressed as percent of the nominal amount, based on the penicillin G concentration and a confirmed 2:1 ratio with benzathine, and should be considered in the context of the assay coefficient of variation (SD/mean) for the measured analyte (penicillin G) being 2.5% and potential systematic errors associated with aliquot measurements.

^{^b}

Reference range of the API is 123‐124° (The Merck Index). Melting point was determined on the BPG powder for injection.

^{^c}

D50 is the 50% point of the particle size distribution and represents the median diameter of the particles in the suspension. D10 and D90 are the 10% and 90% points of the distribution and are used to represent the range of the particle size distribution.

^{^d}

Samples 26 and 27 were the same batch sourced from two different countries

^{^e}

Sample 35 was analyzed three months after the stated expiry date