Table I.

Diffusion Coefficients for Insulin Drug Products Obtained Using DOSY-NMR

Drug product	Drug substance	Lot no.	DOSY diffusion coefficienta (10−6 cm2/s)
Apidra®	Analogue Glulisine B3 N→K B29 K→E	1 2 3	1.14 1.18 1.14
Humalog®	Analogue Lispro B28 P→K B29 K→P	1 2 3	1.08 1.17 1.06
Humulin R®	Insulin regular	1	0.99
		2	1.02
		3	1.10
Novolin R®	Insulin regular	1	1.07
		2	1.07
		3	1.07
Novolog®	Analogue Aspart B28 P→D	1 2	1.21 1.17
		3	1.17

^aThe averaged DOSY diffusion coefficient from all 15 lots of insulin was 1.11 × 10−6 cm2 /s and the RSD was 6%