Insulin Glargine 300

Chemical Identity

Property	Value
Chemical Formula	C267H404N72O78S6
Molecular Weight	6063 Da
CAS Number	160337-95-1
Peptide Class	Insulin Analog (Concentrated)
Concentration	300 units/mL

Structure

Insulin glargine 300 (Toujeo) contains the same insulin glargine molecule as Lantus but at 300 units/mL concentration (versus 100 units/mL). The higher concentration creates a smaller, more compact subcutaneous depot with slower, more constant insulin absorption.

Mechanism of Action

Standard insulin glargine mechanism: binds insulin receptor for glucose uptake and hepatic glucose suppression. The concentrated formulation forms a smaller subcutaneous depot with slower dissolution, providing more stable pharmacokinetics and longer effective duration of action.

Clinical Applications

• Type 1 diabetes: Basal insulin with less hypoglycemia (EDITION trials)
• Type 2 diabetes: Basal insulin with improved tolerability
• Elderly patients: Lower nocturnal hypoglycemia risk
• Patients with hypoglycemia unawareness: More stable glucose profile

Pharmacokinetics

• Half-life: 18-19 hours (effective 30-36 hours)
• Tmax: 12-16 hours (flatter than glargine 100)
• Duration: 30-36 hours
• Variability: 25% less glucose-lowering variability vs glargine 100
• Route: SC injection

Safety and Side Effects

Hypoglycemia (lower nocturnal rates than glargine 100), weight gain, injection site reactions, and lipodystrophy. Higher volume injection required for equivalent dosing.

References

• Riddle, M.C., et al. (2014). EDITION 1: insulin glargine 300 vs 100 for type 2 diabetes. Lancet Diabetes & Endocrinology, 2, 682-689.
• Bolli, G.B., et al. (2015). EDITION 2: glargine 300 in type 2 diabetes. Diabetes, Obesity and Metabolism, 17, 589-596.