Available Dosage Forms of Insulin

Insulin is available in multiple dosage forms including vials, prefilled pens, cartridges for reusable pens, and inhalation powder. 1

Injectable Formulations

Multi-dose vials containing 10 mL of U-100 insulin (1,000 units total) are available for most insulin types 2, 3
U-500 concentrated insulin is available in both vials and prefilled pens to accommodate patients requiring large doses 1
Vials require separate insulin syringes for administration, with common syringe sizes of 1 mL, 0.5 mL, and 0.3 mL allowing doses up to 100,50, and 30 units respectively 1

Standard prefilled pens contain 3 mL of U-100 insulin (300 units total) and are discarded after the insulin is depleted 4, 3
Available for rapid-acting insulins (lispro, aspart, glulisine), long-acting insulins (glargine, detemir, degludec), and premixed formulations 1
Concentrated formulations include U-200 (lispro, degludec) and U-300 (glargine) prefilled pens, which deliver higher doses per volume injected 1
Prefilled pens are preferred for patients with vision impairment or dexterity issues as they facilitate accurate dosing 1

3 mL cartridges (PenFill) containing 300 units of U-100 insulin are designed for use with compatible reusable pen devices 3
The cartridge is replaced when empty, while the pen device itself is reused 1

Inhaled insulin is available as inhalation cartridges for prandial (mealtime) use with a limited dosing range 1
This formulation has rapid pharmacokinetics similar to injectable rapid-acting insulin analogs 1, 5
Contraindicated in patients with chronic lung disease (asthma, COPD) and requires spirometry testing before initiation 1

U-100 (100 units/mL) is the standard concentration for most insulin products 1, 4
U-200 formulations (lispro, degludec) contain twice the concentration, allowing higher doses with less injection volume 1
U-300 glargine is three times as concentrated as U-100, with a longer duration of action 1
U-500 regular insulin has distinct pharmacokinetics with characteristics similar to premixed NPH/regular insulin, typically administered 2-3 times daily 1

Fixed-ratio combination pens containing basal insulin plus GLP-1 receptor agonist are available (insulin glargine/lixisenatide and insulin degludec/liraglutide) 1
Premixed insulin formulations combine rapid-acting and intermediate-acting components in single prefilled pens or vials (e.g., aspart 70/30, lispro 75/25, lispro 50/50) 1, 6

Insulin pens and vials deliver insulin equally effectively; choice depends on patient preference, cost, insulin type availability, and self-management capabilities 1
Connected "smart" insulin pens can transmit dose data and provide dosing recommendations 1
Some insulin types are only available in specific dosage forms (pen-only or vial-only), which may impact prescribing decisions 1