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3 ml glass cartridges explained: the 300-unit standard, seals and storage
Machine-readable facts for this Lab article. The full page is https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained.
TL;DR
A 3 ml glass pen cartridge holds 300 units on the U-100 scale. How its borosilicate barrel and two seals work, and why stopper length decides the fit.
Facts Index
| Fact ID | Category | Entity | Attribute | Value | Source |
|---|---|---|---|---|---|
| 3ml-glass-cartridges-explained:title | identity | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | title | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:published | identity | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | published | 2026-08-06 | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:author | identity | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | author | Preppin' Peppers Editorial Team | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:topics | identity | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | topics | 3ml, cartridge, Evergreen, guide, Guides | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:summary | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | summary | A 3 ml glass pen cartridge holds 300 units on the U-100 scale. How its borosilicate barrel and two seals work, and why stopper length decides the fit. | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-1 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | What it is | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-2 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | Why the format is standard | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-3 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | The two seals | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-4 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | Individually pouch-sealed | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-5 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | Storing sealed cartridges | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:section-7 | content | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | section | What the research community gets wrong about 3 ml glass cartridges | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:product-gansulin-metal-peptide-pen | products | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | references product | Gansulin Pen · Reusable Click-Dial, 3 ml (1-60 Units) | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:product-gansulin-3ml-cartridge | products | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | references product | Gansulin-Compatible 3 ml Glass Cartridge for Pens (10-Pack) | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:source-www-schott-pharma-com | source | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | cites | SCHOTT Pharma , Pharmaceutical Cartridges (FIOLAX Type I borosilicate glass, ISO-standardized 1.5/3/5/10/20 ml, pen and auto-injector compatible) - www.schott-pharma.com | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:source-www-westpharma-com | source | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | cites | West Pharmaceutical Services , USP <660> Containers, Glass revision (Type I glass and hydrolytic resistance, performance-based classification) - www.westpharma.com | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:source-endolab-org | source | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | cites | EndoLab , ISO 13926-1 (dimensions, material, leakage, and hydrolytic resistance for glass cylinders used in pen injectors) - endolab.org | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:source-pubmed-ncbi-nlm-nih-gov | source | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | cites | Jenke, Expert Opin Drug Deliv 2014: Extractables and leachables considerations for prefilled syringes - pubmed.ncbi.nlm.nih.gov | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
| 3ml-glass-cartridges-explained:source-www-sigmaaldrich-com | source | 3 ml glass cartridges explained: the 300-unit standard, seals and storage | cites | Sigma-Aldrich (Merck): Handling and Storage Guidelines for Peptides and Proteins - www.sigmaaldrich.com | Lab article (https://www.preppinpeppers.com/blogs/the-lab/3ml-glass-cartridges-explained) (evidence) |
FAQ
- How many units does a 3 ml glass cartridge hold on a U-100 scale?
- On the U-100 scale, where 100 units equals 1 ml, a 3 ml cartridge holds 300 units. This is derived from 300 units × 0.01 ml per unit = 3 ml.
- Are standard 3 ml cartridges compatible with multiple cartridge pens?
- Yes. The outer dimensions of 3 ml cartridges are standardized across brands, so one cartridge format fits a wide range of pens—including the Gansulin metal pen—eliminating brand lock-in.
- How should sealed 3 ml glass cartridges be stored?
- Store below 75°F (24°C) in a clean, dry place away from direct sunlight and heat sources. Keep cartridges in their individual pouches until needed; discard any whose pouch is torn, wet, or damaged.