That was my thought as well. (the old design thing.)
The “old” design of the epi pen is obsolete.
These injectors are driven by springs and plastic parts.
Older designs had springs that did not always deliver the required force to make the plunger move inside the syringe cartridge inside the injector.
Auto-injectors function because the spring energy expels the contents of the syringe into the body.
The FDA has imposed tighter and tighter regulations on “combination” products that combine an injectable product with a device that allows delivery of the drug.
These combination rules require the creation and maintenance of “Device Design and History Controls” that provide documented evidence of validation for the product.
I have been in Pharma for almost 40 years and regulations just get harder and harder to achieve. The amount of $$$ that we in Pharma spend to meet FDA and other world regulatory rules is often prohibitive. If a company cannot absorb the cost, the pass it on in the piece price of the unit.
Finally, the reimbursement schedules for devices is another regulatory maze that prohibits competition as most companies will stop making the product instead of putting millions of $ into an old product.
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G