Different Manufacturers Of Generic Drugs

In our latest question and answer, the pharmacist discusses the difference between the various generic products produced by different manufactures.

Dec 28, 2017

Gma Sal asked

I took amitriptyline in an uncoated 25mg pill for neuropathy without any problems for a dozen years. Last year my insurance changed and the new drug provided is a brown coated pill of 25mg amitriptyline that causes me all kinds of side effects. My question: is it possible to find the uncoated pill again? Thanks


Most generic drugs are manufactured by multiple manufacturers and often contain different inactive ingredients.

In your question, you mention amitriptyline. Amitriptyline has no less than 6 manufacturers that make the drug. These manufacturers include:

  • Accord
  • Blenheim
  • Major
  • Mylan
  • Northstar
  • Par
  • Sandoz
Differences Among Generic Products

All of the generic products are approved by the FDA. They must contain the same amount of active ingredient when compared to the brand name drug and the other generics. The medication must also be tested to show that is has the same "bioavailability" as the other products. This means that all versions of the product must be tested to have the same rate and extent of absorption in the body.

What is different about each product is that they can contain different inactive ingredients, or fillers and this appears to be your problem. Even though the different generic products will contain the same amount of active ingredient, there are times where the inactive ingredients can cause problems for individuals. It is uncommon, but certainly not unheard of. There is always the possibility of the following:

  • You may have a sensitivity to certain ingredients (e.g. dyes or fillers like lactose).
  • Different genetics and body chemistry could result in differences in how medications are absorbed.
  • Different genetics and body chemistry could result in differences in how medications are metabolized and eliminated from the body.

Pharmacists will often say that different generic products are the same and that there is no difference between them. This obviously is not the case as the vast majority of generic products made by different manufactures look different! This is due to the different inactive ingredients used. They are simply referring to the active ingredient being the same. 

To reiterate this point, below is the ingredient list for two different amitriptyline products:

Amitriptyline 25 Mg - Mylan

  • Corn Starch
  • FD&C Blue No. 1
  • FD&C Yellow No. 10
  • FD&C Yellow No. 6
  • Hydroxypropyl Cellulose
  • Hypromellose
  • Magnesium Stearate
  • Microcrystalline Cellulose
  • Polyethylene Glycol
  • Silicon Dioxide (Colloidal)
  • Sodium Lauryl Sulfate
  • Sodium Starch Glycolate

Amitriptyline 25 Mg - Accord

  • Croscarmellose Sodium
  • Ferric Oxide Lactose
  • Lecithin
  • Magnesium Stearate
  • Microcrystalline Cellulose
  • Polyvinyl Alcohol
  • Silica Talc
  • Titanium Dioxide
  • Xanthan Gum

As you can see, there are some significant differences in the two products, notably the dyes used. These could certainly cause differences in how you tolerate the medication.

If you are having problems with a substituted generic product, ask your pharmacy if they can continue to order your old product. It would be very uncommon for your insurance to have a preference for one generic over another, but it could happen (more commonly with government funded insurances like Medicaid). More likely, the pharmacy has simply substituted your product due to supply issues, pricing issues etc...

At the very least, ask who manufactured your prior product. Once you have that information, you can look into other pharmacies that can get that product for you.

Ready for a more personal experience with your meds?