Lactose, and Gluten, and Gelatin – Oh My!

Medications are composed of more than just the active pharmaceutical drug.  Excipients, also known as inactive ingredients, are also present in pharmaceutical products.  Excipients are needed for bioavailability, stability and palatability of the pharmaceutical product.   Excipients can act as colouring agents, fillers, solvents, preservatives and sweeteners.  Although they are sometimes referred to as “inert” ingredients, case studies have shown that excipients may be the cause of adverse drug reactions, and not the active drug itself.  For example, some patients have experienced a rash after taking penicillin, and so, consider themselves to be allergic to penicillin.  However, their skin reaction may actually be in response to an excipient, and not penicillin.

Excipients can be problematic for a number of patient populations, such as those with lactose intolerance, patients living with celiac disease, and those with dietary restrictions.  Patients sensitive to certain excipients must be careful when taking medications because excipients are present in nearly all medications, whether it is a prescription medication or one available over-the-counter.

Lactose is an ingredient that is both palatable and water-soluble, and thus is commonly used as a filler ingredient and bulking agent, and may be sprayed for a shiny and smooth appearance on tablets.  When ingested, lactose is broken down by lactase enzymes of the small intestine.  The presence of lactose in medications can be challenging for patients with lactose-intolerance.  Lactose intolerance results from decreased activity or lack of the lactase enzyme in the gastrointestinal tract.  Symptoms such as bloating and diarrhea may result from undigested lactose entering the colon.  The amount of lactose used in medications is miniscule compared to the amount in standard portions of dairy products, but may still be a concern for those who are severely lactose intolerant.

Autoimmune destruction of the small intestine villi occurs in response to gluten in patients with celiac disease.  Gluten can be found in wheat, rye and barley.  Patients with celiac disease require a strict gluten-free diet, including medications.  Gluten-containing ingredients are not always easily discerned by just reading a label.  Drug excipients such as starches, dextrates, alcohols and caramel colouring may contain gluten.

Gelatin is a drug excipient that is commonly used, and may be derived from porcine or bovine animal sources.  The source of the gelatin in medications may be a concern for patients with dietary restrictions due to religious beliefs, and such patients may not be compliant with their treatments if they are unsure whether the gelatin present in their medication comes from an acceptable source.

There are solutions available to ensure that patients with concerns such as those above are receiving safe and acceptable therapy.  If not all the ingredients are listed on the prescription or over-the-counter medication label, consult your pharmacist as they can provide you a complete list of ingredients.  If you are unsure whether an exotic-sounding ingredient is a concern, ask your pharmacist, because it is not always obvious.  For example, the ingredient “sodium starch glycolate” may contain gluten, depending on where it’s sourced from.

If you need to take a medication but are sensitive or intolerant to one or more of the excipients and there is no alternate formulation available on the market, your Compounding Pharmacist can devise a custom-made compounded medication for you excluding the ingredients of concern, or replacing them with another.

Our Compounding Pharmacy Team at Custom Care Pharmacy & Compounding Centre has the expertise to develop custom compounded medications tailored to your needs.  Creating a custom compound for those with lactose intolerance, gluten sensitivity or dietary restrictions is not simply a straightforward exclusion or switching of ingredients.  The Compounding Pharmacist has the specialized knowledge to know which ingredients are compatible, and how to maintain pharmaceutical stability and efficacy. 

Custom Care Pharmacy & Compounding Centre is conveniently located in North Oshawa on the southeast corner of Ritson Road and Coldstream Drive.  We also serve patients from across the Greater Toronto Area.  Let us meet your compounding needs and show you why physicians and patients alike consider us to be the best compounding pharmacy!


  1. Excipient-related adverse drug reactions: a clinical approach. Strauss J, Greef OBW. Current Allergy & Clinical Immunology. 2015;28(1):24-7.

  2. Pharmacist’s role in managing special patient needs related to excipients. Snyder L, Hoffman T, Shields K. The Ampul Spring 2009.