Medication Excipients
Most modern drugs that are manufactured and many that are made by compounding pharmacies include other ingredients that enhance or protect the medication. These excipients are non-active ingredients that act as enhancers, stabilizers, or fillers to help make the medication more effective. They sometimes are used to keep medication stable through shipping, storage, and handling. In most cases inactive ingredients are harmless and do not produce any reaction, however some patients can have intolerances or allergies to certain excipients. A compounding pharmacy can provide formulations that are free of many excipients that are found in manufactured drugs.
Types of Excipients
Fillers: When a drug is made into a capsule, it usually will not take up the entire space inside. A filler is used to make sure the entire capsule is filled. This is especially helpful when a drug is measured in very small units like micrograms.
Binders: Ingredients are often added to tablets to help the material stay bound together. Binders help make it possible for drugs to be manufactured in tablets. Many manufactured drugs are made into tablets. A compounding pharmacy can sometimes provide a drug like this in capsules with only one filler. This reduces the number of excipients by eliminating the need for a binder.
Flavors: Flavors are added to medications because active drug ingredients on their own are often unpalatable. For example, in topical anesthetic gels we make for dentists we usually flavor the medication with a mint, strawberry, or grape flavor. In some situations, a sweetener added to mask the taste of a drug can have negative effects on a person who is sensitive to it.
Dyes: The color of a drug can affect how palatable it looks. It can also give some clue as to the flavor of the medication. If a drug is white but tastes orange, there are no clues beforehand as to how it tastes. A drug may be dyed orange to match its orange flavor or green to match its mint flavor. Certain dyes like FD&C yellow #5 are known to cause reactions in some patients. Dyes are not essential to a drug’s effectiveness, so patients sometimes will request a compounded medication that is free of dyes.
Excipients are not added to drugs to cause harm. They are simply added to improve the effectiveness of the medication or to make it easier to take. In many cases a flavor or coloring is added to improve compliance with a medication that needs to be taken regularly. While the majority of patients may never experience a negative side effect that can be related to an excipient, there are still a significant number of individuals that may have intolerances or allergies.
Ingredient Intolerance vs. Allergy
There is an important difference between sensitivity to an ingredient and an allergy. Allergies to an inactive ingredient can result in serious side effects that range from hives to difficulty breathing. They are caused by an adverse immune response to an ingredient. Intolerance to an ingredient usually results in symptoms like upset stomach, feelings of being sick or nauseous, and headaches. An intolerance is a negative side effect that is not associated with the immune response. It is not always possible to tell beforehand whether or not an excipient will be tolerated. An allergy can be tested and confirmed before a prescription is given.
Even though you can not always test for intolerances, they should still be considered in how a medication is made. Patients with chronic illnesses often report sensitivities to ingredients that may produce no effects in the general population. The drug cholestyramine for example is made commercially with fillers and sweeteners. Patients who have certain biotoxin illnesses are more sensitive to these added ingredients. Pure cholestyramine resin without sweeteners or additives is only available from a compounding pharmacy.
Another example of a compounded drug that removes excipients is desiccated thyroid medication. Some commercially available thyroid medications contain numerous fillers and binders. Since thyroid medications are taken daily, often for a patient’s entire life, it is important to have a medication that causes the least amount of side effects. Our compounding pharmacy can make desiccated thyroid in capsules with only one filler – significantly reducing the chance of intolerance to excipients for many individuals.
FDA Standards
The FDA regulates what excipients can be used when a medication is submitted for a new drug approval. The manufacturing process must meet high standards and the excipient must be safe in the doses that will be prescribed. It would be difficult to test all the possible interactions that can occur between inactive ingredients in different drugs, in every type of patient. Therefore, even though excipients are supposed to be “inactive” and have no effects – they often do produce side effects.
Some examples of excipients that commonly cause side effects include:
Aspartame – Used as a sweetener, aspartame must be avoided in patients with phenylketonuria.
Lactose – Patients with syndromes that involve the metabolization of lactose may experience negative side effects if given a drug with this filler.
Tartrazine (Yellow #5) – Tartrazine is a dye used in drugs and food products that may cause hyperactivity in children.
Benefits vs. Risks
When considering whether to prescribe a drug, healthcare professionals try to determine whether the benefits outweigh the risk of side effects. In some cases an intolerance that is not too severe may be considered “acceptable” if the benefits of taking the drug are significant. There are many options available from a compounding pharmacy to get the same drug but reduce the number of excipients. Our pharmacists frequently work with doctors and patients to help get them treatments that are optimized to their unique needs.