It’s one of the things that show up on the ingredients list of some of your favorite supplements: ‘glazing agents’. What are they? Do supplements need them? Are they any good? Are these glazing agents safe? Let’s have a look.
Glazing agents can be natural or synthetic substances used to prevent water loss and degradation. In nature they are common in insects and plants, where they keep moisture in organisms. A simple way to memorize glazing agents is to think of them as wax.
Synthetic glazing agents are used in food, cosmetics, and automobile industries, to produce more robust products, but in some cases they are used simply to ‘improve the presentation’, which I think is not necessarily the right thing in case of supplements – why add something to your daily dose of supplements if it’s not needed? After all, the benefit of supplements comes from their active ingredients and not the way they look.
Glazing agents have E numbers, so you might see some of these listed on the supplements’ label:
- Stearic acid (E570)
- Shellac (E904)
- Lanolin (E913)
Some supplements list hydroxyprophyl methylcelulose (HPMC) and glycerine as glazing agents. HPMC is a semisynthetic product and it is used as a controlled delivery component in oral medications. I think it’s worth to mention that many ingredients can play mutliple roles, e.g. HPMC depending on a grade can be a glazing agent, a bulking agent, or a binding agent.
As a tablet coating element, glazing agent can prevent tablets’ deterioration by moisture in the air. Waxes can be used as enterics which determine where the drug is going to be released in the digestive tract.
To wrap it up, I’d say that glazing agents can add value to the supplements when we consider things like deterioration control or controlled-release of drugs. However, this doesn’t mean that all supplements require this ingredient, so think about it next time you see two similar products on a store shelf.
If you aim for a controlled release of active ingredients then some of these substances could be there. On the other hand, if the only point is to make the tablet look better, then I’d try to avoid that product. Leave a comment with a supplement name and we could have a look if glazing makes any difference there.