Compounding Sublingual Medications

Sublingual means under the tongue. A sublingual medication is placed there and left to dissolve, so the drug crosses the thin lining of the mouth and enters the bloodstream without travelling through the stomach and liver first. Compounding pharmacies prepare troches, rapid dissolve tablets, drops and sprays for that route when a swallowed pill does not fit the patient or when a prescriber wants absorption to happen in the mouth.

What does sublingual mean?

The word joins the Latin "sub," meaning below, and "lingua," meaning tongue. A sublingual dose sits under the tongue against a stretch of mucosa that is thin and densely supplied with blood vessels. Drug that crosses it drains into veins returning to the heart rather than into the vessels that feed the liver.

That is the entire mechanical difference between this route and a swallowed pill. Most of what is said about sublingual dosing follows from where the drug goes in the first few minutes after it is absorbed.

Not every drug crosses the oral mucosa in a useful amount. Molecules that are very large, strongly water-loving, or unstable in saliva are poor candidates, and a preparation only makes sense in this form if enough drug gets across. Whether a particular drug suits the route is a decision for your prescriber and the compounding pharmacist, and so is the dose.

How is sublingual different from buccal and from swallowing a pill?

Three routes get confused because all three start in the mouth. Sublingual is under the tongue. Buccal is in the pouch between the cheek and the gum. A swallowed tablet or capsule is not absorbed in the mouth at all: it goes to the stomach and small intestine, and from there to the liver.

Sublingual and buccal both use oral mucosa, so both largely bypass that first trip through the liver. What separates them is dwell time. A rapid dissolve tablet is built to disappear quickly under the tongue, while a troche is a firmer lozenge parked in the cheek that dissolves over several minutes, which suits a prescriber who wants the dose delivered gradually rather than all at once.

Bayview prepares both shapes of the same drug on a prescriber's order. Ketamine rapid dissolve tablets are made for sublingual placement and dissolve in a short time.

The ketamine troche is the buccal counterpart, held in the cheek and dissolved slowly. Ketamine is a controlled substance, dispensed only on a prescription written for a named patient, and controlled substances are not shipped to New York addresses.

What is first-pass metabolism, and why does it matter?

A swallowed drug is absorbed from the gut into the portal vein, which delivers it to the liver before the rest of the body sees any of it. The liver metabolises part of the dose on that trip. This is the first-pass effect, and for some drugs it removes the majority of what was swallowed.

Absorption through the oral mucosa drains into the general circulation instead, so much of that first pass is skipped. For a drug with heavy first-pass metabolism, the amount that reaches the bloodstream from a sublingual dose can differ substantially from the same amount swallowed. How much it differs is specific to the drug, and translating that into a dose is the prescriber's calculation.

Two caveats are worth holding onto. Saliva carries part of every dissolved dose down the throat regardless, so the bypass is partial rather than total. And skipping the liver on the way in does not remove drug interactions: anything that happens at the receptor, in the kidney, or during later hepatic clearance still applies, and your pharmacist should still see your full medication list.

Why would a pharmacy compound a medication in a sublingual form?

Most often because the commercial product does not exist in that form, or exists only in strengths and ingredients that do not fit the person holding the prescription. Difficulty swallowing, known as dysphagia, is one common reason, and so is a long-standing aversion to pills.

Dose is another. A compounded preparation can be made at a strength that sits between or below the manufactured options, which matters when a prescriber is titrating carefully. Dyes, preservatives, lactose and flavourings can also be left out or swapped when a patient reacts to them.

This is the part of the job that separates a compounding lab from a retail counter, a distinction covered in our post on how compounding and retail pharmacies differ. Compounded preparations are made to an individual prescription and are not FDA-approved products.

Which medications does Bayview compound for sublingual or buccal use?

On a prescriber's order, our lab prepares apomorphine sublingual troches in 2 mg and 3 mg strengths, along with a 3 mg/mL sublingual solution. Apomorphine acts on dopamine pathways rather than on PDE5, it is not an FDA-approved product for erectile dysfunction in the United States, and a prescription written for that use is off-label with limited published evidence behind it.

Sildenafil oral dissolve tablets are a second example: the same PDE5 inhibitor as the familiar swallowed tablet, put into a form that dissolves in the mouth for patients who struggle with conventional tablets.

If the drug itself is what you want to read about rather than the dose form, our overview of sildenafil and how it works covers the mechanism, the timing and the nitrate contraindication in detail.

Tadalafil oral dissolve tablets and a vardenafil version of the same idea round out that group, each compounded to the strength on the prescription rather than to a fixed commercial dose.

They sit alongside the rest of the sexual health and urology preparations in the catalog, most of which are made in oral, topical or injectable forms rather than sublingual ones.

Compounded oxytocin is prepared as a sublingual troche and as a nasal spray. It is not FDA-approved in either of those forms, and the published literature on the uses it is prescribed for consists largely of small studies rather than large controlled trials.

Our longer piece on oxytocin troches and their reported uses goes through that evidence in more detail.

When the mouth is not the right route at all, custom oral suspensions are the usual alternative for someone who cannot manage a tablet, including patients who take medication through a feeding tube.

Everything the pharmacy prepares is listed in the searchable catalog of compounded preparations, where you can filter by body system and by route.

How do you take a sublingual medication correctly?

Follow the directions on your label first, since they are written for your specific preparation. The steps below are the general handling points a pharmacist goes over at the counter.

Wet your mouth before you start

Sip water ten to fifteen minutes beforehand. A dry mouth has too little saliva to dissolve a tablet or troche at the rate the preparation was designed for.

Place it where you were told to

Check whether your preparation is sublingual or buccal, because they are not interchangeable. A sublingual tablet goes under the tongue. A buccal troche goes in the pouch between cheek and gum.

Let it dissolve rather than swallowing it

Chewing or swallowing a sublingual dose sends it down the route the form was made to avoid. Keep talking to a minimum while it dissolves so the dose stays in place.

Wait before eating or drinking

Give it thirty to forty-five minutes after the dose has dissolved. Food and drink wash away whatever is still sitting on the mucosa.

Leave brushing and tobacco out of the window

Brushing immediately before or after a dose changes the surface the drug has to cross. Smoking and chewing tobacco alter blood flow in the mouth, and prescribers commonly ask patients to avoid both for a couple of hours either side of a dose.

What forms do sublingual medications come in?

• Rapid dissolve tablets. Small tablets that break down under the tongue in a short time, leaving little residue. The most common sublingual form.
• Troches and lozenges. Firmer, larger, and slower to dissolve. Usually intended for buccal placement, and flavoured to make the several minutes of dwell time tolerable.
• Solutions and drops. A concentrated liquid measured with a dropper and placed under the tongue, which suits drugs that need a strength no tablet would carry.
• Sprays. A metered spray directed under the tongue or against the inside of the cheek, used in both human and veterinary prescriptions.
• Strips. Thin films that dissolve on contact with saliva. Prescribed less often than the other forms.

When is sublingual not the right route?

Sores, ulcers, oral thrush and mucositis are the clearest reasons to hold off. A dissolving tablet sitting on inflamed tissue is uncomfortable and the mucosa itself may not be in a state to absorb reliably.

Persistent dry mouth is another, whether it comes from medication, radiation or a salivary gland condition. So is any situation where the dose cannot be kept in position for as long as it needs, which is often the case with young children and with patients who are agitated or confused.

And some drugs simply do not cross the mucosa well or are broken down in saliva. In those cases a compounding pharmacy usually moves to a different route rather than a different flavour: a suspension, a capsule, a topical preparation, or a rectal or injectable form, depending on the drug.

What does a compounded sublingual preparation cost?

Price depends on the drug, the strength and the quantity written on the prescription. Apomorphine sublingual troches start at $155, ketamine rapid dissolve tablets at $40, and sildenafil oral dissolve tablets at $113, with the final figure quoted before anything is prepared.

Compounded preparations are not billed through insurance. Each one is made to an individual prescription rather than carrying a national drug code, so they are paid for directly. Questions about payment, shipping and the states where Bayview is licensed are answered on our frequently asked questions page.

What Bayview compounds for this

These preparations are made in our Warwick, Rhode Island lab under USP 795 non-sterile compounding standards, each one to a prescription written for a named patient. On a prescriber's order we prepare compounded apomorphine as 2 mg and 3 mg troches and as a 3 mg/mL sublingual solution, ketamine as sublingual rapid dissolve tablets and as buccal troches, sildenafil, tadalafil and vardenafil as oral dissolve tablets, and oxytocin as a sublingual troche or nasal spray.

Talk to your prescriber

If swallowing pills is a problem, or if you think a sublingual form would suit you better than what you are taking now, that conversation belongs with the person who writes your prescriptions. Dose, route and whether a compounded preparation is appropriate at all are their decisions to make.

Prescribers can send a prescription to us directly, and our pharmacists are available to talk through whether a drug is a reasonable candidate for the sublingual route before anything is written. Call us at (401) 284-4505 with a question about a specific preparation.