Oral Dissolving Strip vs Sublingual Spray: Dose Precision

By Jack Zheng, MS Pharmacy — Founder of MIHIYO Labs

Summary

An oral dissolving strip (ODS) delivers a more precise, better-retained dose than a sublingual spray, even though both act on the oral mucosa. A spray's dose depends on actuation force and technique, and much of the liquid is swallowed rather than absorbed under the tongue: a 2025 crossover study found a 60 mg caffeine mouth spray raised serum caffeine no faster than swallowed coffee (McCarthy et al., 2025). An ODS carries a fixed, pharmacopeia-grade dose in a film that adheres to the mucosa and resists saliva washout (Visser et al., 2015). A well-used spray can still match a film. MIHIYO Labs formulates melatonin as an ODS for this dose precision.

Which delivers a more precise dose: an oral dissolving strip or a sublingual spray?

An oral dissolving strip vs sublingual spray comparison is unusual in this series because both forms target the same tissue — the oral mucosa — so neither has a built-in route advantage. The deciding factors are dose precision and retention. An ODS carries a single, pre-measured dose locked into a film that adheres to the mucosa; a spray meters a liquid whose delivered dose varies with actuation technique and whose absorbed fraction depends on how much stays under the tongue rather than being swallowed. On both counts a film tends to be the more precise tool. But a well-administered spray can match a film, and sprays have real strengths a film does not.

Throughout this article I use "oral dissolving strip (ODS)" to mean a thin polymer film placed under the tongue or against the inner cheek, where it dissolves in saliva over roughly 30–90 seconds and releases its active onto the oral mucosa. A "sublingual spray" is a metered-dose pump or propellant device that sprays a liquid dose under the tongue.

Why both forms use the oral mucosa but deliver dose differently

Both an ODS and a sublingual spray are designed to deliver active across the oral mucosa, the non-keratinized lining of the mouth that is drained by veins emptying into the jugular system rather than the portal vein. The sublingual region is the most permeable of the oral mucosae — its epithelium is roughly 100–200 microns thick and richly vascularized, thinner and more permeable than the buccal mucosa at 500–800 microns (Squier, 1991). Any active that crosses this lining reaches systemic circulation directly. So far the two forms are identical in intent. The difference is what happens to the dose before it gets a chance to cross.

A sublingual spray delivers a liquid bolus, and a liquid does not stay put. The sublingual area has high salivary flow, and tongue movement plus the swallow reflex wash liquid down the throat within seconds, cutting contact time with the absorbing surface (Squier, 1991). The clearest demonstration is in caffeine. McCarthy et al. (Eur J Appl Physiol, 2025, PMID 40000478) gave 14 adults 60 mg of caffeine as a mouth spray, as coffee, or as an energy drink in a randomized crossover, then tracked serum caffeine for 90 minutes. The spray did not raise blood caffeine any faster than the swallowed beverages. The authors' interpretation is direct: most of the sprayed caffeine was swallowed and absorbed through the gut, not across the sublingual mucosa. For a spray, the "sublingual" label describes where you aim it, not necessarily where it is absorbed.

An ODS behaves differently because it is a solid that adheres. The film hydrates in saliva and forms a gel that holds against the mucosa rather than running off it, and mucoadhesive film designs can add a backing layer that reduces saliva diffusion and directs release toward the tissue (Silva et al., 2015). The dose is locked into the film matrix at manufacture, so what you place in your mouth is what dissolves there — there is no actuation step, no propellant, and no liquid to swallow before it can adhere.

How dose precision compares: the numbers

The spine of this comparison is the table below. Each row is a concrete dimension where an ODS and a sublingual spray measurably differ, and each is followed by the pharmacology behind it.

Dose precision per use. A spray meters its dose through a pump or valve, and the volume per actuation is reproducible at the device level. The variability is in the human step. As formulation reviews note, actuating a device by hand is not consistent over time or between people — angle, force, and timing all shift the delivered and retained dose. An ODS removes that step entirely: the dose is cast into the film and verified by content-uniformity testing. Visser et al. (Int J Pharm, 2015, PMID 25448577) showed that orodispersible films of enalapril, prednisolone, and diazepam all met European Pharmacopoeia requirements for uniformity of mass and uniformity of content — meaning each film carries the labeled dose within a tight, pharmacopeia-defined band. With a spray, the dose that actually reaches the mucosa is the metered dose minus whatever is swallowed, and that subtraction varies every time.

Mucosal retention versus swallowing. This is the heart of the within-route difference. The McCarthy 2025 caffeine study is the cleanest available evidence that a sprayed sublingual dose is largely swallowed rather than absorbed under the tongue, because the spray produced no faster serum rise than coffee or energy drink. A film, by contrast, adheres. Silva et al. (Int J Pharm, 2015, PMID 26315122) describe how mucoadhesive oral films hold against the mucosa and how a backing layer can reduce saliva diffusion and direct release toward the tissue, extending the contact time that drives transmucosal absorption. Retention is the variable a film controls and a spray does not.

Onset and bioavailability — the fentanyl head-to-head. Fentanyl is the one molecule with direct, regulated PK comparisons of a sublingual spray and a buccal film, because both are approved as rapid-onset products for cancer pain episodes. Parikh et al. (Clin Ther, 2013, PMID 23497761) found fentanyl sublingual spray reached a median Tmax of 1.5 hours with absolute bioavailability around 76% in healthy volunteers. Vasisht et al. (Pain Med, 2010, PMC2955962) found fentanyl buccal soluble film had an absolute bioavailability of 71%, with about 51% of the dose absorbed directly through the buccal mucosa and the remainder swallowed and absorbed in the gut. The two forms land close — high bioavailability for both — which is the honest headline: when a spray is used correctly with a potent, well-absorbed molecule, it performs in the same range as a film. The film's edge is not a higher ceiling; it is a more reproducible floor.

Technique dependence. A spray's outcome depends on what the user does: aiming under the tongue, holding the liquid there, not swallowing immediately, priming the device, and actuating consistently. Each of these is a place for the delivered dose to drift, and the McCarthy 2025 result shows how easily the intended sublingual delivery collapses into ordinary swallowing. A film's only user variable is placement, and once it adheres the dose is committed.

First-pass bypass when retained. When either form is actually absorbed across the mucosa, the pharmacology is the same: the sublingual veins bypass the liver, so that fraction avoids hepatic first-pass metabolism (Squier, 1991). This is why a sublingual melatonin spray can raise serum melatonin from a small dose (Bartoli et al., Drugs in R&D, 2023, PMID 37438493). The point of the comparison is not that one form bypasses first-pass and the other does not — both can. The point is which form more reliably gets the dose to stay long enough to be absorbed.

Portability. A film is flat, dry, and individually sealed, so a single dose fits in a wallet and does not leak or need priming. A spray is a liquid device that must be carried upright, primed before first use, and protected from leaking. For travel and discreet daily use, the film is the more practical unit.

What this means for MIHIYO products

I formulate melatonin as an ODS rather than a spray specifically because of dose precision and retention. Oral melatonin loses most of its dose to hepatic first-pass metabolism, with absolute bioavailability of roughly 9–33% and large person-to-person scatter (Harpsøe et al., 2015), so the amount that reaches the bloodstream is already variable before delivery technique adds more noise. A spray would stack a second source of variability on top of that — how much liquid is swallowed each night — exactly the effect McCarthy et al. (2025) documented for caffeine. The Sleep-Support ODS instead carries a fixed, low dose in a film that adheres to the mucosa, so the delivered dose is the labeled dose, not the labeled dose minus an unknown swallowed fraction.

A sublingual melatonin spray is not a poor product — Bartoli et al. (2023) showed a spray can raise serum melatonin meaningfully. My choice is about reproducibility from one dose to the next, which matters most for a low-dose active where the target is the physiologic nighttime serum window, not a maximal peak.

Every citation in this article is on independent spray, film, tablet, or gum formulations studied by research groups outside MIHIYO Labs. We do not have a head-to-head human PK study comparing the MIHIYO ODS to a matched sublingual spray. The framework is general; the specific numbers belong to the cited compounds and formulations.

Where a sublingual spray wins

A spray is not the weaker form across the board, and saying so plainly is part of how I want this brand to talk.

People who cannot hold a film in place. A film has to stay put against the mucosa to work. People with very dry mouths, strong gag responses, or difficulty keeping a film positioned may find a quick spray easier to administer. The spray is fast and requires no waiting period.

Flexible titration. A spray can deliver one, two, or three actuations, letting a user or clinician fine-tune the dose in small increments from the same device. A film is a fixed unit dose; adjusting it means using a different strength or a fraction, which a film does not split cleanly.

Speed of administration. A spray acts in a second and needs no dissolution time. For someone who simply wants the dose in and done, that is a genuine convenience.

The honest summary. When a spray is aimed well, held under the tongue, and not swallowed immediately, it can match a film on absorbed dose — the fentanyl data show both forms in the same bioavailability range. The film's advantage is that it removes the steps where a spray's dose drifts. It is more forgiving of imperfect technique, not categorically more powerful.

The bottom line

For an oral dissolving strip vs sublingual spray comparison, the more precise dose usually comes from the film, because an ODS carries a fixed, pharmacopeia-grade dose that adheres to the mucosa, while a spray's delivered dose varies with technique and is largely swallowed — a 60 mg caffeine spray raised blood caffeine no faster than coffee (McCarthy et al., 2025). Both forms use the same oral mucosa and both can bypass first-pass when the dose is retained, and a well-used spray can match a film, as the fentanyl data show. The film simply removes the steps where dose precision slips, which is why I use it for low-dose actives like melatonin.

References

1. McCarthy DG, Stapleton C, et al. Sublingual caffeine delivery via oral spray does not accelerate blood caffeine increase compared to ingestion of caffeinated beverages. European Journal of Applied Physiology. 2025. PMID: 40000478. <https://pubmed.ncbi.nlm.nih.gov/40000478/>

1. Visser JC, Woerdenbag HJ, Crediet S, Gerrits E, Lesschen MA, Hinrichs WLJ, Breitkreutz J, Frijlink HW. Orodispersible films in individualized pharmacotherapy: The development of a formulation for pharmacy preparations. International Journal of Pharmaceutics. 2015;478(1):155-163. PMID: 25448577. <https://pubmed.ncbi.nlm.nih.gov/25448577/>

1. Silva BMA, Borges AF, Silva C, Coelho JFJ, Simões S. Mucoadhesive oral films: The potential for unmet needs. International Journal of Pharmaceutics. 2015;494(1):537-551. PMID: 26315122. <https://pubmed.ncbi.nlm.nih.gov/26315122/>

1. Parikh N, Goskonda V, Chavan A, Dillaha L. Single-dose pharmacokinetics of fentanyl sublingual spray and oral transmucosal fentanyl citrate in healthy volunteers: a randomized crossover study. Clinical Therapeutics. 2013;35(3):236-243. PMID: 23497761. <https://pubmed.ncbi.nlm.nih.gov/23497761/>

1. Vasisht N, Gever LN, Tagarro I, Finn AL. Single-Dose Pharmacokinetics of Fentanyl Buccal Soluble Film. Pain Medicine. 2010;11(7):1017-1023. PMC2955962. <https://pmc.ncbi.nlm.nih.gov/articles/PMC2955962/>

1. Squier CA. The permeability of oral mucosa. Critical Reviews in Oral Biology and Medicine. 1991;2(1):13-32. DOI: 10.1177/10454411910020010301. <https://journals.sagepub.com/doi/10.1177/10454411910020010301>

1. Bartoli AN, Marchesi N, Pascale A, Quaccini A, Govoni S. Bioavailability of Melatonin after Administration of an Oral Prolonged-Release Tablet and an Immediate-Release Sublingual Spray in Healthy Male Volunteers. Drugs in R&D. 2023;23(3):257-265. PMID: 37438493. <https://pmc.ncbi.nlm.nih.gov/articles/PMC10439092/>

1. Harpsøe NG, Andersen LP, Gögenur I, Rosenberg J. Clinical pharmacokinetics of melatonin: a systematic review. European Journal of Clinical Pharmacology. 2015;71(8):901-909. PMID: 26008214. <https://pubmed.ncbi.nlm.nih.gov/26008214/>