Client case · non-oral formulation · freedom to operate & evidence base
Formulating an active substance in a non-oral form: one route is ready to reproduce, the other needs two engineering problems solved
The client was working through bringing an active substance to market in a non-oral form — bypassing hepatic metabolism. We examined two delivery routes — a nasal spray and an oral film — checked freedom to operate and reconciled the claimed effect against the evidence base. The client and country are under NDA; here we show the method and conclusions.
In brief
The client wanted to bring an active substance to market in a non-oral form and, in the brief, described the penetration enhancer as a 'protein'. The review showed the substance is not a protein — it is a stable non-ionic surfactant, so questions of cold chain and protein stabilisers resolve themselves. Of the two routes examined, the nasal spray builds on an already approved product with a fully disclosed composition and is reproducible with a simple aqueous process; the oral film is an open niche but requires solving bitterness masking and dose retention in the mouth. Separately, the patent check confirmed freedom to reproduce the base molecule and pre-emptively ruled out patented delivery devices and one new molecule of the class.
| Metric | Value |
|---|---|
| Oral bioavailability of the active substance | low — the reason for moving to a non-oral form |
| Parenteral administration (injection) | high bioavailability — the speed benchmark |
| Absorption enhancer | non-ionic surfactant, stable — not a protein |
| Peak concentration of the nasal form with enhancer | 10–15 min |
| Expected shelf life | 24–36 months (to confirm per ICH) |
| Delivery routes worked through | 2 — reproducible and innovative |
The starting situation
The client was working through bringing an active substance to market in a non-oral form — to bypass presystemic (hepatic) metabolism: the substance has low bioavailability when taken orally, whereas by injection it is high and serves as the speed benchmark. The brief featured two forms — a nasal spray with a penetration enhancer and an oral film. The penetration enhancer, however, was labelled a 'protein' in the documents, and on that mistaken assumption the downstream reasoning about storage, preservatives and stability was built.
What the analysis showed
We checked every initial assumption against published sources and the official label of the already approved product — and laid out both forms by risk.
- The penetration enhancer is not a protein but a stable surfactant. By chemical structure it is a non-ionic glycoside surfactant (a detergent), with no peptide bonds. The confusion arose because in the literature this substance is almost always mentioned next to the word 'protein' — it is used to work with membrane proteins, but is not itself a protein. The practical consequence is direct: a surfactant needs neither a cold chain nor protein stabilisers, which is confirmed by the room-temperature storage of the approved product (20–25 °C, 15–30 °C permissible).
- Route 1 — nasal spray: reproducible, with a disclosed composition. There is already a regulator-approved product with a fully disclosed composition: a simple aqueous buffered solution with a dose of the active substance and a non-ionic absorption enhancer — not a suspension or an emulsion. Thanks to the enhancer, peak blood concentration is reached within 10–15 minutes, whereas an ordinary nasal spray is absorbed slowly (a significant part of the dose settles in the nasal cavity). The expected shelf life for the class is 24–36 months at room temperature (established only by the product's own stability studies per ICH Q1A(R2)). The microbiological regime was examined separately: a nasal spray is not equated with sterile forms, and two options are legitimate — a multi-dose bottle with a preservative (non-sterile manufacture) and a single-dose one without a preservative (sterile); a typical nasal preservative is itself a surfactant, so its compatibility with the enhancer must be checked separately.
- Route 2 — oral film: an open niche, but with two unsolved problems. No direct clinical work on exactly this film of this substance could be found — which is both a market opportunity and a technology risk. For related substances of the same class the method is established and transferable (solvent casting). But the design runs into two parameters. First, the substance is noticeably bitter, and without taste masking (a cyclodextrin complex plus a sweetener) the patient will not keep the strip in the mouth. Second, without mucoadhesion and dose retention most of the drug is swallowed with saliva — and then the form behaves like an ordinary tablet, with the same bioavailability as when taken orally and slow absorption. It is dose retention, not the mere fact of a 'spray into the mouth', that determines whether hepatic metabolism is bypassed.
- Freedom-to-operate check (FTO) and evidence base. The base molecule is outside patent protection and free for generic reproduction; the standard liquid nasal form is not covered by base patents. The check did, however, cut off risks: active patents on certain patented delivery devices (which cannot be copied — a different atomiser is needed) and one new molecule of the same therapeutic class, protected by patents until roughly 2031–2034 — it cannot be treated as a generic target. A cross-check against a network meta-analysis refined the client's expectations: the formula with the enhancer was not statistically the best for complete pain relief (another agent of the class led, odds ratio OR 4.67), but it showed better results for freedom from associated symptoms (OR around 5). That is, the form's advantage lies in tolerability and speed, not in the maximum of the primary effect.
The result
The client received neither a 'do it' nor a 'don't', but a map of the two routes laid out by risk. The nasal spray was qualified as the priority project: the disclosed composition of an approved product, a simple aqueous process, room-temperature storage, a favourable patent status — the fewest unknowns before development starts. The film was flagged as a more innovative second stage with real market potential, but with two explicitly named engineering problems that must be solved before investing. The brief's original error ('the enhancer is a protein') was corrected before it could affect the choice of equipment, storage regime and preservation system. The patent check removed in advance the protected devices and molecules that would have led to infringement.
The bottom line
The question was not 'do it or not' but 'in what order and with which open problems'. The nasal spray is the priority project with the fewest unknowns; the oral film is an innovative second stage, but only after bitterness masking and dose retention in the mouth are solved. And the 'enhancer is a protein' error was removed before it could impose an unnecessary cold chain and an incompatible preservation system.
Why this is value, not criticism
If the enhancer had stayed a 'protein' in the project, the client might have budgeted for an unnecessary cold chain and protein stabilisers, and along with it chosen an incompatible preservation system — extra costs and the risk of an unstable product. If the film had been launched without resolving taste and dose retention, the result would have been an expensive development indistinguishable in efficacy from an ordinary tablet. If a patented delivery device or a protected molecule had been taken as the basis — a direct legal risk. Reviewing the formulation before development starts costs orders of magnitude less than fixing these errors at the manufacturing or registration stage. The negative and qualifying conclusions here are not nitpicking but exactly what saves budget and time.
Caveats and data status
We separate what is measured, what is an estimate, and what is taken from the original brief — and we don't pass one off as another.
- From published sources and the label. The pharmacokinetic values, the composition and storage regime of the approved product, and the enhancer's molecular weight are taken from published sources and the official label of the approved product, not measured on the client's bench.
- An estimate, not a guarantee. The 24–36 month shelf life is the expected range for the class; the specific value is established only by the product's own stability studies (ICH Q1A(R2)). The comparative-efficacy values (OR) come from a published network meta-analysis.
- The patent conclusion. FTO is a high-level assessment; it does not replace a local legal opinion on specific excipients and devices in the client's jurisdiction.
- From the brief. The description of the enhancer as a 'protein' comes from the client's original brief; the review refuted it. The client, country, specific active substance, therapeutic target and target disease are not disclosed.
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The case is anonymised. The client, country, specific active substance, therapeutic target and target disease are under NDA; details are covered in a diagnostic session. The numbers (10–15 min, 24–36 months, OR 4.67 and around 5, patent protection through 2031–2034) come from a real project: the pharmacokinetics, composition and storage regime are from published sources and the approved product's label; the shelf life is the expected range for the class, not a guarantee; the patent conclusion (FTO) is a high-level assessment that does not replace a local legal opinion. This material is informational and is not a regulatory opinion or investment advice.