Delayed-release capsules are described in a lot of confident language: protected, shielded, survives the stomach. Behind most of that language sits one specific, unglamorous laboratory test. Knowing what it does — and precisely where it stops — is the difference between reading a delivery claim and evaluating one.
USP <2040> is the United States Pharmacopeia’s disintegration-testing standard for delayed-release dosage forms. It is a physical test: finished capsules are held in a simulated gastric-phase medium for a defined period, then transferred to a simulated intestinal-phase medium, and the test records whether and when the capsule disintegrates in each phase. It measures the behavior of the dosage form in defined media. Nothing more.
What the test does
The test exposes finished capsules to a simulated gastric-phase medium for a defined period, then transfers them to a simulated intestinal-phase medium, recording whether and when disintegration occurs in each phase. Two phases, two observations.
It is the relevant standard for this kind of formulation because it evaluates the finished, whole capsule under conditions modeled on the same gastric-to-intestinal transition a delayed-release format is designed around — not a proxy test on the raw ingredient alone. That distinction is the whole point: a raw-material test cannot evaluate a capsule shell, because the shell is what is being evaluated.
What a result looks like
A delayed-release result is a pair of observations. In the gastric phase, the expected behavior is that the capsule does not disintegrate within the defined period. In the intestinal phase, the expected behavior is that it does. A result is therefore reported as behavior per phase, not as a single pass mark.
It is also worth being precise about time language. A disintegration observation is recorded at the point the observation was first made under the test conditions. “First observed by” a given minute is an accurate description; treating that figure as a fixed property of the product — a number it will reproduce in any context — is not.
Why this test exists for enzymes
Proteolytic enzymes as a category are described as vulnerable to gastric acid and digestive proteases, which is the general reason enteric and delayed-release formulations are studied for this class of ingredient. Serrapeptase is itself a protein-digesting enzyme, so an unprotected dose is exposed to exactly the kind of acidic, protease-rich environment that class of ingredient is generally studied as being vulnerable to.
Delayed-release capsule shells respond to that with pH-dependent solubility: the shell material is chosen to stay insoluble in the stomach’s low-pH environment and to become soluble in the higher-pH environment of the small intestine, so the pH shift itself — not elapsed time — is what triggers release. This is a general mechanism used across delayed-release capsule technology, not a description of any single product’s specific shell chemistry.
What the evidence tells you
- Whether a finished capsule held together through a defined gastric-phase exposure in the test medium.
- Whether, and at what observed point, it disintegrated in the intestinal-phase medium.
- That the dosage form as manufactured behaves consistently with a delayed-release design, under the standard’s conditions.
What it does not tell you
- It is not an absorption measurement. Disintegration is the capsule opening. Absorption is a different process, measured differently.
- It is not an in-vivo result. The media are laboratory models of a gastric and intestinal environment. An in-vitro observation cannot be converted into a conclusion about what occurs in a person.
- It says nothing about potency. A capsule can disintegrate exactly as designed and tell you nothing about how much enzyme activity it contained — that is the activity assay, a separate test.
- It is not a claim about every lot. A disintegration result belongs to the lot that was tested.
Where further testing is planned but not complete, there is no result to report. A study that has not produced findings cannot be described, previewed, or characterized in advance — not as promising, not as expected, not as forthcoming evidence. If evidence is unavailable, the honest version of the sentence is that it is unavailable.
How iSerra approaches it
Bilamex™ Dual-Phase Delivery combines two independent protective layers. The outer layer is a delayed-release capsule shell formulated to resist breakdown in the low-pH gastric environment and to disintegrate once it reaches the higher-pH environment of the small intestine. Inside that shell, the enzyme is not loose powder but is carried in individually coated pellets, each carrying its own protective coating — a second, independent barrier after the outer shell opens. The two stages function in sequence rather than redundantly.
Finished capsules are evaluated under USP <2040>. For Lot 6798, the documented result was no disintegration through the 60-minute gastric phase, with complete disintegration first observed by 37 minutes in the intestinal phase. That is one documented lot’s result under the standard’s conditions — a physical observation about the dosage form, not a statement about digestion. Full engineering and testing detail is on The Science.
Practical takeaway
When a product describes protected delivery, ask what was tested and on what. Was the finished capsule tested, or the ingredient? Under which standard? Which lot? And is the result being described as a physical observation, or quietly upgraded into a claim about the body? The upgrade is where most delivery marketing goes wrong.
A disintegration test tells you when a capsule opened in a beaker. That is a real and useful fact, and it is a smaller fact than most delivery claims imply.
USP <2040> — disintegration and dissolution of dietary supplements, delayed-release dosage forms. Background on pH-dependent solubility in delayed-release capsule formulation generally. Reference detail maintained on The Science.
iSerra™ finished-product USP <2040> testing, Lot 6798: no disintegration through 60 minutes gastric phase; complete disintegration first observed by 37 minutes intestinal phase. One documented lot result.
Published research on an ingredient, finished-product testing, and lot-specific testing are three different categories of evidence and are kept separate throughout the Journal. This article introduces no external findings beyond those referenced on The Science.