A development team is running early formulation work on a cannabinoid active ingredient. Someone on the bench modifies the material’s aqueous handling, maybe through a complexation step, a particle-engineering change, or a supplier switch to a differently processed input. Dissolution improves. Everyone is pleased. Then someone in quality asks the question that actually matters. What does this change do to the control strategy?
That question, not the dissolution result, is the subject of this article. Physicochemical behavior in an active pharmaceutical ingredient is never purely a formulation-development topic. It has direct consequences for specifications, analytical methods, process understanding, stability programs, and the evidence a regulator will eventually expect to see. Novel cannabinoid APIs make this connection unusually visible, because their known solubility and metabolic limitations force these questions earlier and more explicitly than they arise with many conventional small molecules. This article uses cannabinoids as the case study, but the lesson applies to any emerging API with nonstandard physicochemical behavior.
Two clarifications up front. First, nothing here implies that cannabinoid products are approved medicines, clinically proven, or interchangeable with established pharmaceutical actives. Second, pharmaceutical development, API development, formulation development, CMC evidence, GMP manufacturing, regulatory approval, clinical evidence, and commercial claims are distinct concepts. Improving a physicochemical property does not collapse the distance between any two of them.
When a Formulation Property Becomes a Quality Attribute
The chain runs roughly like this: an API property (say, aqueous solubility) shapes formulation behavior, which shapes the stability profile, which eventually shapes clinical or product performance and the regulatory evidence built to support it.
ICH Q11 frames this directly for drug substances: manufacturing process development should identify potential critical quality attributes (CQAs) associated with the drug substance so that characteristics affecting product quality can be studied and controlled, and it should define a control strategy that assures process performance and drug substance quality. The guideline does not say every measurable property is automatically critical. It says the determination has to be risk-based, tied to actual impact on quality, safety, or performance, and supported by data rather than assumption.
That distinction matters here. Not every solubility quirk in a cannabinoid API becomes a CQA. Whether it does depends on whether that property demonstrably affects identity, strength, purity, dose delivery, or stability of the eventual product. The job of a development team is to run that risk assessment early rather than discover the answer during process validation, when the cost of finding a control gap is much higher.
Figure 1. Causal relationships of API property leading to regulatory evidence
The CMC Questions Emerging Cannabinoid APIs Rise
Cannabidiol (CBD) and delta-9-THC are documented Biopharmaceutics Classification System Class II compounds: high lipophilicity, low aqueous solubility (roughly 12.6 mg/L for THC and 28.0 mg/L for CBD in one commonly cited estimate), and correspondingly variable, generally low oral bioavailability. That single physicochemical fact ripples through nearly every part of a CMC dossier for a cannabinoid-based drug product. It is worth walking through where.
Identity, strength, purity, and consistency. Highly purified cannabis-derived substances are treated by the FDA as analogous to conventional single-chemical APIs for development and review purposes, but the Agency also notes that a naturally derived cannabinoid will typically carry a different impurity profile than a synthetically produced equivalent, and that impurity controls must reflect the actual source and process. Chemical fingerprinting is called out specifically as important to demonstrating batch-to-batch consistency for cannabis and cannabis-derived material.
Formulation design driven by water solubility. Because unmodified CBD and THC dissolve poorly in aqueous media, oral formulations built without solubility enhancement tend to show low, variable bioavailability, commonly cited in the single-digit to low-teens percentage range depending on the study and dosage form. Approaches used to address this include phospholipid complexation, nanoemulsions, self-nanoemulsifying systems, and lipid-based carriers, several of which report multi-fold increases in dissolution rate or bioavailability in preclinical models. Each of these formulation strategies introduces its own new material attributes (particle or droplet size distribution, complexation efficiency, emulsion stability) that then need their own control points.
Dose uniformity in aqueous or solubilized systems. An API that behaves inconsistently in an aqueous matrix, whether due to incomplete solubilization, precipitation on dilution, or supersaturation followed by recrystallization, creates a direct dose-uniformity risk at the formulation and fill stage. This is a manufacturing consistency question as much as a formulation one, and it belongs in a process characterization study, not a formulation notebook alone.
Stability characterization. CBD and THC are also documented as chemically unstable under certain storage and processing conditions, which affects shelf-life claims and forces a stability-indicating analytical method that can distinguish parent compound from degradation products.
Material attributes affecting manufacturing performance. Particle size, polymorphic form, and solubilizing-excipient interactions can all shift blend uniformity, dissolution testing outcomes, and fill consistency in ways that are easy to miss if the only endpoint tracked is potency.
Analytical specificity. A method validated only for potency will not necessarily resolve parent compound from a closely related degradant or metabolite precursor. ICH Q14 sets out that analytical procedure development should identify the attributes that actually need to be tested, select suitable technology, and evaluate performance characteristics including specificity, accuracy, and robustness across the working range, with the resulting control strategy documented in the dossier. For a molecule with known degradation pathways and structurally similar related substances, specificity is not a checkbox, it is the whole point of the method.
Evidence supporting the control strategy. FDA’s own draft guidance on cannabis and cannabis-derived compounds in clinical research states plainly that sponsors are expected to show they can consistently manufacture a quality product, and that the amount of supporting information expected increases at each successive phase of development. It also flags a cannabinoid-specific pharmacology issue: the major human CBD metabolite, 7-COOH-CBD, is disproportionately expressed in humans relative to animal models, a known translational gap the Agency explicitly wants sponsors aware of.
Where risk belongs in development, not validation. Every one of the items above is cheaper to resolve during formulation and analytical development than during process validation or post-approval change control. That is not a novel insight, but cannabinoid APIs make it concrete because the underlying physicochemical challenges are well-documented in the literature rather than hypothetical.
Bioavailability Is Not the Same Thing as Quality
This distinction deserves its own section because it is where marketing language and CMC evidence most often get blurred, intentionally or not.
Improved dissolution in a USP apparatus, higher apparent permeability in a Caco-2 monolayer, or a longer apparent half-life in a liver microsome assay are all legitimate physicochemical or in-vitro pharmacokinetic findings. None of them, on their own, demonstrate improved human bioavailability. None of them demonstrate improved clinical efficacy. And none of them, by themselves, constitute evidence of product quality in the regulatory sense, which is built from specifications, validated methods, process controls, and stability data, not from a single performance data point.
A six-fold increase in dissolution rate for a CBD-phospholipid complex compared with unmodified CBD, reported in one recent in-vitro study, is a formulation-science result. A study reporting a fourfold or a more increase in rat oral bioavailability for a lipid-based nanocarrier is an animal pharmacokinetic result. A study reporting 92 percent bioavailability for a self-nanoemulsifying system in Sprague-Dawley rats is, again, an animal PK result, not a human clinical outcome. These findings are useful signals for a development team deciding where to invest further characterization effort. They are not substitutes for the human PK, safety, and efficacy data a regulator will eventually require, and treating them as interchangeable is where good science quietly turns into overstated claims.
What Recent Cannabinoid Research Teaches CMC Teams
For companies developing water-soluble cannabinoid ingredients, such as for example the CBD82S, reported findings on its metabolic stability relative to conventional CBD may be significant. In a human liver microsome model, it was reported that CBD82S showed an apparent half-life approximately 25-fold longer than conventional CBD under the conditions tested.
Read correctly, that is exactly what it says: an in-vitro finding, in a liver microsome model, describing apparent metabolic stability under one set of assay conditions. The published summary of the work appropriately cautious on this point, noting that further studies are needed to determine how the increased stability observed in the microsome model translates into actual pharmacokinetic performance. That caveat is the right instinct, and it is worth taking seriously rather than treating as boilerplate.
For a CMC or regulatory team evaluating a finding like this, the useful question is not “does this molecule work better.” The question is, “what additional characterization would be needed before a change in metabolic behavior could be built into a control strategy at all? At minimum, that would include confirmation across multiple microsome lots or donor pools (microsome activity varies donor to donor), orthogonal in-vitro systems such as hepatocytes, a defined analytical method capable of distinguishing parent compound from its metabolites with adequate specificity, and eventually in-vivo pharmacokinetic data in a relevant species before any human PK inference is drawn. None of that is a criticism of the finding. It is simply what separates an interesting in-vitro data point from something a dossier can rely on.
The Quality-Risk Questions Team Should Ask Early
A practical checklist for CMC, QA, QC, and regulatory teams evaluating an emerging API or novel delivery platform, cannabinoid or otherwise:
- Material attributes
- Analytical control
- Manufacturing
- Stability
- Supplier and lifecycle management
- Regulatory strategy
What “Pharma-Grade” Should Actually Mean
“Pharma-grade” is one of the more elastic phrases in this space, and it is worth being precise about what it does and does not mean. Manufacturing under pharmaceutical GMP conditions is a process claim. It says a facility and its procedures meet defined manufacturing and quality-system requirements. It is not, by itself, a regulatory approval, a safety finding, or a claim of clinical effectiveness.
Real evidence of quality looks like defined specifications tied to actual risk assessment, analytical methods that are validated or qualified appropriately for the development stage, documented traceability from raw material to finished product, real stability data supporting the claimed shelf life, and supplier controls that hold up under change. FDA’s guidance is explicit that the level of CMC information expected from a sponsor increases at each phase of clinical development, and that even for a well-characterized botanical or highly purified cannabinoid material, adequate characterization and consistent manufacture must be demonstrated, not simply asserted. A facility operating under GMP is a necessary condition for quality. It is not equivalent to regulatory approval, and conflating the two, intentionally or through loose language, is a credibility problem waiting to surface during due diligence or review.
The Forward-Looking Argument
Cannabinoids are not unique in creating this kind of pressure. Any API with nonstandard solubility, unusual metabolic behavior, or a novel delivery mechanism will eventually force the same set of questions, whether it is a peptide, a nanoparticle-based small molecule, or a next-generation prodrug. What cannabinoids illustrate particularly well, because the physicochemical limitations are so well documented in the literature, is how quickly a formulation-optimization conversation turns into a control-strategy conversation if nobody is watching for the transition.
Organizations that treat formulation science, analytical development, manufacturing controls, and quality risk management as separate workstreams, run in sequence rather than in parallel, tend to find their control gaps late: during process validation, during a pre-approval inspection, or worse, during a stability failure after launch. The earlier a development team connects “this molecule behaves unusually in water” to “here is what that means for our specifications, our methods, and our evidence package,” the fewer expensive surprises show up downstream. In CMC work, the ground truth is rarely the dissolution curve on day one. It is whatever the batch record and the stability data say three years later.
References
- ICH Guideline Q11 on Development and Manufacture of Drug Substances (Chemical Entities and Biotechnological/ Biological Entities) Step 5 Adoption by CHMP for Release for Consultation. 2012. Accessed September 2, 2026. https://www.ema.europa.eu/en/documents/scientific-guideline/ich-guideline-q11-development-and-manufacture-drug-substances-chemical-entities-and-biotechnologicalbiological-entities_en.pdf
- Reddy TS, Zomer R, Mantri N. Nanoformulations as a strategy to overcome the delivery limitations of cannabinoids. Phytother Res. 2023;37(4):1526-1538. doi:10.1002/ptr.7742
- U.S. Food and Drug Administration (2020) Cannabis and Cannabis-Derived Compounds: Quality Considerations for Clinical Research Guidance for Industry DRAFT GUIDANCE. Retrieved September 3, 2026, from https://www.fda.gov/media/140319/download
- Hossain KR, Amani Alghalayini, Valenzuela SM. Current Challenges and Opportunities for Improved Cannabidiol Solubility. International Journal of Molecular Sciences2023;24(19):14514-14514. doi:10.3390/ijms241914514
- Paczkowska-Walendowska M, Piotr Trzaskoma, Aleksandra Dziopa, et al. Innovative Strategies to Enhance the Bioavailability of Cannabidiol: Nanotechnology and Advanced Delivery Systems. Pharmaceuticals2025;18(11):1637-1637. doi:10.3390/ph18111637
- N. K, O. J, Q. B, et al. Evaluation of amorphous and lipid-based formulation strategies to increase the in vivo cannabidiol bioavailability in piglets. International Journal of Pharmaceutics2024;657:124173. doi:10.1016/j.ijpharm.2024.124173
- Muta T, Riya Khetan, Song Y, Garg S. Optimising Cannabidiol Delivery: Improving Water Solubility and Permeability Through Phospholipid Complexation. International Journal of Molecular Sciences2025;26(6):2647-2647. doi:10.3390/ijms26062647
- Committee for Medicinal Products for Human Use ICH Q14 Guideline on Analytical Procedure Development. 2023. Accessed September 3, 2026. https://www.ema.europa.eu/en/documents/scientific-guideline/ich-q14-guideline-analytical-procedure-development-step-5-revision-1_en.pdf
- Muta T, Mukhopadhyay S, Noll B, Song Y, Garg S. Development and in vivo pharmacokinetic evaluation of a phospholipid complex self-nanoemulsifying drug delivery system (PLC-SNEDDS) for enhanced oral bioavailability of cannabidiol. Drug Deliv. 2026;33(1):2702143. doi:10.1080/10717544.2026.2702143
- Trait Biosciences. CBD82STM Demonstrates Greater Metabolic Stability in a Human Liver Microsome Model. Trait BiosciencesAugust 28, 2026. Accessed September 4, 2026. https://traitbio.com/cbd-metabolic-stability/
Dr. Jaclyn Leyson-Azuela, RMT, MPH is a physician with medical writing and scientific consultancy experience, particularly for Trait Biosciences, specializing in clinical operations with interest in PK/PD, regulatory, safety, and drug formulation and development.
