By PathGene Biotech · Technically reviewed by Alex Huang
Calcium L-5-MTHF Stability: Light, pH, Heat and Batch Review
Calcium L-5-MTHF identity: 6S, calcium salt and batch evidence
For calcium L-5-methyltetrahydrofolate (calcium L-5-MTHF), specify CAS 151533-22-1 and confirm the intended (6S) identity, salt form, hydration and carrier status in the agreed specification. A generic “5-MTHF” name does not settle these details. An identity test, total assay and stereoisomer result answer different questions; none should silently stand in for the others.
What one actual calcium L-5-MTHF lot reports
PathGene COA PGL5-260815 lists assay 100.1% against 95.0-102%, calcium 8.2% on an anhydrous and solvent-free basis, water 12.6%, and D-5-methylfolate 0.16%. The assay entry does not explicitly state the same correction basis as the calcium entry: request the analytical calculation rather than assuming it. The reported 100.1% should be retained as the analytical result, not relabeled as an absolute mass fraction or rounded down to align a marketing purity statement.
The identity section includes HPLC retention-time correspondence and an infrared comparison. The D-isomer entry is relevant to stereochemical review, but should not be converted automatically into a universal chiral-purity guarantee. These results refer to this lot. The certificate's storage instruction is sealed packaging in a cool, dry place away from light; it does not establish stability in a finished liquid.
Light, pH and temperature: turn the question into a study plan
| Variable | What to compare | Evidence to keep |
|---|---|---|
| Light | Protected controls versus the intended light exposure, with comparable oxygen and temperature conditions. | Exposure conditions, package, time and retained assay. |
| pH and oxygen | Candidate pH conditions in the actual liquid, with defined air/headspace exposure and matched excipients. | Measured pH, matrix, concentration, oxygen handling and degradant profile. |
| Temperature and time | Actual process heat/time and storage conditions for the intended dosage form. | Temperature history, duration, sampling plan and validated analytical method. |
| Solid form and package | The offered grade's hydration/crystal form and proposed barrier package. | Material characterization and relevant packaged stability data. |
This table is a development checklist, not a tested protocol or a universal optimal pH recommendation. A COA pH value, a study in another matrix or a shelf-life label does not resolve all four variables.
What the published studies actually establish
Yang et al. (2021) studied model systems and folate-enriched egg yolk, finding that oxygen, light and temperature affected 5-MTHF stability. Their matrix-specific protection experiments do not specify an additive dose or shelf life for a different commercial formula.
Lian et al. (2021) investigated a particular calcium 6S-5-MTHF crystal form. Crystal-form evidence must be matched to the supplied material; this reference does not identify PathGene's lot as the study's crystal form or establish an equivalent stability result.
Choose the formulation route before choosing the specification
Capsules and tablets: review blend uniformity, compression or encapsulation conditions, excipient compatibility and moisture exposure. Powders and sachets: assess segregation, hygroscopicity, flavor-system compatibility and high-barrier packaging. Liquids and emulsions: require the most deliberate screening for pH, dissolved oxygen, light exposure, heat treatment, preservative compatibility and shelf-life assay. A literature result from a model system cannot replace final-formula validation.
Pre-purchase COA and document checklist
- Lot-specific COA with identity, assay, water or loss on drying, and appearance.
- Specification showing the agreed form and assay basis.
- SDS, storage and packaging statement.
- Relevant impurity, elemental and microbiology information for the intended use.
- Sample and compatibility-testing plan before commercial scale-up.
- Target-market regulatory and labeling review owned by the finished-product team.
Regulatory boundary
Folate-source acceptance, labeling and permitted claims vary by country and finished-product category. This article is a sourcing and formulation checklist, not a claim, dosage or market-access determination. Confirm the current requirements with the responsible regulatory team before launch.
Review PathGene calcium L-5-MTHF
For the current material profile, visit the calcium L-5-methyltetrahydrofolate product page. When requesting a sample, specify the intended dosage form and processing conditions so the relevant batch documentation can be reviewed.
References
Yang et al. (2021), 5-MTHF degradation and stabilization strategies; Lian et al. (2021), stability comparison of calcium 5-MTHF crystal forms.
Frequently Asked Questions
Can the raw-material COA prove stability in a finished liquid?+
No. A raw-material COA verifies the released lot against its own specification. A liquid product needs its own compatibility and shelf-life study in its final matrix and package.
Should assay be compared on an as-is or dry basis?+
Use the basis agreed in the specification. When comparing suppliers, ask for the assay basis and the water result so the comparison is meaningful.
What should a calcium L-5-MTHF stability study record?+
Record exact salt and solid form, concentration, pH, light exposure, oxygen conditions, temperature and duration, formula matrix, package and assay method. A batch-release COA is not a finished-product shelf-life study.
Does a result above 100% mean a calcium L-5-MTHF batch is impossible?+
Do not interpret a reported assay as a literal mass fraction without its method and basis. Review the reference-standard assignment, water and solvent corrections and agreed limits. Batch PGL5-260815 reports assay 100.1% within its 95.0-102% specification.
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