Theanine
Compositional Guideline for Theanine permitted for use in listed medicines.
Name of the ingredient
Theanine (AAN)
Synonyms
L-Theanine
Definition of the ingredient
Theanine is an analogue of the proteinogenic amino acids, L-glutamate and L-glutamine. It is obtained through chemical synthesis from L-glutamic acid (obtained from the fermentation of corn starch) and ethylamine. It contains not less than 98% L-Theanine.
Structure
Molecular formula
C7H14N2O3
Molecular weight
174.2
CAS Number
3081-61-6
Table 1. Ingredient specific requirements
Test | Method reference | Acceptance criteria |
|---|---|---|
Description | ||
Appearance | Visual | White fine or crystalline powder |
Odour/taste | Organoleptic | Characteristic (neutral to slightly sweet) |
Characteristics | ||
Chloride | USP <221> | ≤210 ppm |
Loss on drying | USP <731> | ≤1% |
pH (1% water solution) | USP <791> | 5-6 |
Specific Rotation | USP <781> | +7.7o to + 8.5o |
Identification | ||
Infrared Absorption | USP FCC Spectrophotometric Identification Tests, Appendix IIIC | The spectrum of the sample exhibits maxima at the same wavelengths as those in the spectrum of the reference standard |
HPLC | USP FCC | The retention time of the major peak (excluding the solvent peak) in the chromatogram of the sample solution is the same as that observed in the standard solution |
Assay | ||
L-Theanine | USP FCC | ≥98 % |
Table 2. Incidental constituents
Test | Method reference | Acceptance criteria | ||
|---|---|---|---|---|
Residual solvents | ||||
Ethanol | USP <467> | ≤0.5% | ||
Ethylamine | GC-MS USP <621>, USP <736> | ≤50 ppm | ||
Incidental metals and non-metals | ||||
Total heavy metals | USP <2232> | ≤10 ppm | ||
Arsenic | USP <2232> | ≤1.0 ppm | ||
Cadmium | USP <2232> | ≤0.5 ppm | ||
Lead | USP <2232> | ≤0.5 ppm | ||
Mercury | USP <2232> | ≤0.1 ppm | ||
Other organic or inorganic impurities or toxins | ||||
Residue on Ignition | USP <281> | ≤0.2% | ||
Microbiology | ||||
While substance manufacturers are encouraged to include limits for objectionable microorganisms, it is the product into which those substances are formulated that is subject to a legally binding set of criteria. The Therapeutic Goods Order No. 100 'Microbiological Standards for Medicines' mandates that any finished product that contains the ingredient, alone or in combination with other ingredients, must comply with the microbial acceptance criteria set by Clause 11 of the Order. | ||||
Key to abbreviations
AAN = Australian Approved Names
CAS = Chemical Abstract Services
HPLC = High-Pressure liquid Chromatography
USP = United States Pharmacopeia