This analysis is designed to confirm the identity and determine the amount and peptide purity of Dihexa in tablets, capsules, lyophilized samples and raw API powders. HPLC testing provides information about the target compound content and its purity relative to chromatographically detectable impurities.
Dihexa
Dihexa is a synthetic peptide-derived compound with the sequence Hexanoyl-Tyr-Ile-Ahx-NH2. Its molecular weight is approximately 504 Da.
An important consideration in Dihexa analysis is its limited solubility in water. The choice of solvent can therefore significantly affect how much of the compound enters solution and can subsequently be measured by HPLC. Water is used as the standard preparation procedure for lyophilized samples, while DMSO and methanol are available as alternative solvents.
What the Analysis Determines
- Identity of Dihexa
- Amount of Dihexa in the sample
- Peptide purity
- Dihexa content per tablet or capsule
- Dihexa content in mg per vial for lyophilized samples
- Optional m/m purity for raw API powders
Analysis Parameters
- Target compound: Dihexa
- CAS number: 1401708-83-5
- Molecular weight: 504 Da
- Sequence: Hexanoyl-Tyr-Ile-Ahx-NH2
- Testing method: HPLC
- Detection limit: less than one twentieth of the usual dosage per vial
- Result format for oral products: mg per tablet or capsule and peptide purity
- Result format for lyophilizates: mg per vial and peptide purity
- Alternative result format: m/m purity and peptide purity
- Minimum oral sample: 3 tablets or capsules
- Minimum lyophilizate sample: one whole unopened vial containing the lyophilizate
- Minimum raw API powder sample: 30 mg in a sealed glass vial to prevent moisture absorption
- Default solvent for lyophilized samples: water
- Optional solvents: DMSO or methanol
- Average turnaround time: 7 business days
Important Notice – Dihexa Solubility
Dihexa has limited solubility in water, which must be considered particularly when analyzing lyophilized samples.
Water – Standard Procedure
Water is the default solvent used for standard sample preparation. However, Dihexa is poorly soluble in water. Insoluble particles are removed by filtration before HPLC analysis because only material transferred into solution can be analyzed.
If part of the Dihexa remains undissolved, it may be removed during filtration and the measured concentration may therefore be lower than the total amount originally present in the sample.
DMSO
DMSO provides improved dissolution of Dihexa and reduces potential losses caused by removing insoluble particles before analysis. When DMSO is selected, the prepared solution is intended for analytical testing only.
Methanol
Methanol provides very good dissolution of Dihexa and is suitable when maximizing extraction of the target compound before HPLC analysis is required. The resulting solution is likewise intended for analytical testing only.
For tablets and capsules, the standard analytical procedure is recommended.
The alternative m/m purity result format is intended exclusively for raw API powders.
Additional Analyses
Solvent – Methanol
- Methanol can be used instead of the standard aqueous preparation procedure. Its improved ability to dissolve Dihexa can reduce losses associated with removal of insoluble material.
TFA Analysis
- Detection and measurement of trifluoroacetic acid (TFA) in the sample.
Raw Data
- Delivery of the available raw analytical data from the primary test and all applicable additional analyses.
Solvent – DMSO
- DMSO can be used to dissolve Dihexa before analysis. This option can improve transfer of the target compound into solution and reduce losses during filtration.
Fentanyl Presence Analysis
Alternative Result Format – m/m Purity
- Alternative reporting of the result as mass-by-mass purity. This option is intended exclusively for raw API powders.
Variance Testing
- Analysis of multiple sample units to assess variation within a single batch. All submitted samples must originate from the same batch of the same product.
pH Measurement
- Measurement of bacterial endotoxins, particularly lipopolysaccharides (LPS), in the sample. This analysis is available only for finished products and should not be ordered for raw powders.
- The standard test provides accurate results up to 10 EU per vial. Values above 10 EU per vial are estimated and require an additional test with a different dilution for precise determination. Sending two vials is therefore recommended.
- Where endotoxin levels above 10 EU per vial are expected, the method can be calibrated for the higher range in advance.
- Elemental analysis providing accurate measurement of nitrogen and sulphur content. The results can be used to determine Net Peptide Content (NPC).
Additional Report
- A separate additional laboratory report issued under a different client name.
- LC-MS screening for contamination with other peptides or peptide degradation products. Detection is limited to peptides included in the available testing portfolio.
- The initial screening provides identification only. If contamination is detected, quantitative measurement may subsequently be ordered.
- TAMC and TYMC testing checks the product for the presence of bacteria, yeasts and moulds. Additional unopened sample units must be submitted for analysis. The average turnaround time for this test is 14 days.
- Detection of arsenic, cadmium, lead and mercury in the sample. Testing for other metals can be arranged individually.
