Scientific Catalog: Pharmaceutical Impurities & Reference Standards

Published Sept 16, 2025 by pharmaffiliates

Impurity standards are essential for quality control, method validation, and regulatory compliance in the pharmaceutical industry. Below are selected impurities and reference compounds from the Pharmaffiliates catalog:

Guaifenesin Impurity B (CAS 14007-09-1)

• Type: API impurity / reference standard
• Parent Drug: Guaifenesin (an expectorant used in cough and cold medicines)
• Application: Used in impurity profiling, HPLC method validation, and regulatory testing to ensure guaifenesin formulations meet ICH guidelines.

Guaifenesin Impurity D (CAS 16929-60-5)

• Type: API impurity / reference compound
• Parent Drug: Guaifenesin
• Application: Supports QC testing and stability studies in guaifenesin formulations, ensuring drug purity and compliance.

Flumequine Impurity B (CAS 42835-47-2)

• Type: Fluoroquinolone impurity
• Parent Drug: Flumequine (antibacterial quinolone)
• Application: Used for impurity characterization and regulatory submissions in fluoroquinolone research.

Ceftazidime Pentahydrate Impurity F (Pyridine Sulfur Trioxide, CAS 26412-87-3)

• Type: Beta-lactam impurity standard
• Parent Drug: Ceftazidime (a third-generation cephalosporin antibiotic)
• Application: Critical for analytical testing, ICH impurity profiling, and QC validation in ceftazidime formulations.

Atropine Impurity D (Hydrobromide Salt)

• Type: Tropane alkaloid impurity
• Parent Drug: Atropine (used in ophthalmology and as an antidote in poisoning)
• Application: Ensures stability studies and impurity limit testing in atropine formulations.

Di-o-tolylmethanol (CAS 2845-91-2)

• Type: Organic reference standard
• Relevance: A synthetic intermediate and potential process impurity.
• Application: Supports process validation, impurity tracking, and synthesis quality control.

6,7-Dimethoxyquinazolin-4(3H)-one (CAS 13794-72-4)

• Type: Quinazolinone derivative / reference compound
• Relevance: Structural scaffold in several antihypertensive and anticancer drugs.
• Application: Used for R&D studies, impurity profiling, and analytical testing.

Methylbufotenin (CAS 1019-45-0)

• Type: Tryptamine alkaloid derivative
• Relevance: Related to indole alkaloids and serotonin analogs.
• Application: Used as a reference compound in neuropharmacological and psychoactive substance research.

Conclusion

These impurity and reference standards are vital for regulatory submissions, stability studies, and analytical method validation. By providing high-purity compounds like Guaifenesin Impurities B & D, Flumequine Impurity B, Ceftazidime Impurity F, and Atropine Impurity D, Pharmaffiliates supports global pharmaceutical companies in meeting ICH, USP, and EMA guidelines.