Pseudoephedrine
[CAS# 90-82-4]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Metal sulfides and sulfates
• Name: Pseudoephedrine
• Synonyms: (+)-Pseudoephedrine; (1S,2S)-2-Methylamino-1-phenylpropan-1-ol
• Molecular Formula: C₁₀H₁₅NO
• Molecular Weight: 165.23
• CAS Registry Number: 90-82-4
• EC Number: 202-018-6
• SMILES: C[C@@H]([C@H](C1=CC=CC=C1)O)NC

Properties

• Melting point: 117-118 °C
• alpha: 52 ° (c=0.6, EtOH)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H317-H319-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P272-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1B	H317
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

Discovery and Use of (+)-Pseudoephedrine**

(+)-Pseudoephedrine is a widely used decongestant and sympathomimetic amine that relieves nasal congestion. Pseudoephedrine, including its (+)-enantiomer, was first synthesized and identified in the early 20th century as a derivative of ephedrine. It belongs to the phenethylamine class and is structurally similar to amphetamines, but its effects are focused on nasal and sinus decongestion. The chemical formula of (+)-pseudoephedrine is C10H15NO.

(+)-Pseudoephedrine is valued for its ability to relieve nasal congestion by constricting blood vessels in the nasal mucosa. This action reduces swelling and allows for easier breathing, making it an effective treatment for symptoms associated with allergies, colds, and sinusitis. It is often included in multi-symptom cold medications because of its ability to relieve nasal congestion as well as other symptoms such as coughing and sneezing. The recommended dose for adults is generally 30 mg to 60 mg every 4 to 6 hours, with extended-release formulations providing longer-lasting relief. It is available in a variety of forms, including tablets, capsules, and syrups, providing flexibility in treatment options.

(+)-Pseudoephedrine acts as a sympathomimetic by stimulating alpha-adrenergic receptors in the nasal mucosa. This stimulation causes vasoconstriction, which reduces blood flow and reduces nasal swelling. The decongestive effect helps relieve congestion and improves airflow, promoting easier breathing and reducing discomfort.

While safe when used as directed, (+)-pseudoephedrine can cause side effects such as increased heart rate, blood pressure, and insomnia, especially in high doses or for long periods of time. It should not be used by people with severe hypertension, cardiovascular disease, hyperthyroidism, and those taking monoamine oxidase inhibitors (MAOIs).

Because (+)-pseudoephedrine can be abused in the illegal production of methamphetamine, it is subject to strict regulatory controls in many countries. In the United States, for example, it is a prescription drug and is regulated under the Combating the Meth Epidemic Act to prevent its use for illegal purposes.

References

2024. Pharmacology of chlorphenamine and pseudoephedrine use in the common cold: a narrative review. Current Medical Research and Opinion, 40(11).
DOI: 10.1080/03007995.2024.2424422

2023. TTD: Therapeutic Target Database describing target druggability information. Nucleic Acids Research, 52(D1).
DOI: 10.1093/nar/gkad751

2024. A randomized placebo controlled trial demonstrates the effect of dl-methylephedrine on brain functions is weaker than that of pseudoephedrine. Scientific Reports, 14.
DOI: 10.1038/s41598-024-71851-z