Scopolamine is a naturally occurring tropane alkaloid and anticholinergic active pharmaceutical ingredient, also known as hyoscine. For pharmaceutical manufacturing, scopolamine is commonly handled in the form of Scopolamine Hydrobromide, also known as Hyoscine Hydrobromide. The hydrobromide is an established pharmaceutical substance with a USP monograph defining identity, assay, organic impurities, water content, optical rotation and other quality requirements.
Scopolamine acts primarily as a competitive antagonist at muscarinic acetylcholine receptors. By reducing cholinergic signaling, it can influence smooth-muscle activity, secretions and vestibular pathways. This pharmacological mechanism supports its use in pharmaceutical formulations intended for motion sickness and nausea and vomiting associated with certain clinical situations.
Scopolamine Hydrobromide is the hydrobromide salt of the stereochemically defined scopolamine molecule. The pharmaceutical trihydrate is identified by CAS Number 6533-68-2, while the anhydrous hydrobromide substance is associated with CAS Number 114-49-8. The active scopolamine moiety itself has CAS Number 51-34-3.
FDA substance records identify Scopolamine Hydrobromide Trihydrate with the molecular formula C17H21NO4·HBr·3H2O and molecular weight 438.31 g/mol. The anhydrous hydrobromide has a molecular weight of 384.27 g/mol. The distinction between anhydrous and hydrated forms is important when preparing pharmaceutical specifications, calculating assay results and defining packaging and stability requirements.
Scopolamine is primarily associated with prevention of motion sickness and management of nausea and vomiting. It is also used in specific pharmaceutical formulations and delivery systems, including transdermal products. FDA information for the transdermal system identifies scopolamine as the active drug substance and describes its antimuscarinic pharmacological activity.
Because scopolamine is a potent pharmacologically active alkaloid, appropriate handling, containment and quality-control procedures are important during API manufacturing, testing, packaging and transportation.
Scopolamine Hydrobromide is a crystalline pharmaceutical substance. USP describes the material as a hydrated hydrobromide and calculates its assay against the anhydrous scopolamine hydrobromide basis. The USP assay requirement is 98.0–102.0% on that basis.
The API is characterized by infrared identification, chromatographic identity and HPLC assay. The USP chromatographic method uses UV detection at 210 nm. Organic impurities include tropic acid, norscopolamine, hyoscyamine, apohyoscine and apoatropine, together with a limit for other individual impurities.
Quality control of Scopolamine Hydrobromide includes identity, HPLC assay, organic impurity testing, residue on ignition, optical rotation, pH and water determination. USP specifies NMT 13.0% water, reflecting the hydrated nature of the pharmaceutical substance. Residue on ignition is controlled at NMT 0.1%.
USP also specifies optical rotation of −24° to −26° using an anhydrous sample concentration of 50 mg/mL in water. The pH requirement is 4.0–5.5 for a 50 mg/mL aqueous solution. These concentrations should not be confused with a generic 1% API solution specification.
Pharmaceutical-grade Scopolamine Hydrobromide should be supported by appropriate analytical and quality documentation. Typical API documentation can include Certificate of Analysis, identity results, HPLC assay, related-substance profile, water determination, residue-on-ignition results, optical rotation, pH data, residual-solvent information and applicable GMP documentation.
Scopolamine Hydrobromide should be stored under controlled conditions that protect the material from moisture, light and environmental contamination. The USP specifies preservation in tight, light-resistant containers. Packaging selection should therefore be consistent with the validated stability profile of the specific hydrated API.
A pharmaceutical API technical package may include specification sheets, Certificate of Analysis, analytical methods, impurity information, stability data, safety documentation and applicable regulatory or manufacturing documentation.
Scopolamine Hydrobromide has an established pharmacopoeial analytical framework and clearly defined numerical requirements for assay, water, residue on ignition, optical rotation, pH and organic impurities. These characteristics make it a well-defined API for quality-focused pharmaceutical manufacturing and formulation development.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Residue on Ignition | NMT 0.10% |
| pH (1% Solution) | 4.0–5.5 |
| Individual Impurity | NMT 0.20% |
| Total Impurities | NMT 0.70% |
| Water Content | NMT 13.0% |