Quinine HCl

Quinine Hydrochloride Dihydrate, commonly abbreviated as Quinine HCl, is the monohydrochloride dihydrate salt of quinine, a defined quinoline alkaloid. The commercial dihydrate is identified by CAS 6119-47-7, molecular formula C20H24N2O2·HCl·2H2O, and molecular weight 396.91 g/mol. It is chemically distinct from quinine base, quinine sulfate, and anhydrous quinine hydrochloride.

Commercial grades include flavor, high-assay chemical, and pharmacopoeial materials. Established products range from ≥95% flavor grade to high-assay reagent grades, while BP 2026 / Ph. Eur. 12th material uses a 99.0–101.0% dry-basis assay together with defined requirements for optical rotation, pH, and related Cinchona alkaloids.

Ingredient Profile & Common Uses

Quinine Hydrochloride Dihydrate is a discrete quinine salt rather than a Cinchona bark powder or mixed botanical extract. Its structure combines quinoline and quinuclidine features characteristic of quinine, while hydrochloride formation and two molecules of crystallization water define the commercial dihydrate. These attributes distinguish it from other quinine salts that use different molecular calculations and analytical frameworks.

Commercial grade selection is driven by analytical framework and intended use. Flavor-grade material is positioned for controlled bitter-flavor applications, reagent and synthesis grades emphasize quantitative chemical assay, and pharmacopoeial materials add tighter requirements for stereochemical identity, related Cinchona alkaloids, pH, and dry-basis reporting. The grade designation therefore carries meaningful procurement and QA information beyond a single percentage value.

The hydrochloride dihydrate combines intense bitterness with practical aqueous handling, making concentration control and uniform low-level distribution important during formulation. Development work typically evaluates dissolution sequence, sensory intensity, pH environment, light exposure, and matrix compatibility, particularly in beverage and flavor systems where relatively small concentration changes can significantly alter the finished sensory profile.

Application Areas

Carbonated Beverage Flavor Systems

Quinine hydrochloride is used as a bitter flavor ingredient in tonic-style carbonated beverages. In the United States, 21 CFR 172.575 limits quinine to 83 ppm in the finished beverage, expressed as quinine.

Beverage & Spirit Flavoring

Quinine monohydrochloride dihydrate is identified as FL No. 14.155 in the EU flavoring framework, supporting its established commercial identity in applicable beverage and spirit flavoring systems.

Flavor & Sensory Development

Its intense bitterness makes the hydrochloride salt useful in bitter-flavor development, sensory comparison, sweetness-bitter balance studies, taste-masking research, and standardized sensory evaluation.

Analytical & Compendial Applications

Defined chemical identity and established pharmacopoeial specifications support use in analytical method development, chromatographic testing, assay work, related-alkaloid evaluation, and compendial quality-control programs.

Typical Specifications

Chemical Identity & Physical Properties

ParameterSpecification / Property
Product NameQuinine Hydrochloride Dihydrate
Common Commercial NameQuinine HCl Dihydrate
Chemical IdentityQuinine monohydrochloride dihydrate
CAS Number6119-47-7
Molecular FormulaC20H24N2O2·HCl·2H2O
Molecular Weight396.91 g/mol
Parent CompoundQuinine
Ingredient TypeDefined quinine hydrochloride salt
Chemical ClassQuinoline / Cinchona alkaloid
Product FormWhite to almost white crystalline powder or crystals
Water Solubility62.5 g/L
pH — Synthesis Grade6.0 at 10 g/L in water, 20°C
Flavor IdentifierFL No. 14.155
FEMA Number2976

BP 2026 / Ph. Eur. 12th Grade Parameters

ParameterCommercial Grade Specification
AppearanceWhite or almost white or colorless, fine silky needles, often in clusters
IdentificationPasses specified pharmacopoeial identification tests
Appearance of SolutionClear and ≤ Y6
pH6.0–6.8
Specific Optical Rotation−245° to −258°
Rotation BasisDry basis; c = 2.0 in 0.1 M HCl
Dihydroquinine Hydrochloride≤10.0%
Other Impurity Eluted Before Quinine≤5.0%
Any Other Impurity≤2.5%
Related Cinchona AlkaloidsHPLC
Sulfates≤500 ppm
Loss on Drying6.0–10.0%
Sulfated Ash≤0.1%
Assay99.0–101.0% on dry basis
Residual SolventsMeets pharmacopoeial requirements

Compound Identity & Purity

The hydration state is an essential part of the compound identity. Quinine hydrochloride dihydrate has a molecular weight of 396.91 g/mol because its formula includes two molecules of crystallization water. Using an anhydrous hydrochloride molecular weight in formulation or analytical calculations would therefore produce incorrect mass-to-mole conversions.

A percentage result also needs to be interpreted together with its analytical method and reporting basis. Commercial grades use approaches including acidimetric and nonaqueous titration, while pharmacopoeial specifications may report results on a dry basis. These values describe quantitative assay but do not necessarily define chromatographic purity.

Related Cinchona alkaloids are evaluated separately in compendial quality systems. Dihydroquinine, for example, may be present within defined pharmacopoeial limits even when the overall quantitative result approaches 100%. Procurement teams should therefore distinguish total assay from HPLC-related-substance data when comparing commercial grades.

Technical & Quality Considerations

Analytical evaluation should distinguish quantitative assay from stereochemical identity and the related-alkaloid profile. Optical rotation provides an important identity parameter for stereochemically defined quinine, while chromatographic testing separates quinine from related Cinchona alkaloids such as dihydroquinine. The analytical method and reporting basis should therefore be reviewed together with the numerical assay result when comparing grades.

Physical behavior is characterized by strong bitterness, aqueous compatibility, and sensitivity to formulation conditions. Commercial synthesis-grade data report water solubility of 62.5 g/L, while pharmacopoeial material is specified within a mildly acidic pH range. Light protection is also relevant during handling and storage. These characteristics influence dissolution, solution preparation, sensory intensity, and processing sequence.

During scale-up, low inclusion levels increase the importance of weighing accuracy, premixing, and uniform distribution. Beverage systems should be evaluated for dissolution, final quinine-equivalent concentration, clarity, flavor balance, pH, and applicable regulatory limits. Analytical and compendial applications require hydrate-corrected molecular calculations, appropriate reference materials, method alignment, and separate interpretation of quantitative assay and related-substance results.

Packaging & Commercial Supply

Essencefield supports product evaluation, formulation trials, commercial orders, and ongoing ingredient supply. Packaging, storage, and shipping arrangements are determined by product characteristics, order quantity, stability requirements, and destination-market needs.

Supply ItemGeneral Information
SampleAvailable upon request for formulation, testing, and supplier evaluation
Order Quantities100 g · 1 kg · 5 kg · 25 kg · 100 kg · 500 kg · Bulk
Sample Lead TimeTypically 5–7 days after sample confirmation
Production Lead TimeTypically 15–30 days after order and specification confirmation
PackagingSuitable protective inner packaging with bags, cartons, drums, or other appropriate outer packaging
StorageStore in tightly sealed, suitable protective packaging in a cool, dry environment. Protect from moisture, heat, and direct sunlight. Specific storage conditions follow the approved product specification.
DocumentationCOA · Product Specification · TDS · SDS · Applicable declarations (as applicable)

Final order quantities, lead times, packaging, documentation, and shipping arrangements are confirmed according to the selected product and commercial requirements.

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