Evidence-Based Complementary and Alternative Medicine

Review Article

Global Comparison of Stability Testing Parameters and Testing Methods for Finished Herbal Products

Table 1

Common testing parameters of oral solid and liquid dosage forms of herbal products.
ParameterSolid dosage formLiquid dosage form
CapsulesaExtractsGranulesbHerbal infusion bagscPillsdPowderseTabletsfTrochesAromatic waterDecoctionEmulsionInfusionFluid extractsgSolutionSuspensionSyrupTincture
PhysicalDescription1⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁
Purity            ⋁ ⋁  
Transparency/clarity             ⋁   
Hardness⋁     ⋁          
Friability⋁   ⋁ ⋁          
Water content2⋁⋁⋁⋁⋁⋁⋁     ⋁ ⋁  
Uniformity of dose unit3⋁ ⋁⋁⋁⋁⋁     ⋁ ⋁⋁⋁
Weight variation4⋁     ⋁          
Particle-size variation5  ⋁  ⋁    ⋁ ⋁ ⋁  
Viscosity          ⋁ ⋁⋁⋁⋁ 
Relative density               ⋁ 
Resuspendability6              ⋁  
Reconstitution time              ⋁  
Dispersion7              ⋁  
Rheological properties              ⋁  
Phase separation          ⋁      
Polymorph conversion              ⋁  
ChemicalAssay/content⋁⋁⋁⋁⋁⋁⋁⋁⋁ ⋁ ⋁⋁⋁⋁⋁
Identification⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁ ⋁⋁⋁
Dissolution⋁ ⋁ ⋁ ⋁     ⋁ ⋁  
Disintegration⋁ ⋁ ⋁ ⋁⋁    ⋁    
pH⋁⋁        ⋁ ⋁⋁⋁⋁⋁
Preservative content8              ⋁  
Ethanol content            ⋁ ⋁ ⋁
Extractable substances          ⋁  ⋁⋁  
BiologicalMicrobial limit9⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁⋁
1Includes organoleptic characteristics such as color, odor, form, shape, size, and texture or absorption of moisture and the softening. 2Includes loss on drying. 3Includes uniformity of mass or uniformity of weight 4or average weight. 5Includes granule size variation, granule size distribution, or particle-size distribution 6or redispersibility 7or dispersibility. 8Includes antimicrobial and antioxidant preservative contents. 9Includes microbial content or microbial purity. aIncludes soft and hard gelatin capsules. bIncludes for oral solution or suspension. cIncludes herbal tea in sachets or herbal tea bags. dIncludes coated or uncoated pills, dripping pills, or pellets. eIncludes powders used for oral solutions or suspensions. fIncludes coated or uncoated tablets or sugar-coated tablets (pastilles). gIncludes liquid extract, internal fluid, oral liquid, or liquid mixture.