Quality of Herbal Products

Quality Control

the strategy for minimizing errors by managing each stage of production from cultivation to the final product used for medicinal purposes

different strategies of quality control are used to?

identify unknown vs known compounds and single vs multiple compounds

pharmacognostic methods of quality control

botanical (microscopic and macroscopic), chemical (identification and assay)

macroscopic

appearance of plant, allows for identification

microscopic

cell and tissue structure of plant

pharmacognostic methods follow

tests written in official documents

assay

quantification of compounds

fingerprint chromatography

HPLC/TLC - chemical analysis

taxonomical equivalence doesn't always mean

chemical equivalence

chemical profile depends on

environment/habitat, cultivation and processing

marker compounds

specific compounds present in the herb that can be used to identify the type of plant and measure the quality of it

why might two samples differ in chemistry?

same herbs grown in different environments can have varying chemical profiles which leads to different pharmacological effects (lack of chemical consistency).

poor cultivation practices can lead to inconsistencies.

standardisation

measuring against a standard ensures consistency between plants

physiochemical testing includes

moisture content, ash values, solubility, stability

microbiological checks ensure

no harmful bacteria, fungi or contamination present

pharmacological evaluation confirms

biological activity and therapeutic effect

analytical techniques

seperate and identify

quality control methods include

Pharmacognostic Methods

Characteristic Fingerprint Chromatograms

Defined amounts of Marker Substances Standardization of the extracts when they are produced

Physicochemical Characteristics

Microbiological Monitoring

Basic Pharmacological Research

herbolome concept

all chemical constituents of a herbal preparation

metabolome

all metabolites in an organism

herbal mixtures are

more complex than single organisms

phytotherapy

science based use of plant extracts for medicinal purposes

metabolic fingerprinting

MS/NMR identify overall chemical pattern of herb not just single compounds

complete biological profile includes

genomics, proteomics, metabolic, transcriptomics

geonomics

DNA

Proteomics

proteins

metabolics

metabolites

transcriptomics

mRNA

Genomics-Transcriptomics-Proteomics-Metabolomics

Genetic map - Expressed mRNAs - Proteins synthetised - Secondary molecules synthetised

challenges when making drugs from herbal mixtures

habitat, soil, climate, harvesting and processing, extraction method, storage

known compounds

marker compounds, known actives, known fingerprints

unknown compounds

complex mixtures, unidentified constituents

single vs multi herb mixtures

multi herb are harder to standardise, often require multiple quality control fingerprinting and pharmacological validation

complete process of quality control

Botanical identification (macro + micro)

Pharmacognostic tests (per Pharmacopoeias)

Chemical QC (identification tests and assay of marker compounds)

Fingerprint chromatograms

Standardisation of extracts

Physicochemical tests

Microbiological monitoring

Basic pharmacological research

macroscopy

colour, odour, taste, shape

Microscopy

trichomes, stomata, calcium oxalate, fibres

chemical quality control methods

TLC, HPLC/UPLC, GC-MS, CE (capillary electrophoresis)

CE is used for

non-volatile compounds

volatile/semi-volatile compounds are

essential oils

advantages of extraction technologies

low solvent use, green energy, suitable for thermolabile compounds

disadvantages of extraction methods

equipment cost, difficulty extracting polar compounds, explosion risk

PHWE

pressurised hot water extraction (volatile/semi-volatile)

PLE

pressurised liquid extraction (non-volatile)

aloe vera

used to treat constipation

batch to batch variation

Even with identical species and extraction conditions, chemical and pharmacological variability persists.

chromatographic fingerprinting

Confirms identity, detects adulteration, ensures batch consistency, assesses chemical equivalence

importance of omics

identifying plant species, understanding biosynthetic pathways, linking chemical profiles to biological activity, discovering biomarkers