Extraction and Standardization of Medicinal Herbal Products

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1 Extraction and Standardization of Medicinal Herbal Products By: Dr Masoud Sadeghi Dinani Department of Pharmacognosy Isfahan University of Medical Sciences

2 Medicinal Plants About 80% of all the world s medicines are originally derived from plant sources especially those found in tropical regions Large number of plant-derived medicines and other useful compounds have yet to be discovered 15% of the known angiosperm species have been studied World Health Organization (WHO) approximately US $14 billion per year 15 to 25% annually more than US $5 trillion in 2050

3 Medicinal Plants Quality of herbal preparations Species differences Organ specificity Diurnal and seasonal variation Environment Field collection, Cultivation methods Substitution Adulteration Processing Manufacturing practices Contamination

4 Pre-extraction Procedures Identifying the correct plants of interest Preserving the compounds within the plants Freezing Drying Grinding Air-drying (Natural drying) Microwave-drying Oven-drying Freeze-drying (Lyophilisation)

Contemporary Methods principles of extraction that are based on the Polarity solubility

5 Extraction of Medicinal Plants Traditional Methods use of hot water extracts to make teas or natural plant dyes Salves and decoctions are often made from a single plant source Contemporary Methods principles of extraction that are based on the Polarity solubility in water various alterational solubilities based on salts and ph increase yield at lower cost

6 Extraction of Medicinal Plants Infusion Decoction Maceration Digestion Easiest and simplest methods Alteration in temperature and choice of solvents Volume of solvents

7 Extraction of Medicinal Plants Percolation Continuous extraction Better yield Volume of solvent Limitations

8 Extraction of Medicinal Plants Soxhlet Hot continuous extraction Smaller quantity of solvent Non-polar compounds Hazardous and flammable liquid organic solvents Potential toxic emissions

9 Extraction of Medicinal Plants Ultrasonic Extraction high-frequency sound (20 khz to 2000 khz) extraction process is fast and cheep essential oils, polysaccharides, menthol, cardiac glycosides, pyrethrins and camptothecin Shearing forces large molecules, such as DNA or large proteins Heat labile compounds

10 Extraction of Medicinal Plants Microwave-Assisted Extraction yields comparable to Soxhlet extraction methods but in much less time 1 to 10 g samples, irradiation powers around 100 to 150 W essential oils, taxanes, azadirachtin-related limonoids, glycyrrhizic acid, cocaine, artemisinin, ginsenosides, camptothecin reduced extraction time and solvent volume Improved recoveries Polar molecules and solvents with high dielectric constant Thermal degradation short intervals

Extraction of Medicinal Plants Supercritical Fluid Extraction Dual characteristic of supercritical fluids High degree of recovery in a short period of time Carbon dioxide

11 Extraction of Medicinal Plants Supercritical Fluid Extraction Dual characteristic of supercritical fluids High degree of recovery in a short period of time Carbon dioxide critical point 31 C and 73 atm low cost, environmentally benign nature, lack of flammability and reactivity Large scale decaffeination of green coffee beans extraction of hops

Extraction of Medicinal Plants Extraction rates are enhanced less degradation of solutes relatively low temperature thermally labile components Extractions can be selective

12 Extraction of Medicinal Plants Extraction rates are enhanced less degradation of solutes relatively low temperature thermally labile components Extractions can be selective to some extent relatively non-polar natural products alternatives to Hydrodistillation essential oils, artemisinin, azadirachtin, phloroglucinols, triterpenoids and steroids

13 Extraction of Medicinal Plants More polar substituents addition of a small amount of a liquid modifier methanol, ethanol, dichloromethane, and acetonitrile Vindoline High pressures required Equipment is expensive must be handled with care

14 Extraction of Medicinal Plants Phytonics Process Hydrofluorocarbon-134a (HFC-134a) Advanced Phytonics Limited (Manchester, UK) Production of high quality natural fragrant oils, flavors and biological extracts

15 Extraction of Medicinal Plants Extraction of volatile compounds Distillation Hydrodistillation Steam distillation Fresh materials Dried materials

16 Extraction of Medicinal Plants Extraction by Scarification oil of lemon oil of orange, and oil of bergamot Two principal methods Sponge Ecuelle

17 Extraction of Medicinal Plants Extraction by Non-Volatile Solvent fine quality of either lard or olive oil Used as a flavouring base Three chief methods Enfleurage Maceration Pneumatic (Spraying)

18 Extraction of Medicinal Plants Extraction by Volatile Solvent Soxhlet using the solvent light petroleum distilled off at a low temperature

column chromatography (LC) High-performance liquid

19 Isolation of Natural compounds Analytical and Preparative Chromatography Protocols Thin layer chromatography (TLC) Liquid column chromatography (LC) High-performance liquid chromatography (HPLC) Gas chromatography (GC) Fast protein liquid chromatography (FPLC)

Isolation of Natural compounds Droplet countercurrent chromatography (DCCC) Centrifugal droplet countercurrent chromatography (CPC) High-speed countercurrent

20 Isolation of Natural compounds Droplet countercurrent chromatography (DCCC) Centrifugal droplet countercurrent chromatography (CPC) High-speed countercurrent chromatography (HSCCC) Elution extrusion countercurrent chromatography (EECCC) Ion-exchange chromatography Size-exclusion chromatography Affinity Chromatography

Herbal Registration in use for at least 30 years 15 must usually have been in the EU evidence of safety

21 Standardization of Herbal Products American Herbal Products Association (AHPA) information and controls that serves to optimize the batch-to-batch consistency of a botanical product THR licenses Traditional Herbal Registration in use for at least 30 years 15 must usually have been in the EU evidence of safety adherence to appropriate manufacturing standards provision of appropriate product information to users

22 Standardization of Herbal Products Medicines and Healthcare Products Regulatory Agency (MHRA) Committee on Herbal Medicinal Products (HMPC) Directive on Traditional Herbal Medicinal Products (Directive 2004/24/EC) Manufactured herbal medicinal products THR requirements full effect on 30 April 2011 Sell through period for herbal medicines 30 April 2014

23 Standardization of Herbal Products HMPC list November 2013 covers 165 herbal medicinal products Costs of regulatory compliance and manufacturing quality requirements Exclusion of newer herbs with less than 30 years of use Complex herbal preparations Foods or food supplements

24 Standardization of Herbal Products Pharmacopoeial Standards Volatile oil content Haemolytic activity Foaming index Bitter value Tannin contentent Fat content Acid value Saponification value Iodine value Assay for Aluminium, Arsenic, Borate, Calcium, Chloride,

25 Standardization of Herbal Products Phytochemical Assay alkaloids Carbohydrates Glycosides Saponins Phytosterols Phenols Tannins Flavonoids Diterpenes

26 Standardization of Herbal Products Recent advances in analytical methods Constituents relevant to standardization are Constituents with know clinical activity (active principles) Constituents with known pharmacological activity or which otherwise contribute to efficacy (active markers) Constituents relevant for quality control (analytical inactive-markers) Constituents with potential negative impact (negative markers, e.g. allergens, toxins)

27 Standardization of Herbal Products Macro and microscopic examination Foreign organic matter Ash values Moisture content Qualitative chemical evaluation Quantitative chemical evaluation Biological activity Toxicological studies

28 Standardization of Herbal Products Microbial contaminants and aflatoxins Heavy metals Radioactive contamination Pesticide residues Labelling of herbal products Good Agricultural and Collection Practices (GACP) Good Manufacturing Practices (GMP)

Good pharmacopoeial practices: Chapter on monographs on herbal medicines

Annex 7 Good pharmacopoeial practices: Chapter on monographs on herbal medicines Background Following the fiftieth meeting of the WHO Expert Committee on Specifications for Pharmaceutical Preparations,