Product Development and Clinical Studies of Traditional Medicines

1
Product Development and Clinical Studies of
Traditional Medicines

• N. L. Phang
• Nova Laboratories Sdn. Bhd.
• Malaysia
• (www.nova.com.my)

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Objectives

• To discuss the main issues and regulatory
  guidelines on product development.
• To describe develop process of a traditional
  medicine with therapeutic claim.
• To illustrate with a case study
• The development of a botanical drug
  containing standardized Phyllanthus niruri
  extract EPN 797.

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Successful herbal productDevelopment of
bromhexine

• Ethnobotany approach in drug development
• Bromhexine (Trade name Bisolvon)
• Is a popular mucolytic agent for cough.
• It is derived from Indian Adhatoda vasica (the
  malabar nut tree) which is traditionally used in
  cough therapy.

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Definition of herbal products

• Three categories of herbal products
• A. Drugs (NCE, new chemical entities)
• Single active ingredient pharmaceuticals
  originating from plants.
• E.g. vinblastine, digoxin.

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Definition of herbal products (Contd)

• B. Botanical drugs (Multi-component botanical
  drugs)
• Botanical drugs are manufactured medicines
  obtained exclusively from plants to relieve,
  prevent or cure a disease or to alter
  physiological and pathological process.
• E.g. None in USA, several in clinical trials.
• Dietary supplements / herbal supplements
• Plant components with health benefits.
• E.g. Garlic or Echinacea

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Why do we develop botanical drugs?

• Diverge chemical range
• Enormous propensity to synthesize diverse
  bioactive compounds.
• (Multiple and mutually potentiating therapeutic
  effects)
• Complex molecules with unique
  properties.
• Biomanufacturing factories
• Relatively low-cost, highly effective and
  complex.
• 3. Higher investment cost on chemical synthesis.
• 4. Perception that phytochemicals provide a safer
  and more holistic approach to disease treatment
  and prevention.

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Development process of botanical drugs

• Development of botanical drugs is a hard and
  expensive task.
• Each new drug requires a big investment and a
  minimum of 5 - 10 years of work.
• Therefore, we have to adopt a very carefully
  planned strategy.
• The development of botanical drug emphasizes on
  three important aspects of the product
• Quality
• Efficacy
• Safety
• Inter-related as efficacy and safety largely
  depend on the quality.

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Herbal product developmentThe 6S Process

• Selection
• Herb informatics
• Unmet health need
• Sourcing
• Chemotaxonomy
• Raw material analysis
• Structure
• Identification of active constituents
• Method validation

• Standardization
• Chemical profile
• Pharmacological profile
• Safety
• Historical / traditional use
• Toxin analysis
• Safety studies in animals
• Substantiation
• . Review of pre-existing data
• Prospective clinical study

Joseph Chang, Biochemical Pharmacology, Vol.
59, pp 211-219, 2000.
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Study the guidelines for botanical drugs

• The final products are strictly controlled by the
  regulatory authorities.
• It is important to study the requirements of
  several important regulatory guidelines.

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USA FDA CDER Guidelines for botanical drugs

• The Guidance for Industry Botanical Drug
  Products quality standards for standardized
  plant extracts (botanical drugs).
• Guidelines for the development of drug products
  from botanicals.
• It is now possible to market these products under
  the New Drug Application (NDA) approval process.

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Abbreviated preclinical and clinical testing
protocols
For plants with safe history of human use USA
FDA proposed abbreviated preclinical and clinical
testing protocols for botanical drugs derived
from plants.
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Companies in North America and the UK currently
involved in development of botanical drugs for
clinical trials
Company Areas of clinical testing
Ancile pharmaceuticals. San Diego, CA Sleep, anxiety disorders
CV Technologies. Edmonton, Canada Respiratory infection
GW Pharmaceuticals. Salisbury, UK Cannabis-based prescription medicines
Oxford Natural Products. Oxford, UK Dysmenorrhoea, hepatitis-C symptoms, cognitive decline
PhytoCeutica. New Haven, CT Cancer, neurovascular disease
Phytomedics. Dayton, NJ Autoimmune diseases, cancer
Phytopharm. Godmanchester, UK Appetite suppressant, inflammatory bowel disease, Alzheimers disease, cancer
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WHO EMEA guidelines

• The WHO Guidelines for the Assessment of Herbal
  Remedies, adopted by the International Conference
  of Drug Regulatory Authorities (Ottawa, October
  1991).
• EMEA Guidelines.

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Pharmacopoeial monographs Quality specification

• Define the quality standards of herbal products.
• E.g USP NF (USA), Indian Pharmacopoeia, Chinese
  Pharmacopoeia.

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USP NF

• 21 monographs for medicinal plants and medicinal
  extracts.

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Structure of USP botanical monograph
Monograph for Gingko (USP26 NF21) Monograph for Gingko (USP26 NF21)
Definition of herbal product Microbial limits
Identification tests Limit tests For soil and sand contamination
Content tests Quantitative determination of marker compounds Content of flavonol glycosides by HPLC Content of terpene lactones by HPLC Heavy metals vii.. Pesticide residues

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Indian Herbal Pharmacopoeia Volume 2 Monograph
for Phyllanthus

• Describes analytical methods (HPLC) of marker
  compounds
• Phyllanthin and Hypophyllanthin

phyllanthin
hypophyllanthin
phyllanthin
hypophyllanthin
(a) Reference standards
(b) Sample preparation
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Chinese Pharmacopoeia Volume 1Monograph for
Ginkgo

• -- Describes assay method (HPLC) for flavonol
  glycosides.

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Main specification requirement of botanical
drugs

• Chemical standardization
• i. quality identification of the product.
• ii. quantitative determination of the marker
• compound(s) of the product.

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Chemical standardization
Chemical standardization emphasizes the
importance of determination of the content of the
herbal products.
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Importance of measurement

• A quotation from Lord Kelvin
• When you can measure what you are speaking
  about, and express it in numbers, you know
  something about it

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Malaysian guidelines
Guidelines for Standardization of Herbal
products
Guidelines for Levels and Kinds of Evidence to
Support Claims for Therapeutic Products
-- Published by National Committee For Research
And Development In Herbal Medicine (NRDHM)
-- Similar to FDA guidelines, they allow the
development of botanical drugs with
therapeutic claim.
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HEPAR-P capsuleApproved for clinical trial

• HEPAR-P Capsule contains standardized Phyllanthus
  niruri extract.
• 1st local product approved by Medical Research
  Ethics Committee, Ministry of Health Malaysia.
• For clinical testing to evaluate antiviral
  activities in patients with chronic hepatitis B.

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Two phases of development process Pre-clinical
and clinical studies

• Pre-clinical studies (Animal studies)
• Evaluate the pharmacological activities.
• Evaluate the toxicity.
• Clinical studies (Human studies)
• Evaluate the efficacy.
• Evaluate the toxicity.

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Flow chart of development of HEPAR-P Capsule (1)
Medical plant
Extract
Fractions
Toxicology
Bioassays
Chemical characterization
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Flow chart of development of HEPAR-P Capsule (2
- Contd)
Chemical standardization Qualitative
quantitative analytical methods
Standardized extract EPN 797
Pure compound
Drug Delivery Technology
New chemical entity
Manufacturing technology for Finished product
Stability studies
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Flow chart of development of HEPAR-P Capsule (3 -
Contd)

• Quality control protocol
• Chemical standardization
• Biological standardization

Complete monograph (of herbal product)
Approved herbal supplement
Animal toxicology studies (on the finished
product) -- Rodents Non-rodents -- According
to FDA / WHO / Malaysian guidelines
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Flow chart of development of HEPAR-P Capsule (4 -
Contd)

• LD 50
• Acute toxicology studies
• Sub-acute toxicology studies
• Chronic toxicology studies

Completion of pre-clinical studies
Submission to National Committee for Research and
Development In Herbal Medicine (NRDHM)
Approval to conduct clinical trial at appointed
hospitals
Report of clinical trial by clinical
investigators Recommendation by NRDHM
Application to DCA for registration with
therapeutic claim
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Specification of a botanical drug

• Chemical standardization
• Identification of chemical constituents
• Measurement of marker compounds
• Biological standardization
• In vitro anti-HBsAg activity (ELISA method)
• In vivo liver protective activity in rats
• Stability of the finished product
• Accelerated stability study
• Real time stability study

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Chemical structureCorilagin Phyllanthus
flavonoids
Corilagin Polyphenol (Anti-viral liver
protective)
Phyllanthus flavonoids (Liver protective)
Chemical structure of rutin, one of the
Phyllanthus total flavonoids.
Chemical structure of corilagin.
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TLC fingerprint
TLC identification of Phyllanthin and
fingerprints of HEPAR-P capsule
Niranthin
Hypophyllanthin
Phyllanthin
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TLC fingerprints (Contd)
TLC identification of rutin in HEPAR-P capsule
TLC identification of corilagin in HEPAR-P capsule
Corilagin
Rutin
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Chemical standardizationHEPAR-P Capsule

• Content of one HEPAR-P Capsule
• 250 mg of Phyllanthus niruri extract EPN
  797 standardized to contain
• Corilagin 10 mg
• Total flavonoids 45 mg

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HPLC analysis of corilagin
Chromatogram of Phyllanthus niruri extract EPN 797
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Biological standardization

• Chemical standardization is inadequate.
• Botanical drug contains a complex mixture of
  chemical compounds.
• Chemical standardization does not give a complete
  picture of a herbal product.
• We have combined biological assays with chemical
  fingerprints to provide assurance of efficacy and
  consistency.

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HEPAR-P CapsuleQuality control

• Chemical standardization
• Ensures batch-to-batch consistency in chemical
  composition.
• Biological standardization
• Ensures batch-to-batch reproducible biological
  activities.

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Biological standardization

• Liver protective In vivo (animal study)
• Anti-viral In vitro (ELISA test)

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Result of liver protective study
Effect of Phyllanthus on CCL4 induced Liver
injury in rats.
Effect of Phyllanthus on CCL4 induced Liver
injury in rats.
AST (U/L)
ALT (U/L)
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Result of Inactivation of HBsAg study
In vitro inhibitory activity against Hepatitis B
surface antigen (HBsAg) by HEPAR-P
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HEPAR-P CapsuleMonograph

• Quality specification (as compared to USP , IHP ,
  CP)
• Definition of product
• Chemical identification
• Chemical assays for characteristic marker
  compounds
• Assays for biological activity (or biological
  assay)
• Heavy metals
• Microbial limits

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Specification of HEPAR-P Capsule
Specification
Appearance description
Identity
Impurities
Potency
Contaminants
Quality
Heavy metals Microbial Pesticide residues
Color Smell
Product related
Process related
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Safety of HEPAR-P CapsuleAnimal toxicology
studies

• Toxicology evaluation on the finished product
• Acute studies (14 days, rodents and non-rodents)
• Sub-acute studies (90 days , rodents and
  non-rodents)
• Chronic study Rodents (180 days)
• Chronic study Non-rodents (270 days)

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Pre-clinical studies for HEPAR-P Capsule (Animal
studies)

• Identification The active fraction.
• Characterization The marker compound(s).
• Establishment Chemical standardization methods.
• (Optional Biological standardization methods)
• Animal toxicology studies.
• Stability studies.
• Formulation development.
• To establish a complete monograph of the
  product.
• Medical Research Ethnics Committee approval
  to conduct clinical trial.

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Completion of pre-clinical studiesApproval for
clinical trial
-- Approval by National Committee For
Research And Development In Herbal Medicine
(NRDHM). -- Clinical trial at Selayang General
Hospital on Jan / Feb., 2005.
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Clinical studies (Human studies)

• Clinical evaluation of safety and efficacy in
  human subjects by appointed clinical
  investigators.
• Report of the clinical evaluation by the
  investigators.
• Recommendation by National Committee for Research
  and Development in Herbal Medicine.
• Submission to DCA for registration of product as
  botanical drugs with approved therapeutic claim.

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Conclusion

• The development of botanical drugs is likely to
  be a major area of plant biotechnology expansion
  in the 21st century.
• The future of botanical drugs will depend on
  consumer and regulatory acceptance.
• 3. The important challenge is to provide
  science-based evidence to consumers and
  regulatory authority on
• i. Efficacy (By clinical evaluation in human),
  
• ii. Quality (Establish monograph of the
  standardized extract), and
• iii. Safety (By toxicological evaluations in
  animals and in human).

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Thank you