Product Development and

Clinical Studies of

Traditional Medicines

N. L. Phang

Nova Laboratories Sdn. Bhd.

Malaysia

(www.nova.com.my)

Objectives

1. To discuss the main issues and regulatory guidelines on product development.

2. 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.

Successful herbal product:Development 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.

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.

Definition of herbal products (Cont’d)

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.

C. Dietary supplements / herbal supplementsPlant components with health benefits.E.g.: Garlic or Echinacea

Why do we develop botanical drugs?

1. Diverge chemical rangeEnormous propensity to synthesize diverse bioactive compounds.

(Multiple and mutually potentiating therapeutic effects)

Complex molecules with unique properties.

2. 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.

Development process of botanical drugs

i. Development of botanical drugs is a hard and expensive task.

ii. Each new drug requires a big investment and a minimum of 5

- 10 years of work.

iii. Therefore, we have to adopt a very carefully planned strategy.

iv. 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.

Herbal product development:The 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.

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.

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.

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.

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, UKDysmenorrhoea, hepatitis-C symptoms, cognitive decline

PhytoCeutica. New Haven, CT Cancer, neurovascular disease

Phytomedics. Dayton, NJ Autoimmune diseases, cancer

Phytopharm. Godmanchester, UKAppetite suppressant, inflammatory bowel disease, Alzheimer’s disease, cancer

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.

Pharmacopoeial monographs: Quality specification

• Define the quality standards of herbal

products.

• E.g: USP NF (USA), Indian Pharmacopoeia,

Chinese Pharmacopoeia.

USP NF

• 21 monographs for medicinal plants and medicinal extracts.

Structure of USP botanical monograph Monograph for Gingko (USP26 NF21):

i. Definition of herbal product iv. Microbial limits

ii. Identification tests v. Limit tests – For soil and sand contamination

iii. Content tests – Quantitative determination of marker compounds

a. Content of flavonol glycosides by HPLC

b. Content of terpene lactones by HPLC

vi. Heavy metals

vii.. Pesticide residues

Indian Herbal Pharmacopoeia Volume 2: Monograph for Phyllanthus

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

hypophyllanthin

phyllanthin hypophyllanthin

phyllanthin

(a) Reference standards (b) Sample preparation

Chinese Pharmacopoeia Volume 1:Monograph for Ginkgo

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

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.

Chemical standardization

Chemical standardization emphasizes the

importance of determination of the content

of the herbal products.

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 …”

Malaysian guidelines

-- Published by National Committee For Research And

Development In Herbal Medicine (NRDHM)

Guidelines for Standardization of

Herbal products

Guidelines for Levels and Kinds of Evidence to Support Claims for Therapeutic Products

-- Similar to FDA guidelines, they allow the development of

botanical drugs with therapeutic claim.

HEPAR-P capsule:Approved 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.

Two phases of development process:

Pre-clinical and clinical studies

1. Pre-clinical studies (Animal studies)

• Evaluate the pharmacological activities.

• Evaluate the toxicity.

2. Clinical studies (Human studies)

• Evaluate the efficacy.

• Evaluate the toxicity.

Flow chart of development of HEPAR-P Capsule (1)

Medical plant

Extract

Fractions ToxicologyBioassays

Chemical characterization

Flow chart of development of HEPAR-P Capsule (2 - Cont’d)

Standardized extract – EPN 797

Drug Delivery Technology

Manufacturing technology for

Finished product

Stability studies

Pure compound

New chemical entity

Chemical standardization

Qualitative & quantitative analytical methods

Flow chart of development of HEPAR-P Capsule (3 - Cont’d)

Complete monograph (of herbal product)

Approved herbal supplement

Animal toxicology studies (on the finished product)

-- Rodents & Non-rodents

-- According to FDA / WHO / Malaysian guidelines

Quality control protocol• Chemical standardization• Biological standardization

Flow chart of development of HEPAR-P Capsule (4 - Cont’d)

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

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

Specification of a botanical drug

i. Chemical standardization• Identification of chemical constituents• Measurement of marker compounds

ii. Biological standardization• In vitro anti-HBsAg activity (ELISA method)• In vivo liver protective activity in rats

iii. Stability of the finished product• Accelerated stability study• Real time stability study

Chemical structure:Corilagin & 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.

TLC fingerprint

Niranthin

HypophyllanthinPhyllanthin

TLC identification of Phyllanthin and fingerprints of HEPAR-P capsule

TLC fingerprints (Cont’d)

TLC identification of rutin in HEPAR-P capsule

Corilagin

TLC identification of corilagin in HEPAR-P capsule

Rutin

Chemical standardization:HEPAR-P Capsule

Content of one HEPAR-P Capsule

250 mg of Phyllanthus niruri extract EPN 797

standardized to contain:i. Corilagin 10 mgii. Total flavonoids 45 mg

HPLC analysis of corilagin

Chromatogram of Phyllanthus niruri extract EPN 797

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.

HEPAR-P Capsule:Quality control

• Chemical standardization

– Ensures batch-to-batch consistency in

chemical composition.

• Biological standardization

– Ensures batch-to-batch reproducible

biological activities.

Biological standardization

• Liver protective – In vivo (animal study)

• Anti-viral – In vitro (ELISA test)

Result of liver protective study

0

50

100

150

200

Control CCL4 control Treatment withPhyllanthus

0

50

100

150

200

Control CCL4 control Treatment withPhyllanthus

ALT

(U

/L)

AS

T

(U/L

)

Effect of Phyllanthus on CCL4 induced Liver injury in rats.

Effect of Phyllanthus on CCL4 induced Liver injury in rats.

Result of Inactivation of HBsAg study

In vitro inhibitory activity against

Hepatitis B surface antigen (HBsAg) by HEPAR-P™

HEPAR-P Capsule:Monograph

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

Specification of HEPAR-P Capsule

Specification

Appearance description

Identity Impurities Potency Contaminants Quality

Color

SmellProduct related

Process related

Heavy metals

Microbial

Pesticide residues

Safety of HEPAR-P Capsule:Animal toxicology studies

Toxicology evaluation on the finished product:

i. Acute studies (14 days, rodents and non-rodents)

ii. Sub-acute studies (90 days , rodents and non-rodents)

iii. Chronic study – Rodents (180 days)

iv. Chronic study – Non-rodents (270 days)

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.

Completion of pre-clinical studies:Approval 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.

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.

Conclusion

1. The development of botanical drugs is likely to be a major area of plant biotechnology expansion in the 21st century.

2. 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).

Thank you