B Pharmacy Sem 6: Herbal Drug Technology

Subject3 : Herbal Drug Technology

Unit 1 – Herbal Raw Materials & Biodynamic Agriculture

Authentication, processing, agricultural best practices in Ayurveda, Siddha, Unani, Homeopathy

Unit 2 – Nutraceuticals & Herb‑Drug/Food Interactions (examples: garlic, ginseng, St. John’s wort)

Unit 3 – Herbal Cosmetics & Excipients (fixed oils, waxes, gums, colorants, flavors)

Unit 4 – Herbal Formulations & Industry Standards

Unit 5 – Quality Standards (WHO/ICH guidelines, GMP, patenting/regulatory aspects)

Unit 1: Herbal Raw Materials & Biodynamic Agriculture

This unit covers the collection, authentication, and cultivation of medicinal plants, emphasizing quality control and sustainable agricultural practices in various traditional systems.

3.1 Authentication of Herbal Raw Materials

• Macroscopic & Microscopic Examination

  • Macroscopic: Leaf shape, color, texture, aroma

  • Microscopic: Cell types (trichomes, stomata), powdered drug characters

• Chemical Profiling

  • Thin‑Layer Chromatography (TLC): Fingerprint profiles of marker compounds

  • High‑Performance Liquid Chromatography (HPLC): Quantitative assay of actives

• DNA Barcoding

  • Mechanism: Sequence standardized genomic regions (rbcL, matK)

  • Use: Detect adulteration and ensure species genuineness

3.2 Pre‑Harvest Cultivation Practices

• Soil & Climate Requirements

  • Soil: pH 6–7, well‑drained loam for most herbs

  • Climate: Adequate sunlight, appropriate rainfall; shade vs. full sun species

• Biodynamic Agriculture

  • Concept: Holistic farm management using homeopathic preparations (e.g., horn manure, horn silica)

  • Practices:

    • Crop rotation and green manuring for soil fertility

    • Planting by lunar/planetary cycles to enhance potency

• Organic Farming Standards

  • No synthetic pesticides/fertilizers

  • Use of bio‑fertilizers (vermicompost, mycorrhizae)

  • Integrated Pest Management (neem oil, pheromone traps)

3.3 Post‑Harvest Processing

• Drying & Storage

  • Methods: Shade drying vs. oven‑drying (≤ 40 °C) to preserve actives

  • Moisture Content: ≤ 10% to prevent microbial growth

  • Storage: Airtight, light‑resistant containers at < 25 °C

• Size Reduction & Extraction

  • Grinding: Uniform particle size for consistent extraction

  • Extraction Solvents: Water, ethanol, hydroalcoholic mixtures based on polarity of phytochemicals

• Standardization

  • Definition: Adjusting extract to a specified content of marker compounds

  • Techniques: Addition of purified marker or blending batches to uniform potency

Key Exam Tips

• Authentication: Differentiate TLC (qualitative) vs. HPLC (quantitative).

• Biodynamic vs. Organic: Biodynamic adds homeopathic preparations and lunar timing.

• Drying: Temperature control critical to protect heat‑sensitive compounds.

• Standardization: Ensures batch‑to‑batch uniformity—vital for efficacy and safety.

Unit 2: Nutraceuticals & Herb–Drug/Food Interactions

This unit explores dietary supplements with health benefits (nutraceuticals) and how herbal constituents can interact with drugs or foods, influencing efficacy and safety.

3.2.1 Nutraceuticals

Foods or food components that provide medical or health benefits, including the prevention and treatment of disease.

• Definition & Categories

  • Nutraceutical: “Nutrition” + “pharmaceutical”—beyond basic nutrition

  • Categories:

    • Dietary Supplements: Vitamins, minerals, amino acids (e.g., omega‑3 capsules)

    • Functional Foods: Fortified foods (e.g., probiotic yogurt)

    • Herbal Products: Standardized botanical extracts (e.g., green tea polyphenols)

• Key Examples

  • Omega‑3 Fatty Acids (fish oil)

    • Benefit: Cardiovascular protection, anti‑inflammatory

    • Dose: 1–4 g EPA/DHA daily

  • Curcumin (turmeric extract)

    • Benefit: Anti‑oxidant, anti‑inflammatory

    • Challenge: Poor bioavailability—use with piperine or in nanoformulations

  • Probiotics (Lactobacillus, Bifidobacterium)

    • Benefit: Gut health, immune modulation

    • Note: Strain‑specific effects; viability critical

3.2.2 Herb–Drug Interactions

Herbal constituents may alter the pharmacokinetics or pharmacodynamics of conventional drugs.

• Mechanisms

  • Enzyme Induction/Inhibition: Changes in CYP450 activity (e.g., ↑ metabolism → ↓ drug levels).

  • Transporter Modulation: P‑gp efflux pump effects (e.g., altered absorption/brain penetration).

  • Additive/Toxic Effects: Overlapping toxicities (e.g., hepatotoxic herbs + hepatotoxic drugs).

• Notable Examples

  • St. John’s Wort

    • Effect: Induces CYP3A4 & P‑gp → ↓ warfarin, oral contraceptives, protease inhibitors

    • Clinical: Breakthrough bleeding, transplant rejection risk

  • Grapefruit Juice

    • Effect: Inhibits CYP3A4 in gut wall → ↑ bioavailability of statins, calcium‑channel blockers

    • Clinical: Risk of statin myopathy, hypotension

  • Ginkgo biloba

    • Effect: Inhibits platelet‑activating factor & interacts with anticoagulants

    • Clinical: ↑ bleeding risk with warfarin, NSAIDs

3.2.3 Herb–Food Interactions

Certain foods can influence the activity of herbal products, affecting their therapeutic outcomes.

• Examples

  • Black Pepper (Piperine) + Curcumin

    • Effect: Piperine inhibits glucuronidation → ↑ curcumin bioavailability (~2000%)

  • Milk + Tannins (in Green Tea)

    • Effect: Proteins bind catechins → ↓ antioxidant absorption

  • High‑Fat Meals + Fat‑Soluble Phytochemicals

    • Effect: Enhance absorption of lipophilic compounds (e.g., carotenoids, curcuminoids)

Key Exam Tips

• Nutraceutical vs. Functional Food: Supplements in capsule form vs. fortified everyday foods.

• Enzyme interactions: Remember St. John’s Wort ↑ enzymes, grapefruit juice ↓ gut CYP.

• Additive toxicities: Always check overlapping side-effect profiles (e.g., bleeding risk).

• Bioavailability tricks: Dietary components (piperine, fat) can dramatically alter absorption.

Unit 4: Herbal Formulations & Industry Standards

This unit covers the preparation, manufacture, and regulation of herbal products, focusing on dosage forms, delivery systems, GMP, and regulatory requirements—presented in a clear, exam‑friendly format.

4.1 Conventional Herbal Dosage Forms

• Decoctions & Infusions

  • Method: Boiling (decoction) or steeping (infusion) plant parts in water

  • Use: Traditional liquid preparations (e.g., roots, leaves)

  • Key Point: Short shelf‑life; must be freshly prepared

• Tinctures & Fluid Extracts

  • Tincture: Herb in hydroalcoholic solvent (20–60 % ethanol)

  • Fluid Extract: Standardized 1 mL extract = 1 g crude herb

  • Use: Concentrated liquid dose; better stability than decoctions

• Powders, Tablets & Capsules

  • Powder: Dried, milled herb; may require filler/binder

  • Tablet/Capsule: Standardized extract with excipients for uniform dosing

  • Key Point: Ensures convenience, dose accuracy, patient compliance

4.2 Novel Herbal Delivery Systems

• Phytosomes

  • Concept: Complex of phytoconstituent + phospholipid to improve bioavailability

  • Example: Silybin–phosphatidylcholine complex

• Liposomes & Nanoparticles

  • Mechanism: Encapsulate extracts in lipid or polymer carriers → targeted delivery & controlled release

  • Benefits: Enhanced absorption, protected actives, reduced dosing frequency

• Transdermal Patches & Gels

  • Use: Localized or systemic delivery of herbal actives (e.g., arnica gels)

  • Advantage: Avoids first‑pass metabolism, steadier plasma levels

4.3 Good Manufacturing Practices (GMP)

• Quality Systems

  • SOPs: Defined procedures for every manufacturing step

  • Documentation: Batch records, deviation reports, change controls

• Facility & Equipment

  • Design: Segregated zones for raw materials, processing, and packaging

  • Validation: Equipment qualification (IQ/OQ/PQ), cleaning validation

• Personnel & Training

  • Requirement: Trained staff with clear responsibilities

  • Hygiene: Gowning, GMP awareness, periodic audits

4.4 Stability, Standardization & Scale-Up

• Standardization

  • Definition: Adjust extract to a defined content of marker compounds

  • Techniques: HPLC, UV‑Vis assays

• Stability Testing

  • Accelerated Conditions: 40 °C/75 % RH to predict shelf‑life

  • Parameters: Potency, moisture content, microbial limits

• Scale‑Up Considerations

  • Process Transfer: Lab → pilot → commercial scale with reproducible yields

  • Critical Controls: Extraction time, solvent ratio, temperature

4.5 Regulatory Requirements

• Ayurvedic & Traditional Standards

  • Ayush GMP Guidelines: Facility, personnel, product-specific monographs

  • WHO Monographs: Quality specs on identity, purity, contaminants

• Labeling & Claims

  • Mandatory: Latin binomial, batch number, expiry date, dosage instructions

  • Permissible Claims: Structure–function; no disease treatment claims without approval

• Pharmacopoeial Standards

  • Sources: Indian Pharmacopeia (IP), British Herbal Pharmacopoeia (BHP), USP Herbal Chapters

  • Compliance: Tests for ash values, extractive values, heavy metals, pesticide residues

Key Exam Tips

• Dosage Forms: Know water‑based vs. hydroalcoholic vs. solid forms and their pros/cons.

• Novel Systems: Phytosomes = lipid complexes; nanoparticles protect actives.

• GMP: Emphasize documentation and validation.

• Regulation: Ayush vs. WHO vs. Pharmacopoeia—match guideline to product type.

Unit 5: Quality Standards

This unit focuses on ensuring safety, purity, and efficacy of herbal products by applying international guidelines, analytical tests, and contaminant limits in a clear, exam‑ready format.

5.1 International Quality Guidelines

• WHO Guidelines for Herbal Medicines

  • Scope: Quality control, safety, efficacy, pharmacovigilance

  • Key Elements: Good agricultural/collection practices (GACP), GMP, stability requirements

• ICH Guidelines (Q1–Q14)

  • Relevance: Stability testing (Q1), analytical method validation (Q2), impurities (Q3)

• Ayush Standard Operating Procedures

  • Application: Traditional system–specific monographs, manufacturing protocols

5.2 Phytochemical Assays

• Qualitative Tests

  • TLC Fingerprinting: Profile comparison against reference standard

  • Colorimetric Reactions: Specific reagents yield characteristic colors (e.g., alkaloids with Dragendorff’s reagent)

• Quantitative Tests

  • HPLC/UPLC: Precise assay of marker compounds (e.g., curcumin, flavonoids)

  • UV‑Vis Spectrophotometry: Total phenolics (Folin–Ciocalteu) or tannins assays

5.3 Contaminant & Adulterant Testing

• Heavy Metals

  • Limits: Pb, Cd, Hg, As typically ≤ 10 ppm each

  • Method: Atomic absorption spectroscopy (AAS) or ICP‑MS

• Pesticide Residues

  • Limits: As per Codex Alimentarius or national pharmacopeias

  • Method: GC‑MS or LC‑MS/MS

• Microbial Contamination

  • Limits: Total aerobic count, yeasts & molds, absence of pathogens (E. coli, Salmonella)

  • Method: Plate count, PCR for specific organisms

• Foreign Matter & Adulterants

  • Visual Inspection: ≤ 2 % foreign matter

  • Chemical Screening: Marker absence/presence to detect substitution

5.4 Physical & Physicochemical Tests

• Moisture Content

  • Method: Loss on drying or Karl Fischer titration

  • Limit: ≤ 10 % in dried herbs/extracts

• Ash Values

  • Total Ash: Inorganic residue after combustion (≤ 5 %)

  • Acid‑insoluble Ash: Silica content (≤ 1 %)

• Extractive Values

  • Definition: % w/w of constituents extracted in specific solvent (water, ethanol)

  • Use: Batch consistency check

• Viscosity & pH

  • Relevance: Gels, syrups — ensure uniformity and stability

5.5 Stability & Shelf‑Life Determination

• Accelerated Stability

  • Conditions: 40 °C/75 % RH (6 months equivalent to 2 years real time)

  • Parameters: Assay, degradation products, moisture, microbial limits

• Real‑Time Stability

  • Conditions: Label‑storage conditions (e.g., 25 °C/60 % RH)

  • Outcome: Official expiry date

Key Exam Tips

• Guidelines: WHO GACP → GMP → ICH for global alignment.

• Assays: TLC for quick fingerprint; HPLC for precise quantification.

• Contaminants: Know heavy metal & microbial limits and test methods.

• Physical Tests: Ash and extractive values are fundamental for identity & consistency.

• Stability: Differentiate accelerated vs. real-time protocols.