Galenical Preparations

Galenical preparations refer to medicinal formulations prepared from natural

sources, primarily plant-based, according to methods derived from the ancient Greek
physician Galen. These preparations are the foundation of herbal medicine and were
historically the main form of drug formulation before the advent of synthetic
pharmaceuticals. Galenical formulations typically involve the extraction and
preparation of active ingredients from herbs, roots, leaves, and other natural materials,
often in combination with excipients (inert substances used to formulate the drug).

Detailed Explanation:

1. Origins and Historical Context:

The term "Galenical" is derived from Galen (129-216 AD), a prominent Greek
physician who significantly influenced the preparation and use of natural remedies.
His principles guided the extraction of plant-based substances, ensuring the
therapeutic properties of the plants were preserved. These practices formed the basis
of early pharmacy.

2. Types of Galenical Preparations:

Galenical preparations can take various forms, including:

 Tinctures: Alcoholic or hydro-alcoholic solutions of plant extracts.

 Infusions: Preparations made by soaking plant material in hot water, similar to
brewing tea.
 Decoctions: More concentrated than infusions, these are made by boiling plant
material in water to extract the active ingredients.
 Extracts: Concentrated forms of plant material where the solvent is
evaporated, leaving a solid or semi-solid product.
 Syrups: Sweetened, often medicinal liquids containing plant extracts.
 Ointments and Creams: Topical formulations made by mixing plant extracts
with fats or oils for external application.

3. Preparation Process:

The process of creating galenical preparations typically involves several key steps:

 Collection of raw materials: Plants or natural materials are harvested at the

appropriate time to ensure maximum potency.
 Drying: The plant material is dried to preserve the active components and
prevent decomposition.
 Extraction: Various solvents (water, alcohol, oils) are used to extract the
active ingredients from the plant material. The method of extraction depends
on the type of preparation being made (e.g., infusion, tincture, or decoction).
  Concentration and preservation: In some cases, the extracted solutions are
concentrated by evaporation, and preservatives are added to ensure the
stability and shelf life of the product.

4. Benefits of Galenical Preparations:

 Natural source: They utilize whole plant extracts, providing a mixture of

compounds that may have synergistic effects, enhancing the overall
therapeutic outcome.
 Personalized medicine: Historically, they allowed for customized
formulations based on the patient’s specific needs and symptoms.
 Minimal synthetic chemicals: These preparations are often free from
artificial preservatives, colors, and additives, making them suitable for
individuals seeking natural remedies.

5. Modern Use and Relevance:

Although modern pharmaceutical practices focus more on synthetic drugs and active
pharmaceutical ingredients (APIs), galenical preparations remain relevant in herbal
medicine, homeopathy, and alternative therapies. Herbalists and practitioners still
prepare and prescribe these remedies for their holistic approach to health.

6. Regulatory Considerations:

In the modern era, galenical preparations are subject to regulatory scrutiny to ensure
safety, efficacy, and quality. Various pharmacopeias (official drug reference books)
provide guidelines on the preparation, standardization, and testing of galenical
products.

7. Examples of Galenical Preparations:

 Belladonna tincture: Historically used for its antispasmodic and pain-

relieving properties.
 Cough syrups: Often contain natural plant extracts like eucalyptus, honey,
and thyme.
 Arnica ointment: Used for topical relief of bruises, muscle aches, and
inflammation.

8. Challenges in Galenical Preparations:

 Standardization: Ensuring consistent concentrations of active ingredients can

be difficult due to variability in plant material.
 Stability: Natural products may degrade or lose potency over time if not
properly preserved.
 Scientific validation: Many galenical preparations are not backed by robust
clinical trials, making their efficacy a subject of ongoing research.
Types of Extracts

Here are the common types of extracts used in galenical preparations:

1. Aqueous Extracts

 Description: Water-based extracts where water is used as the primary solvent

to extract active components from plant material.
 Preparation: Often prepared by infusing or decocting plant materials in
boiling water.
 Examples: Herbal teas, infusions, and decoctions (e.g., chamomile tea or
dandelion root decoction).
 Use: Suitable for extracting water-soluble compounds like alkaloids, tannins,
and flavonoids.

2. Alcoholic Extracts (Tinctures)

 Description: Alcohol is used as the solvent to extract plant materials,

particularly useful for compounds not easily soluble in water.
 Preparation: Dried or fresh plant material is soaked in alcohol (ethanol),
typically at a specific ratio like 1:4 or 1:5.
 Examples: Tinctures of echinacea, valerian, and ginseng.
 Use: Ideal for extracting both water-soluble and alcohol-soluble constituents,
such as volatile oils and resins. Long shelf life due to alcohol.

3. Hydro-Alcoholic Extracts

 Description: A combination of water and alcohol is used to extract a broader

range of compounds from plants, balancing the solubility properties of both
solvents.
 Preparation: The plant material is soaked in a water-alcohol mixture at
various concentrations depending on the solubility of desired components.
 Examples: Herbal tinctures, such as mother tinctures in homeopathy.
 Use: Useful for extracting both polar (water-soluble) and non-polar (alcohol-
soluble) substances, such as alkaloids and glycosides.

4. Powdered Extracts (Dry Extracts)

 Description: These are solid extracts obtained by evaporating the solvent

completely, resulting in a dry, concentrated powder of the active components.
 Preparation: After the plant material is extracted using water, alcohol, or
other solvents, the liquid is evaporated to leave a dry powder.
 Examples: Green tea extract, ginger extract, and ginkgo biloba extract.
 Use: Commonly used in tablets, capsules, or powdered formulations due to
their long shelf life and ease of standardization.
5. Soft Extracts (Semi-Solid Extracts)

 Description: Semi-solid extracts where the solvent is partially evaporated,

leaving behind a thick, paste-like consistency.
 Preparation: The plant material is extracted with a solvent (often water or
alcohol), and the solvent is partially removed to form a soft, concentrated
product.
 Examples: Aloe vera gel, belladonna soft extract.
 Use: Suitable for external or topical preparations like ointments, creams, and
gels.

6. Oil Extracts (Oleoresins and Essential Oils)

 Description: Fatty oils or volatile oils are extracted from plant materials, often
using solvents like hexane or steam distillation.
 Preparation: Volatile oils are typically extracted via steam distillation, while
fatty oil extracts (oleoresins) are obtained by solvent extraction followed by
evaporation.
 Examples: Peppermint oil, eucalyptus oil, and turmeric oleoresin.
 Use: Primarily used in aromatherapy, topical applications, or as flavoring
agents.

7. Acetone or Ether Extracts

 Description: Non-polar solvents such as acetone or ether are used to extract

lipid-soluble components from plant material.
 Preparation: Plant material is soaked in acetone or ether, and the solvent is
evaporated to yield a concentrated extract.
 Examples: Extracts used in topical applications or in industrial processes.
 Use: Suitable for extracting lipophilic substances such as terpenoids, resins,
and essential oils.

8. Glycerin Extracts (Glycerites)

 Description: Glycerin is used as the solvent to extract active ingredients from

plant material, often as an alternative to alcohol.
 Preparation: The plant material is macerated in glycerin for a specific period.
 Examples: Glycerites of herbal extracts, such as glycerin extracts of echinacea
or elderberry.
 Use: Ideal for alcohol-sensitive individuals or children. Glycerin acts as both a
preservative and a sweetening agent.

9. Vinegar Extracts

 Description: Vinegar (acetic acid) is used as the solvent for extraction,

primarily for extracting alkaloids and other water-soluble compounds.
 Preparation: Plant material is soaked in vinegar to extract active ingredients.
  Examples: Herbal vinegar extracts used in folk medicine (e.g., apple cider
vinegar infused with herbs).
 Use: Useful for making natural remedies, especially for digestive and
metabolic health.

Methods of Extraction

Methods of extraction are key to isolating active ingredients from natural sources,
whether for pharmaceutical, nutraceutical, or cosmetic purposes. Different methods
vary based on the nature of the bioactive compounds, the desired final product, and
the solvent used. Below is a detailed explanation of common extraction methods and
the apparatus used for each.

1. Maceration

Description: Maceration is the simplest and oldest extraction technique. It involves

soaking the plant material in a solvent at room temperature for a fixed period, during
which the soluble compounds are extracted.

Procedure:

 The plant material is cut into small pieces and placed in a container.
 The solvent (water, ethanol, or oil) is poured over the plant material.
 The mixture is left to stand for a period (usually 2-7 days) with periodic
stirring to enhance extraction.
 Afterward, the solvent is filtered to remove solid residues, and the extract is
collected.

Apparatus:

 Glass or stainless steel maceration tank or vat: The plant material is soaked
in this.
 Stirrer: For periodic mixing to aid the dissolution of active ingredients.
 Filter cloth or filtration system: To remove solid particles from the liquid
extract.

Advantages:

 Simple and low-cost.

 Suitable for heat-sensitive compounds.

Disadvantages:

 Time-consuming and yields less concentrated extracts.

Maceration is a widely used extraction technique in pharmaceutical and herbal

industries, involving soaking plant material in a solvent to dissolve the active
compounds. There are different types of maceration techniques based on the nature of
the extraction process and the desired outcome.
Figure: Maceration experimental device

Here are the main types of maceration:

1. Simple Maceration

Description: This is the traditional form of maceration where the plant material is
soaked in a solvent (usually water, alcohol, or oil) at room temperature for a specific
period (typically 3-7 days).

Procedure:

 Plant material is cut into small pieces.

 It is soaked in a solvent, stirring occasionally.
 After the set period, the liquid is filtered and used as the extract.

Applications: Simple maceration is used for preparations like tinctures, herbal

infusions, and some pharmaceutical formulations.

2. Modified Maceration (Double Maceration or Triple Maceration)

Description: In modified maceration, the extraction process is performed in two or

three stages to increase the yield of active ingredients.

Procedure:

 The plant material is macerated with a portion of the solvent.

 After the first maceration, the liquid is separated.
 The same plant material is then macerated with a fresh portion of the solvent
in a second or third cycle.
 All portions of the extract are combined to make the final product.
Applications: Used when higher yields of extract are required, especially in cases
where the active compounds are less soluble.

3. Digestion

Description: Digestion is a form of maceration that involves applying gentle heat

during the extraction process. Heat increases the solubility of active compounds and
speeds up extraction.

Procedure:

 The plant material is soaked in a solvent at a temperature slightly above room

temperature (30-40°C) for a few hours to several days.
 The mixture is then filtered to obtain the extract.

Apparatus:

 Water bath or controlled heat source to maintain a constant temperature.

Applications: Digestion is useful for extracting compounds that are not fully soluble
at room temperature but are heat-stable. This method is commonly used in
pharmaceutical preparations involving viscous extracts, such as syrups.

4. Maceration with Circulation

Description: In this method, the solvent is continuously circulated over the plant
material to maintain fresh contact between the solvent and the plant, enhancing the
extraction process.

Procedure:

 A circulation pump keeps the solvent flowing through the plant material.
 The solvent passes through a filter to remove plant particles and recirculates
through the system.

Apparatus:

 Circulation system with pumps and filters.

Applications: This method is used in large-scale industrial extractions for better

efficiency and to reduce the amount of solvent required. It is often employed in the
production of tinctures and herbal extracts.

5. Cold Maceration

Description: Cold maceration is performed without the application of heat. It is

mainly used for heat-sensitive compounds that could degrade when exposed to higher
temperatures.
Procedure:

 The plant material is soaked in a cold solvent for a prolonged period (days or
even weeks).
 The mixture is stirred periodically and then filtered to obtain the extract.

Applications: This method is ideal for extracting volatile oils, delicate flavonoids, or
other heat-sensitive bioactive compounds. It is commonly used in the production of
high-quality herbal infusions, such as essential oils and extracts used in aromatherapy.

6. Kinetic Maceration

Description: Kinetic maceration uses mechanical agitation (shaking or stirring) to

speed up the extraction process by increasing the contact between the plant material
and the solvent.

Procedure:

 Plant material is placed in a solvent.

 The mixture is mechanically stirred or shaken continuously or intermittently.
 After a set time, the mixture is filtered.

Apparatus:

 Mechanical stirrer or shaker.

Applications: This method accelerates extraction and can be used in large-scale

processes where time efficiency is crucial.

7. Turbo-Maceration

Description: Turbo-maceration is an advanced technique that employs high-speed

blenders or homogenizers to break down plant material during maceration, increasing
the surface area for solvent contact and speeding up the extraction process.

Procedure:

 The plant material is mixed with solvent in a high-speed blender or

homogenizer.
 The mechanical action breaks down the plant material while simultaneously
extracting the active ingredients.
 The mixture is filtered to remove the plant residues.

Apparatus:

 High-speed blender or homogenizer.

Applications: Turbo-maceration is used when a fast extraction is required or when

working with tough plant materials. It is commonly employed in the production of
plant extracts for cosmetic and nutraceutical industries.
8. Countercurrent Maceration

Description: In countercurrent maceration, fresh solvent flows in the opposite

direction to the plant material movement. This method maximizes the extraction
efficiency by ensuring that the solvent in contact with the plant material is constantly
saturated with the least-extracted portions.

Procedure:

 The solvent flows in a countercurrent direction to the movement of plant

material through a system.
 This maximizes solvent contact with fresh plant material and optimizes
extraction.

Apparatus:

 Countercurrent extraction system with a continuous feed of solvent and

plant material.

Applications: This method is used in large-scale operations where maximum

extraction yield is essential, such as in the production of essential oils and botanical
extracts.

2. Percolation

Description: Percolation involves continuously passing solvent through plant

material, maximizing extraction efficiency by keeping the solvent in contact with the
material for longer periods.

Procedure:

 The plant material is moistened with solvent and allowed to swell.

 It is placed in a percolator, and fresh solvent is passed through it
continuously.
 The solvent extracts the active ingredients and the liquid extract (percolate) is
collected at the bottom.

Apparatus:

 Percolator: A cylindrical vessel (usually glass or metal) with an outlet at the

bottom to collect the percolate.
 Stirrer or agitator: Sometimes included to help extract materials evenly.
 Filter: To prevent plant material from clogging the percolator outlet.

Advantages:

 More efficient than maceration.

 Continuous extraction process provides better yield.
Disadvantages:

 Requires specialized apparatus (percolator).

 May require frequent solvent replacement.

Figure: a,b) Percolation assembly c) Soxhlet apparatus

Here are the main types of percolation:

1. Simple Percolation

Description: This is the traditional method of percolation where the solvent slowly
passes through the plant material, which is packed in a percolator (a cone-shaped
vessel). The solvent extracts the soluble compounds as it moves through the material.

Procedure:

 The plant material is moistened and allowed to swell.

 It is packed into the percolator.
 The solvent is added to the top, and it percolates through the material under
gravity.
 The extract is collected at the bottom.

Apparatus:

 Percolator (a conical vessel with an opening at the base to allow solvent

flow).
Applications: Simple percolation is commonly used for preparing tinctures, liquid
extracts, and other herbal products in small to medium-scale productions.

2. Continuous Percolation (Soxhlet Percolation)

Description: In continuous percolation, fresh solvent is continuously cycled through

the plant material, ensuring that the material is always exposed to solvent. Soxhlet
percolation is a common example where the solvent is boiled, condensed, and then
passed through the plant material repeatedly.

Procedure:

 Plant material is placed in a chamber within the Soxhlet apparatus.

 The solvent is heated to boil, and its vapor condenses, dripping over the plant
material.
 The solvent containing dissolved compounds is siphoned back to the boiling
flask and re-circulated.

Apparatus:

 Soxhlet extractor (includes a boiling flask, thimble, and condenser).

Applications: This method is particularly efficient for extracting compounds that are
only moderately soluble in the solvent. It is widely used in laboratories and industries
for continuous extraction over time.

3. Reserved Percolation (Intermittent Percolation)

Description: Reserved or intermittent percolation is a modified form of percolation

where the solvent is added in portions over a period of time. After a portion of the
solvent is passed through the material, it is left in contact with the plant material for
further extraction, then drained before another portion is added.

Procedure:

 A portion of the solvent is added to the packed plant material in the percolator.
 The solvent is allowed to stay in contact with the material for a while before
being drained.
 This process is repeated with fresh portions of the solvent, which are
combined to form the final extract.

Apparatus:

 Percolator.
Applications: Reserved percolation is suitable when complete extraction of the active
compounds is required, especially for large-scale operations.

4. Repercolation

Description: In repercolation, the percolate obtained from one batch of extraction is

used as the solvent for another batch of plant material. This technique is repeated
several times to concentrate the extract.

Procedure:

 Plant material is packed into the percolator, and the solvent is passed through.
 The extract obtained is used as the solvent for a fresh batch of plant material.
 The process is repeated multiple times to increase the concentration of the
active compounds.

Apparatus:

 Percolator.

Applications: Repercolation is used when a highly concentrated extract is needed,

and it is more efficient than simple percolation when dealing with large-scale
production.

5. Modified Percolation

Description: This is a variation of percolation where the process is altered to increase

efficiency. It includes methods like heating the solvent, pressurizing the system, or
applying vacuum to speed up the extraction process and improve yield.

Procedure:

 Plant material is placed in a percolator, and modifications like heating or

pressurizing the solvent are introduced.
 The solvent is passed through the material, and the extract is collected.

Apparatus:

 Percolator with heating or pressurizing capabilities.

Applications: Modified percolation is useful for extracting heat-stable compounds or

speeding up the extraction process in industrial settings.

6. Countercurrent Percolation
Description: In countercurrent percolation, the flow of solvent and plant material are
in opposite directions, ensuring that fresh solvent is in contact with the least-extracted
material. This enhances the extraction efficiency.

Procedure:

 Plant material and solvent move in opposite directions in the percolator.

 As the plant material moves down, the solvent moves up, extracting the active
compounds efficiently.

Apparatus:

 Percolation system designed for continuous countercurrent flow.

Applications: This method is suitable for large-scale industrial extractions where

maximizing efficiency and minimizing solvent use are important.

7. Pressurized Percolation

Description: This method involves applying pressure to the solvent during

percolation to increase the penetration of the solvent into the plant material. The
increased pressure enhances extraction by forcing the solvent deeper into the material.

Procedure:

 The plant material is packed into a percolator.

 Solvent is passed through under pressure to improve extraction efficiency.

Apparatus:

 Percolator with pressure control.

Applications: Pressurized percolation is useful for extracting compounds from dense

or hard-to-penetrate materials and is often used in the extraction of essential oils or
other difficult-to-extract substances.
Difference between maceration & percolation

Feature Maceration Percolation

A process where the plant material A process where the solvent is
is soaked in a solvent for a set continuously passed through a
Definition
period, allowing the solvent to column of plant material to
extract soluble compounds. extract soluble compounds.
The solvent remains in contact with
The solvent passes through the
the plant material for an extended
Mechanism plant material, dissolving
time to dissolve the active
compounds as it flows.
ingredients.
Time Longer (days or weeks) depending Faster (hours or days), due to
Required on the material and solvent. continuous flow of solvent.
Solvent Static (plant material is soaked in Dynamic (solvent continuously
Movement the solvent without movement). flows through the material).
Lower efficiency due to lack of Higher efficiency because fresh
Efficiency solvent movement and limited solvent continually contacts the
contact. plant material.
Generally uses a smaller volume
Requires a larger volume of solvent
Solvent Use of solvent, making the process
to ensure adequate extraction.
more efficient.
Yield may be lower or take longer Yield is typically higher and
Yield
to reach maximum extraction. achieved more quickly.
Suitable for small-scale or home- Better suited for large-scale and
Scaling
based preparations. industrial applications.
Requires a percolator, a
Apparatus Simple containers like jars or
specialized apparatus designed for
Used macerators.
continuous extraction.
More control, as the solvent flow
Control Over
Less control; extraction is passive. can be adjusted for optimal
Process
extraction.
Common Used for preparing tinctures, Commonly used for tinctures,
Applications infusions, and macerated oils. liquid extracts, and essential oils.
Requires careful monitoring but
Labor Less labor-intensive but requires a
can be automated for large-scale
Intensity long soaking period.
production.
3. Infusion

Description: Infusion involves soaking the plant material in hot or boiling water for a
short time to extract water-soluble compounds.

Procedure:

 Plant material is added to hot water (similar to making tea).

 The mixture is steeped for a short period (5-30 minutes), depending on the
material.
 The liquid is then filtered to remove plant particles.

Apparatus:

 Infusion pot or flask: Heat-resistant glass or stainless steel containers.

 Filtration system: To strain the plant material after extraction.

Advantages:

 Easy to perform with basic equipment.

 Suitable for delicate, water-soluble compounds (e.g., tannins, glycosides, and
flavonoids).

Disadvantages:

 Not suitable for heat-sensitive or non-water-soluble compounds.

4. Decoction

Description: Decoction is a more intense process than infusion. The plant material is
boiled in water for a long time to extract tough or fibrous materials such as roots or
bark.

Procedure:

 The plant material is placed in boiling water for 15-60 minutes, depending on
the hardness of the material.
 The liquid is then filtered.

Apparatus:

 Boiling flask or pot: Usually made from heat-resistant glass or stainless steel.
 Hot plate or burner: To boil the water.
 Filter: To strain the solid plant material from the liquid extract.
Advantages:

 Suitable for tough plant materials (e.g., roots, seeds, bark).

Disadvantages:

 Prolonged heating may degrade heat-sensitive compounds.

5. Soxhlet Extraction

Description: Soxhlet extraction is a continuous extraction technique that recycles

solvent through the plant material, providing efficient extraction of bioactive
compounds.

Procedure:

 The plant material is placed inside a thimble in the Soxhlet apparatus.

 Solvent is heated, evaporated, and condensed, and the condensate passes
through the plant material, extracting its active ingredients.
 The solvent continuously recycles, allowing thorough extraction.

Apparatus:

 Soxhlet extractor: Composed of a thimble holder, condenser, and a

distillation flask for solvent recovery.
 Heating mantle or water bath: To maintain the desired temperature for
solvent vaporization.
 Thimble: Holds the plant material inside the Soxhlet chamber.

Advantages:

 Highly efficient.
 Can extract large quantities of bioactive ingredients with minimal solvent use.

Disadvantages:

 Requires specialized equipment.

 Consumes a significant amount of energy.

6. Steam Distillation

Description: Steam distillation is mainly used for extracting essential oils from plant
materials. Steam is passed through the plant material, vaporizing volatile compounds,
which are then condensed and collected.
Procedure:

 Steam is generated in a boiler and passed through the plant material.

 The steam carries the volatile oils with it, which are condensed back into a
liquid.
 The essential oil separates from the water and is collected.

Apparatus:

 Distillation still: A closed system that includes a boiler, condenser, and

collection flask.
 Separator funnel: Used to separate the essential oil from the aqueous
distillate.

Advantages:

 Ideal for volatile oils.

Disadvantages:

 Only suitable for volatile compounds.

 Large-scale operations require substantial infrastructure.

7. Supercritical Fluid Extraction (SFE)

Description: This advanced method uses supercritical CO₂ as a solvent for extracting
bioactive compounds, particularly oils and lipophilic compounds.

Procedure:

 Supercritical CO₂ is passed through the plant material, dissolving the

bioactive ingredients.
 The CO₂ is depressurized to allow the collection of the compounds.

Apparatus:

 Supercritical fluid extractor: Includes a pressurization system, extraction

vessel, and collection vessel.
 CO₂ tanks: Supply the supercritical fluid.
 Heat exchanger: Maintains the temperature needed to keep CO₂ in a
supercritical state.

Advantages:

 Environmentally friendly, leaves no solvent residues.

 High efficiency and purity of the extract.
Disadvantages:

 Expensive, complex equipment.

 Only viable for lipophilic compounds.

8. Ultrasonic-Assisted Extraction (UAE)

Description: Ultrasonic waves break the plant cell walls, allowing solvents to more
easily extract bioactive compounds.

Procedure:

 Plant material is suspended in a solvent.

 Ultrasonic waves create cavitation bubbles that rupture the plant cell walls,
releasing active ingredients into the solvent.
 The mixture is filtered to collect the extract.

Apparatus:

 Ultrasonic bath or ultrasonic probe: To apply ultrasonic waves to the

mixture.
 Stainless steel or glass container: Holds the plant material and solvent.

Advantages:

 Reduces extraction time and increases efficiency.

Disadvantages:

 Limited scalability for large-scale extractions.

9. Microwave-Assisted Extraction (MAE)

Description: Microwaves are used to heat solvents and plant materials, accelerating
the extraction process.

Procedure:

 The plant material and solvent are placed in a microwave reactor.

 Microwaves heat the solvent and plant material, increasing extraction
efficiency.
 The extract is then filtered to remove solids.

Apparatus:
  Microwave extractor: A microwave unit designed for extraction purposes.
 Closed vessel: To prevent solvent evaporation during the process.

Advantages:

 Very fast and efficient.

Disadvantages:

 May degrade heat-sensitive compounds if not controlled.

10. Cold Pressing

Description: A mechanical process that extracts oils from plant materials (usually
seeds or fruits) without heat.

Procedure:

 The plant material is placed into a hydraulic press.

 High pressure is applied to squeeze out the oil without using heat.

Apparatus:

 Hydraulic press or mechanical expeller: Provides high pressure to extract

the oils.

Advantages:

 Ideal for preserving heat-sensitive oils (e.g., essential fatty acids).

Disadvantages:

 Not suitable for extracting non-oil compounds.

 Lower yield compared to solvent extraction.

Preparation of Galenicals: Extracts, Tinctures, and Spirits

1. Extracts

Definition: Extracts are concentrated preparations of the active constituents of plants,

prepared by soaking plant materials in solvents like water, alcohol, or other suitable
liquids to dissolve and remove the active components. Once the desired constituents
are extracted, the solvent is evaporated, yielding a concentrated product.

Types of Extracts
 1. Fluid Extracts: These are liquid extracts where 1 part of the dry herb
produces 1 part of the extract (1:1 ratio). They are highly concentrated and can
be diluted or used directly.
2. Soft Extracts: These are semi-solid extracts where the solvent is partially
removed, and the extract retains a soft, paste-like consistency.
3. Dry Extracts: Here, most of the solvent is evaporated, leaving a solid or
powdery residue, often used in tablet or capsule formulations.

Method of Preparation:

a. Simple Maceration:

 Plant Material: Crushed or powdered plant material is used.

 Solvent: Water, ethanol, or a hydroalcoholic mixture.
 Process:

1. The plant material is soaked in the solvent in a macerator for a

specified time (days or weeks), depending on the plant and solvent.
2. The mixture is stirred periodically to increase extraction efficiency.
3. After the set time, the mixture is filtered to separate the extract from
the plant material.
4. The filtrate is concentrated by evaporating some or all of the solvent,
depending on the desired type of extract.

b. Percolation:

 Plant Material: Coarsely ground plant material.

 Solvent: Alcohol, water, or a combination of both.
 Process:

1. The plant material is moistened and packed into a percolator.

2. The solvent is poured over the material and allowed to percolate
slowly.
3. The extract is collected at the bottom, and the process continues until
the desired quantity is obtained.
4. The extract is then concentrated by evaporation.

Apparatus:

 Macerator (a simple jar or container), Percolator (cone-shaped vessel for

solvent extraction), and evaporators for solvent removal.

Examples:

 Aloe extract (used in cosmetics and laxatives), belladonna extract (used for
muscle relaxation).

2. Tinctures
Definition: Tinctures are alcoholic or hydroalcoholic solutions prepared from plant
materials or animal products. They typically contain 20-60% alcohol and are less
concentrated than extracts. Tinctures are widely used for their ease of preparation and
long shelf life.

Types of Tinctures:

1. Simple Tinctures: Prepared from a single plant or animal material.

2. Compound Tinctures: Prepared by combining multiple plant materials or
active ingredients.

Method of Preparation:

a. Simple Maceration:

 Plant Material: Coarsely powdered or finely cut.

 Solvent: Alcohol or a mixture of alcohol and water.
 Process:

1. The plant material is placed in a closed container and soaked with the
solvent (usually ethanol or a combination of ethanol and water).
2. The mixture is allowed to stand for 1-2 weeks, during which it is
shaken or stirred periodically.
3. After the maceration period, the liquid is filtered to remove solid plant
material.
4. The filtrate is used as the tincture.

b. Percolation:

 Plant Material: Coarsely ground.

 Solvent: Alcohol (e.g., ethanol) or hydroalcoholic mixtures.
 Process:

1. The plant material is moistened and packed into a percolator.

2. The solvent is added at the top and allowed to percolate slowly through
the plant material.
3. The tincture is collected at the bottom of the percolator.
4. Once the desired volume of tincture is collected, it is bottled for use.

Apparatus:

 Macerator, Percolator, and filters for removing plant material after

extraction.

Examples:

 Tincture of iodine (used as an antiseptic), opium tincture (used for pain

relief and diarrhea control).
3. Spirits

Definition: Spirits are alcoholic solutions of volatile substances such as essential oils.
They are typically prepared using ethanol as the solvent, which helps in dissolving the
volatile constituents. Spirits are more concentrated than tinctures but are used in
smaller amounts.

Types of Spirits:

1. Medicated Spirits: Contain active ingredients and are used for medicinal
purposes.
2. Non-Medicated Spirits: Used for flavoring or perfumery.

Method of Preparation:

a. Simple Solution:

 Volatile Substance: Essential oils or volatile compounds like camphor,

menthol, or ammonia.
 Solvent: Alcohol (usually ethanol).
 Process:

1. The volatile substance is dissolved directly in alcohol.

2. The solution is filtered if needed to remove undissolved particles.
3. The final spirit is stored in airtight containers to prevent evaporation of
the volatile constituents.

b. Distillation:

 Plant Material: For spirits like peppermint spirit, the plant material
containing the essential oil is used.
 Solvent: Alcohol.
 Process:

1. The plant material is soaked in alcohol.

2. The mixture is then distilled, where the alcohol and volatile oils are
vaporized and then condensed.
3. The condensed liquid is collected as the spirit.

Apparatus:

 Distillation setup (boiling flask, condenser, and receiver) for spirit

production.
 Filters and storage containers for spirits.

Examples:
  Camphor spirit (used as a topical analgesic), peppermint spirit (used for
digestive disorders).

Difference between extracts, tinctures and spirits

Preparati Solvent
Concentration Method Typical Use
on Type Used
Water, Maceration, Used in pharmaceutical
Highly
Extracts alcohol, or percolation, solvent formulations, tablets,
concentrated
both evaporation and capsules
Less
Alcohol or For oral or topical
concentrated Maceration or
Tincture hydroalcoho medicinal use, e.g.,
(20-60% percolation
lic iodine tincture
alcohol)
Volatile and For medicinal or
Alcohol Simple solution or
Spirits highly aromatic purposes, e.g.,
(ethanol) distillation
concentrated camphor spirit