HERBAL FORMULATIONS
Reference:
Herbal Drug Technology V.M. Shinde and Mrs K.S Bodas-Yadav- Nirali Prakashan
Objectives
To understand the concept of conventional and novel dosage forms.
To learn about different conventional solid, liquid and semisolid dosage forms.
To learn about advantages, preparation and applications of different types of novel dosage
forms.
8.1 INTRODUCTION
In past three decades, there is exceptional rise in herbal drug demand in global market. According
to World Health Organization about 80% of world’s population uses herbal medicines as their
healthcare needs. Herbal products are the products derived from whole plant, parts of plants or
extracts which are used to treat various diseases. The herbal materials like unprocessed seeds and
plant cuttings can be used as starting materials and finished herbal preparations like powders or
dried extracts act as intermediates in the preparation of finished herbal products or herbal dosage
forms. Various commonly available herbal dosage forms are decoctions, herbal teas, tinctures,
glycerites, herbal soaps, herbal tablets, herbal syrups, herbal capsules, herbal creams and
ointments. Growing interest in herbal dosage forms demand for their large scale production.
Dosage forms are the means by which drug molecules are introduced in the body. As per WHO
Finished herbal products consist of one or more herbal preparations made from one or more
herbs. These may contain excipients in addition to the active ingredients.
Definition: According to WHO, Herbal dosage forms are physical form like liquid, solid, semi-
solid products produced from herbs, with or without excipients, in a particular formulation (such
as decoctions, tablets and ointments). The herbal materials such as dried roots or fresh juices or
herbal preparations such as extracts are used to produce herbal dosage forms.
Challenges in Herbal Formulation:
The toxicological, epidemiological, and other data available regarding herbal formulation
is confusing.
Authentication of herbal materials is difficult.
Pharmacological, toxicological, and clinical documentation is tedious task.
It is difficult to follow Pharmacovigilance guidelines in case of herbal drugs.
There is need to study herb-drug interaction.
Standardization, safety and efficacy measurement of herbal formulations are a big
challenge.
There are various hurdles in conduction of Clinical trial of herbal formulations.
Steps in Herbal Drug Formulation:
1. Selection, drying and grinding of herbal drugs: Based on medicinal properties, the
specific part of the plant is selected. The plant material is then dried using sun drying,
shade drying or oven drying techniques. The plant material is subjected to pulverizing and
sieving.
2. Extraction of plant material: The powdered plant material is extracted by using different
techniques like cold maceration, hot maceration or soxhlet extraction depending on
chemical nature of phytoconstituents.
3. Filtration and concentration of extract: Extract is further concentrated using vacuum
evaporation to get solid mass free of solvent. This extract can be directly used to make
formulation or purified further.
4. Powdered extract: The extract is converted into dry powder by spray drying techniques.
This powdered extract is used to make various dosage forms.
5. Preparation of dosage forms: Various dosage forms like tablets, capsules, ointments,
creams, syrups etc. are made using dried extract or powdered extracts.
8.2 TYPES OF CONVENTIONAL HERBAL DOSAGE FORMS
The different types of conventional herbal dosage forms are discussed as follows:
8.2.1 Liquid Herbal Dosage Forms
Liquid herbal dosage forms are usually solutions, syrups, emulsions or suspensions containing
one or more active substances in a suitable vehicle. As per British pharmacopoeia liquid dosage
forms include oral solutions, emulsions, suspensions, powders and granules for oral solutions and
suspensions, oral drops, powders for oral drops, syrups, powders and granules for syrups etc.
Different types of herbal liquid dosage forms are as follows:
(a) Decoctions: These are herbal formulations prepared by boiling the crude drug with specific
volume of water for specific period of time. The extract is then cooled and filtered. Decoctions are
normally intended for immediate use, or use within a 24-hour to 72 hrs. It is suitable for hard
plant materials.
Dosage: 3 to 4 times a day up to 500 ml per day.
Examples: E.g. Sijunzi decoction, Chinese herbal remedy is mixture of Panax ginseng, Poria
cocos, Atractylodes macrocephala and Glycyrrhiz uralensis.
(b) Infusions: Infusions are made by using cold or hot water for herbal extraction and are dilute
solutions. For heat sensitive drugs, cold infusions are prepared by soaking drug in cold water for
several hours. Hot infusions are prepared by pouring hot water and plant material. Infusion should
be stored in cold and dry place. The shelf life of infusion is up to 24 hours.
Dosage: 3 to 4 times a day upto 500 ml per day.
Examples: Tea, coffee, lemon infusion;
(c) Tincture: It is an alcoholic or hydro alcoholic extract of herbal material, by using 1 part of
herbal material and 5–10 parts of solvent like ethanol. Tinctures can be stored in cool, dry and
dark place for 2 years.
Dosage: 5 ml diluted to 25 ml, can be taken 2 to 3 times a day.
Examples: Tincture of Iodine, Benzoin tincture, Cannabis tincture.
(d) Syrups: According to WHO, syrups are viscous liquids containing high amount of sugars or
other sweetening agents. They are prepared by various methods such as dissolving, mixing,
suspending or emulsifying herbal extracts or decoctions in a solution of honey, sucrose or other
sweetening agents. Syrups can also be prepared by using infusions. Syrups may or may not
contain medicine or flavouring agent. The syrup which does not contain medication but contains
only flavouring agent is called as flavoured or non-medicated syrup. Medicated syrup consists of
medication and flavour to mask its unpleasant taste. Due to high sugar content syrups are
susceptible to microbial contamination so they contain preservatives.
Advantages of Syrup:
Unpleasant taste of medications can be masked.
It is easy to swallow medication in syrup form as they are thick. Hence only small portion
of medicament comes in contact with the taste buds and remaining is swallowed as it is.
It is easy to administer drug in pediatric patient as they are sweet in taste.
Syrups also have a soothing effect on irritated tissues.
Preparation of Herbal Syrups:
Different steps of Herbal Syrups preparation are as follows:
1. Preparation of decoction of plant material: Accurately weighed quantity of plant
material is extracted with sufficient quantity of boiling water. The boiling is continued till
the volume of solution reduces to one fourth of its original volume. Then the liquid is
cooled and filtered.
2. To prepare simple syrup: 40 gm of sucrose is dissolved in sufficient water to get 100 ml
of concentrated simple syrup. Then the solution is filtered.
3. To prepare final syrup, plant decoction is mixed with simple syrup in 1: 4 ratio
respectively to get 100 ml of herbal syrup. (Preservatives, colourants and flavouring
agents may be added)
Evaluation of Herbal Syrup:
The syrups are evaluated for organoleptic characters, pH, specific gravity, total solid content,
thermal stability, degradation product and microbial tests.
pH can be determined by using pH meter.
Determination of total solid content: To determine total solid content accurately, weighed
quantity of syrup sample is placed in the empty pre-weighed petri dish. Sample is
evaporated using water bath and further dried at low temperature. The final weight of petri
dish is again taken. The total solid content is determined by using following formula.
Total solid contents = (Weight of petri dish after drying – Weight of empty petri
dish) / Sample weight × 100
Ostwald viscometer is used to determine viscosity of syrup.
Specific gravity is measured using Pycnometer 25°C.
Stability testing: Stability testing of herbal syrups is carried out by storing the syrups at
room temperature and accelerated temperature conditions. Then at the interval of 24 hr, 48
hr and 72 hr syrups are evaluated for physicochemical parameters, turbidity, thermal
stability, degradation and homogeneity etc.
Dosage: 1 to 2 teaspoonful thrice a day.
Examples: Hempushpa syrup, Brahmi syrup, Cough syrup, Heart tonic syrup.
(e) Oral emulsions: These are liquid dosage forms consisting of two immiscible phases, which
are stabilized by addition of emulsifying agent. One liquid can be uniformly dispersed in another
immiscible liquid in the form of small droplets using emulsification equipment such as agitators,
homogenizers, colloid mills and ultrasonic devices etc.
Examples: Intralipid® emulsion, Smoflipid®, Perikabiven® etc.
(f) Aromatic waters: These are water based formulations saturated with essential oil. Aromatic
water is prepared by mixing distilled water with one part of essential oil and ten parts of calcium
powder. It is shaken well and then kept aside for 12 hours, and then filtered and volume is
adjusted. It should be made in small quantities to protect it from decomposition.
Examples: Cardamom water, Peppermint water, Camphor water.
(g) Herbal glycerites: These are tincture like dosage forms which are prepared by extracting
herbal drug with 50–60 % of glycerine as extraction medium. The shelf life of glycerites is about
six months to two years. This form is suitable for preparation of pediatric medicines. Glycerin
cannot be used for herbs containing gums or resins.
Examples: Echinacea extract, Echinacea herbal extract, Rhodiola extract.
(h) Oxymels: These are sweet and sour formulations containing honey and vinegar.
Examples: Oxymels are used for herbal tonics like Eark, Cayenne, and Lobelia.
8.2.2 Solid Herbal Dosage Forms
(a) Herbal tea bags: These bags contain mixture of single or more herbs sufficient for single time
making infusion. Herbal materials such as dried flowers or leaves or powdered herbal drug are
packed in cloth bags. These bags should be free of roots or barks, which are bulky and weight and
should be poured on hot water for making infusion.
(b) Dried or powdered herbs: Herbs are dried and pulverized to fine powder. The powder can be
administered either directly by mixing it with warm water. It can be available in capsule or sachet
form.
(c) Dry extract powders: Dry Plant extract is prepared by evaporation of the solvent used for
extraction. Powdered extract can be prepared by spray-drying or freeze-drying of a liquid extract
with or without using an adsorbent, or made by drying and milling to produce a powder. It may
contain excipients, stabilizers and preservatives. Dry extracts can be incorporated into capsules,
tablets or granules.
(d) Herbal mixtures: Herbal mixtures are combination of two or more plants. The plants are
dried and pulverised. Then plant powders are mixed in specific proportions to get herbal mixture.
These are also prepared by mixing dried powdered extracts in specific proportions. Herbal
mixtures are generally used to treat various ailments or as health supplements.
Examples: herbal mixture for pain, herbal mixture for fever.
(e) Granules: Granules are agglomerations of small spherical particles made from dried fluid
extracts. They can be administered after reconstitution with water as solution or suspensions.
They can be used for making tablet compression or capsule filling. To prepare granules dried
liquid extract is mixed with diluents, binders or other suitable excipients, and the solvent is added
to promote agglomeration. Then the wet mass is dried and sized to yield the desired product.
Examples: Vasavalehahurna granules, chyavanprash granules, gastrocare oral dispersible
granules.
(f) Pills: Pills are spherical dosage forms larger than granules made from dried herbal extracts or
herbal materials. Pills are made by triturating dried powdered herbs or dry extract with binders
and solvents.
Examples: Madhunashini vati, Chandraprabavati, Khadiradivati
(g) Capsules: These are solid dosage forms containing drug and appropriate filler packed in hard
gelatin container. The dry powdered herbal ingredients or granules are packed in hard gelatin
capsules while herbal oils and oil soluble herbal ingredients are available in soft gelatin capsules.
Advantages of capsules are:
They mask unpleasant taste of medicines.
Provide uniformity of dosage.
Stability of herbal capsule is relatively better than aqueous herbal preparations.
Stability of capsules are better content rapidly than tablets.
Examples: Fenugreek capsules, Chlorella capsules, Pudinhara, Moringa capsules etc.
(h) Tablets: Tablets are solid dosage forms made up of the herbal extract powder, plant powder
or granule is blended with excipients such as binders, glidants, disintegrating agents, diluents etc.
and compressed to form a defined shape and size. Tablets are coated or uncoated. Tablets are
coated to mask unpleasant taste of drug and to protect the contents from acidic environment of
stomach.
Fig. 8.1: Herbal tablets
Tablets can be prepared by following methods:
(i) Direct compression method: In this method, herbal ingredients are accurately weighed and
mixed with appropriate excipients. Then by using tablet compression machine all the ingredients
are directly compressed to form tablets.
(ii) Wet granulation method: In this method, accurately weighed herbal extracts are triturated
with excipients and binder solution of desired concentration. The wet mass thus obtained is then
passed through sieve to obtain granules. Then granules are dried, sieved and mixed with
lubricants. These granules are punched by tablet compression machine into desired size and
shape.
(iii) Granulation by preliminary compression: This method is used for moisture-sensitive
drugs. First dry extract powder is compressed to form large slugs or tablets. Then these slugs are
break into small pieces and sieved through specific sieve to obtain granules. These granules are
mixed with lubricating and disintegrating agents and compressed to form tablets.
Coating of tablets:
Coating is done to mask undesirable colour, odour and taste, to protect from moisture or to make
sustained release product. It is carried out using pan coating or press coating method.
Evaluation:
According to various pharmacopoeias tablets are evaluated for pre-compression parameters such
as bulk density, tapped density, Hausner’s ratio, Carr’s index and angle of repose. Post
compression evaluation parameters such as hardness, thickness, friability, weight variation and
content uniformity should be checked.
Hardness of tablets can be measured by using Monsanto hardness tester or Pfizer hardness
tester.
Friability is checked by using friabilator apparatus. It is necessary to evaluate tablets
ability to withstand wear and tear.
All tablets in a batch should have uniform weight. So uniformity of weight is determined
by weighing 20 tablets randomly and calculating average weight. The individual tablet
weight compared with average weight should be within prescribed limits given in
Pharmacopoeias. Content of drug in tablet should be uniform and within prescribed limits
mentioned in pharmacopoeias.
Disintegration time determines rate of absorption of tablet. It can be determined using
disintegration test apparatus.
The dissolution test is carried out using dissolution test apparatus. It is important to know
rate at which drug will be available for absorption in body.
Examples: Spirulina tablets, Rheumatil tablets, Orthocare tablets, Vitamin C tablets.
(i) Lozenges:
These are solid dosage forms which slowly and pleasantly release medication in mouth. It can
give local or systemic action. Lozenges contain excipients like flavouring agents and sweetened
bases. To make lozenges herbal extract is boiled with sucrose and water. Then colouring and
flavouring agents are added during cooling. The molten mass is added into moulds to get lozenges
of desired shape. Lozenges are generally used to treat throat infections.
Examples: Zecuf, Koflet lozenges, Herbal cough lozenges etc.
Other Herbal Dosage Forms
(a) Ointments
These are semi-solid, greasy preparations containing anhydrous immiscible base generally used
for skin, rectum or nasal mucosa. Herbal ointments are prepared by mixing finely powdered herbs
or extracts with oily base and emulsifying agents. The process of making ointment involves
heating of oil phase and aqueous phase separately and then mixing of both the phases while
constant stirring until the mixture get congealed.
The ointment bases are as follows:
(a) Hydrocarbon bases like hard or soft paraffin.
(b) Absorption bases like wool fat, bees wax.
(c) Neutral oil bases like olive oil, almond oil.
Examples: Calendula ointment, Herboheal ointment, Pilex, Pain care ointment etc.
(b) Herbal balms: These dosage forms are like ointments used to relieve pain. These are made by
mixing herbs having analgesic and anti-inflammatory effect with ointment base.
Examples: Tiger balm, Herbal pain balms, Lip balms.
(c) Herbal creams: Creams are semi-solid dosage forms containing in hydrophilic base. Herbal
creams are prepared by mixing finely powdered herbal drug or an extract in a cream base. It has
relatively shorter shelf life as compared to ointments.
Examples: Herbal fairness cream, Baby creams, Acne control creams.
(d) Inhalations: Inhalations are preparations intended to be used in bronchial tube or lungs in the
form of aerosols. These are of two type’s dry powder inhalers or inhalation liquid preparations.
Traditionally steam inhalation method is used to administer volatile substances from herbal drugs.
To prepare dry powder inhalers dry extracts are pulverized into fine particles. Then it is mixed
with excipients to make homogeneous mixture. For liquid inhalation preparations dry herbal
extracts are mixed with a vehicle to form solution or suspension and pH is adjusted.
Examples: Astha aid drops, Karvol plus inhalation capsules.
(e) Plasters and patches: These are made by spreading soft or dry herbal extract on support made
up of fabric or synthetic resin. Plasters and patches are intended to use topically on the skin and
deliver the active ingredients through the skin, usually to get relief of pain, backache or sore
muscles.
Examples: Herbal pain relief patch, Capsicum patch, Herbal medicated plasters etc.
(f) Medicated oils: Medicated oils are prepared by mixing, macerating or boiling herbal drug,
extract of fresh juice with suitable fixed oil. The drug is boiled with oil to remove water
completely, then filtered and cooled. Medicated oils are mostly used topically or sometimes
orally.
Examples: Indulekha oil, Tea tree oil, Sesna oil, Peppermint oil etc.
(g) Herbal soaps: These are prepared by incorporating herbal drugs having antifungal or
antimicrobial properties with detergent base.
Examples: Neem and turmeric soap, Herbal care soap, Papaya skin whitening soap.
(h) Herbal pastes: These are similar to ointment which contains 50% of drug powder
incorporated in fatty base. For topical use herbal ingredients are dispersed in fatty base while for
oral use they are dispersed in aqueous base. Herbal pastes are less greasy than ointments.
Examples: Dantkanti toothpaste, Miswak, Aloevera toothpaste, complete care toothpaste.
(i) Herbal suppositories and Herbal pessaries: Herbal suppositories are made by mixing finely
powdered herbs or extracts with cocoa butter base. Herbal suppositories are used to treat
inflammation of the nasal mucosa, membranes and used as laxative. Herbal pessaries meant for
vaginal use are made by incorporating herb powder or extract in vegetable-gelatin base.
Examples: Tea tree pessaries, neem oil suppository, Herbal vaginal pessaries.
(j) Herbal liniments: Herbal liniments are used in treatment of soreness in muscles and ligaments
and pain. They should not be applied on cut or broken skin. Liniments are prepared by using oil
or alcoholic extracts of heat producing herbs like cayenne.
Examples: Liniment plus, penil, pain fighter liniment.
SHORT
HERBAL FORMULATIONS
Objectives
To understand the concept of conventional and novel dosage forms.
To learn about different conventional solid, liquid and semisolid dosage forms.
To learn about advantages, preparation and applications of different types of novel dosage
forms.
8.1 INTRODUCTION
In the past three decades, there has been a remarkable rise in the global demand for herbal drugs.
According to the World Health Organization (WHO), nearly 80% of the world’s population uses
herbal medicines as part of their healthcare. Herbal products are derived from whole plants, plant
parts, or their extracts and are used to treat various diseases. Herbal preparations include
unprocessed seeds, plant cuttings, powders, and dried extracts which act as intermediates in the
preparation of finished herbal products.
Common herbal dosage forms include decoctions, herbal teas, tinctures, glycheries, herbal soaps,
tablets, syrups, capsules, creams, and ointments. The rising popularity of herbal dosage forms has
led to increased demand for their large-scale production.
Dosage forms are the means through which drugs are introduced into the body. As per WHO,
finished herbal products consist of one or more herbal preparations made from one or more herbs
and may contain excipients in addition to the active ingredients.
Definition: According to WHO, herbal dosage forms are physical forms like liquid, solid, or
semisolid products derived from herbs, with or without excipients.
Challenges in Herbal Formulation:
Confusing toxicological, epidemiological, and chemical data.
Difficulty in authenticating herbal materials.
Extensive pharmacological and clinical documentation needed.
Challenges in adhering to Pharmacovigilance guidelines.
Need to study herb-drug interactions.
Difficulties in standardization, safety, and efficacy testing.
Complications in conducting clinical trials.
Steps in Herbal Drug Formulation
1. Selection, drying and grinding: Based on medicinal use, the correct part of the plant is
selected, dried (using sun/shade/oven), pulverized, and sieved.
2. Extraction: Using maceration, hot maceration, or Soxhlet extraction based on
phytochemical nature.
3. Filtration and concentration: Using vacuum evaporation to remove solvents and
produce a concentrated extract.
4. Powdered extract: Spray drying the extract into a powder for further use.
5. Preparation of dosage forms: Tablets, capsules, ointments, creams, syrups are produced
using the extract.
8.2 TYPES OF CONVENTIONAL HERBAL DOSAGE FORMS
8.2.1 Liquid Herbal Dosage Forms
Liquid forms include solutions, syrups, emulsions, suspensions, oral drops, tinctures, etc.
(a) Decoctions: Prepared by boiling herbs with water, cooled and filtered.
Dosage: 3–4 times daily, up to 500 ml
Example: Sijunzi decoction
(b) Infusions: Prepared using hot/cold water. Cold infusions for heat-sensitive drugs.
Shelf life: 24 hours
Examples: Tea, lemon infusion
(c) Tinctures: Alcoholic or hydroalcoholic extracts.
Ratio: 1:5 to 1:10
Dosage: 5 ml diluted to 25 ml, 2–3 times/day
Examples: Iodine tincture, Benzoin tincture
(d) Syrups: Thick liquids with sugar and herbal extracts. Can be medicated or flavoured.
Advantages: Mask taste, easy for children, soothing
Examples: Brahmi syrup, Heart tonic
Preparation Steps:
1. Decoction
2. Simple syrup
3. Combine 1:4 ratio
Evaluation: pH, viscosity, specific gravity, solid content, microbial stability.
(e) Oral Emulsions: Two immiscible phases, stabilized with emulsifiers.
Examples: Intralipid, Smoflipid
(f) Aromatic Waters: Essential oils mixed with distilled water.
Examples: Cardamom, Camphor water
(g) Glycerites: Glycerine-based extracts.
Example: Echinacea extract
(h) Oxymels: Honey and vinegar formulations.
Examples: Cayenne oxymel
8.2.2 Solid Herbal Dosage Forms
(a) Tea Bags: Powdered herbal mix in cloth bags for infusion.
(b) Dried Herbs: Powdered and consumed directly or packed in capsules.
(c) Dry Extract Powders: Spray/freeze dried extracts with/without additives.
(d) Herbal Mixtures: Mixed powders from multiple herbs for ailments.
Examples: Herbal fever/pain mixtures
(e) Granules: Dried extract granulated with excipients.
Examples: Vasavalehahurna, chyavanprash
(f) Pills: Larger than granules, mixed with binders and rolled.
Examples: Madhunashini vati
(g) Capsules: Solid or soft gelatin containers.
Examples: Fenugreek, Chlorella, Pudinhara
Advantages: Taste masking, uniform dose, higher stability
(h) Tablets: Compressed herbal powder/granule into specific shapes.
Methods: Direct compression, Wet granulation, Slugging
Evaluation:
Hardness, friability, weight variation
Disintegration, dissolution tests
Examples: Spirulina, Orthocare tablets
(i) Lozenges: For mouth/throat use, made by boiling extract with sucrose.
Examples: Koflet, Herbal cough lozenges
8.2.3 Other Herbal Dosage Forms
(a) Ointments: Greasy semisolids with herbal powders/oils.
Base Types: Paraffin, wax, almond oil
Examples: Calendula, Pilex
(b) Herbal Balms: Used for pain relief with anti-inflammatory herbs.
Examples: Tiger balm
(c) Herbal Creams: Hydrophilic base with powdered herbs/extracts.
Examples: Baby cream, Acne cream
(d) Inhalations: Steam or aerosols, liquid/dry inhalers.
Examples: Karvol capsules
(e) Plasters and Patches: Herbal extracts on fabric/resin support for local application.
Examples: Capsicum patch
(f) Medicated Oils: Fresh herb juice in oil, boiled, filtered.
Examples: Indulekha oil, Peppermint oil
(g) Herbal Soaps: Herbal actives in detergent base.
Examples: Neem soap, Papaya soap
(h) Herbal Pastes: 50% drug powder in aqueous/fatty base.
Examples: Dantkanti, Aloe vera toothpaste
(i) Suppositories & Pessaries: Cocoa butter or gelatin base for vaginal/rectal use.
Examples: Neem suppository
(j) Liniments: Alcohol/oil-based extracts for pain relief.
Examples: Penil, Cayenne liniment
