MEDICAL UNIVERSITY – PLEVEN
DEPARTMENT OF PHARMACOLOGY
DRUGS & DOSAGE FORMS
Dr G. Stavreva, Dr D. Pendicheva
 THE ORIGIN OF DRUGS
 GALENIC PREPARATIONS (PHYTOMEDICINALS)
 FORMULATION OF DRUG SUBSTANCES
 SOLID DOSAGE FORMS
 LIQUID DOSAGE FORMS
 SEMISOLID DOSAGE FORMS
 AEROSOLS
THE ORIGIN OF DRUGS
Modern drugs, available for use today, are obtained from many sources:
 50% of total prescriptions are composed of synthetic or semisynthetic (based
on natural active ingredients) chemical agents
 25% contain higher plant principles
 12% are microbial-derived products
 7% are mineral in character
 6% are animal-derived
I. Classification of drug sources
1. Natural sources of drugs
1.1. Higher plants: the whole plant, leaves, root, bark, seeds, flowers
1.2. Microorganisms: bacteria, fungi, molds
1.3. Minerals
1.4. Animals: organs, tissues, corporal fluids
2. Synthetic sources of drugs
2.1. Inorganic elements and compounds
2.2. Organic compounds
II. Natural sources of drugs
The discipline of pharmacognosy deals with information on drugs from plant and
animal sources and their constituents.
The plant or animal as a “row material” is composed of many chemical substances,
commonly termed ingredients:
 Active ingredients exert a physiological effect and they are responsible for the
therapeutic activity of the natural drug.
 Inert ingredients have no definite pharmacological activity but their presence
may modify the absorbability or potency of the active constituents.
The term crude drug is usually applied to any part of plant or animal organs, or
whole organisms, either in the fresh state or dried and either grounded or
ungrounded. Natural drugs are used in their crude form, or active
ingredients are extracted and purified for therapeutic use.
2
1. Higher plants
Plants are biosynthetic laboratory for a multitude of chemical compounds:
glycosides, alkaloids, steroids. The active ingredients might be found in any
part (or all parts) of the plant: leaves, root, bark, seeds, fruits, flowers, etc.
2. Microorganisms
Microbial metabolites used as drugs, especially the antibiotics and
antineoplastic agents are produced by fermentation.
 a strain of mold Penicillium chrysogenicum produces Penicillin G
 Clavulanic acid is a product of fungus Streptomyces clavuligerus
 Microorganism from sea water, identified as Cefalosporium
acremonium, gives material for the production of semisynthetic
cephalosporins
 Streptomycine was isolated from a strain of Streptomyces griseus
 Gentamicin is produced by Micromonospora purpurea, an
actinomycete
3. Minerals
 Precipitated sulfur is a very fine powder for external use, acting as
parasiticide, which is used in the treatment of skin disorders
 Purified sulfur is used internally only, as a laxative
 Talc powder is an absorbent, etc.
4. Animals
Animal organs, tissues, fluids and other animal derivatives can be used to
obtain active ingredients:
 Beef and pork pancreas are the source of the natural insulin sold
today
 Exogenous thyroxine can be obtained from the thyroid glands of
animals, usually pigs
 Most commercial preparations of Corticotrophin are obtained from
either hog or sheep pituitary glands
 Vesicular extracts from sheep and bulls are used to yield
prostaglandins
III. Synthetic sources of drugs
In searching for similar activity, many new drugs have been synthesized.
Semisynthetic drugs are based on natural ingredients:
 Reserpine and synthetic antipsychotic agents
 Morphine and synthetic analgesics
 Curare and synthetic neuromuscular blockers
 Adrenaline and amphetamines
Hormones, vitamins, antiepileptic drugs, synthetic antibiotics are only a small
part of the modern drugs, produced by synthesis.
3
Plant Species
Popular
name
Crude
Drug
Active ingredients
Pharmacological action
Drug
Atropa
Belladonna
Deadly
night shade
roots
Radix Belladonnae
anticholinergic: antispasmodic,antisecretory,
mydriatic, CNS-activity
Atropine
Scopolamine
Datura
stramonium
Jimson weed,
thorn apple
leaves
Folium Stramonii
anticholinergic: antispasmodic,antisecretory,
mydriatic, CNS-activity
Asthma cigarettes
Hyosciamus
Niger
Papaverum
somniferrum
Opium poppy
leaves
Folium Hyosciami
opium – dried
exudate of the
incised seed capsule
leaves
Folium Digitalis
leaves
Folium Digitalis
seeds
Semen Strophanthi
the overground part
Herba Adonidis
vernalis
roots
Radix Rauwolfiae
roots end rhizome
Radix et rhizoma
Valerianae
bark
Cortex Chinae
anticholinergic: antispasmodic, antisecretory,
mydriatic,CNS-activity
Asthma cigarettes
Henbane
alkaloids: atropine,
hyosciamine, hyoscine
(scopolamine)
alkaloids: atropine,
hyosciamine, hyoscine
(scopolamine)
alkaloids: atropine,
hyosciamine, hyoscine
(scopolamine)
alkaloids: morphine, codeine,
papaverine
cardiac glycosides
centrally acting analgesics,
antitussives,
smooth muscle relaxant (papaverine)
cardiotonics
Morphine
Codeine Papaverine
cardiac glycosides
cardiotonics
Digitoxin
Digoxin
Strophanthin G and K
cardiac glycosides
cardiotonics
cardiac glycosides
mild cardiotonics
sedatives
hypotensive, antipsychotic
Digitalis
Purpurea
Digitalis
Lanata
Strophanthus
Gratus et Kombe
Foxglove
Adonis
Vernalis
Rauwolfia
serpentine
Valeriana
officinalis
Pheasant’s eye
Cinchona
Grecian
Foxglove
Chandrika,
Patalagandhi
alkaloids: reserpine
Digitoxin
Adinorm
Reserpine
volatile oil, valerenic acid and
valepotriates
sedatives
Valeriana
alkaloids: quinidine,
quinine, cinchonine
Quinine
Quinidine
antiarrhythmic, antimalarial, antipyretic
4
GALENIC PREPARATIONS (PHYTOMEDICINALS)
The term “Galenic preparations” is related to classes of natural drug
products obtained from plants by using simplified pharmaceutical procedures.
Such preparations (known as tinctures, extracts, syrups, spirits, aromatic
waters, etc.) popularly have been called galenicals, after Galen, the 2nd
century Greek physician. They are relatively impure products intended only
for oral or external use, which consist of active ingredients in the same
proportion as they are in the crude drug.
I. Tinctures (tinctura, -ae, -ae)
Tinctures are defined as alcoholic or hydroalcoholic solutions derived from
plant crude drugs by maceration (soaking) or percolation (filtering). They are
prescribed in small quantity (10 – 30 g) and are used as drops.
Examples: Tinctura Valerianae; Tinctura Adonidis vernalis, Tinctura Strychni.
II. Extracts (extractum, -i, -a)
Extracts are defined as concentrated preparations of plant drugs obtained by
removal of the active ingredients of the drug with suitable liquids and
evaporation of all or nearly all of the solvent.
Three forms of extracts are recognized:
1. Liquid extracts (extracta fluida) – liquid preparations. Examples:
Extractum Althaeae fl. (Althaea officinalis – hollyhock)
2. Solid or pilular extracts (Extracta solida or spissa) – concentrated
plastic masses, which are suited especially for use in pills, ointments
and suppositories. Example: Extractum Valerianae spissum
3. Powdered extracts (Extracta sicca) – dry powders with contents of
humidity less than 5%. Examples: Extractum Opii siccum, Extractum
Belladonnae siccum.
III. Syrups (Sirupus, -i, -i) – syrups are concentrated solutions of sugar in
water. Types:
1. Simple syrups – contain sugar and water
2. Medicated syrups – contain some added medicinal substances
3. Flavored syrup contains aromatic substances or concentrated fruit
juices (raspberry, cherry, strawberry). Simple and flavored syrups are
useful for preparing liquid oral dosage forms (as Remedium
corrigens).
5
Examples: Sirupus Codeini (antitussiva), Sirupus Rubi idaei (cherry syrup)
IV. Aromatic waters (Aqae aromaticae s. medicatae)
Aromatic waters, also known as medicated waters, are clear aqueous
solutions of volatile oils or other aromatic substances. Their odor or taste is
similar to those substances from which they were prepared. They are used
principally as flavored and perfumed constituents. Examples: Aqua Menthae,
Aqua Rosae, ets.
V. Spirits (Spiritus medicatus) – Spirits are alcoholic solutions of volatile
substances. They are used mainly externally. Examples: Spiritus Mentholi,
Spiritus Lavandulae, ets.
FORMULATION OF DRUG SUBSTANCES.
CLASSIFICATION OF DRUG DOSAGE FORMS
Drug substances and crude drugs are developed into drug dosage
forms in order to optimize stability, safety and effectiveness of drug
substances and to make them suitable for administration. According
to the consistence, they are classified as:
1. Solid dosage forms
2. Liquid dosage forms
3. Semisolid dosage forms
4. Aerosols
SOLID DOSAGE FORMS
Solid dosages, such as tablets, have many advantages over other
types: greater stability, less risk of chemical interaction between
different medicaments, smaller bulk, accurate dosage, and ease of
production.
I. Classification of solid dosage forms
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1. Powders
2. Tablets
2.1. Tablets for oral administration
 compressed tablets
 buccal tablets
 sublingual tablets
 chewable tablets
 effervescent tablets
 sugar-coated tablets
 film-coated tablets
 enteric coated tablets
 controlled-release tablets
2.2. Tablets for parenteral administration
 tablets for solution
 inserts
 pellets (tablets for implantation)
3. Capsules
 hard gelatin capsules
 soft gelatin capsules
 enteric-coated capsule
4.Granulae
5. Pills
6. Troches
II. Characteristics of solid dosage forms
POWDERS
Historically, powders represent one of the oldest dosage forms.
They posses some advantages: flexibility in compounding and
relatively good chemical stability. The main disadvantages are their
unsuitability for dispensing unpleasant tasting or hygroscopic drugs
and inaccuracy of dose (for bulk powders).
Classification of powders:
1. According to the division into prescribed doses:
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 bulk powders (Pulveres nondivisi) – all doses are given
inseparably (as a bulk). They may be classified as:
 oral powders – e.g., antacid and laxative powders
 dentifrices
 dusting powders
– locally applied nontoxic preparations.
Commercial dusting powders are available in sifter-top
containers and pressure aerosols.
 insufflations – finely divided powders introduced into body
cavities (ears, nose, throat) with a powder blower (insufflator).
Specialized equipment has been developed for the
administration of micronized powders of relatively potent drugs
(e.g., pressure aerosols)
 divided powders (Pulveres divisi)
are divided into the
prescribed number of doses and are given orally. Each individual
dose (0.1–1.0 g) should be transferred to a powder paper.
2. According to the composition:
 simplex powders (Pulveres simpliciti) consist of one active
ingredient and suitable inert substances (constituents)
 complex powders (Pulveres compositti) are mixtures of more
than one active ingredient and constituents.
TABLETS
Tablets (tabuletta, -ae) are solid dosage forms containing drug substance
with or without suitable diluents, and prepared by compression. This is the
most frequently used dosage form of administering a drug. They are
swallowed, chewed, or held sublingually. Scoring of some tablets into halves
or quadrants facilitates breaking them if a smaller dose is needed. A tablet’s
color or shape can help identify it. Advantages: simplicity and economy,
stability and convenience in packaging, accuracy of dosage, compactness,
portability, and ease of administration.
Tablet types and their abbreviations:
1. Tablets for oral administration
 compressed (or plain) tablets (CT)
– These tablets are formed by
compression and contain no special coating. They are made from
powdered, crystalline or granular materials, in combination with binders,
diluents, etc. (e.g., Analgin, Aspirin, Paracetamol, Saridon, etc.)
 sublingual tablets (linguettae s. tabulettes sublinguales):
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 are relatively small and dissolve rapidly.
 they are placed under the tongue and allowed to dissolve
 after absorption, the drug enters the systemic circulation without
passing through the portal circulation, thus avoiding first-pass
inactivation in the liver.
 absorption of lipid-soluble molecules through the oral mucosa is rapid
and the effect of drugs given in this way may become apparent within 2
min. Nitroglycerin and organic nitrates are commonly administered by
this route.
 Drugs that are destroyed by the gastrointestinal fluids or are subject to
substantial presystemic metabolism may be formulated into such
tablets.
Examples: Nitroglycerin, Methyltestosterone, Validol, etc.
 buccal tablets (tabulettes buccales) are small, flat, oval tablets,
intended for buccal administration by inserting them into the buccal pouch
(the space between the teeth and the cheek). They are dissolved or
eroded slowly. Example: Desaminooxytocine (Sandopart)
 chewable tablets are large, hard tablets, difficult to swallow, intended to
be crushed before ingesting. Example: Combantrin, Centrum junior, etc.
 effervescent tablets (tabulettes effervescentes) contain sodium
bicarbonate and an organic acid in addition to the drug substance. In the
presence of water, these additives react liberating carbon dioxide which
acts as disintegrator and produces effervescence. These tablets are
soluble and they are taken readily and absorbed rapidly (e.g., Upsarin, Vit
C, Supradin, etc.)
 sugar-coated tablets (SCT, dragee, -s) are smooth, oval compressed
tablets containing sugar coatings. Sugarcoating provides both protection
and sweet taste but the coating operations take a long time. Example:
Nifedipin, Vitaferro, etc.
 film-coated tablets (FCT, film-tabulettae) are compressed tablets which
are covered with a thin layer or a film of polymeric substances to protect
their contents from moisture or to mask the taste of the ingredients.
 enteric-coated tablets (ECT, tabulettes enterosolventes) are coated
with substances that resist solution in gastric fluid but disintegrate in the
alkaline contents of the intestine. Enteric coating is used for drugs with a
gastric irritant action, for drugs which are unstable in the acid medium of
the gastric contents or if the drug should act on the intestine. (e.g.,
Voltaren, Salazopyrin).
9
 controlled-release tablets are formulated to release the drug slowly over
a prolonged period of time. These dosage forms have been referred to as
prolonged-release (PR) or sustained-release (SR) dosage forms as well.
2. Tablets for parenteral administration
 inserts are intended for insertion into body orifices. Metronidazole,
Isoconazole, Clotrimazole are vaginal tablets (tabulettes vaginales).
 pellets (tablets for implantation) are small, sterile tablets, used by
implantation when prolonged and continuous absorption is desired
(Estradiol, Disulfiram, etc.)
 tablets for solutions are used for preparing solutions for external use
CAPSULES
Capsules (capsula, -ae) are solid dosage forms in which the drug substance
is enclosed in either a hard or soft soluble container of suitable form of
gelatin. They are intended to mask the smell and taste of the drug substance.
Capsules are tasteless, easily administered and some patients prefer them to
the tablets.
1. Hard gelatin capsules (capsulae gelatinosae durae s. operculatae),
also referred to as dry-filled capsules (DFC), consist of two sections, one
slipping over the other, thus completely surrounding the drug formulation.
Commercially filled capsules have the conventional oblong shape.
2. Soft elastic capsules (SEC; capsulae gelatinosae molles s. elasticae)
are soft, globular, gelatin shells somewhat thicker than that of hard gelatin.
They may be round, oval, oblong, or tube-shaped and the contents may
be liquid, paste, or powder. Oil-soluble drugs, (e.g. vit A, E) can be
administered in SEC.
3. Enteric-coated capsules remain intact in the stomach, but dissolve and
release the contents of the capsule once it reaches the small intestine.
They delay the release of drugs which are inactivated by the stomach
contents or may irritate the gastric mucosa. Enteric coatings are prepared
of synthetic polymers.
PILLS
Pills (pilula, -ae) are small, round dosage forms for oral administration which
are prepared by the pharmacist. They are rarely prescribed today. The
powdered ingredients are mixed together with binding agents and solid
extracts (excipiens, -entis) and made into a plastic mass (massa pilularum).
The pill mass is rolled into spheres and coated with talc, gelatin, or sugar.
TROCHES
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Troches (lozenges or pastilles) are discoid-shaped oral forms containing a
drug substance in a flavored base. They are placed in the mouth where they
slowly dissolve, liberating the active ingredient. The drug involved can be
antiseptic, local anesthetic, antibiotic, antitussive, or decongestant.
GRANULES
Granules (granulae) are dosage forms related to powders. They are
particularly suitable for the preparation of solutions or mixtures of drugs, such
as antibiotics, that are unstable in the presence of water.
Effervescent granules contain sodium bicarbonate and citric acid or tartaric
acid in addition to the active ingredients. On solution in water, carbon dioxide
is released. These forms mask the unpleasant taste and ensure better
absorption of the medications.
PRESCRIPTION WRITING
Rp./ Nitroglycerini 0,5 mg
Da scatulam № 1 in linguettis
Signa (Scribe). Place 1 tablet under tonge.
#
Rp./ Aspirni Protect 100 mg
Da scatulam № 1 in tabulettis entreosoventis
S. Take 1 tablet daily.
#
Rp./ Aspirni C
Da scatulam № 1 in tabulettis effervesentibus
S. Take 1 tablet 3–4 times daily, dissolved in 250 ml water.
#
Rp./ Tabulettarum Analfini 500 mg
(Tabl. Analgini 500 mg)
Da scatulam № 1.
S. Take 1 tablet 3–4 times daily
#
Rp./ Isoptini SR 120 mg
D. scat. № 1 in film-coated tablets.
S. Take 1 tablet daily at 8:00 a.m.
#
Rp./ Аllergosani 25 mg
Da scatulam № 1 in dragées.
(Da scatulam № 1 in sugar-coated tablets)
Signa. Take 1 tablet 3–4 times daily.
11
#
Rp./ Amoxicillini 1 g
D. scat. № 1 in capsulis (caps.).
S.Take 1 capsules every 8 hours for 5 days.
#
Rp./ Pulv. Natrii hydrocarbonatis 50 g
D. S. Take 1 teaspoon 1 hour after meals and bedtime.
#
Rp./ Codeini phosphatis 10 mg
Sacchari lactatis 300 mg
M. f. pulvis. D. t. d. № 20
S. Take 1 powder 3 times daily.
#
Rp./ Pulveris dermatici Topocini 5 g
(Pulv. derm. Topocini 5 g)
D. scat. № 1.
S. For external application.
#
Rp/ Flac. Zinnati 125 mg/5 ml – 60 ml
(Granulorum Zinnati 125 mg/5 ml – 60 ml)
(Suspensionis Zinnati 125 mg/5 ml – 60 ml)
Da. Signa. 2 ml every 12 hours (for baby with body mass 10 kg)
LIQUID DOSAGE FORMS
I. DEFINITION OF LIQUID DOSAGE FORMS
Liquid dosage forms are prepared by dissolving the active
ingredient(s) in an aqueous or nonaqueous solvent, by suspending the
drug in appropriate medium or by incorporating the drug substance into
one or two phases of an oil and water system.
These forms can be formulated for different routes of administration:
oral use, introduction into body cavities , or applied externally.
The oral liquid forms can be readily administered to children or people
unable to swallow tablets or capsules.
The absorption rate of oral dosage forms decreases in the following
order: aqueous solution > aqueous suspension > tablet or capsule.
Drug substances are less stable in aqueous media, than in the solid
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dosage forms and it is important to properly stabilize and preserve
them. There is a risk of chemical interactions and microbial
contamination for some of the products.
II. CLASSIFICATION OF LIQUID DOSAGE FORMS
1. Solutions (solutio, – onis, -ones)
 aqueous solutions
 nonaqueous solutions
2. Emulsions (emulsio, -onis, -ones)
3. Suspensions (suspensio, -onis, -ones)
4. Mucilages (mucilago, -inis, -ines)
5. Liniments (linimentum, -i, -a)
6. Infusions and decoctions (infusum, -i; decoctum, -i)
7. Drops (guttae, -arum)
8. Mixtures (mixtura, -ae, -ae)
9. Sterile dosage forms for injection
 ampoules (ampulla, -ae)
 vials (flacon, -is)
 bottles (olla, -s)
 prefilled disposable syringes (or pre-filled syringes)
II. CHARACTERISTICS OF LIQUID DOSAGE FORMS
SOLUTIONS
Solutions (solutio, -onis, -ones) are homogeneous mixtures that are
prepared by dissolving a solid, liquid, or gas in another liquid. The molecules
of the dissolved substance are dispersed among those of the solvent. Many
pharmaceuticals are simply solutions of a medicament in water, alcohol,
ether, glycerin, oils, or some other solvent. Various aromatic waters (e.g.,
chloroform or peppermint water) may also be used as solvents. Solutions are
intended for internal, external, and parenteral administration.
1. Aqueous solutions include those pharmaceutical forms that are prepared
with purified water (aqua destillata – deionized, demineralized water) or
aromatic water as a solvent. Simple solutions for oral administration,
douches, enemas, gargles, mouthwashes, nasal and otic solutions are
assigned to this category.
2. Nonaqueous solutions are the alcoholic and hydroalcoholic solutions,
ethereal solutions, glycerin solutions, etc.
13
Solutions may be prepared in bulk or as single-use packages, and they are
usually bottled automatically (few of them can be prepared extemporally).
EMULSIONS
Emulsions (emulsio, -onis, -ones) are two-phase systems in which one
liquid is dispersed throughout another liquid in the form of small droplets.
They are classified as:
 oil-in-water (O/W) emulsion – oil is the dispersed phase and an aqueous
solution is the continuous phase
 water-in-oil (W/O) emulsion – an aqueous solution is the dispersed phase
and oil is the continuous phase
These forms can be administered orally, topically, or parenterally
(intramuscularly). Specialized uses include emulsions for intravenous feeding
of lipid nutrients (Intralipid). Other radiopaque emulsions are used as
diagnostic agents for X-ray examinations.
Emulsions are thermodynamically unstable. They appear white and tend to
separate on standing. In order to prepare suitable emulsions and to have
them remain stable for a suitable period of time, a number of emulsifying
agents are used in their preparation. They can be natural substances (acacia
or Gumma arabicum, tragacanth, pectin, gelatin, egg yolk, lecithin, etc.),
finely divided solids, or synthetic agents.
SUSPENSIONS
Suspensions (suspensio, -onis, -ones) are two-phase systems
consisting of a finely divided solids dispersed in liquids. If the drug
is insoluble or poorly soluble, a suspension may be the most
suitable dosage form. The taste of drugs can be improved if they
are supplied in suspension form rather than solutions. Suspensions
may be formulated for oral, parenteral (intramuscular or
intraarticular) or topical administration. Antibiotic granules are
generally used for preparation of suspensions in pediatric practice.
Well formulated suspensions should posses certain basic
properties. The dispersed phase should settle slowly, if at all
possible, and be dispersed readily on shaking.
The main ingredients in a suspension are:
 a drug
 natural viscosity agents (natural gums and cellulose derivatives)
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 an external medium – it is usually water for oral preparations; or
other polar liquids (glycerin, alcohol)
MUCILAGES
Mucilages (mucilago, -inis, -ines) are thick, viscid, adhesive
liquids, produced by dispersing gum in water, or by extracting the
mucilaginous principles from plant substances with water (Gumma
arabicum, Radix althaeae, etc.). They are unstable and should
never be made in quantities larger than those that can be used
immediately, unless a preservative is added.
Mucilages are used primarily to prevent immediate sedimentation of
insoluble substances in liquids. They can prevent mucous irritation
caused by some drug substances (e.g., Chlorali hydras).
INFUSIONS AND DECOCTIONS
Infusion (infusum, -i, -a) is a dilute solution of the readily soluble
constituents of crude drugs (from the soft parts of plants). Fresh
infusions are prepared by macerating the drugs for a short period of
time (15 min) with boiling water.
Decoction (decoctum, -i, -a) are extracts of the water-soluble and
heat-stable constituents from crude drugs (from the hard parts of
plants) by boiling in water for 30 min, and cooling.
These forms are of short duration and should never be administered
in quantity for more than 3 days.
DROPS
Drops (guttae, -arum) are solutions, tinctures, or mixtures of highpotent drug substances. These forms are intended to be
administered internally or externally (as eye drops or collyrium,
nasal, and otic drops). Drops are prescribed in small quantity (10 –
30 g). For officinal forms, the right number of drops per 1 ml of liquid
have to be labeled.
MIXTURES
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Mixtures (mixtura, -ae, -ae) are multicomponent liquid containing
two or more active ingredients, dissolved, suspended, or dispersed
in a suitable liquid base (water, alcohol, glycerin, aromatic water, or
infusions and decoctions). Some mixtures may contain tinctures.
Suspended solids may separate slowly on standing, but are easily
redispersed on shaking (shake mixtures
– mixturae
agitandae).Syrups are added as Remedium corrigens, in quantity of
20% of the total volume (30% for children). Mixtures are unstable
dosage forms with short duration and they are subject to
contamination by microorganisms during the period of their use.
STERILE DOSAGE FORMS FOR INJECTION
Sterile dosage forms for injection differ from all other drug dosage forms
because of their unique use for injection directly into body tissue through the
primary protective systems of the human body, the skin and mucous
membranes. Therefore, they must be exceptionally pure and free from
contaminants.
Injections may be classified in several categories:
1. Solutions ready for injection
2. Dry, soluble products ready to be combined with a solvent just prior to
administration (ex tempore)
3. Suspensions ready for injections
4. Emulsions
5. Liquid concentrates ready for dilution prior to administration
These injections may be administered by such routes as intravenous,
subcutaneous, intradermal, intramuscular, intraarticular, and intrathecal. The
nature of the product will determine the route of administration. Suspensions
would not be administered directly into the blood stream because of the
danger of insoluble particles blocking capillaries. Unstable emulsions, if
injected intravenously may cause lipid embolism (excluding some forms with
special characteristics). Hypertonic solutions are administered only
intravenously. When compared with other dosage forms, injections possess
certain advantages:
1. They provide drugs for immediate action
2. The therapeutic dose is adjusted more accurately and readily
3. Drugs can be administered parenterally in cases of unconscious or
uncooperative state of the patient, or because of lack of absorption from
the GIT.
Among the disadvantages are requirement of asepsis, pain factor, risk of
local irritation, difficulty in correcting the error.
16
Parenteral products are packaged in ampoules, vials, bottles, plastic
bags, and prefilled disposable syringes. Containers for injections can be
made of glass or thermoplastic polymers. They may range in size from 1000
ml bottles to 1 ml or less ampoules, vials, or syringes. Each vial is sealed
with a rubber closure held in place by an aluminum cap.
The most widely used solvent for parenteral preparations is sterile water for
injection (aqua redestillata or bidestillata – pyrified water rendered sterile and
pyrogen-free by repeated distillation). Other common solvents include sodium
chloride injection, peach oil (for water-insoluble drugs), etc.
PRESCRIPTION WRITING
Rp./ Sol. Natrii citratis 4% 150 ml
D. S.Take 1 tablespoon 3 times daily.
#
Rp./ Pulv. Natrii citratis 6 g
Aquae destillatae ad 150 ml
Misce. Da. Signa.Take 1 tablespoon 3 times daily.
#
Rp./ Infusi radicis Primulae 6 g/180 g
Ephedrini hydrochloridi 300 mg
Liquoris Ammonii anisati
Natrii benzoatis aa 3 g
M. f. mixtura.
D. S. Take one tablespoon 3 times daily.
#
Rp./ Tincturae Valerianae 20 g
(T-rae Valerianae 20 g )
D. S. Take 20 drops 3 times daily.
#
Rp./ Solutionis Xylometazolini 0,1% 10 ml
(Sol. Xylometazolini 0,1% 10 ml)
D. t. d. № 1 in flaconis (fl.).
S. Put 2 drops into nose 3 times daily.
#
Rp./ Penicillini G 1 000 000 IU
(Benzylpenicillini 1 000 000 IU)
D. t. d. № 20 in fl.
S. 500 000 IU i.m. every 8 hours (after dissolving in 5 ml distilled water).
#
Rp./ Solutionis Lydoli 5% 2 ml
17
(Sol. Pethidini 100 mg/2 ml)
Da tales doses № 10 in ampullis.
Signa. 2 ml every 6 hours i.m.
(on the yellow prescription form)
#
Rp./ Sol. Diazepami 10 mg/2 ml
D. t. d. № 5 in amp.
S. 1 or 2 ml intravenously slowly (5 min)
diluted with 20 or 40 ml 40% glucose.
(on the green prescription form)
#
Rp./ Fraxiparini 0.3 ml
(Nadroparini 0.3 ml)
D. t. d. № 10 in pre-filled syringes.
S. 0.3 ml per day subcutaneously in
the area of the navel for 7–14 days.
SEMISOLID DOSAGE FORMS
Semisolid dosage forms include ointments, liniments, gels,
suppositories, plasters, and plaques.
I. CLASSIFICATION OF SEMISOLID DOSAGE FORMS
1. Ointments (unguentum, -i, -a)
 ointments (unguentum, -i, -a)
 creams (creme, -ores)
 pastes (pasta, -ae, -ae)
2. Gels (gel, -i)
3. Liniments (linimentum, -i, -a)
4. Suppositories (supositorium, -i, -a)
 rectal suppositories (suppositoria rectalia)
 vaginal suppositories (suppositoria vaginalia)
 urethral suppositories (suppositoria urethralia)
5. Plasters
 medicated plasters (emplastrum, -i, -a)
18
 transdermal delivery systems (TTS)
6. Plaques
II. CHARACTERISTICS OF SEMISOLID DOSAGE FORMS
 OINTMENTS (unguentum, -i, -a) are semisolid preparations intended
for external application to the skin or mucous membranes; usually, but
not always, they contain medicinal substances.
The types of ointment bases used as vehicles (vehiculum, basis unguenti)
are selected for optimum delivery of the drug. Ointment properties vary, since
they are designed for specific use, ease of application, or extent of
application.
Oleaginous bases are described as ointments, emulsion bases may be
termed creams, and the forms containing large amounts of solids are termed
pastes.
 Ointment bases (vehiculum, basis unguenti) should be nonirritating,
easily removable, nonstaining, stable, non-pH-dependent and widely
compatible with a variety of medicaments. They are categorized into
four classes:
1. Oleaginous bases: vegetable fixed oils: olive oil, almond oil, sunflower
oil; animal fats; minerals:Vaseline (vaselinum), and paraffin (hard paraffin,
paraffinum solidum; liquid paraffin, paraffinum liquidum). Bases of this type
are occlusive, nearly anhydrous and provide an optimum stability for
medicaments.
2. Absorption bases: anhydrous lanolin (lanolinum anhydricum, sheeps
wool fat). It contains not more than 0,25% of water. It is suitable whenever a
large volume of aqueous solutions must be incorporated into the ointment.
Lanolin (lanolinum) – anhydrous lanolin is converted to lanolin by the
addition of 30% water. It is good emollient and protectant.
3. Emulsion bases: most commonly used type of ointment bases. The oil
phase is typically made up of Vaselinum and/or liquid petrolatum (Paraffinum
liqidum).
4. Water-soluble bases – they are generally prepared of polyethylene glycol.
TYPES OF OINTMENTS:
1. OINTMENTS (UNGUENTUM, -I, -A) are prepared of solid active
ingredients (1–25%), finely powdered and then incorporated into the
oleaginous base. According to the way of administration they can be:
19
ointments for skin application (unguenta dermatica: 20–100 g), eye ointments
(unguenta ophthalmica: 3–10 g), nose ointments (unguenta nasalia), etc.
2. PASTES (PASTA, -AE, -AE) contain powders dispersed in the vehicle in
quantity more than 25%. They are usually stiffer, less greasy and more
absorptive than ointments. Pastes adhere reasonably well to the skin and
they are suited for application on and around moist lesions. Pastes are less
macerating than ointments. They easily may be removed from the skin. They
are divided into pastes for application on the skin (pastae dermaticae) and
dental pastes (pastae dentifricae). An official paste is the Zinc Oxide paste.
3. CREAMS (CREME, -ORES) are similar to ointments but they contain a
water phase (water, aromatic water, etc.). They are classified as:
 cold creams with roughly dispersed water phase and cooling properties
 emollient creams with finely dispersed water phase, which soften the skin.
4. GELS or jellies (gel, -i) are semisolid dosage forms with high degree of
clarity, ease of application and ease of removal and use. The active
ingredients are incorporated into water-soluble bases. The gels often provide
a faster release of drug substance as compared to creams and ointments.
Gel formulations include ophthalmic preparations of pilocarpine, carbachol;
topical preparations for burn therapy; anti-inflammatory treatment; treatment
of acne, etc. Depending on their ingredients some gels may function as
protective coatings. Gels are prepared in adhesive forms in order to increase
the contact time of the active ingredients, e.g., topical dosage forms for
aphthous stomatitis.
LINIMENTS
Liniments (linimentum, -i, -a) are thick, viscid liquids, emulsions,
suspensions, etc. They are intended for external application. They usually are
applied with friction and rubbing onto the affected area. The oily liniments are
milder in their action but are more useful when massage is required.
SUPPOSITORIES
Suppositories (suppositorium, -i, -a) are solid dosage forms of various
weights and shapes for insertion into the rectum, vagina, or the urethra. After
insertion, suppositories soften, melt, and dissolve in the cavity fluids.
Suppository vehicles (bases) can be classified into two types: fatty (e.g.,
Cocoa butter) and water soluble (e.g., polyethylene glycol). Cocoa butter is a
naturally occurring triglyceride, being solid at room temperature and melting
quickly at body temperature.
20
Types: (1) Rectal suppositories (suppositoria rectalia) are administered
rectally either to treat local conditions such as hemorrhoids or to achieve
systemic absorption (sedatives, tranquilizers, and analgesics).
Rectal suppositories can be used when the patient is enable to take
medication by mouth, or when the patient is unconscious. The lower, middle
and upper hemorrhoidal veins surround the rectum. Only the upper vein
conveys blood into the portal system, thus drugs absorbed into the lower and
middle hemorrhoidal veins will bypass the liver. Disadvantages to the use of
rectal suppositories include possible uncertain, local irritation and possible
accidental loss of the medication.
(2) Vaginal suppositories are applied vaginally for a local effect.
Following intravaginal administration, some drug absorbtion from the intact
vaginal mucosa is likely.
(3) Urethral suppositories (suppositoria urethralia) are cylindrical
dosage forms, administered urethrally to treat local conditions. They are
unusual dosage forms.
PLASTERS
Plasters (emplastrum, -i, -a) are substances intended for external
application made of such materials and of such consistency as to adhere to
the skin. They are intended to protection and support and/or to bring
medication into close contact with the skin.
 adhesive plasters
 medicated plasters are used for local or regional drug delivery
 transdermal delivery (or therapeutic) systems (TTS) are used for longterm systemic delivery of therapeutic agents through the skin (e.g.,
antihypertensive, antianginal, analgesic, steroidal and contraceptive drugs).
Examples: Nitroderm TTS, Estraderm TTS, Durogesic, etc.
PLAQUES
Plaques are special devices for local controlled, prolonged drug therapy,
which are intended for application under the eyelid or in the conjunctival sac
of the eye (plaques used in the treatment of glaucoma) or on the palate
(plaques with antifungal action).
AEROSOLS (SPRAY)
These drugs are designed to carry the drug into the respiratory tree of the
patient or on the skin and mucous (nasal, etc.). According to the chemical
21
characteristics, they are categorized in three groups: gases (nitrous oxide,
oxygen), vapors of volatile liquids (ether, halothane, chloroform), and
aerosols (sprays).
Aerosols are heterogeneous systems consisting of very finely subdivided
liquid or solid particles (optimum size 0,5–3 μm) dispersed in a gas medium.
The pressurized aerosol packages contain different propellants (compressed
gases) driving the drug in the form of mist or foam. They can be inhaled
(nasally or orally) or applied topically to dispense a variety of agents for
treatment of systemic and topical diseases. Metered dose inhalers (with a
metering valve) contain multiple doses and they are intended for delivering
measured quantities of drug. Examples: Salbutamol, Salmeterol, Fenoterol,
etc.
Powders may be administered by mechanical devices that require manually
produced pressure and a deep inhalation by the patient (e.g., Cromolin
sodium).
Nebulizers are devices used for administration of solutions giving sufficiently
small droplets. Nebulised solutions may be breathed directly or by a plastic
face mask or a tent.
Advantages: rapid onset of action; bypass the hepatic circulation; avoidance
of degradation in the gastrointestinal tract; lower dosage that minimizes
adverse reactions; simple, convenient and acceptable therapy.
PRESCRIPTION WRITING
1. Ointments
Rp./ Acidi borici
1,0
Vaselini albi ad 20,0
Msce fiat unguentum.
D. S. Apply twice daily to the affected skin. Not for children under 3
years.
#
Rp./ Unguenti dermatici Acidi borici 5% 18,0
D. tub. № 1.
S. Apply twice daily to the affected skin. Not for children under 3 years.
#
Rp./ Ung. derm. Gentamycini 0,1% 15,0
D. tub. № 1.
S. Apply twice daily to affected skin.
#
Rp./ Unguenti ophthalmici Gentamycini 0,3% 5,0
22
(Ung. Ophth.) Gentamycini 0,3% 5,0
D. tub. № 1.
S. Apply in the lower conjunctival sac of the affected eye twice daily.
#
Rp./ Ultraproct 15,0
(Ultraproct 15 g)
D. tub. № 1.
S. Apply rectally in the evening.
2. Pastes
Rp./ Acidi salicylici 2,0
Zinci oxydi
25,0
Vaselini
48,0
M. f. pasta.
D. S. Apply externally to the burned area once daily.
#
Rp./ Pastae Zinci 25,0
D. tub. № 1.
S. Apply externally to the burned areas once daily.
3. Gels
Rp./ Geli Troxevasini 2 % 40,0
D. tub. № 1
S. Apply twice daily to the affected area (for treatment of varices).
4. Creams
Rp./ Creme Clotrimazoli 1% 20,0
D. tub. № 1.
S. Apply externally to the affected area.
5. Liniments
Rp./ Olei Lini
Aquae Calcis aa 50,0
M. f. linimentum.
D. S. Apply to the burned area.
6. Suppositories
Rp./ Paracetamoli 150 mg
(Paracetamoli 0,150)
D. scat. № 1 in supp.
S. Insert 1 suppository into rectum twice daily.
23
#
Rp./ Morphini hydrochlorici 0,01
Butyri Cacao
q. s.
M. f. supp.
D. t. d. № 3.
S. Insert 1 supp. into rectum in case of pain.
#
Rp./ Doloproct
D. scat. № 1 in supp.
S. Insert 1 supp. into rectum in the evening.
7. Plasters
Rp./ Nitrodermi TTS 25 mg
D. scat. № 1
S. Stick 1 plaster daily on the precordial area.
8. Aerosols
Rp./ Ventolini inhaler 0,1 mg
D. t. d. № 1 in flac.
S. For inhalation in case of asthma attack.
#
Rp./ Bicromati 20,0
D. scat. №1 in caps.
S. Inhale 2 capsules every 12 hours, with spinhaler.
EXTEMPORANEOUS PRESCRIPTIONS
1. Antacid powder with anaesthesine (benzocaine)
Rp./ Anaesthesini
Bismuthi subnitratis aa 3,0
Magnesiae oxydi
40,0
M. f. pulvis.
D.S. Half a teaspoon to be taken with meal.
2. Powder with caffeine for general refreshment
Rp./ Coffeini puri 0,05
Sacchari albi 0,2
M. f. pulvis
D. t. d. № 20
S. Take one powder each morning and at lunch-time.
24
3. Bourget powder with antiacid action
Rp./ Natrii bicarbonatis 8,0
Natrii phosphatis 4,0
Natrii sulfatis
2,0
M. f. pulv.
D. t. d. № 10
S. 1 powder to be dissolved in 1 l of water. Drink 1 tea-cup half an hour
before meal.
4. Emulsion with laxative action
Rp./ Olei Ricini
20,0
Gummi arabici
10,0
Aquae destillatae ad 200,0
M. f. emulsion.
D. S. To be taken all at once.
5. Spasmolytic drops with atropine (for 7 days)
Rp./ Atropini sulfatis
0,01
Aquae destillatae ad 20,0
M. D. S. Take 20 drops 3 times daily.
6. Eye drops with Pilocarpine
Rp./ Sol. Pilocarpini hydrochloridi 2% 10 ml
D. t. d. № 1 in flac.
S. Place 1 drops in each eye 3 times daily.
7. Drops for treatment of abdominal colics
Rp./ Dionini (Aehylmorphini)
Papaverini hydrochlorici
Extr. Belladonnae
aa 0,2
Aquae Laurocerasi
20,0
M. D. S. Take 20 drops 3 times daily.
8. Mixtura nervina (for 7 days)
Rp./ Natrii bromatis
Kalii bromatis
aa 6,0
T-rae Valerianae
T-rae Adonidis vernalis aa 10,0
Coffeini-Natrii benzoatis
1,0
Phenobarbitali-Natrii
0,6
Sirupi Menthae
60,0
25
Aquae destillatae
ad 200,0
M. D. S. Take 1 tablespoon 3 times daily, after meals.
9. Suppositories with morphine (with systemic action)
Rp./ Morphini hydrochloridi 0,01
Butyri Cacao q. s.
M. f. supp.
D. t. d. № 6.
S. Insert 1 supp. into rectum in case of pain.
10. Liniment for treatment of burning
Rp./ Olei Lini
Aquae Calcis aa 50,0
M. f. linimentum.
D. S. Apply to the burned area.
26