2. 2
Pharmaceutics
Pharmaceutics is the science of dosage form
design.
There are many chemicals with known
pharmacological properties but a raw chemical
is of no use to a patient.
Pharmaceutics deals with the formulation of a
pure drug substance into a dosage form.
3. 3
Active Drug Substance
(Active pharmaceutical ingredient - API)
Chemical compound with pharmacological (or
other direct effect ) intended for use in
diagnosis, treatment or prophylaxis of diseases.
International non-proprietary names (INN,
generic names)
4. 4
Direct clinical use of the active drug substances „as
they are“ is rare due to a number of good reasons:
API handling can be difficult or impossible (e.g.,
low mg and µg doses)
Accurate drug dosing can be difficult or
impossible
API administration can be impractical, unfeasible
or not according to the therapeutic aims
Some API can benefit from reducing the exposure
to the environmental factors (light, moisture…), or
they need to be chemically stabilised due to the
inherent chemical instability
5. 5
Direct clinical use of the active drug substances „as
they are“ is rare due to a number of good reasons:
API can be degraded at the site of administration
(e.g., low pH in stomach)
API may cause local irritations or injury when they
are present at high concentrations at the site of
administration
API can have unpleasant organoleptic qualities
(taste, smell – compliance!)
Administration of active substance would mean to
have no chance for modification (improvement) of
its PK profile
6. 6
From drug substance to pharmaceutical
preparation
Besides the choice of the active drug
substance, you need to also make a
responsible decision regarding the route of
administration and the DOSAGE FORM (drug
delivery system) – wrong choice can cause
failure of therapy
You should also be able to handle and
administer the drug properly or advise the
patient about it – wrong use can cause failure
of therapy
7. 7
Excipients
Excipients (inactive pharmaceutical
ingredients)
– Its selection depends on technological,
biopharmaceutical and/or stability reasons.
– Diluents/fillers, binders, lubricants, coatings,
preservatives, colorants and flavouring
agents
8. 8
Pharmaceutical dosage form
Pharmaceutical dosage form
– Determines the physical form of the final
pharmaceutical preparation
– Is a drug delivery system which is formed by
technological processing (drug formulation)
– Must reflect therapeutic intentions, route of
administrations, dosing etc.
9. 9
Pharmaceutical preparation (PP)
Pharmaceutical preparation (PP)
– particular pharmaceutical product containing active
and inactive pharmaceutical ingredients formulated
into the particular dosage form.
– Packed and labelled appropriately
– Two major types of PP according the origin:
Manufactured in large scales by pharmaceutical
industry (original and generic preparations)
Compounded individually in compounding
pharmacies
10. 10
1- Pharmaceutical preparations
manufactured by pharmaceutical industry
1.1- Original pharmaceutical preparations
– undergo full and very extensive
pharmacological/ toxicological and
pharmaceutical pre-clinical and clinical
development and evaluation
– particularly important is the proof of
effectiveness and safety
11. 11
- Can be released after the expiration of the patent
protection of the original preparation
– The approval for clinical use is easier due to the prior
experience with the original preparation
– Must be pharmaceutically equivalent: same API, dose,
pharmaceutical dosage form and the same route of
administration as in original preparation
– Must be clinically bioequivalent: i.e. it must be of very
close PK profile as original preparation. PK parameters
(Cmax, tmax, AUC) are within 80-125 % range as
compared with the original preparation.
1.2- Generic pharmaceutical preparations
(„authorised copies of original preparations“)
12. 12
2- Pharmaceutical preparations
compounded individually
These PP are compounded individually for a particular
patient according to the physician's prescription in a
pharmacy licensed for compounding
In contrast to the past, they are used rather rarely and
mostly in specific situations
It is highly advisable that whenever the particular suitable
PP is approved and commercially available it should be
preferred over the compounding
The major disadvantage is the lack of standardization (it is
always a „single-patient batch“), unavailability of rigorous
QC testing and the appropriate clinical evaluation.
13. 13
The individually compounded PP
can be a justified choice when:
The drug in a particular dosage form is not
commercially available on the market
The extraordinary low or high dose is needed (young
children, elderly people, special situations – e.g.,
intoxications). In this case right dosage strength need
not be readily commercially available for every patient
The patient suffers from the allergy on a specific
excipients (e.g., lactose – a filler, some
colorizing/flavouring or antimicrobial agents -
parabens) or another drug appearing in the PP
Patient is unable to use a PP in its commercially
available dosage form (e.g., children, elderly)
14. 14
Classification of pharmaceutical dosage
forms according to physical properties
– Gaseous dosage forms
– Liquid dosage forms
– Semisolid dosage forms
– Solid dosage forms
15. 15
Gases
Medicinal gases, inhalation/volatile
anaesthetics (vaporised before administration
by inhalation)
Aerodispersions of solid particles (e.g.,
antiasthmatic inhalations) or liquid particles
(antiasthmatic inhalations or sprays)
16. 16
Liquids
Solutions – one homogenous phase, prepared by dissolving one or
more solutes in a solvent
Emulsions
a dispersion system consisting of two immiscible liquids
o/w or w/o
cloudy appearance
Suspensions
A dispersion system where solid particles (dispersed phase) are
dispersed in liquid phase (dispersion medium)
According to the size of dispersed particles (1 nm- 0,5 mm) a
molecular, colloidal and coarse dispersions can be distinguished
May require shaking before administration
Not intended for systemic administration of drugs with high
potency
17. 17
Semisolid dosage forms
1- Unshaped (without specific physical shape)
Gels -A semisolid systems in which a liquid phase is
constrained within a 3D cross-linked matrix.
Creams – semisolid emulsion systems (o/w, w/o)
containing more than 10% of water.
– o/w creams - more comfortable and cosmetically
acceptable as they are less greasy and more easily
water washable
– w/o creams – accommodate and release better
lipophilic API, moisturizing, Cold creams
18. 18
Semisolid dosage forms
1- Unshaped (without specific physical shape)
Ointments – semisolid dosage forms with the
oleaginous (hydrocarbon), water-soluble or
emulsifying base
– Oleaginous (hydrocabon) base: Petrolatum
(Vaseline – white, yellow)
– Water-soluble base: Polyethylenglycol (PEG)-
ointment – syn. macrogol ointments
Pastes – semisolid dispersion system, where a solid
particles (> 25%, e.g. ZnO) are dispersed in
ointments – mostly oleaginous (Petrolatum)
19. 19
Semisolid dosage forms
2- Shaped
Suppositories (for rectal administration)
– different shapes
– Melting/dissolving at body temperature
– Oleaginous (cacao butter, adeps
neutralis) or aqueous (PEGs,
glycerinated gelatine)
Pessaries (vaginal suppositories)
– Similar as above, PEGs or glycerinated
gelatine are often used as base.
20. 20
Solid Dosage Forms
– Unshaped (without specific shape)
- powders for external/internal use
– Shaped
- Tablets
- Capsules
- Implantates (Sterile disks inserted surgically into
body tissues and designed to release drug(s) over
extended period of time)
- Transdermal patches
- Lozenges (consists of sugar and gum to medicate
the mouth and throate)
21. 21
Classification of pharmaceutical dosage forms
according to the route of administration
– for systemic administration
Peroral (p.o)
Sublingual (S.L) and buccal.
Rectal
Parenteral
Transdermal
Inhalation
22. 22
Classification of pharmaceutical dosage forms
according to the route of administration
– for local administration
Topical (on the skin or mucosa)
Into/onto - the eye, nose, ear
- the oral cavity
- the vagina, rectum
- the brochi
- the skin
Local parenteral (viz Parenteral above)
Oral (local effect within GIT; antacids, adsorbents)
23. 23
Prescription Writing
The prescription is one of the most important
therapeutic transactions between physician and
patient.
The art of prescription writing is an ancient inheritance.
The ancients started their prescription with an appeal
to the gods for its success.
The ancient symbol, Rx, signifying the appeal, was
established centuries ago and has been carried down
to the present time.
24. 24
Prescription Writing
To avoid undesirable and/or serious effects on
the patient, both physician and pharmacist
must render the highest of professional
services.
Accurate diagnosis; proper selection of
medication, dosage form and route of
administration; proper size and timing of dose;
precise dispensing; accurate labeling; and
correct packaging all must be provided.
26. 26
For Arthur H. Recipe
Take thou
Potassium Acetate of.............................one drachm.
Of Solution of Acetate of Ammonium........three and a half
drachms.
Of Spirits of Nitrous Ether...........................two drachms.
Of Infusion of Buchu (a quantity sufficient) up to four
ounces.........
Signa: -Mix. Let a mixture be made.
Label: -One drachm three times a day after meals.
28. 28
Form of the Written Prescription
A prescription consists of the superscription,
the inscription, the subscription, the signa, and
the name of the prescriber
1- Superscription
The date when the prescription order is written;
the name, address and age of the patient; and
the symbol Rx (an abbreviation for "recipe," the
Latin for "take")
29. 29
Form of the Written Prescription
2- Inscription
The body of the prescription, containing the
name and amount or strength of each
ingredient.
3- Subscription
The directions to the pharmacist, usually
consisting of a short sentence such as: "make
a solution," "mix and place into 10 capsules,"
or "dispense 10 tablets."
30. 30
Form of the Written Prescription
4- Signature
From the Latin "signa," meaning "write," "make," or
"label," this sections contains the directions to the
patient.
These should always be written in English; however,
physicians continue to insert Latin abbreviations, e.g.
"1 cap t.i.d. pc," which the pharmacist translates into
English, "take one capsule three times daily after
meals." Since the pharmacist always writes the label in
English, the use of such abbreviations or symbols
should be discouraged.
31. 31
Form of the Written Prescription
Follow: 4- Signature
The instruction, "take as directed," is not
satisfactory and should be avoided.
The directions to the patient should include a
reminder of the intended purpose of the
medication by including such phrases as "for
pain," "for relief of headache," or "to relieve
itching"
32. 32
Form of the Written Prescription
5- Labeling
When the physician wants his patient to know
the name of the drug, the box on the
prescription form marked "label" should be
checked.
6- Refills
The physician should designate the number of
refills he wishes the patient to have.
33. 33
Proprietary vs. Non-Proprietary
("Generic") Prescriptions
In recent years, some hospitals and private
physicians are indicating on the prescription
their willingness or desire that the pharmacist
dispense a non-proprietary or "generic-named"
preparation instead of the trade name item
written on the prescription. Some have a box
on the prescription designated "N.P.P." In this
way, the pharmacist can use a form of the drug
which may be less expensive to the patient.
34. 34
Types of Drugs
Legend Drugs: These drugs may not be
dispensed by a pharmacist without a
prescription from a physician.
Controlled Drugs: In addition to requiring a
prescription, these drugs require additional
safeguards for storage. Refills are also limited.
Over-the-Counter (OTC) Drugs: These drugs
do not require a prescription.
35. 35
Controlled Substances
Schedules of Controlled Drugs: These drugs are
divided into five schedules.
Drugs can be scheduled, unscheduled, or moved from
one schedule to another as the need arises.
Schedule I
Drugs in this schedule have a high abuse potential
(narcotic and hallucination effects). Examples are
heroin, marijuana.
36. 36
Controlled Substances
Schedule II
Drugs in this schedule have a high abuse potential with
severe psychic or physical dependence liability.
Included are certain narcotic analgesics, stimulants,
and depressant drugs. Examples are opium, morphine,
codeine, hydromorphone, methadone, meperidine,
oxycodone, anileridine, cocaine, amphetamine,
methamphetamine, phenmetrazine, methylphenidate,
amobarbital, pentobarbital, secobarbital,
methaqualone, and phencyclidine.
37. 37
Controlled Substances
Schedule III
Drugs in this schedule have an abuse potential less
than those in Schedules I and II and include
compounds containing limited quantities of certain
narcotic analgesic drugs, and other drugs such as
barbiturates, glutethimide, methyprylon, and
chlorphentemine. Any suppository dosage form
containing amobarbital, secobarbital, or pentobarbital is
in this schedule.
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Controlled Substances
Schedule IV
Drugs in this schedule have an abuse potential
less than those listed in Schedule III and
include such drugs as barbital, phenobarbital,
chloral hydrate, ethchlorvynol, meprobabmate,
chlordizepoxide, diazepam, oxazepam,
chloroazepate, flurazepam, etc.
39. 39
Controlled Substances
Schedule V
Drugs in this schedule have an abuse potential
less than those listed in Schedule IV and
consist primarily of preparations containing
limited quantities of certain narcotic analgesic
drugs used for antitussive and antidiarrheal
purposes.
40. 40
Requirements for Prescriptions
Written for Controlled Substances
Required Information on the Prescription
Must be dated and signed on the day it is
issued. Must have the full name and address of
the patient.
Must have the name, address, and registration
number of the physician.
May be prepared by the secretary, but must be
signed by the physician.
41. 41
Refilling Prescriptions for
Controlled Substances
Refills for Schedule II drugs are not permitted.
Refills for Schedule III, IV, and V drugs are
permitted if the number of refills is indicated
on the prescription. However, the prescription
order may be renewed only up to five times
within six months after the date of issue. After
five renewals or after six months a new
prescription order is required.
