PHARMACEUTICAL SOLID DOSAGE FORM:
·
Solid
dosage forms are available mostly in unit dosage forms, ie dosage form which
are taken by numbers such as tablets, capsules, pills etc.
·
Some
solids are packed and supplied in bulk. The bulk forms meant for internal use
are supplied either as granules or fine powders. The bulk powder meant for
external use are dusting powders, tooth powders etc.
POWDERS:
·
Powders
are the solid dosage form of medicament, which are meant for internal or
external use. They are available in crystalline and amorphous form. In
crystalline powders the constituent atoms and molecules are packed
in a regularly ordered, repeating three-dimensional pattern. Amorphous powders
are non-crystalline materials which possess no long-range order.
·
Any
material ranging in particle size from 0.1 to 10000 µ may be described as
powder. However powders used in pharmacy generally have a size between 0.1 to
10 µ.
·
The
powders are generally used in the following forms:
- Bulk powder for internal use,
Eg: Fine powders or granules - Bulk powder for external use,
Eg: snuffs, dusting powders and tooth powders. - Simple and compound powders for
internal use. - Powders in the form of
compressed tablets and tablet triturates. - Powders enclosed in cachets and
capsules. - Insufflations: Micronized
powders meant for being blown in the nasal tract, ears, tooth sokets,
vagina etc. - Parenteral powders: Powders for
dissolution into vehicles before injection.
DUSTING
POWDER:
Dusting
powders are meant for application to the intact or broken skin.
They are
meant for external applications.
Desired
Property:
- Ease of flow
- Spreadability
3. The
powder should adhere to the skin and possess good covering.
4. The
dusting powder should protect the skin from drying and irritation.
5. Dusting
powder should not have any irritant effect.
Types:
Dusting
powders are of two types
1.
MEDICAL
2.
SURGICAL
·
Medical
dusting powders are used mainly for superficial skin conditions whereas
surgical dusting powders are used in body cavities and also on major wounds as
a result of burns.
·
Surgical
dusting powders must be sterile (free from bacteria or other living microorganisms) before their use.
Formulation:
It is
generally prepared by mixing two or more ingredients one of which must be
either starch, kaolin or talc. Talc and kaolin are most commonly used because
these are chemically inert.
Use:
Dusting
powders are mainly used for antiseptic (preventing the growth of
disease-causing microorganisms.), astringent (a mild protein precipitant
suitable for topical application to shrink tissues), adsorbent (Substance that
binds to the drug surface), antiperspirant (a substance that is applied to the
skin, especially under the arms, to prevent or reduce perspiration.) and
antipruritic (used to relieve itching.)Action.
INSUFFLATIONS:
·
Insufflations
are meant for powders being blown in various body cavities, like nose, throat,
ears etc.
·
They
are generally applied with the help of insufflators. It sprays the powder into
a stream of finely divided particles all over the site of application.
Desired
Quality
- It should be finely divided
powder. - They should be absolutely free
from irritation and sensitizing quality.
Disadvantages:
- It is difficult to obtain a
measured quantity of the drug as a uniform dose - Particles adhere to each other
and to the wall of the insufflators due to the electrostatic force.
Use:
Used for
local effects, as in the treatment of ear, nose and throat infections with
antibiotics (a medicine such as penicillin or its derivatives that inhibits the
growth of or destroys microorganisms.).
SNUFFS:
These are
finely divided solid dosage forms of medicament which are inhaled into nostrils
for its antiseptic, bronchodilator and decongestion action.
DENTIFRICES:
Dentifrices
or tooth powders are hygienic products of everyday use. They may also be
medicated in order to exercise some definite action on individual person.
These are
applied with the help of tooth brush for cleaning the surface of the teeth.
Formulation:
They
contain abrasive agents such as calcium sulphate, magnesium carbonate, sodium
carbonate and sodium chloride. It may also contain some detergent and suitable
flavor.
Detergent
action is given by incorporating surfactants.
Flavour and
taste qualities are very significant in the formulation of dentifrices.
GRANULES:
·
The primary powder particles are made
to adhere to form larger, multiparticle entities called granules and the
process is known as granulation. The bitter, nauseous and unpleasant powders cannot be given in tablet
form or in a capsule because a large number of them are required to be taken as
a single dose.
·
They
also cannot be given as liquid form because of stability problem.
·
Such
medicaments are given in the form of granules. The drug is mixed with sugar,
flavouring agent and a granulating agent to prepare a coherent mass, which is
passed through a sieve to convert it into granules and then dried.
·
These
dried granules are supplied in single dose sachets which are dissolved in water
before taking.
Eg:
Granules of antibiotics, such as erythromycin, and penicillin salts.
EFFERVESCENT
GRANULES:
·
The
effervescent granules are the specially prepared solid dosage form of
medicaments, meant for internal use.
·
They
contain a medicament mixed with citric acid, tartaric acid and sodium
bicarbonate.
·
Sometimes
saccharin or sucrose may be added as a sweetening agent.
·
Before
administration, the desired quantity is dissolved in water, the acid and
bicarbonate reacts together and produce effervescence. The carbonated water
produced from the release of carbondioxide serves to mask the bitter taste of
drugs. Moreover carbon dioxide stimulates the flow of gastric juice and helps
in the absorption of medicaments.
3NaHCO3 +
C6H8O7.H2O = C6H5Na3O7 + 3CO2 + 3H2O
Sodium
Bicarbonate + Citric Acid = Sodium Citrate
TABLETS:
·
Tablets
are solid unit dosage form which are prepared by molding or by compression.
·
Compressed
tablets offer a number of advantages to the patients as well as the physician
and the pharmacists and that is why their popularity continues to increase.
·
For
the patient a tablet or a capsule is the most convenient form to use, because
it neither involves measurement of dose and easy to carry. Tablets are also
easy to be administered and dispensed. It is also a stable dosage form and
maintain accuracy of dosage.
CAPSULES:
·
Capsules
are solid unit dosage from in which one or medicaments and inert substances are
enclosed within a small shell, generally prepared from a suitable form of
gelatin.
·
Depending
on their formulation, the gelatin capsule shell may be hard or soft.
PILLS:
·
Pills
are small rounded solid dosage forms containing medicament and are intended to
be administered orally. Pills are spherical in shape and sometimes coated with
varnish, silver leaf, and gold leaf to improve the finish, mask the unpleasant
tastes and increase stability.
·
In
olden days pills were preferred because of their spherical shape which can be
easily swallowed. But now a days it is not used because of the following
reasons:
- Disintegration time of the
pills is uncertain. - It is difficult to prepare
pills of a uniform size. - It is difficult to prepare
pills of uniform weight.
Pharmaceutical Solid Dosage Form notes PDF
Pharmaceutical Solid Dosage Form notes PPT
