Transcript Ointment - Farmasi Unand

Compounding
Ointment
(Unguentum)
Dr. Muslim Suardi, MSi., Apt.
Faculty of Pharmacy University of Andalas
Ointment
“A highly viscous or semisolid
preparation usually containing medication,
used on the skin as a cosmetic, emollient, or
medicament”
“a homogeneous, viscous, semi-solid
preparation, most commonly a greasy, thick
oil with a high viscosity, that is intended for
external application to the skin or mucous
membranes”
Topical Medication
“a medication that is applied to body
surfaces such as the skin or mucous
membranes to treat ailments via
a large range of classes
including but not limited
to creams, foams, gels,
lotions & ointments”
Ointment
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Ointments are used topically for
several purposes as:
Protectants Antiseptics
Emollients Antipruritics
Keratolytics Adstringents
Ointment
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The vehicle or base of an ointment is
of prime importance if the finished
product is expected to function as any
one of the above categories.
In the case of a protective ointment, it
serves to protect the skin against
moisture, air, sun rays and other
external factors.
Ointment
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It is necessary that the ointment
neither penetrates the human skin
barriers nor facilitates the absorption
of substances through this barrier.
An antiseptic ointment is used to
destroy or inhibit the growth of
bacteria.
Ointment
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Frequently bacterial infections are
deeply seated; a base which has the
capacity to either penetrate/dissolve &
release the medication effectively is
therefore desired.
Ointments used for their emollient effect
should be easy to apply, be non-greasy
& effectively penetrate the skin
Types of Ointment Bases
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Hydrocarbon bases: hard paraffin, soft
paraffin, microcrystalline wax, ceresine
Absorption bases: wool fat, beeswax
Water soluble bases: macrogols 200,
300, 400
Emulsifying bases: emulsifying
wax, cetrimide
Vegetable oils: olive oil, coconut
oil, sesame oil, almond oil & peanut oil
Ointment Bases
“5 classes of ointment bases which are
differentiated on the basis of their
physical composition”
 Oleaginous bases
 Absorption bases
 W/O emulsion bases
 O/W emulsion bases
 Water soluble/miscible bases
Evaluation of Ointments
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Drug content
Release of medicament from base
Medicament penetration
Consistency of the preparation
Absorption of medicament into blood
stream
Irritant effect
Properties Affect Choice
of An Ointment Base
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Stability
Penetrability
Solvent property
Irritant effects
Ease of application & removal
Percutaneous Absorption
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The potential of the drug to cross the
stratum corneum
The potential of the drug to leave the
formulation
The influence of the formulation on
the stratum corneum.
Percutaneous Absorption
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The larger surface area, the higher the
drug absorbed
Incresing the hydration of formulations or
dressings on the skin generally enhance
percutaneous absorption
The greater the amount of rubbing, the
greater the absorption
The longer the contact, the greater the
absorption
Percutaneous Absorption
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Affords an ease of administration not
found in other routes, & patient
compliance is generally good with
dermatological formulations.
There is also the possibility of continuous
drug administration exemplified by the
transdermal patches.
Dermatological formulations can be easily
removed if necessary
Methods of Preparation of
Ointments
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Trituration
Fusion
The Major Disadvantage
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Drug absorbed limited to ±2 mg/day
Become a significant limitation if the
route is being considered for systemic
therapy.
Several chemicals have been found
that promote the percutaneous
absorption of drugs (called penetration
enhancers).
Penetration Enhancers
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Improve the solubility of the active
drug in the stratum corneum & facilite
the diffusion of the drug through the
barrier into the systemic circulation
Below is a list of penetration
enhancers used in dermatological
formulations.
Commonly used enhancers: DMSO,
urea, & TEA.
Penetration Enhancers
Chemical
Classification
Alcohols
Examples
MetOH, EtOH, propanol, octanol
Fatty Alcohols
Myristyl, cetyl, & stearyl alcohol
Fatty Acids
Myristic, stearic, & oleic acid
Fatty Acid Ester
Isopropyl, & isopropyl palmitate
Polyols
Propylene glycol, PEG, glycerol
Anionic surfactants
Na lauryl sulfate
Cationic surfactant
Benzalkonium, & cetylpyridinium chloride
Amphoteric surfactants Lecithins
Nonionic surfactants
Spans, Tweens, poloxamers, Miglyol
Advantages
Advantages
Disadvantages
Hard Gelatin Capsules