formulation, ointment bases, preparation methods.

1. SEMISOLID
DOSAGE FORMS-2
Presented By:
K. Arshad Ahmed Khan
M.Pharm
Departmernt of
Pharmaceutics
RIPER.

2. Ingredients :
Active pharmaceutical ingredients
Bases
Preservatives
Humectants
Anti oxidants
Emulsifier
Gelling agent
Permeation enhancer
Buffers

3. It is one of the most important ingredient used in
the formulation of semisolid dosage form
Ointments and suppository base do not merely
acts as the carrier of the medicaments, but they also
control the extent of absorbtion of medicaments
incorporated with them

4. They should be:
 Compatible with skin ph and drug
 Inert ,non irritating and non sensitizing
 Good solvent and/or emulsifying agent
 Emollient , protective , non greasy and easily
removable
 Release medicaments easily at the site of
administration
 Pharmaceutical elegant and possess good stability.

5. BASES
OLEAGENOUS
BASE
ABSORBTION
BASE
EMULSION
BASE
WATER
SOLUBLE
BASE

6. 1. Oleaginous ( hydrocarbon) bases:
They consist of a combination of more than one oleaginous
material such as water insoluble hydrophobic oils and fats
They are highly compatible ; occlusive ; good emollients
They are anhydrous, do not absorb water, readily(hydrophobic)
insoluble in water, non washable
Example : Vaseline,hard parafin, liquid paraffin,white ointment.
Uses : protective, emollient and vehicle for solid drugs.

7. 2. Absorption (Emulsifiable) base:
Have capacity to absorb considerable quantities of
water or aqueous solution and turns to w/o without
marked changes in the consistency.
They are anhydrous, water insoluble and water
unwashable.
They have good emollient but poor occlusive
property.
Uses: protective, emollient and vehicle for aqueous
solutions and solid drug.

8. 3. Emulsion bases:
According to the type of emulsion these bases are
classified as either W/O or O/W.
W/O EMULSION
BASE
O/W EMULSION
BASE
Hydrous Hydrous
Will absorb water Will absorb water
Insoluble in water Insoluble in water
Not washable washable

9. 4. Water soluble Bases:
 These include both hydrous and non hydrous
dermatological non- emulsion bases which are water
soluble and contain no oil phase.
 Water soluble, water washable, non greasable
 Because they softens with the addition of water, large
amount of aqueous solutions are not effectively
incorporated into the bases.
Example : carbowax compounds such as the poly
ethylene glycol bases containing pectin, cellulose,
bentonite and gelatin.

10. Some bases , although, resist microbial attack but
because of their high water content, it require an anti
microbial preservative.
Commonly used preservative include:
Methyl hydroxy benzoate
Propyl hydroxy benzoate
Chlorocresol
Benzoic acid
Phenyl mercuric nitrate

11. Oxygen is highly reactive atom that is capable of
becoming of potentially damaging molecules
commonly called “free radicals”.
Free radicals are capable of attacking the healthy
cells of the body, causing them to loose their structure
and functions
To prevent this an anti oxidant are added.
Example : Butylated hydroxy anisole , Butylated
hydroxy toluene

12. CLASSIFICATION OF ANTIOXIDANT
ANTIOXIGENS REDUCING
AGENT
ANTIOXIDANT
SYNERGIST
Acts by reacting with
the free radicals.
e.g.
•Butylated hydroxy
anisole (BHA)
•Butylated hydroxy
tocopherols (BHT)
(used for oil system)
Have lower redox
potential than
drug,hence gets
oxidized first.
e.g.
•Ascorbic acid
•Potassium and
sodium metabisulfite
•Thiosulfite
(used for aqueous
system)
Chelating or
sequestering agents,
enhance the effect of
anti oxidants.
e.g.
•Citric acid
•Tartaric acid
•Lacithin

13. Gelling agents
 Gelling agent forms a gel dissolves in a liquid phase as a
colloid mixture that forms a weakly cohesive internal
structure.
 These are organic hydro colloids or hydro phillic
inorganic substances.
Example : tragacanth, sodium alginate, pectin, gelatin,
cellulose derivatives.
Material % Brook field
viscosity
Carbomer 94 1 resin NF 0.15 2900
Carbomer 94 1 resin NF 0.25 6300
Guar gum 1.50 8040
Methyl cellulose 2.00 5200
Sodium alginate 2.50 10400

14. Permeation enhancer
Skin can acts as a barrier with the introduction of
various penetration enhancers, penetration of the
drug through the skin can be improved.
Permeation enhancer Drug used
Methanol,carvacrol,
linalool
Propranolol
hydrochloride
Limonene Indomethacin ,
ketoprofin
Geraniol
Nerolidol
Diclofenic sodium
Oleic acid Piroxicam

15. Anionic Cationic Non ionic
•Alkyl sulphates
•Soaps
•D odecyl benzene
•Sulfonates
•Lactylates
•Sulfosuccinates
•Monoglycerides
•Sulfonates
•Phosphate esters
•Silicones
•Taurates
•Quaternary
ammonium
compounds
•alkoxyalkylamines
•Polyoxyethylene
•Alkyl-aryl ethers
•Polyoxy ethylene
•Sorbitan esters
•Sorbitan fatty acid
esters
•Glyceryl fatty acid
esters

16. A humectant is a hygroscopic substance . It is
often a molecule with several hydrophilic groups,
most often hydroxyl group.
Humectants are used to:
 Increase the solubility of active ingredients
 To elevate its skin preparation
 Elevate the hydration of the skin.

17. Buffers are added to variopus purpose such as:
 Compatibility with skin
 Drug solubility
 Drug Stability
 Influence on ionization of drug
Example: Sodium acetate , Sodium Citrate , Potassium meta
phosphate

18. Purified water
Water for Injection
Water for injection may be used in
ophthalmic semi solid preparation like eye
ointments , gels etc

19. PREPARATION OF SEMI SOLIDS
Trituration
method
Fusion
method
Chemical
reaction
method
Emulsificatio
n method
Ex. Ointments
creams
pastes
Ex. Ointments
creams
pastes
Ex. Ointments
creams
Ex. Ointments
creams
(Ointments, creams, pastes)

20. PREPARATION METHODS FOR
SUPPOSITORIES
Hand molding Heat molding
Automatic
machine
molding
Compression
molding
Ex. Rotary machine
linear machine

21. SIZE REDUCTION
LEVIGATION
MIXING WITH BASE
SPATULATION OR
TRITURATION
MIXING BASE TO
PRODUCE FINAL WEIGHT
HOMOGENIZATION
FILLING

23. Thank
you…..