Pre-lab 6
Items Covered In This Lab
1. Problems :
Dilution and Concentration
2. Prescriptions :
1) Castor oil emulsion
2) BaSO4 enema
3) Turpentine oil enema
DILUTION AND CONCENTRATOIN (P: 40)
Add 100 ml water
1 gm NaCl
in 200 ml solution
1 gm NaCl
in 100 ml solution
1%
0.5 %
Amount before dilution = Amount after dilution
Q1 C1
=
Q2 C2
N.B. Q 1 & Q 2 must have the same units
C1 & C2 must have the same units
DILUTION AND CONCENTRATOIN
Dilution of Alcohols and acids
 Since there is a volume contraction when alcohol &
water are mixed together
 we can not calculate the volume of water needed to
dilute alcohol to a desired v/v strength
 Strength of official concentrated acids % w/w
 Strength of official diluted acids  % w/v
N.B.
% w/ v = % w/w X specific gravity
Example:
How much water should be mixed with 5000 ml of 85%
(v/v) alcohol to make 50% (v/v) alcohol ?
Answer:
Q 1 = 5000 ml
5000 ml X
C 1 = 85% v/v
Q 2= ?
C 2 = 50% v/v
Q1 C1 = Q2 C2
85%
= Q2 X
50 %
Q2 = 8500 ml
Therefore ; use 5000 ml of 85% (v/v)
alcohol & enough water to make 8500 ml
EMULSIONS (P:88)
 Two immiscible liquids, e.g. water and oil, one of which is
dispersed as small globules (internal phase) in the other (external
phase) by the aid of emulsifying agent (e.g. gum acacia).
Oil (internal
phase)
Emulsifying
agent
H2O
(external
phase)
To prepare acacia emulsion,
A Primary Emulsion must be made first
With fixed ratios of Oil : Water : Gum
Type of oil
Example
Ratio of primary
emulsion (O:W:G)
Fixed
Castor oil
Almond oil
Arachis oil
4:2:1
Mineral
Liquid Paraffin
3 : 2 : 1.5
Turpentine oil
Volatile
Peppermint oil
Male fern
Oleo-resin
Extract
2:2:1
1:2:1
Ricin(Castor) Oil Emulsion (P: 94)
Rx
Ricin oil (castor oil)
Gum acacia
Water
Fiat: Hastus
Sig. : statin
16 ml
Q.S.
80 ml
Use : Purgative
Calculation :
Castor oil  fixed oil.
 ratio to prepare primary emulsion
Oil : Water : Gum
4 :
2 : 1
 16 ml : 8 ml : 4 gm
Final volume = 80 water+ 16 ml oil = 96 ml
Dry gum Method
8 ml Water
on the
otherside
Trituration16must
be:
ml
on oneside
1.FromOilthe
wrist.
2.In one direction.
3.In all parts of the
morter.
4.Continueous.
5.Very Fast.
In a dry mortar;
add gummotion
& grind
Triturate
with whipping
with
pestle
Continue
for
2 min.is(stabilization)
untiltriturating
primary
emulsion
formed
Place gum
in ,cracking
a line in thesound)
center
(white
, thick
Dry gum Method
10ml Water
10ml Water
Dpwise
&
portion-wise
triturate
& triturate
adjust volume to
96 ml with water
Wip with
a tissue
Primary Emulsion
Transfer to
a cup measure
ricin(Castor) Oil
Label : White
Keep in a Cool Place
Shake The Bottle
The Draught
To be taken at once.
Rx
Ricin oil
Gum acacia
Water
Fiat: Hastus
Sig. : statin
16 ml
Q.S.
80 ml
BaSO4 Enema (suspension) (p: 87)
Rx
Barium sulphate
Mucilage of acacia
Starch enema ad
Fiat: Enema
12 g
10 ml
50 ml
Use : Roentgenographic examination of lower bowel.
Starch enema (3%)
Rx
Starch
3g
Water to 100 ml
Use : emollient enema as starch coats the mucous
membrane & relieve local irritation.
Label : Red
Shake The Bottle
The Enema
To be used as directed.
Preparation of STARCH ENEMA:
COOL
Add starch
suspension
to boiling
water while
on flame
Add 3 g Starch
Starch Suspension
Add 20 ml water STARCH
Stirr
Boil 80 ml water
ENEMA
Boil the mixture on the flame
on flame with stirring with
glass rod until translucent
viscous liquid (2 min)
BaSO4 ENEMA
Add BaSO4 in
mortar & grind
with pestle
Transfer to cup
measure
Add Acacia
mucilage
Rx
Barium sulphate 12 g
Mucilage of acacia 10 ml
Starch enema ad 50 ml
Fiat: Enema
Add starch enema
till pourable (25 ml)
Continue volume
with starch enema
to 50 ml.
Turpentine Enema (emulsion) (p: 97)
Rx
Turpentine oil
Starch enema
Fiat: enema
Mitte : 50 ml
Sig. : m.d.u
X 0.5
to
5 ml
2.5 ml
100 ml 50 ml
Use : anthelmintic for thread worm
Starch enema (3%)
Rx
Starch
3g
Water to 100 ml
Calculation :
F= 50/ 100 = 0.5
Label : Red
Shake The Bottle
The Enema
To be used as directed.
Preparation of Starch Enema:
As previously mentioned
Preparation:
1-in a colorless 200 ml bottle put 47.5 ml cool
starch enema (as turpentine oil is volatile)
2- Add 2.5 ml turpentine oil dropwise & shake
vigorously after each addition
 White viscous liquid that leaves film on the wall of
the bottle (when inverted upside down)
Thank you