Prelab 6

Presented by Ahmed Magdy

Pharmaceutics I

Prelab contents

1. Preparations Cough Syrup.Black draught (infusion).Heavy magnesium oxide suspension.2. Problems Dose calculations Percent preparation Percent error

Cough syrupRxCodeine phosphate 0.3 gCpd Tartarazine solution 1 mlBenzoic acid solution 2 mlWater 2 mlLemon syrup 20 mlSyrup to 100 mlSend 50 mlFiat: Cough SyrupSig: Ʒi t.d.s.p.c.

Calculation:

Vehicle = 50 – (10+1+1+0.5) =37.5 ml

¾ vehicle = ¾ X 37.5 = 28.125 ml = 28 mlFactor = 50/100 = 0.5

X 0.50.15 g

1 ml1 ml10 ml50ml

0.5 mlCough SuppressantColoring agentPreservative

Solvent for drug

Vehicle Sweetening and flavoring agent

Use: Cough Syrup for treatment of dry cough

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Glass-rod

0.000 g

0.15 g codeine

phosphate

1 ml water

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1 ml benzoic acid solution

0.5 ml Compound tartarazine solution

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10 ml lemon syrup

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Adjust volume to

50 ml with syrup

Label

The Cough Syrup One teaspoonful to be taken three times daily after meals.

Fiat: Cough SyrupSig: Ʒi t.d.s.p.c.

Infusion preparationBlack draught

RxMagnesium Sulphate 250 gm Compound tincture of cardamom 100 ml Aromatic spirit of ammonia 50 ml Fresh infusion of senna to 1000 mlFiat :mist–send 100 mlSig : 30 ml O.m.

2.5 gm10 ml 5 ml100 ml

F = required / prescribed = 100/1000 = 0.1

Saline laxative.Carminative.Antacid and carminative.Irritant laxative.

Use: purgative in chronic constipation.

Procedure:

1) Prepare 120 ml of 5 % senna infusion ?? 5% Senna infusion means5 g 100 ml ?? 120 ml 6 g senna Boil 120 ml H2O in kettle or flask and funnel.Then remove from flame.Crush 6 g of senna leaves and add to the boiled water. Leave for 15 min with occasional shaking (keep the

kettle beside the flame and keep it covered).

Filter on small wet piece of cotton (Don’t press it).

Procedure :

2) Transfer 50 ml of the infusion to a cup measure

3) Dissolve MgSO4 in the infusion while warm.

4) Cool then add tincture of cardamom and ammonia spirit.

5) Adjust the volume to 100 ml with cold infusion

The label:

The Mixture One coffeecupful to be

taken in the morning.

Shake The Bottle

Fiat :mistSig : 30 ml O.m.

Infusion Boil Water only and add senna leaves to water after boiling

Decoction

Don’t cool before filtering. After filtration Don’t press the cotton After filtration Don’t complete volume (to avoid dilution)

Boil Water with ammi visnaga for 15 min.

Cool before filtering.

After filtration press the cotton

After filtration complete volume to 100 ml in cup measure to replace water lost by evaporation.Calculate for 20% excess water to guard against loss by evaporation during boiling

Calculate for 20% excess infusion to guard against loss by filtration.

Used for heat stable drugs.Ex: woody plants or seeds (as ammi visnaga)

Used for heat sensitive drugs. Ex: leaves (as senna leaves).

Heavy magnesium oxide suspension

RxHeavy magnesium oxide ჳii Magnesium sulphate ჳvii Glycerin ჳiAcacia mucilage i ℥ Peppermint water ad iii ℥ Fiat: mist. Sig.: m.d.s.Use: Laxative

2x4=8 g7x4=24 g1x4=4ml1x30=30ml3x30=90ml

Laxative and antacid.Saline purgativeWetting agentSuspending agentvehicle

1-grind MgSo4 with pestle

6-add acacia mucilage portion wise with levigation

3-add Mg oxide4- mix the two powders together

5-add glycerin and levigate

7- Transfer to cup measure.

8-Rinse the mortar with small portion of peppermint water

9-Adjust volume to 90ml with peppermint water.

The Mixture To be taken as directed.

Label

Shake The Bottle

Fiat: mist. Sig.: m.d.s.

Label Sig.

One teaspoonful 5 ml Ʒi

One tablespoonful 15 ml ℥ss

One coffeecupful 30 ml ℥i

One wineglassful 60 ml ℥ii

CALCULATION of DOSES

CHILDREN DOSEYoung’s rule CHILD DOSE =

Cowling’s rule CHILD DOSE =

Fried’s rule CHILD DOSE =

Clark’s rule CHILD DOSE =

Using BSA (body surface area) CHILD DOSE =

NOMOGRAM

% Preparation

Percent weight-in-volume (%w/v):

expresses the number of grams of a constituent in 100 ml .of solution or liquid preparation

Percent volume-in-volume (%v/v):

expresses the number of milliliters of a constituent in 100 ml. of solution or liquid preparation

Percent weight-in-weight(%w/w):

expresses the number of grams of a constituent in 100 g. of solution or liquid preparation.

The term % used without qualification means……??

for solutions or liquid preparations (solid in liquid)

% w/v

for solutions of liquids in liquids % v/v

for mixtures of solids % w/w

for solutions of gases in liquids % w/v

Milligrams percent (mg%) :

Expresses the number of. milligrams of a substance in 100 ml. of solution It is used frequently to denote the concentration of a drug or natural substance in a biological fluid, as in the blood.

Parts per million (ppm):

For very dilute solutions e.g.in designating test limits The limit of arsenic in zinc oxide is 6 parts per million (6 ppm) or 0.0006%.

1% solution is prepared by dissolving 1 g of a solid or 1 ml of a liquid in sufficient of the solvent to make final volume of the solution is 100 ml.

N.B

Ratio strength

It is anthor way of expressing concentration

It is a ratio the first figure of which is 1

For example 5% means 5 parts per 100 5 : 100 1:20

When a ratio strength 1 :1000 is used to designate conc. , it is interpreted as :

1) For solids in liquid:

1 gram of solute or constituent in 1000 milliliters of solution or liquid preparation, or 1 grain of solute or constituent in a volume of solution or liquid preparation represented by that of 1000 grains of water.

2)For liquid in liquids:

1 milliliter of constituent in 1000 milliliters of solution or liquid preparation, or 1 minim of active ingredient in 1000 minims of solution or liquid preparation.

3)For solids in solids

1 gram of constituent in 1000 grams of mixture or 1 grain of active ingredient in 1000 grains of mixture.

Examples

(1) Express 0.02% as a ratio strength0.02 → 100 1 → x ⇨x= 1 x 100/0.02 = 5000 ∴ Ratio strength = 1 : 5000(2) Express 1 : 4000 as a percentage

strength 1 → 4000 x → 100 ⇨ x = 100 x 1/4000 =

0.025% ∴ % strength = 0.025 %

Example:When the maximum potential error is ±4 milligrams in total of 100 mg what is the percentage of error?Anwer: (4/100) x 100% = 4 %

N.B. error and the quantity desired are expressed in the same denomination.

% error = ( error / quantity desired) x 100

Percentage of error

When certain % of error is not to be exceeded and the maximum potential error of a balance is known the smallest quantity that can be weighed is calculated from this equation :

Smallest quantity =(max. potential error/permissible % error) x100

% error = error

Quantity measured

Quantity measured=

error

% error

If the quantity increases

% error decreases

If quantity decreases

%error increases

Smallest quantity =(max. potential error/permissible % error) x100

x 100

x 100

Example: What is the smallest quantity that can be weighed with a potential error of not more than 5% on a balance sensitive to 6 milligrams?Answer: (100 x 6) / 5 =120 mg

Thank you