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Pharmaceutics I . Prelab 6 Presented by Ahmed Magdy. Prelab contents. 1. Preparations Cough Syrup. Black draught (infusion). Heavy magnesium oxide suspension. 2. Problems Dose calculations Percent preparation Percent error. Cough syrup. X 0.5. Rx
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Pharmaceutics I Prelab6 Presented by Ahmed Magdy
Prelab contents 1. Preparations Cough Syrup. Black draught (infusion). Heavy magnesium oxide suspension. 2. Problems Dose calculations Percent preparation Percent error
Cough syrup • X 0.5 Rx Codeine phosphate 0.3 g CpdTartarazine solution 1 ml Benzoic acid solution 2 ml Water 2 ml Lemon syrup 20 ml Syrup to 100 ml Send 50 ml Fiat: Cough Syrup Sig: Ʒit.d.s.p.c. • 0.15 g Cough Suppressant • 0.5 ml Coloring agent 1 ml Preservative • 1 ml Solvent for drug • 10 ml Sweetening and flavoring agent • 50ml Vehicle • Calculation: Use: Cough Syrup for treatment of dry cough • Factor = 50/100 = 0.5 • Vehicle = 50 – (10+1+1+0.5) =37.5 ml • ¾ vehicle = ¾ X 37.5 = 28.125 ml = 28 ml
0.15 g codeine phosphate 0.000 g Glass-rod 1 ml water Cup measure 0.5 ml Compound tartarazine solution 1 ml benzoic acid solution Cup measure
10 ml lemon syrup Cup measure Adjust volume to 50 ml with syrup Cup measure
The Cough Syrup One teaspoonful to be taken three times daily after meals. Fiat: Cough Syrup Sig: Ʒit.d.s.p.c. Label
Infusion preparationBlack draught Rx Magnesium Sulphate 250 gm Compound tincture of cardamom 100 ml Aromatic spirit of ammonia 50 ml Fresh infusion of sennato 1000 ml Fiat :mist–send 100 ml Sig : 30 ml O.m. 2.5 gm 10 ml 5 ml 100 ml Saline laxative. Carminative. Antacid and carminative. Irritant laxative. F = required / prescribed = 100/1000 = 0.1 Use: purgative in chronic constipation.
Procedure: • Prepare 120 ml of 5 % senna infusion ?? 5% Senna infusion means 5 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. Fiat :mist Sig : 30 ml O.m. • Shake The Bottle
Decoction Infusion • Boil Water with ammivisnaga for 15 min. • Boil Water only and add senna leaves to water after boiling • Cool before filtering. • Don’t cool before filtering. • After filtration press the cotton • After filtration Don’t press the cotton • After filtration Don’t complete volume (to avoid dilution) • 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 ammivisnaga) Used for heat sensitive drugs. Ex: leaves (as senna leaves).
Heavy magnesium oxide suspension Rx Heavy magnesium oxide ჳii Magnesium sulphate ჳvii Glycerin ჳi Acacia mucilage ℥i Peppermint water ad ℥iii Fiat: mist. Sig.: m.d.s. Laxative and antacid. Saline purgative Wetting agent Suspending agent vehicle 2x4=8 g 7x4=24 g 1x4=4ml 1x30=30ml 3x30=90ml • Use: Laxative
3-add Mg oxide 4- mix the two powders together 5-add glycerin and levigate 1-grind MgSo4 with pestle 8-Rinse the mortar with small portion of peppermint water 9-Adjust volume to 90ml with peppermint water. 6-add acacia mucilage portion wise with levigation 7- Transfer to cup measure.
Fiat: mist. Sig.: m.d.s. Label • Shake The Bottle The Mixture To be taken as directed.
CHILDREN DOSE Young’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 =
N.B • 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.
Ratio strength It is anthor way of expressing concentration For example 5% means 5 parts per 100 5 : 100 1:20 It is a ratio the first figure of which is 1
When a ratio strength 1 :1000 is used to designate conc. , it is interpreted as :
Examples (1) Express 0.02% as a ratio strength 0.02 → 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 %
Percentage of error 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 % % error = ( error / quantity desired) x 100 • N.B.error and the quantity desired are expressed in the same denomination.
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
Smallest quantity =(max. potential error/permissible % error) x100 % error = error x 100 Quantity measured error Quantity measured= x 100 % error If the quantity increases % error decreases If quantity decreases %error increases
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