Section 3

1. Section 3 • Metric System • Conversions • Mixed Solvents • Camphor Water

3. Kilo (k) x10 ÷ 10 Hecto (h) ÷ 10 x10 Deka (D/da) x10 ÷ 10 Gram or liter or meter ( g ) – ( l ) – (m) x10 ÷ 10 Deci (d) x10 ÷ 10 Centi(c) x10 ÷ 10 Milli(m) x1000 ÷ 1000 Micro (µ) x1000 ÷ 1000 Nano (n)

4. Measure of length: Meteris the fundamental unit. **

5. Measure of volume: liter is the fundamental unit.

6. Measure of weight: gram is the fundamental unit.

7. How to reduce to lower or higher denomination: Examples: • Reduce 1.23 kg to grams 1.23kg=1.23 x103 =1.23x1000 =1230 g • Reduce 85 µm to cm 85 µm = 0.085mm = 0.0085cm

8. To add or substract:1) reduce them to a common denomination2)arrange numbers for addition or subtraction as ordinary decimals. • Example: Total wt of substances in a capsule: 0.075 g = 20 mg = 0.0005 g = 4 mg = 500 mcg = = 0.075g 0.020g 0.0005g 0.004 g 0.0005g 0.100 g=100 mg

9. To multiply or divide: • Example: Multiply 820 ml by 12.5 & express the result in liters 820 x 12.5 =10250 ml =10250/1000=10.250 L

10. Conversions

11. The dose of a drug is 1/10 gr. per kg. of body weight. How many milligramsshould be given to a person weighing 154 lb.? • 1 kg  2.2 lb ??  154 lb Wt of the person =1x154/2.2 = 70 kg • 1/10 gr  1 kg ?? gr  70 kg The dose for this person = 70 x 1/10 =7 gr. • 1 gr  65 mg7 gr  ?? mg the required dose = 65 x 7 = 455 mg

12. F= 50/100 Mixed Solvents Rx Phenobarbital Orange oil Alcohol Glycerin Sucrose Water q.s. • Fiat: Elixir • Mitte: 50 ml • Sig: ℨio.n. • Uses: Sedative in epilepsy. 0.4 gm 0.1 ml 25.6 ml 35 ml 12 gm 100 ml 0.2 gm 0.05 ml 12.8 ml 17.5 ml 6 gm 50 ml Sedative Flavoring agent Solvent Cosolvent Sweetening agent Vehicle

13. 5) In dry cup measure add 12.8 ml alcohol 6) Dissolve Phenobarbital 7) Add 1 drop of the orange oil 8) Add Glycerin, Stir slowly and 8 wise (Alcoholic solution) Procedure: 1) In a beaker add 15 ml water.??? 2) dissolve Sucrose 3) Filter (if necessary) (Aqueous solution) 7) Add aqueous solution to the alcoholic solution portion wise with continuous stirring slowly and 8 wise. (clear solution) 8)Adjust volume with water. 50 ml

14. Label: The Elixir One teaspoonful to be taken every night.

15. N.B. • Why the aqueous solution is added to the alcoholic solution ? To prevent volatility of alcohol and to prevent precipitation of substances dissolved in alcohol on dilution.

16. Camphor Water ℞ Camphor 0.1 gm Alcohol 1.5 ml Purified water to 100 ml Uses: carminative internally & antiseptic & anaestheticin eye lotion.

17. N.B. • Camphor is soluble only 1 in 700 of water, Camphor is very soluble in alcohol. • The addition of the alcoholic solution to water yield a finely-divided precipitate of camphor, which in this condition, passes into solution more quickly then camphor simply powdered.

18. Procedure: Dissolve the camphor in alcohol (dry measure) Water 98.5 ml (Check tightness of the screw cap before use) Add alcoholic solution of camphor in small portions (2 drops by 2 drops) to water each addition followed by vigorous shaking  Clear solution

19. Label: The Camphor Water [ E.P.]