Expectorants

1. Expectorants

2. COUGH • • Cough is a protective reflex, its purpose being expulsion of respiratory secretions or foreign particles from air passages. • • It occurs due to stimulation of mechano or chemo receptors in throat, respiratory passages or stretch receptors in the lungs. • • Cough may be : Use ful, Useless. • Useful-Productive cough: This cough serves to drain the air way. Its suppression is not desirable, may even be harmful. • Useless-Non productive cough: This cough should be suppressed

3. Expectorants • Expectorants are the class of drugs that help in removing sputum from the respiratory tract either by • Increasing the fluidity (or reducing the viscosity) of sputum Or • Increasing the volume of fluids that have to be expelled from the respiratory tract by coughing. • They do not actually stop coughing. This is important because a productive cough should not be suppressed because it is the body's way of removing excess mucus, foreign particles, or microorganisms from the airways. • Expectorants also help to relieve chest congestion that occurs because of a cold, the flu, or allergies.

4. Classification of Expectorants According the their mechanism of action • Sedative expectorant • Stimulant expectorant

5. Sedative Expectorants :- • These are stomach irritant expectorants which are able to produce their effect through stimulation of gastric reflexes. • e.g. Bitter drugs – Ipecac, Senega, Indian Squill • Compounds –Ammonium chloride, Sodium citrate, Potassium iodide, Antimony potassium tartrate.

6. Stimulant Expectorants :- These are the expectorants which bring about a stimulation of the secretory cells of the respiratory tract directly or indirectly. Since these drugs stimulate secretion, more fluid in respiratory tract and sputum is diluted. e.g. ­ Eucalyptus, lemon, anise ­ Active constituents of oil like terpine hydrate, anethole

7. AMMONIUM CHLORIDE Mol. Formuls :- NH4ClMol. Weight :- 53.49 Preparation: Ammonium chloride is made by reacting hydrochloric acid with ammonia the solution is evaporated to dryness. NH3 + HCl NH4Cl The Product is Purified by recrystallisation or by sublimation . Ammonium chloride is also prepared by heating ammonium sulphate with sodium chloride. 2NaCl + ( NH4)2SO4 2NH3 + 2HCl + Na2SO4 Ammonium sulphate NH4Cl

8. Properties:- Ammonium chloride (NH4Cl) is a weak inorganic acid, exists as a white crystalline powder or fine crystals. As ammonium chloride is freely soluble in water. It is an odorless. A solution of contain 0.8 % W/V of Ammonium chloride is Isotonic with serum.

9. Identification Test Acidity testing:- Dissolve 1 g of ammonium chloride in 10 ml distilled water. Add few drops from methyl red indicator. NH4Cl + 2H2O NH4OH + H3O+ + Cl- Color of methyl red indicator according to change of pH

10. Chemical identification testing: Make a solution of 0.1 g of ammonium chloride in water (2 ml) in a test tube. Acidify with few drops 2M nitric acid. Add 0.4 ml silver nitrate (AgNO3) solution and shake very well. Observe the color. what is the chemical structure of this precipitate?

11. Assay: Acid-base titration method. NaOH 0.1 g of NH4Cl + 50 ml of H2O + 5 ml HCHO + 1 to 2 drops of phenolphthalein Each ml of 0.1 N NaOH is equal to 0.005349 g of NH4Cl.

12. Assay: It was previously assayed by precipitation titration by using the Volhard’s method. Now, it is assayed by Acid-base titration method. About 0.1 g of NH4Cl sample accurately weighed is kept in a conical flask, about 50 ml of water is added to dissolve it followed by 5 ml of neutralized formaldehyde solution. Formaldehyde solution may have a small amount of formic acid formed due to atmospheric oxidation. This should be carefully neutralized with dilute sodium hydroxide solution, using phenolphthalein as an indicator. There should be no excess alkali in this reagent. After keeping aside for a couple of minutes, the liberated hydrochloric acid is made to titrate with standard sodium hydroxide solution, by adding some more of phenolphthalein indicator. Each ml of 0.1 N sodium hydroxide consumed is equal to 0.005349 g of NH4Cl.

13. Ammonium chloride undergoes hydrolysis to yield ammonium hydroxide and hydrogen chloride, This reaction is facilitated by adding formaldehyde. as it fixes ammonia, by forming hexamine. The acid can now be titrated with alkali without interference. These reactions can be represented as follows: NH4Cl + H2O NH4OH + HCl NH4OH + 6CH2O C6H12N4 + 10H2O HCl + NaOHNaCl + H2O Hexamine

14. Uses : As expectorant in cough preparations. As acidifying agent to correct metabolic alkalosis. Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35–7.45). Symptom neuromuscular irritability, tetany, abnormal heart rhythms coma, seizures,

15. Potassium Iodide • Mol. Formula :- KIMol. Weight :- 166 • Preparation:- • Industrial methods of Preparation; It consist the action of iodine on moist iron filling to form ferro-ferric iodide [FeI3 or FeI2, FeI3]. which then decompose with potassium carbonate. • Fe + I2 FeI2; FeI3 • FeI2; FeI3 + 4K2CO3 8KI + FeO;Fe2O3 + CO2 Ferro-Ferric Iodide Potassium carbonate • Ferroso-ferric oxide Ferro-Ferric Iodide

16. Properties:- Colorless; odorless; transparent or opaque crystal or white granular power. It has saline and bitter taste. It is soluble in water ( 1gm in 0.7 ml) Glycerin ( 1gm in 2 ml) Alcohols ( 1gm in 23 ml) and Acetone ( 1gm in 75 ml) Aqueous solution of KI dissolves Iodine to form KI3 KI + I2 KI3

17. Use:- • It is use in expectorant cough. • It is also mild antifungal activity. • Supplying iodine for treatment of thyroid deficiency.

18. Emetics

19. Emetics (Vomiting ) Emetics are the drug which cause the vomiting. It is defined as the process of evacuation or elimination of gastric content. An emetic is very helpful for the elimination of the harmful substance from stomach and duodenum when poison is known to have been swallowed.

20. General Classes of Emetics • Drugs acting on the chemoreceptor trigger zone (CTZ) of the medulla. • e.g. Apomorphine • Drug acting on the stomach • e.g. Ipecacuanha, Ammonium bicarbonate.

21. Copper sulphate Mol. Formula :- CuSO4.5H20 Mol. Weight :- 249.7 Preparation:- It is obtained by roasting copper containing sulphide ore in presence of air, or by hating copper in furnace with Sulphur. The mixture of copper sulphate an CuO formed, which is treated with H2SO4 it will give the ppt of Copper Sulpate. 2Cu + 2H2SO4 + O2 2CuSo4 + 2H2O

22. Properties:- • Cupric sulfate, or copper sulphate, is the inorganic compound with the chemical formula CuSO4(H2O)x, where x can range from 0 to 5. The pentahydrate (x = 5) is the most common form. • It exists in bright blue crystalline granules or powder. • Anhydrous copper sulfate is a white powder. • It exothermically dissolves in water and solution is acidic to litmus paper.

23. Assay: • Its principle is based on the instability of cupric iodide which is formed in the reaction between CuSO4 and KI and which decomposes to yield Cu2I2with the liberation of free iodine. • 2CuSO4 + 4KI 2 CuI2 + 2K2SO4 • 2CuI2Cu2I2+ I2 • An accurately weighed quantity of copper sulphate is dissolved in water. To this a slight excess of KI is added followed by acetic acid. The liberated iodine is titrated with standard sodium thiosulphate[Na3S2O3 ] solution by using starch as an indicator. The titration is continued until faint blue colour persists • I2 + 2Na3S2O3 Na2S406 + 2NaI • 1 ml of 0.1 N Na2S303 = 0.02497 g of CuSO4.5H20

24. Storage It has to be protected from air, heat and moisture. Uses. It finds use as an emetic in a dose, of 300 mg in 30 ml of water.

25. Potassium sodium tartrate • KNaC4H4O6·4H2O 282.1 • Preparation :- Potassium bitartratewith 68 % tartaric acid first dissolved in water then saponified with hot NaOH [caustic soda] to pH 8, decolorized with activated charcoal, filtered. The filtrate is evaporated at 100 °C. The salt is separated from the mother liquor by centrifugation • Properties:- • It is a large colorless monoclinic needles.

26. Uses. • It finds use as an emetic in water. • It has been used medicinally as a laxative [increase bowel movements]. • It has also been used in the process of silvering mirrors. • It is an ingredient of Fehling's solution • It is used as a combustion accelerator in cigarette paper. • also an ingredient in the Biuret reagent which is used to measure protein concentration.

27. Haematinics

28. Haematinics A medicine that increases the haemoglobin content of the blood; used to treat iron-deficiency anaemia. The main hematinics are iron, B12, and folate B9.

29. Ferrous Sulphate Mol. Formula :- FeSO4.7H20 Mol. Weight :- 278.0 Preparation:- It is obtained by dissolving iron in excess of dil. Sulphuric acid. After effervescence ceases, filter and cool. The green colour crystal farmed. All the procedure should carried free from exposure to air as ferrous sulphate is oxidized and crystal get coated with brownish yellow ferric sulphate. Fe + H2SO4 FeSo4 + H2↑

30. Properties:- • It occurs in the form of greenish crystal or crystalline powder. • Astringent taste. • As ferrous sulphate is oxidized and crystal get coated with brownish yellow ferric sulphate in air. • Soluble in water and ins9oluble in alcohols. • Ferrous sulphate when heated decomposes to yield ferric oxide, sulphur dioxide and sulphuric acid. • 2 (FeSO4.7H20) Fe2O3 + SO2 + H2SO4 + 13H2O • Ferrous sulphate react with sodium carbonate solution, CO2 is evolved Ferric oxide

31. Assay: Method 1 It is assayed by oxidation and reduction type of reaction using 0.1 N KMnO4 solution in the presence of dil. H2SO4. Weigh accurately 1gm FeSO4.7H20 is dissolve in 20 ml of dil. H2SO4. then titrate with 0.1 N KMnO4 Each ml of 0.1 N KMnO4 consumed is equal to 0.0291 g of FeSO4.7H20. Method 2: It is assayed taking accurately 1gm FeSO4.7H20 is dissolve in30ml water and 20 ml of dil. H2SO4 in conival flask then titrate with 0.1 N ceric ammonium nitrate in burette, using ferroin sulphate solution as an indicator. End point ret to light blue

32. 0.1 N ceric ammonium nitrate 1gm FeSO4.7H20 + 30 ml H2O + 20ml H2SO4 + 1 to 2 drops of ferroin sulphate End point red to light blue