phr 113 / lecture 6 · pharmacognosy phr 113 / lecture 6. physical and chemical properties of...
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Pharmacognosy PHR 113 / Lecture 6
Physical and chemical properties of carbohydrates
• Monosaccharide and disaccharides are crystalline compounds, soluble in water and sweet to taste.
• Disaccharides must be digested to monosaccharides before absorption into blood and used for energy production in cells.
• Polysaccharides are amorphous compounds, not soluble in water,not sweet to taste.
• They form suspensions instead of solution.• Must be digested before being absorbed.
Starch
Starch is composed of –• linear polysaccharide amylose with α(1,4)-linked glucose units
• branched polysaccharide amylopectin with α(1,4)-linked glucosechains and branch-points with α(1,6)-linkages.
Starch
α(1-4) linkage
α(1-6) linkage
α(1-4) linkage
Cellulose
A linear polymer of β-1,4-linked glucose
Glycogen
Glycogen is composed of –• linear polysaccharide with α(1,4)-linked glucose units
• branched polysaccharide with α(1,4)-linked glucose chains and branch-points with α(1,6)-linkages.
β-1,6 linkage
α-1,6 linkage
Pharmaceutical importance of carbohydrates
Starch:Binder. Diluent. Disintegrant.
Glucose: Granulating and Coating agent, Sweetener
Lactose:Anhydrous lactose- Filler and binder. Lactose mono hydrate –Filler (or) diluent.
Pharmaceutical importance of carbohydrates
Sucrose: Binding agent. Bulking agent. Sweetener. Tablet coatingagents. Diluent, plasticizer Excipient in Chewable tablets.
Powdered cellulose: Binder, Diluent, Lubricant, Disintegrant
Microcrystalline cellulose: Thickening agent.
Guar gum:Synonym - Guar flour, Jaguar gumBiological source - Cyamopsis tetragonolobus Linn.
Family- Leguminosae
Uses:• Binder and disintegrant• Emulsifying agent• Bulk laxative
Pharmaceutical importance of carbohydrates
Agar:Synonym: Agar-Agar, Vegetable gelatin.
Biological source: Gelidium amansii.Family- Gelidaceae
Uses:• Laxative• Emulsifying agent• Preparation of jellies• Preparation of suppositories
Pharmaceutical importance of carbohydrates
Acacia:Synonym - Gum acacia, Gum ArabicaBiological source - Acacia Arabica
Family- LeguminosaeUses:• Demulcent• Emollient• Suspending agent• Emulsifying agent• Binding agent• Stabilizing agent
Pharmaceutical importance of carbohydrates
Tragacanth
Synonym - gum tragacanth.
Biological source - Astragalus gummiferFamily- Leguminosae
Uses:• Demulcent• Emollient• Suspending agent• Emulsifying agent
Pharmaceutical importance of carbohydrates
Thank you
Mohammad Ahad A Khan, PhDAssistant Professor, Department of Pharmaceutical SciencesNorth South University, Bangladesh Room: SAC 1013email: [email protected]: +880 17 0386 4707