September 30, 2023

Assay of aspirin: Medicinal Chemistry Practical

Assay of aspirin: Medicinal Chemistry Practical

BP406P Medicinal Chemistry I Practical


To perform Assay of aspirin.


  1. A textbook of Medicinal Chemistry-I,Pragi Arora,Varun Arora,Davinder Kumar,Page no:282,283.
  2. Indian Pharmacopoeia Volume I  1996, Page No:69,70.
  3. Pharmaceutical titrimetric analysis theory and practical,A.A Napoleon,Page No:11-17.


Aspirin, Sodium hydroxide solution (0.5N),Hydrochloric acid (0.5N),Phenol red indicator, Burette, Conical flask, Funnel, Beaker etc.



Weighed accurately 0.75g of Anhydrous sodium carbonate previously heated at 2700C. Dissolve in 100 ml of water and added 0.1ml of methyl red solution. Added the titrant slowly from the burette with constant stirring until the solution becomes faintly pink.

Heated the solution.Cool and continue.If pink colour fades on heating continue this process until a faint pink colour is no longer affected by continous boiling.

Each ml of 0.5M HCl = 0.026495g of Na2CO3


Weighed accurately 1.5g of aspirin and dissolved in 15ml ethanol added 50ml of 0.5M sodium hydroxide boil gently for 10 minutes, cool and titrated the excess alkali with 0.5M HCl using phenol red solution as indicator.

Perform a blank determination the difference between the titration represent the volume of sodium hydroxide consumed.

Each ml of 0.05M NaOH = 0.04504g of C9H8O

Second Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

S Y B Pharm Sem IIIS Y B Pharm Sem IV
BP301T Pharmaceutical Organic Chemistry II TheoryBP401T Pharmaceutical Organic Chemistry III Theory
BP302T Physical Pharmaceutics I TheoryBP402T Medicinal Chemistry I Theory
BP303T Pharmaceutical Microbiology TheoBP403T Physical Pharmaceutics II Theory
BP304T Pharmaceutical Engineering TheoryBP404T Pharmacology I Theory
BP305P Pharmaceutical Organic Chemistry II Practical BP405T Pharmacognosy I Theory
BP306P Physical Pharmaceutics I PracticalBP406P Medicinal Chemistry I Practical
BP307P Pharmaceutical Microbiology PracticalBP407P Physical Pharmaceutics II Practical
BP308P Pharmaceutical Engineering PracticalBP408P Pharmacology I Practical
BP409P Pharmacognosy I Practical

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