July 20, 2024

Suspension Definition, advantages and disadvantages

Suspension Definition, advantages and disadvantages

What is suspension?

A  suspension is a dispersion of finely divided, insoluble solid particles (the disperse phase) in a fluid (the dispersion medium or continuous phase). 
A dispersed phase with a mean particle diameter of up to 1 um is usually termed a colloidal dispersion
A solid in liquid dispersion, in which the particles are above colloidal size, is termed a coarse suspension

Why suspensions?

Certain drugs are chemically unstable in solution but stable when suspended (ensures chemical stability while permitting liquid therapy.)
Ease of swallowing liquids and the flexibility in the administration of a range of doses
Overcome a disagreeable taste of certain drugs in solution form, when the drug is administered as undissolved particles of an oral suspension

What are the advantages of suspension?

1. Suspensions are a useful drug delivery system for therapeutic agents that have low solubility. Although low-solubility therapeutic agents may be solubilised and therefore administered as a solution, the volume of the solvent required to perform this may be large. In addition, formulations in which the drug has been solubilised using a co-solvent may exhibit precipitation issues upon storage.
2. Pharmaceutical suspensions may be formulated to mask the unpleasant/ bitter taste of the drug. E.g. Chloramphenicol.
3. Pharmaceutical suspensions may serve as an alternative means used to administer drugs to children including paediatric and geriatric patients and older patients who have difficulty swallowing solid dosage forms.
4. Drug in suspension exhibits a higher rate of bioavailability than other dosage forms. Bioavailability is in following order, Solution > Suspension > Capsule > Compressed Tablet > Coated tablet.
5. Pharmaceutical suspensions may be formulated to provide controlled drug delivery, e.g. as intramuscular injections.
6. Chemical stability of certain drugs e.g., Procaine penicillin G can be improved when formulated as suspensions.
7. Pharmaceutical suspension offers resistance to degradation of drugs due to hydrolysis, oxidation or microbial activity.
8. Duration and onset of action can be controlled e.g., Protamine Zinc-Insulin suspension.
9. When compared to solution dosage forms, relatively higher concentration of drugs can be incorporated into suspension products

What are the disadvantages of suspensions?

1. Pharmaceutical suspensions are fundamentally unstable and for this reason, it requires formulation skill to ensure that the physical stability of the formulation is retained over the period of the shelf-life.
2. Aesthetic pharmaceutical suspension is difficult to formulate that is they lack elegance.
3. Accuracy of dosage is less reliable than with solution unless the suspension is packed in the unit dosage form.
4. Suspension formulations may be bulky and therefore difficult for a patient to carry.
5. Preparation must be shaken prior to measuring a dose.
6. Pourability and syringeability issues (e.g., injectable suspensions)
7. Crystal formation (Ostwald ripening) and breaking of suspension.


Biphasic Liquids: Suspension: Definition, advantages, and disadvantages, Classifications, Preparation of suspensions, Flocculated and Deflocculated suspension Emulsions: Definition, Advantages & Disadvantages, Classification, Emulsifying agent, Test for the identification of the type of Emulsion, Methods of preparation, Stability of emulsion


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

F Y B Pharm Sem-IS Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

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