1 Suspension 1

2  Suspension:  Suspension: A suspension is a two-phase system consisting of a finely divided solid particles dispersed in liquid, or gas.And  Pharmaceutical Suspension. A liquid preparation containing undissolved material. A"SHAKE WELL" label is applied to the container 2

3 Parts of the Suspension  Suspension is made of two phase system, consisting of a finely divided solid particles (Dispersed phase) distributed in a particular manner throughout another medium (Continuous phase). 3

4 Suspension Dispersed phase Continuous phase (Dispersion medium) Particle size of Dispersed phase Iess than 1 micrometer (µm) Colloid Particle size of Dispersed phase more than 1 micrometer (µm) Suspension 4

5 Compositions Of Pharmaceutical Suspension Main parts Insoluble particles Liquid medium Excipients Suspending agent Surfactant Viscosity enhancer Preservative Favoring agent Sweetener Colours Buffers Stabilizers *The order in which these ingredients are blended is important to the stability of the preparation 5

6 Pharmaceutical application of suspension  Patients compliance  Improve solubility  Mask taste  Fast absorption  Improve stability for drugs 6

7 Pharmaceutical Applications of Suspension  Patients who have problems in swallowing solid dosage forms require drugs to be dispersed in a liquid.  Oral suspensions permit the formulation of poorly soluble drugs in the form of liquid dosage form.  Drugs, which possess unpleasant taste in solution dosage form like paracetamol, chloramphenicol palmitate etc. can be formulated as palatable suspension as they are suitable for administration to peadiatric patients.  The rate of absorption of a drug from suspension is usually faster than solid dosage form but slower than solution.  If drug is unstable when in contact with vehicle, suspension should be prepared immediately prior to handing out to the patient in order to reduce the amount of time that the drug particles are in contact with dispersion medium. e.g Ampicillin suspension 7

8 Routes of administration of suspension External use (Topical ) Oral administration Ophthalmic Otic Parenteral suspensions 8

9 Routes of administration of suspension   External use (Topical): There consistency range from fluid to paste. e.g fluid suspension calamine lotion. Zinc cream consists of high percentage of powders dispersed in an oily (paraffin) phase.   Oral administration: non sterile dispersion   Ophthalmic and Otic: sterile and possess very fine particles   Parenteral suspensions: sterile e.g Vaccines formulated as dispersions 9

10 Injectable Suspensions  µm.  Suspensions contain less than 5% of drug solid with mean particle diameter within µm.  Owing to the presence of particles in these formulations, these particles are more difficult to process and sterilize than solution for injection  During the manufacture of suspension for injection the components are prepared and sterilized separately.  They are then aseptically combined

11  The final product of injectable suspension can not be filter sterilized owing to the presence of particles in the formulation.  Powders for use in sterile suspensions can be sterilized by gas, but gas residues must be avoided. Injectable Suspensions

12 Suspensions are useful formulation for Inhalations   The volatile component are adsorbed onto the surface of the diffusible solid to ensure uniform dispersion throughout the liquid.   An example for a suspension used for inhalation is menthol and eucalyptus   These materials used as an adjunct to fluid replacement in acute diarrhea treatment

13 Aerosols: another form for pharmaceutical suspension *Aerosols are dispersions of a liquid or solid in air. *Many pharmaceutical aerosols consist of solids dispersed in a non-aqueous propellant or propellant mixture. 13