This document discusses the key ingredients used in pharmaceutical suspensions and their purposes. Wetting agents are added to disperse solids, solvents maintain the liquid phase, and surfactants aid dispersion. Gums, electrolytes, and flocculating agents control particle aggregation. Thickeners and viscosity enhancers slow sedimentation. Buffers stabilize the suspension's pH from 7.4 to 8.4. Osmotic agents regulate pressure. Coloring agents impart color and elegance. Preservatives prevent microbial growth. External vehicles construct the final suspension structure.

1. B.Pharm-I Sem (2017-18) Pharmaceutics-1 Unit-3
Prashant Singh, Asst. Professor, Dept. of Pharmacy, ITM, GIDA, GKP-273209
COMPOSITION OF A PHARMACEUTICAL SUSPENSION
Ingredients Use Example
Wetting agents They are added to disperse solids in continuous liquid
phase
Solvents- Glycerol, propylene glycol, sorbitol.
Surfactants- tweens & spans for internal preparations,
Sodium lauryl sulphate for external preparation
Gum- acacia and tragacanth
Flocculating agents They are added to floc the drug particles Electrolytes- KCl, NaCl
Sulfate, citrates, phosphates salts
Viscosity enhancers,
thickeners, suspending
agents.
They are added to increase the viscosity of suspension &
slowing down sedimentation
tragacanth, acacia gum, starch, agar, guar gum & sodium
alginate, Methyl Cellulose (MC), Micro Crystalline
Cellulose (MCC), Bentonite
Buffers and pH
adjusting agents
They are added to stabilize the suspension to a desired pH
range. pH of suspension preferably at 7.4 to 8.4
Sodium citrate, Sodium acetate/ (carbonates, citrates,
gluconates, phosphate and tartrates.)
Osmotic agents They are added to adjust osmotic pressure comparable to
biological fluid
Dextrose, mannitol sorbitol, sodium chloride, sodium
sulphate, glycerol.
Coloring agents They are added to impart desired color to suspension and
improve elegance. Synthetic dyes should be used within
range of( 0.0005 % to 0.001%)
Titanium dioxide (white), Brilliant blue (blue), Indigo
carmine(blue), Amaranth (red), Tartarazine (yellow),
Annatto seeds(yellow to orange)
Preservatives They are added to prevent microbial growth Benzoic Acid & Hydroxyl Benzoates,
Benzoates, Parabens, Alcohol
External liquid vehicle They are added to construct structure of the final
suspension
Structured Vehicle (applicable only to deflocculated
suspensions. They are aqueous solutions of natural and
synthetic gums. E.g. methyl cellulose, sodium carboxy
methyl cellulose, acacia, gelatin and tragacanth.)