Pharmaceutical Suspensions Study

A pharmaceutical suspension is a coarse dispersion in which the internal phase (therapeutically active ingredient) is dispersed uniformly throughout the external phase. The internal phase consists of insoluble solid particles with a size range of 0.5 to 5 microns, which is maintained uniformly throughout the suspending vehicle with the aid of a single or combination of suspending agents.

The term 'Disperse System' refers to a system in which one substance (the dispersed phase) is distributed, in discrete units, throughout a second substance (the continuous phase). This term is relevant to pharmaceutical suspensions as they are heterogeneous systems consisting of two phases, with the dispersed phase being a solid in liquid dispersion in which the particles are of colloidal size.

Theoretical considerations of suspensions include sedimentation, which is the settling of particles in the suspension, Brownian movement, which is the random movement of particles due to collision with molecules of the dispersion medium, and electrokinetic properties, which relate to the movement of particles under the influence of an electric field.

The formulation of pharmaceutical suspensions involves the uniform dispersion of the internal phase throughout the external phase with the aid of suspending agents. The packing of suspensions should be done in containers that protect the product from light, moisture, and air. Storage requirements include keeping the product in a cool, dry place, and proper labeling should include the name of the product, its strength, and expiration date.

The evaluation of pharmaceutical suspensions involves assessing parameters such as particle size, viscosity, sedimentation volume, and redispersibility. The dissolution study of suspensions examines the rate and extent of drug dissolution. Innovation of suspensions involves the development of novel delivery systems, such as nanosuspensions or microspheres, to improve drug efficacy and patient compliance.