Suspension

Definition

A suspension is a heterogeneous mixture in which solid particles are dispersed throughout a liquid but do not dissolve. In pharmacology, suspensions are important because they can influence how a drug is administered and absorbed by the body, affecting its bioavailability. The stability of the suspension and the size of the solid particles can impact how the drug is delivered and its effectiveness.

5 Must Know Facts For Your Next Test

1. Suspensions require proper shaking or stirring before use to ensure even distribution of the solid particles.
2. The particle size in a suspension is usually larger than in solutions, typically greater than 1 micrometer, which can affect the rate of absorption.
3. Drug formulations in suspension may have improved taste masking, making them more palatable for patients, especially children.
4. Stability of suspensions is crucial, as they can settle over time; additives like suspending agents are often included to help maintain uniformity.
5. Routes of administration for suspensions include oral and parenteral, each influencing the absorption rates and therapeutic outcomes differently.

Review Questions

• How does the particle size in a suspension affect its bioavailability and administration?
  • The particle size in a suspension plays a significant role in its bioavailability. Larger particles may dissolve more slowly, leading to delayed absorption compared to smaller particles. The size influences how the drug interacts with biological membranes upon administration; smaller particles can pass through barriers more easily, potentially increasing the rate and extent of absorption. Understanding this relationship is crucial when formulating suspensions for effective drug delivery.
• Discuss the importance of stability in drug suspensions and how it relates to patient compliance.
  • Stability in drug suspensions is vital for ensuring that patients receive a consistent dose of medication over time. If a suspension is unstable, solid particles may settle at the bottom, leading to uneven dosing if not properly mixed before administration. This inconsistency can negatively impact patient compliance, especially in pediatric patients who may refuse medication that tastes unpleasant or appears separated. Therefore, maintaining stability through appropriate formulation techniques is essential for effective treatment outcomes.
• Evaluate the advantages and disadvantages of using suspensions compared to solutions in drug formulation.
  • Using suspensions has several advantages over solutions, including better taste masking, improved stability for certain drugs, and controlled release profiles. However, there are also disadvantages; suspensions require shaking before use to ensure uniformity and may have variable absorption rates due to particle size differences. Additionally, formulations might be bulkier and less convenient for some patients compared to liquid solutions. Balancing these factors is essential when selecting the appropriate dosage form for specific therapeutic needs.

Related terms

emulsion: A mixture of two immiscible liquids where one liquid is dispersed in the other, often stabilized with an emulsifier.

solubility: The ability of a substance to dissolve in a solvent, which affects how well a drug can be absorbed into the bloodstream.

bioavailability: The proportion of an administered drug that reaches systemic circulation in an active form and is available for therapeutic effect.