Suspension medications are a common type of liquid medicine designed to deliver active drug ingredients that do not dissolve in a liquid. Unlike solutions, where the drug is fully dissolved, suspensions contain fine solid particles dispersed throughout a liquid medium. These solid particles will naturally settle over time, which is why thorough shaking is always required before each use. This ensures the medicine is evenly distributed, allowing for an accurate and consistent dose every time it is administered.
Defining Characteristics
A defining characteristic of suspension medications is that their active drug components are solid particles that remain undissolved and dispersed throughout the liquid. Because these particles are not truly dissolved, they will inevitably settle to the bottom of the container when the medication sits undisturbed. This physical property distinguishes them from solutions where the drug is fully dissolved.
Suspension medications are typically cloudy or opaque due to their dispersed particles. These solid particles are generally larger than 1 micron in diameter, distinguishing them from molecularly dispersed solutions and smaller, non-settling colloid particles. This size means the drug particles can often be visible to the naked eye or under a microscope, unlike clear solutions.
Reasons for Using Suspension Medications
Suspension medications offer practical advantages for both drug development and patient administration. Many active pharmaceutical ingredients are not soluble in water or common solvents. Suspensions provide a practical method to deliver these otherwise insoluble drugs in a liquid form, making administration possible.
Suspensions can also mask the unpleasant taste of certain drugs. Their solid particles, often coated, reduce direct contact with taste buds, making bitter medicines more palatable, especially for children. Furthermore, liquid suspensions allow for flexible dose adjustments, which is useful for pediatric and geriatric patients or those needing precise, individualized dosing. They also provide an easier and safer administration route for patients with difficulty swallowing pills, such as young children, older adults, or those with dysphagia.
Proper Handling and Storage
Proper handling of suspension medications is crucial for effectiveness and safety. The most important step is to shake the bottle thoroughly before each use. This redistributes settled drug particles evenly, ensuring each measured dose contains the correct amount of medication. Without adequate shaking, initial doses may be too weak, and later doses too strong as the drug accumulates.
Accurate measurement is essential for precise dosing. Always use the specific measuring device provided, such as an oral syringe or medicine cup, as household spoons are inaccurate. Storage conditions are also important for stability. Check the medication label for specific instructions; some suspensions require refrigeration or light protection.
Finally, observe the expiration date. Expired medication can have reduced effectiveness or safety concerns and should be disposed of according to local guidelines.