1.7 Drug Stability

Drug stability refers to the ability of a drug product to maintain its properties and efficacy over time. The stability of a drug can be influenced by various factors, including temperature, light, and humidity. Understanding drug stability is crucial for ensuring patient safety and drug efficacy.

Oral Suspensions

Oral suspensions are liquid preparations that contain solid particles dispersed in a liquid medium.

Stability Concerns

Settling of Particles: Over time, particles can settle at the bottom. Requires shaking before use.
Microbial Growth: Suspensions can be susceptible to bacterial or fungal contamination.

Insulin

Insulin is a hormone used to regulate blood sugar levels.

Stability Concerns

Temperature Sensitivity: Insulin can degrade if exposed to extreme temperatures. Typically stored in the refrigerator.
Clumping or Frosting: Indicators that insulin may have lost its potency.

Reconstitutables

These are dry powdered drug products that need to be mixed with a liquid before administration.

Stability Concerns

Short Shelf-Life Post Reconstitution: Once mixed, they often have a limited stable period.
Proper Storage: Requires refrigeration or specific storage conditions post-mixing.

Injectables

Injectables are drug formulations administered via injection.

Stability Concerns

Sterility: Must remain free from contaminants.
Precipitation: Some injectables can form solid particles if not stored correctly.

Vaccinations

Vaccines help the body develop immunity to specific diseases.

Stability Concerns

Cold Chain Management: Many vaccines need to be stored at specific temperatures to maintain efficacy.
Expiry: Vaccines have a strict shelf life post-manufacture.

Key Points

Oral Suspensions: Require shaking and are prone to microbial growth.
Insulin: Sensitive to temperature and visual changes indicate degradation.
Reconstitutables: Have a limited shelf-life once mixed with a liquid.
Injectables: Need to maintain sterility and be free from precipitation.
Vaccinations: Require strict temperature management and adherence to expiry dates.

Conclusion

The stability of drug products is paramount in ensuring their therapeutic efficacy and patient safety. Pharmacy technicians must be well-versed in the stability concerns of various drug formulations to guide proper storage, handling, and administration. By doing so, they play a critical role in ensuring that patients receive medications that are both safe and effective.