Final answer:
Preservatives are essential in small-volume parenteral preparations to maintain safety and freshness, inhibit spoilage by microorganisms and ensure long-term stability and efficacy of the medication. They must be safe for patient use and effective under various storage conditions.
Step-by-step explanation:
Why Preservatives are Added to Small-Volume Parenteral Preparations
Preservatives are added to small-volume parenteral preparations primarily to maintain or improve safety and freshness. These substances extend the product's lifespan by preventing the growth of microorganisms such as bacteria, fungi, mold, and yeast, which could lead to spoilage and potentially cause foodborne illnesses, including botulism. Antioxidants, a type of preservative, are crucial in preventing fats and oils within pharmaceutical products from becoming rancid and maintaining their efficacy. Furthermore, preservatives like sorbic and benzoic acid work more effectively at lower pH levels, inhibiting enzymes or reducing intracellular pH to control microbial growth. Long-term storage and stability of parenteral preparations are imperative to ensure that the medications are both safe and effective when administered to patients.
In the context of parenteral preparations - which are injectables - it is vital to prevent microbial contamination to protect patient health. Therefore, the preservatives must be nontoxic, nonreactive, and able to maintain the intended quality of the medication throughout its shelf life and various storage conditions, such as temperature changes and freeze-thaw cycles. In addition to ensuring post-preparative stability, preservatives can influence the range of bacteria targeted and decrease toxicity, which are beneficial properties for treating infections.