Nonsterile Compounding, Beyond-Use Dates and Labeling

Introduction to Nonsterile Compounding and Fundamental Techniques

United States Pharmacopeia General Chapter 795 establishes standards for nonsterile pharmaceutical compounding. Nonsterile compounding involves preparing customized dosage forms such as solutions, suspensions, capsules, creams, and suppositories to meet individual patient needs. Pharmacy technicians prepare nonsterile compounds under the supervision of a licensed pharmacist, as permitted by state law. Within this compounding relationship, clinical judgment, final verification, and patient counseling belong exclusively to the licensed pharmacist.

Compounded formulations consist of two main categories of components: Active Pharmaceutical Ingredients (APIs) and excipients. Active Pharmaceutical Ingredients provide the intended pharmacological effect in a compounded preparation. In contrast, excipients are inactive ingredients used to provide stability, bulk, flavoring, or proper consistency. A diluent is a specific type of inactive liquid or solid substance used to reduce the concentration or increase the volume of a drug. When water must be incorporated into a nonsterile compounded preparation, Purified Water, USP, or water of higher compendial quality must be used. Tap water or drinking water is strictly prohibited for use in nonsterile compounding formulations.

Technicians use specific physical techniques to manipulate solid and liquid ingredients. Trituration is the mechanical reduction of solid particle size by grinding using a mortar and pestle. When working with coarse crystals, reducing particle size ensures a smooth, non-gritty final preparation. Levigation is the process of reducing the particle size of a solid powder using a small amount of liquid in which the powder is insoluble. Mineral oil and glycerin are commonly used levigating agents for compounding ointments and creams. Pulverization by intervention uses a small amount of a suitable volatile solvent to help reduce a gummy solid to a fine powder, after which the solvent is allowed to evaporate. Spatulation is the blending of powders or semi-solids on an ointment slab using a compounding spatula.

To ensure safety and therapeutic uniformity, blending different ingredients requires precision. Geometric dilution blends a small amount of drug with an approximately equal amount of diluent, then repeatedly adds diluent in amounts approximately equal to the mixture until blending is complete. Imagine evenly dispersing a single drop of red dye into a large bowl of white frosting: by gradually adding frosting in equal steps, you ensure that the active ingredient is dispersed uniformly throughout the entire batch.