What Does USP Mean to You?

This important document outlines the responsibilities of the extemporaneous compounder.

If you are like most pharmacists, you probably would respond by saying, "I don't know very much about USP <795>.” USP Chapter <795>— Pharmaceutical Compounding Nonsterile Preparations addresses the extemporaneous compounding of pharmaceuticals and defines what constitutes good compounding practices. The extemporaneous compounding of pharmaceuticals is not part of routine practice in most pharmacies yet it is still an integral part of pharmacy practice.

Like other aspects of the medication-use process, extemporaneous compounding can be vulnerable to medication errors. For example, a pharmacist intended to refill a prescription for a compounded suspension of the anticonvulsant primidone. Instead of using primidone tablets as he usually did, the pharmacist decided to improve the formulation by using bulk powder. However, he retrieved baclofen bulk powder from stock and used this to prepare the suspension. The patient, a toddler, was given 2 doses of the suspension. The child became less responsive and was taken to the local emergency department and then transferred to another hospital for further treatment. Thankfully, the patient recovered and was discharged the next day.

In a second case, a 15-year-old male with a history of traumatic brain injury was administered a cloNIDine suspension which had been compounded at a community pharmacy. After receiving a dose, the patient became unresponsive and was admitted to the hospital. Upon discharge from the hospital, the patient resumed taking the same cloNIDine suspension and again became unresponsive. It was then identified that the cloNIDine suspension was compounded incorrectly, resulting in a suspension that was 1000 times more concentrated than prescribed. The pharmacist calculated the amount of drug needed in grams rather than milligrams and used 1.35 g of cloNIDine instead of 1.35 mg.

USP <795> outlines the responsibilities of the compounder, which can be summarized as being responsible for compounding preparations of acceptable strength, quality, and purity with appropriate packaging and labeling in compliance with requirements established by applicable laws and agencies (eg, state boards of pharmacy). Specifically, the responsibilities of the compounder include the following general principles:

• Personnel are capable and qualified to perform their assigned duties.
• Compounding ingredients of the appropriate identity, quality, and purity are purchased from reliable sources.
• All equipment used in compounding is clean, properly maintained, and used appropriately.
• Only authorized personnel are allowed in the immediate vicinity of the drug compounding operations.
• There is assurance that processes are always carried out as intended or specified and are reproducible.
• The compounding environment is suitable for its intended purpose and to prevent errors.
• Adequate procedures and records exist for investigating and correcting failures or problems in compounding, in testing, or in the preparation itself.

The chapter requires that areas designated for compounding have adequate space to prevent mix-ups between ingredients, containers, etc, and are designed to prevent accidental cross contamination. The availability of potable water, washing facilities, and appropriate equipment is also discussed in this chapter.

An area of significance is stability criteria and beyond-use dating. USP <795> specifies that compounders use and apply drug-specific and general stability documentation when available and consider the nature of the drug, degradation, packaging containers, storage conditions, and the duration of therapy when assigning a beyond-use date. Beyond-use dates are to be assigned conservatively and, in addition to using available stability information on ingredients, the compounder should also use his or her pharmaceutical education and experience. Consult USP <795> for specific information regarding beyond-use dating for nonaqueous, aqueous, and other formulations.

The information in this article is adapted from USP <795> and does not represent the entire chapter. For more information, please consult USP <795> in its entirety in the latest edition of the USP—NF.

Dr. Gaunt is a medication safety analyst and the editor of ISMP Medication Safety Alert! Community/Ambulatory Care Edition.