Compounding TPN admixtures: then and now

Abstract

Compounding TPN admixtures has significantly developed since the first clinical reports by Dr. Dudrick and colleagues from the University of Pennsylvania approximately 35 years ago. Today, the responsibility for the compounding of sage parenteral nutrition admixtures for patients incapable of oral or enteral nutrition primarily rests with the pharmacy department. Although others may influence the desirable components to be contained therin, no one is more qualified to deal with the physicochemical issues and aseptic technique compounding requirements than a registered pharmacist. In fact, the United States Pharmacopeia (USP) , the official drug compendium in the US since 1906, has published Chapter 797 entitled "Pharmaceutical Compounding--Sterile Preparations", enforceable by the FDA, and makes clear the role of the pharmacist in the compounding of safe parenteral admixtures. Ultimately, after careful pharmaceutical review of the final formulation, the composition of the final admixture for infusion will be determined based on the ability to safely compound the prescribed additives in the desired quantities of a specified volume of sterile fluid. There will always be instances, where, for example the patient's needs cannot be safely met through the TPN admixture, primarily because of stability, compatibility and/or sterility issues. When this occurs, suitable alternative methods of delivering the additives in question must be sought so as not to compromise the safety issues of the final TPN infusion. Although there have been many advances in the development of nutritional additives, compounding devices, and containers, significant safety issues continue to arise necessitating further modification of paretneral nutrition protocols. ASPEN, through periodic reviews of tis published guidelines, such as the 1998 Safe Practices for Parenteral Nutrition Formulations, is in a key position to keep nutrition support clinicians abreast of the central issues affecting the safety of TPN therapy.(Journal of Parenteral and Enteral Nutrition

The compounding of TPN admixtures is a complicated task given the requirements for strict aseptic technique and the multitude of components that are extemporaneously added to make the final formulation. Stability, compatibility and sterility issues are of greatest concern to pharmacists during the preparation of these highly complex dosage forms. A full knowledge of these issues and pharmacy specialization in this area are the necessary prerequisites in order to safely provide TPN therapy.