Drug Safety 5 (Suppl. 1): 101-106, 1990 0114-5916/90/0001-0101/$3.00/0 © ADIS Press Limited All rights reserved. DSSUP1773.
Parenteral Nutrition
Pharmaceutical Problems of Compatibility and Stability
M.I. Barnett, A. G. Cosslett, J.R. Duffield, D.A. Evans, S.B. Hall and D.R. Williams Welsh School of Pharmacy, University of Wales College of Cardiff, Cardiff, United Kingdom
Summary
A typical All-in-One (AIO) parenteral nutrition mixture in a 3-litre polymeric infusion bag will consist of lipid emulsion, amino acids, glucose, electrolytes, trace elements and vitamins. This varied mixture of chemical entities provides the potential for a number of chemical and physicochemical interactions that can compromise the clinical safety and efficacy of the product. The destabilisation of the lipid emulsion in the presence of electrolytes is a major problem. Although a predictive equation for the maximum concentrations of mono-, di- and trivalent ions causing instability has been proposed, it is too simplistic to be of significant value. The reasons for this are discussed as well as the stability implications of other additives to the parenteral nutrition mixture.
Parenteral nutrition is an effective method of providing nutritional support to patients who cannot be fed by the enteral route or who cannot utilise nutrients given by this route. The administration of complete parenteral nutrition using the 'big bag' system was first described by Solassol et al. in 1974. The system has been considerably developed during the past 10 years and is now in general use for large numbers of patients in both the hospital situation and in the home. A typical parenteral nutritional mixture contains fat emulsion, amino acids, glucose, electrolytes, trace elements and possibly vitamins, and is administered as a mixed system currently referred to as an All-in-One system (AIO). Because these mixtures contain many chemical entities, there is a high potential for chemical and physicochemical interactions that may result in incompatibilities and problems of stability in both the short and long term. The objective of this paper is to highlight and
interpret some of the pharmaceutical problems associated with AIO systems.
1. All in One Parenteral Systems The responsibilities of the pharmacist with respect to the compounding of safe and effective parenteral nutrition systems may be summarised as follows: I) to ensure the maximum chemical and physicochemical compatibility and stability of all the constituents in an AIO system 2) to provide the maximum guarantee of sterility of the finished product 3) to achieve a cost-effective approach to the prescribed regimen. These objectives can only be achieved if there is a good understanding of the basic stability of the lipid emulsions used in these systems and if the prop-
Drug Safety 5 (Suppi. 1) 1990
102
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Parenteral Nutrition
Pharmaceutical Problems of Compatibility and Stability
M.I. Barnett, A. G. Cosslett, J.R. Duffield, D.A. Evans, S.B. Hall and D.R. Williams Welsh School of Pharmacy, University of Wales College of Cardiff, Cardiff, United Kingdom
Summary
A typical All-in-One (AIO) parenteral nutrition mixture in a 3-litre polymeric infusion bag will consist of lipid emulsion, amino acids, glucose, electrolytes, trace elements and vitamins. This varied mixture of chemical entities provides the potential for a number of chemical and physicochemical interactions that can compromise the clinical safety and efficacy of the product. The destabilisation of the lipid emulsion in the presence of electrolytes is a major problem. Although a predictive equation for the maximum concentrations of mono-, di- and trivalent ions causing instability has been proposed, it is too simplistic to be of significant value. The reasons for this are discussed as well as the stability implications of other additives to the parenteral nutrition mixture.
Parenteral nutrition is an effective method of providing nutritional support to patients who cannot be fed by the enteral route or who cannot utilise nutrients given by this route. The administration of complete parenteral nutrition using the 'big bag' system was first described by Solassol et al. in 1974. The system has been considerably developed during the past 10 years and is now in general use for large numbers of patients in both the hospital situation and in the home. A typical parenteral nutritional mixture contains fat emulsion, amino acids, glucose, electrolytes, trace elements and possibly vitamins, and is administered as a mixed system currently referred to as an All-in-One system (AIO). Because these mixtures contain many chemical entities, there is a high potential for chemical and physicochemical interactions that may result in incompatibilities and problems of stability in both the short and long term. The objective of this paper is to highlight and
interpret some of the pharmaceutical problems associated with AIO systems.
1. All in One Parenteral Systems The responsibilities of the pharmacist with respect to the compounding of safe and effective parenteral nutrition systems may be summarised as follows: I) to ensure the maximum chemical and physicochemical compatibility and stability of all the constituents in an AIO system 2) to provide the maximum guarantee of sterility of the finished product 3) to achieve a cost-effective approach to the prescribed regimen. These objectives can only be achieved if there is a good understanding of the basic stability of the lipid emulsions used in these systems and if the prop-
Drug Safety 5 (Suppi. 1) 1990
102
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Water phase
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