Antimicrobial preservation efficacy of liquid glucose and liquid maltitol syrups with and without 0.1% sorbic acid

Abstract Objectives Amongst paediatric pharmaceutical forms, syrups offer advantages such as ease of administration and good palatability. They also exhibited microbial self-preservation properties that may be useful to enhance shelf life of liquid formulation. The objective of our works is to test the self-preservation efficacy of maltitol and glucose syrup without or with sorbic acid as described in the European pharmacopoeia. Methods The European Pharmacopoeia test of antimicrobial preservation efficacy was performed on liquid glucose syrup and liquid maltitol syrup with and without 0.1% sorbic acid. Results Unpreserved glucose and maltitol syrups did not meet the European Pharmacopoeia acceptance criteria for antimicrobial preservative efficacy due to the regrowth of Aspergillus brasiliensis on day 28 whereas glucose and maltitol syrups with 0.1% sorbic acid pass the test. Conclusions The addition of a preservative (sorbic acid) in glucose and maltitol syrups allows the validation of the antimicrobial preservative efficacy test of the European Pharmacopoeia. Further tests are needed to see if preservative efficacy is maintained despite dilutions or in the presence of active pharmaceutical ingredients.