Antimicrobial preservation efficacy of glucose and maltitol syrups with and without preservatives for paediatric formulations
Centre Hospitalier Universitaire Amiens-Picardie, Amiens, France
Among paediatric dosage forms, syrups offer advantages such as ease of administration and good compliance due to their organoleptic properties. They also present self-preservation properties that can be useful to improve the shelf life of liquid formulations without adding paraben-type preservatives.
The objective of our work is to test the antimicrobial preservation efficacy of maltitol and glucose syrups with or without preservative (sorbic acid), using the European Pharmacopoeia monograph.
Materials and methods
The European Pharmacopoeia antimicrobial preservative effectiveness test was applied to maltitol and glucose syrups, with and without 0.1% sorbic acid.
We observed a log reduction greater than or equal to 5 log for bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) in both syrups, with and without preservatives, at D14 and a total bactericidal effect at D28 (6 log reduction compared to the initial inoculum at D0)
For Candida albicans (CA) and Aspergillus brasiliensis (AB), a reduction greater than or equal to 2 log was observed at D14. At D28, we noted the absence of colonies for CA for all syrups (with and without sorbic acid) as well as an absence of increase in the number of colonies for AB in the syrups with preservatives. However, a regrowth of AB was observed at D28 in the preservative-free syrups. No contamination was found during this study.
All the counts made on the inocula were in accordance with the expectations and thus allow to validate the results of the test on the different syrups.
Only the syrups with the preservative allow to pass the antimicrobial preservation efficacy test of the European Pharmacopoeia. These results are consistent with the tests performed using the simple syrup found in the literature. It would be interesting to repeat this test on diluted syrups to determine a possible dilution limit.