THE PRESERVATION OF SOME ORAL LIQUID PREPARATIONS - THE REPLACEMENT OF CHLOROFORM BY OTHER PRESERVATIVES

Chloroform should be considered as an obsolete preservative for,pharma ceutical preparations, because of its toxicological implications and i ts physical instability. The effectiveness oi possible alternatives fo r chloroform in three-oral liquid pharmaceutical preparations was inve stigated, using a microbiological challenge test. Magnesium trisilicat e mixture (British Pharmacopoeia) can be adequately preserved with met hylparaben (2 g/l). Only insignificant amounts of methylparaben were a bsorbed by the solids present-in the magnesium I:trisilicate mixture. Ferrous sulfate mixture (British Pharmacopoeia) can be preserved with a mixture of methylparaben (1.8 g/l) and propylparaben (0.2 g/l). Sorb ic acid (1 g/l) is a suitable preservative for promethazine hydrochlor ide syrup.