Preservatives in liquid pharmaceutical preparations.

Sodium benzoate, potassium sorbate, and methyl hydroxybenzoate are commonly used as preservatives in liquid pharmaceutical preparations. The purpose of this study is to determine the amount of the aforementioned preservatives in pharmaceutical products, as some recent studies have reported serious side effects associated with the ingestion of these substances. The content of 37 liquid pharmaceutical products were simultaneously determined by high performance liquid chromatography. Preparations were analyzed in triplicate for their preservative content using a sensitive and reproducible HPLC method modified in our laboratory. Preservative levels were found to fall outside the typical allowed concentration range for 70% of the samples, with some exhibiting significantly higher concentrations. The reason behind such findings is unclear, and could be due to poor quality control or to intentionally extend the shelf-life of the products. These findings highlight issues related to quality control and to patient’s safety. Consequences on patient health need to be evaluated, especially since most liq-