Parabens are preservatives which avoid microbiological contamination of drug products (by mushrooms or microorganisms) and stop the degradation of active substances (which diminishes the medicinal product efficacy).
Parabens are present in certain foods, cosmetics and medicinal products. Their type and concentration are different depending on the concerned product. They are esters of the para-hydroxybenzoic acid (methylparaben, ethylparaben, propylparaben, butylparaben) and are classified as “excipient with notorious effect” due to their allergy risk.
Afssaps’ interest in parabens goes back to 2004, when Philippa Darbre, a researcher from the University of Reading and her colleagues, found parabens in breast tumor biopsies.
In vitro studies showed a weak probability of cancer, nevertheless a doubt persisted. On the other hand, animal studies evidenced the possibility of an effect on male fertility. This was the alert signal.
Recently, Afssaps listed all the pharmaceutical specialties containing parabens. 400 medicinal producs were identified, 306 of which contained propylparaben (the most used on medicinal products and suspected to have a potential risk on fertility).
A study co-ordinated by Afssaps and performed by an independent research organism is now ongoing. It aims to give an answer to the question regarding male fertility risk after a childhood exposure. The other European Union countries and the European Medicines Agency (EMA) are waiting for these results to make a stand. The study report is expected in November 2011.
To this date, it has not been possible to propose chemical alternatives to parabens having a better security profile and a matching efficacy.
Nevertheless, the presence and the quantity of a preservative in a medicinal product has to be scientifically justified in the marketing authorization dossier.
Certain preservatives (ex. sugar and ethanol) have a known profile, but they also have consequences to health. Other chemical preservatives could be used but the risk linked to their use has not yet been documented.
In order to limit the presence of preservatives in general, the Agency as well as the European Authorities invite laboratories to use physical instead of chemical preservation methods in their products (changes in packaging, development single-dose preparations). However, in certain cases this is not possible.
Source : Afssaps
Parabens and medicinal products – Questions and answers
Pharmacovigilance bulletin n.° 27 – June 2005