Evaluation of Protective and Therapeutic Effects of Dexpanthenol on Nasal Decongestants and Preservatives: Results of Cytotoxic Studies in Vitro

Abstract

More than 600 million units of nasal decongestants are sold worldwide annually. The cytotoxic and ciliary toxic potential of decongestants, as well as the preservatives of these products, in particular benzalkonium chloride (BKC), is well established. Recently, a beneficial effect of dexpanthenol on the tolerability of the alpha-sympathomimetic xylometazoline and BKC has been described; however, it was unclear if this effect, resulting in significantly higher cell counts in a cytotoxicity study and an increase in ciliary beat frequency in a ciliary toxicity study was of protective or therapeutic nature. The objective of this study was (a) to evaluate whether dexpanthenol would be a useful additive to nasal decongestants to counter the cytotoxic and ciliary toxic effects of the active ingredient and the preservative and (b) to find out whether this beneficial effect is of protective or therapeutic nature. Systematic cytotoxic in vitro tests were performed. After exposure to xylometazoline (0.1%), the effect of dexpanthenol (5%) and BKC (0.01%) was determined by placebo-controlled assessment of cell growth in a human amniotic cell line. Dexpanthenol significantly reduces the toxic effects of xylometazoline regarding cell growth (p < 0.001) when applied in advance. When BKC is eliminated from the nasal sprays, a further significant increase of cell growth was found (p < 0.001). When dexpanthenol is therapeutically applied after xylometazoline, effects on cell growth are only one-half of those of the protective approach. The additive application of dexpanthenol (5%) given before nasal decongestants or preserved nasal sprays is able to improve the tolerability of these substances and to counteract the toxic effects.