Abstract
BACKGROUND: Topical lanolin is commonly used on nipples to aid breastfeeding success. The raw material undergoes refinement to remove contaminants such as pesticides, which may accumulate from exogenous environmental sources. The level of refinement influences final lanolin purity. For use in nipple creams, a lanolin which complies with a published monograph (either USP or Ph. Eur.) is desirable to ensure a non-toxic product with neutral taste and smell, and low allergenicity. METHODS: The aim of this study was to determine the residual trace pesticide levels and quantify the Free Lanolin Alcohols (FLA) levels in two commercially available lanolin products (HPA LANOLIN (Lansinoh Laboratories Inc.); PURELAN (Medela AG)) and two lanolin ingredients (PHARMALAN PH EU-SO-(RB) and CORONA-8 SO-(RB) (Croda, Goole, UK)) using established validated methods. Test samples were subjected to Gas-Chromatographic and Liquid-Chromatographic analysis to quantify and identify a panel of 178 pesticide residues. FLA levels and the presence of oxidative metabolites were also determined. RESULTS: The purity of the lanolin ingredients was consistent with expectations based on their level of refinement; lanolin in compliance with the Ph. Eur. monograph demonstrated the highest level of purity. Differences were seen between the lanolin nipple creams tested, in terms of FLA levels and pesticide residue levels. Specifically, the HPA LANOLIN contained an extremely low level of FLA (0.61%), which was fourfold less than in the PURELAN (2.76%). Additionally, the HPA LANOLIN did not contain any detectable pesticide residues. The PURELAN was found to contain a number of pesticide residues, however the detected levels were low and within the permitted limits and so despite their presence, the PURELAN was still compliant with the relevant monographs. CONCLUSIONS: This data reinforces that the purity of monograph compliant Lanolin makes it suitable for use on the nipples of breastfeeding mothers. A higher level of refinement leads to a reduction in pesticide contaminants also reduces FLA levels in the final material, minimizing the risk of allergenicity.