White petrolatum is widely used as an ointment base.In this study,we examined the quality characteristics of pharmaceutical petrolatums and a cosmetic petrolatum.There are 6 brands of pharmaceutical white petrolatum which are Perfecta and White 1S made by Sonneborn Co.and Ultima,Snow,Snow V and Regent made by Penreco Co.<br>We measured the melting point and viscosity of the white petrolatums.Perfecta had the highest melting point and Ulitima had the lowest.Snow had the highest viscosity and Perfecta the lowest.These results show that the characteristics of white petolatums vary among brands.Spectrophotometry was used to evaluate potential allergenicity.For extracts of Ultima,Regent and a cosmetic petrolatum,absorption was not observed in the 260 to 270 nm range suggesting that Ultima,Regent and the cosmetic petrolatum have a low content of polycyclic aromatic hydrocarbons which cause skin irritation.Upon investigating the brands of white petrolatum used in the base of commercial ointments,we found that the brand of petrolatum varied among the ointments.In order to ensure the proper use of ointments,suitable ointments should therefore be selected in consideration of patient needs.
