ecco spiegato, purissima si trova in molti testi, forse per differenziare extra pura?

The best grade lanolin in the world is called Medical Grade Lanolin. It gets its name because it is safe to use in a medical capacity. Every hospital in the Western World uses this substance – after surgeries to help wounds heal, as a newborn nursing cream, and in burns units on the wounds to protect and heal.

But we went one better – we created ULTRA Medical Grade, 3 x more pure than Medical Grade. Completely odourless, colourless, non-sticky, creamy goodness.

https://www.victoriahealth.com/editorial/lanolips