Pharmacare Magnesium Sulphate Paste BP. A drawing paste to help treat minor skin infections including boils and reduce swelling. Contains Glycerol 61% w/w, Magnesium Sulphate 38.5% w/w, Phenol 0.5% w/w. Mix well before use and apply paste to piece of gauze or lint. Place on skin and bandage. Change after 12-24 hours. For external use only. Prolonged or repeated use may damage surrounding skin.