Topical antiviral compositions, delivery systems, and methods of using the same

A method of treating and/or preventing molluscum contagiosum in a subject in need thereof comprising:

• administering a topical composition to the skin of a subject,
• wherein the topical composition comprises a nitric oxide (NO)-releasing active pharmaceutical ingredient in an amount of about 0.5% to about 25% by weight of the topical composition and the NO-releasing active pharmaceutical ingredient is a NO-releasing compound comprising an NO donor selected from the group consisting of a diazeniumdiolate, nitrosothiol, nitrosamine, hydroxyl nitrosamine, hydroxyl amine and hydroxyurea;
• and
• wherein the topical composition has a Cm of greater than 160 pmol of NO/mg, as measured by in vitro release testing, thereby treating and/or preventing molluscum contagiosum in the subject.

A method of reducing the appearance and/or size of a lesion on a subject in need thereof comprising:

• administering a topical composition to the lesion on the subject,
• wherein the topical composition comprises a nitric oxide (NO)-releasing active pharmaceutical ingredient in an amount of about 0.5% to about 25% by weight of the topical composition and the NO-releasing active pharmaceutical ingredient is a NO-releasing compound comprising an NO donor selected from the group consisting of a diazeniumdiolate, nitrosothiol, nitrosamine, hydroxyl nitrosamine, hydroxyl amine and hydroxyurea;
• and
• wherein the topical composition has a Cm of greater than 160 pmol of NO/mg, as measured by in vitro release testing, thereby reducing the appearance and/or size of the lesion on the subject.