Which auxiliary label is commonly required for ointments with light-sensitive drug substances?

Which auxiliary label is commonly required for ointments with light-sensitive drug substances?

• A. Avoid prolonged sunlight exposure
• B. Refrigerate after opening
• C. For external use only
• D. Shake well before using

Answer: (A)

Light can cause certain drug substances in ointments to degrade, reducing potency and potentially forming unwanted byproducts. To protect these photosensitive components, an auxiliary label that instructs to avoid prolonged sunlight exposure helps ensure the medication remains effective from the time of dispensing until use. The other labels address issues not directly related to light stability: refrigeration after opening is about temperature control for some products, a general warning for external use isn’t specific to stability, and shaking before use applies to suspensions rather than ointments.

Light can cause certain drug substances in ointments to degrade, reducing potency and potentially forming unwanted byproducts. To protect these photosensitive components, an auxiliary label that instructs to avoid prolonged sunlight exposure helps ensure the medication remains effective from the time of dispensing until use. The other labels address issues not directly related to light stability: refrigeration after opening is about temperature control for some products, a general warning for external use isn’t specific to stability, and shaking before use applies to suspensions rather than ointments.