JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Pharmacy II PHYSICAL PHARMACEUTICS-II Previous Question Paper (September/October - 2023 - R17)

Zero order kinetics refers to a reaction where the rate of degradation or elimination is constant and independent of the concentration of the drug. The rate of reaction is given by the equation:

where k₀ is the zero-order rate constant. In this process, the amount of drug removed per unit time remains uniform regardless of the remaining drug concentration.

Photolytic degradation can be prevented by minimizing the exposure of light-sensitive pharmaceutical products to ultraviolet and visible radiation. Key strategies include:

• Packaging in light-resistant containers: Using amber-colored glass or opaque plastic bottles that filter out specific wavelengths of light.
• Secondary packaging: Enclosing primary containers in secondary cardboard cartons or foil overwraps to provide a complete barrier against light.
• Formulation adjustments: Incorporating light-absorbing additives or stabilizers, such as antioxidants or UV absorbers, into the formulation to protect the active pharmaceutical ingredient.
• Storage conditions: Storing light-sensitive products in cool, dark environments or specialized light-protected storage cabinets to prevent photochemical reactions during shelf life.