I need a reference or guideline for below
Throughout the manufacturing process, light-sensitive drugs must be protected. Longer wavelength light, above 500 nm, is recommended for granulation, compression and packaging areas. For this, the best option is brown colored light, which has wavelengths of between 500 nm and 800 nm.
Based on the following ICH guideline the photostability of drug substance and the drug product should be assessed. And accordingly precautionary measures should be taken to protect the drug product during manufacturing, handling, packing and storage, transportation. The type of light protection should be determined based on photostability studies.
STABILITY TESTING: PHOTOSTABILITY TESTING OF NEW DRUG SUBSTANCES AND PRODUCTS - ICH Guidelines Q1B
Exposure to light is a concern with numerous medications due to the potential for photodegradation or other chemical reactions during manufacturing, storage, and administration. This may result in potency loss, altered efficacy and adverse biological effects. The sensitivity of a drug to a distinct spectral region of light may vary with its chemical structure, photoreactivity, and nature of the dosage form. The photochemical behavior of a drug provides guidance for handling, packaging, and labeling of drug products. The use of the appropriate containers and packaging material can protect the products from the deleterious effects of light.
Spectral Regions of the UV, Visible, and Solar Radiation
The spectral regions of the UV, visible, and solar light involved in the photochemical reactions are as follows:
UVA: 320–400 nm.
UVB: 290–320 nm.
UVC: 200–290 nm.
Visible: 400–700 nm.
Solar: including UVA, UVB, and visible ranges.
The majority of the photochemical reactions occur with the help of the UVA, UVB, or visible light.
Therefore based on the photostability studies, the type of light siurce to be used during manufacturing such drug product should be decided so as to avoid photochemical reactions and degradation of the product.