Photostability studies

[ant_k]

Hello,

Is there any official indication about the duration of photostability studies (according ICH Q1B there are no specific requirements..).

Thank you!

[LC_labrat]

ICH Q1B section 1-C does include a duration, it's just written in exposure terminology rather than length of time. The duration is 1.2 million lux hours.

[tjb]

The ICH guidelines states:

"For confirmatory studies, samples should be exposed to light providing an overall illumination of not less than 1.2 million lux hours and an integrated near ultraviolet energy of not less than 200 watt hours/square meter to allow direct comparisons to be made between the drug substance and drug product."

These details tell you the total exposure for each type of light that the API or samples must be exposed to. Most photostability cabinets will usually have some sort of a totaliser and an intensity setting. The higher the intensity the less time it will take to reach the required total. Just be aware that setting this too high may impart unwanted heat to the samples. We had one instance in the past where some of our ODT's shriveled up because the settings were too agressive.

It will typically take around a week (5 days) to achieve the required exposures (two different exposures).

[ant_k]

[quote="tjb"]The ICH guidelines states:

"For confirmatory studies, samples should be exposed to light providing an overall illumination of not less than 1.2 million lux hours and an integrated near ultraviolet energy of not less than 200 watt hours/square meter to allow direct comparisons to be made between the drug substance and drug product."

These details tell you the total exposure for each type of light that the API or samples must be exposed to. Most photostability cabinets will usually have some sort of a totaliser and an intensity setting. The higher the intensity the less time it will take to reach the required total. Just be aware that setting this too high may impart unwanted heat to the samples. We had one instance in the past where some of our ODT's shriveled up because the settings were too agressive.

It will typically take around a week (5 days) to achieve the required exposures (two different exposures).


Thanks for informing.
I also noticed that ICH Q1B_Comments for Application helps.