0.05% Retinoine should be processed in sweet almond oil. Retinoine is insoluble in oil, how can this be best tackled?

First and foremost you will have to work with the pure tretinoine. 50 mg on 100 ml is still properly tradeable. I would dissolve the 50 mg in 10% Cremophor EL. 10% ethanol can also be added or the amount of Cremophor EL increased.

I would start by looking at whether to dissolve 1g ethanol + 2g Cremophor EL in 8g Sweet almond oil; then it can be further worked with Tretinoine.