Tigasor Acitretin 25mg CapsulesTigasor Acitretin 25mg Capsules Higher Strength Oral Retinoid for Severe Psoriasis Tigasor 25mg Capsules by Maxitech contain Acitretin 25mg, a higher strength systemic oral retinoid for the treatment of severe cases of psoriasis that have not responded to other treatments. Acitretin works by regulating abnormal skin cell growth and reducing inflammation, improving psoriatic plaques. It is a higher strength option in our psoriasis care range.