Oral pharmaceutical forms of administration with a delayed action

摘要

A partially delayed oral pharmaceutical dosage form (A) comprising tramadol (I) as active agent, (I) is at least partially in the form of a compound (I') formed in situ and having at water solubility of 50 mg/ml or less (especially 5 mg/ml or less). An independent claim is included for the preparation of (A), by mixing tramadol (I) with an acidic drug or auxiliary (II) (or its water-soluble salt) and optionally auxiliaries, wetting and formulating with application of energy.