Composition contains (i) a polypeptide (I), i.e. insulin (bovine, porcine or human) and/or at least one of insulin analog, derivative and/or active metabolite; (ii) at least one surfactant and (iii) optionally at least one preservative, isotonicity agent, buffer and/or other auxiliaries. It is a clear solution with pH 1-6.8. ACTIVITY : Antidiabetic. No details of tests for antidiabetic activity are given. MECHANISM OF ACTION : Insulin replacement.