OBJECTIVE To optimize the gel formulations of a novel anti- psoriasis drug C34. METHODS C34 gel was prepared by five different prescription. The stability of five gel bases were investigated. The in vitro releasing degree of gel formulations was measured,and screened the optimal formulation. RESULTS There were no marked changes in the spread and appearance. The C34 gel prepared with the gel base of 1% carbopol 974,10% 1,2- propylene glycol,2% triethanolamine and 5% glycerin) showed a good release in vitro. ...