[A new topical preparation for the treatment of burns. I. Technical aspects of preparation].

In the present paper some problems connected with the formulation of a topical preparation of the hydro-ointment type intended for the treatment of deep dermal burns were examined. Sixteen ointment bases containing hydroxypropyl-methylcellulose, hydroxyethylcellulose, Carbopol 934 and Pluronic F-127 as gel-forming substances were evaluated. The local anaesthetic agents carbizocaine and lidocaine served as active ingredients. Suitability of ointment bases was evaluated on the basis of their liberating capability for drugs, rheological properties and washability. The results show that an increase in the concentration of the gel-forming substance in the ointment resulted in a decrease in carbizocaine liberation. A decrease in the released amount of drugs occurred also after an addition of a humectant additive to the ointment base. The local anaesthetic agents under study decreased the viscosity of ointment bases. The highest coefficient of washability was found in the Carbopol ointment base. From the viewpoint of administration, the base with 1% Carbopol, or a combined base with 2% Methocel and 0.5% Carbopol proved to be most suitable.