ABSTRACT
The aim of the present study was to formulate suspension type inhalation aerosols by various types of auxiliary materials, and to select the formulation with the highest proportion of the effective particle size. The examined suspension type aerosol contained sodium cromoglycate as an active compound. For the stabilization of the suspension, the applied surface active ingredients were oleic acid and oleyl oleate, and dimethyl siloxane polymer was selected as hydrophobizing agent. Factorial design was used for the optimization of the experimental results. On the basis of our results, the correct types and amounts of auxiliary materials can be selected to obtain the therapeutically effective formulation.
Subject(s)
Administration, Inhalation , Aerosols , Chemistry, Pharmaceutical , Cromolyn Sodium/administration & dosage , Cromolyn Sodium/chemistry , Dimethylpolysiloxanes , Drug Stability , Oleic Acid , Silicones , Surface-Active Agents , Wetting AgentsABSTRACT
The aim of this study was to examine the influence of the concentrations of surfactant and suspending agent on the quantity of effective particles (size < 10 microm) delivered by metered-dose inhalers. A 2-factor, 3-level, face-centred central composite design was used to construct a second-order polynomial model which describes the effect of formulation factors (suspending agent, surface-active ingredient) on the therapeutically important characteristic (effective particle size) delivered by metered-dose inhalers. Oleic acid was selected as the surface-active ingredient, and the suspending agent was anhydrous alcohol. A non-linear model demonstrated with good correlation the effect of the amounts of surfactant and suspending agent on the quantity of particles of effective size. The results obtained enable determination of the correct amount of surface-active ingredient and the optimum quantity of the suspending agent, thus enabling formulation of a therapeutically effective formulation.
