Development and evaluation of fast-dissolving film of salbutamol sulphate.

The objective of this work was to prepare and optimize the fast-dissolving film of salbutamol sulphate, which can be useful in an acute attack of asthma. The film was prepared using a solvent evaporation technique and is taken through the sublingual route. The film contains polyvinyl alcohol as a polymer, glycerol as a plasticizer, and mannitol as filler. A 33 full factorial design was utilized for the optimization of the effect of independent variables such as amount of polyvinyl alcohol, amount of glycerol, amount of mannitol on the mechanical properties, and % drug release of film. The multiple regression analysis of the results led to equations that adequately describe the influence of the independent variables on the selected responses. Polynomial regression equations and contour plots were used to relate the dependent and independent variables. The experimental results indicated that polymer concentration, plasticizer concentration, and filler concentration had complex effects on film mechanical behavior and % drug release. Furthermore, the desirability function was employed in order to determine the best batch out of all 27 batches of the factorial design. The % relative error was calculated, which showed that observed responses were in close agreement with the predicted values calculated from the generated regression equations. It was found that the optimum values of the responses for fast release film could be obtained at medium levels of polyvinyl alcohol and glycerol, and a high level of mannitol. The prepared film was clear, transparent, and had a smooth surface. The concept of similarity factors Sd was used to prove similarity of dissolution between distilled water and simulated saliva (pH 6.8) or simulated gastric fluid (pH 1.2).