Process Optimization and Characterization of Combination Dry Powder for Inhalation: Perspective Approach to Traditional Formulation

The present investigation is focused on to study influence of excipients on physical characteristics of combination dry powder inhaler formulation and to compare it with traditional combination Dry Powder for Inhalation. Formulation contains salmeterol xinafoate (SX) and fluticasone propionate (FP).  The formulation was prepared by Spray drying of suspensions obtained by solvent displacement method. The excipients used were α-lactose monohydrate and Poloxamer 188. The powders generated were of a suitable size for inhalation with satisfactory yield. It was found that in optimum concentration with poloxamer 188; lactose gave increased spray drying thermal efficiency. FTIR study showed the close agreement among the spectra of all spray dried formulations and APIs. Effect of excipients was further investigated by different physical characters of spray-dried formulations. The formulation was evaluated for in vitro drug release and in vitro aerosolization study by the modified USP II dissolution apparatus and using an Andersen cascade impactor (ACI). Dissolution study gave immediate drug release profiles. In vitro aerosolisation showed better degree of FPF as compared to marketed formulation containing lactose. The stability study indicated that all the formulations were quite stable at accelerated storage conditions. The results obtained from all observations indicate that in presence of poloxamer.188; lactose was found to be superior over traditional combination dry powder inhaler formulation containing salmeterol xinafoate and fluticasone propionate. Key Words: Dry Powder for Inhalation, Combination Inhalation Therapy, Long-acting β-2 agonist, Long acting corticosteroid, Pulmonary Drug Delivery.