Design and Exploration of Modified Cyclone Separator for Improved Yield of Spray-Dried Cubosomal Powder using Design of Experiment
Akash Deep & Vikas Rana
Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala (Punjab), India
Summary
This research work aimed to study effect of cyclone design or dimensions on cyclone separator performance in bench-top spray-dryer for the production of spray-dried cubosomal powder. The different cyclone separators were designed by modifying five geometrical parameters, i.e., length of cyclone body (Lb), length of cyclone cone (Lc), Height (H) and Width (W) of inlet section, and gas/air exit diameter (De) of standard cyclone separator. Further, the designed cyclones were evaluated using Lapple’s equations, i.e., number of effective turns (Ne), inlet velocity of air (Vi), pressure drop (∆P) and cut-point diameter (dpc). The modified cyclone (type XVII) with highest Ne, Vi, ∆P and lowest dpc was selected for preparation of powder in comparison to standard cyclone (type I). Further, the Design of experiment was employed to evaluate the effect of formulation, process parameter and cyclone design (type I and XVII) on device removal efficiency (DRE), aerosolization efficiency (AE), fine particle fraction (FPF) and yield of cubosomal powder. Experimental results indicated that modified cyclone has significantly improved the yield of powder with insignificantly increasing the ∆P. The optimized spray-dried powder possesses sufficient geometrical standard diameter (dG) (3.9 ± 0.25 µm) & aerodynamic diameter (dA) (2.04 ± 0.15 µm) to deliver formulation to deeper lung tissues. It was found that modified cyclone was advantageous over standard one in increasing 1.8 folds yield with DRE, AE and FPF of 94.2%, 52.2%, and 63.8% respectively. Overall, this improvement in powder yield with desirable aerosolization properties will be beneficial in early-stage research and development involving bench-top spray-dryer.
Key Message
The modified cyclone has greatly improved the recovery of smaller inhalable particles. Thus, it could be envisaged that the application of developed cyclone could be extended to the recovery of any particulate delivery system in the size range of 1-5 µm, which was not effectively possible earlier with Lab-scale spray-dryer.