Purpose To assess the influence of powder particle shape on the micronization efficiency using PilotMill-zero. Methods A 23 factorial design was used to individuate the best working conditions to produce inhalable bacitracin and capreomycin powders using a PilotMill-zero (Food Pharma Systems®, Italy). Air jet pressure, milling time, and powder amount were the investigated factors, while maximum desirability was intended as the smallest mean volume diameter (dmv) and span, and the highest yield. Powders were characterized in terms of particle dimensions and morphology (SEM) before and after micronization. Powder bulk and tap density were also determined to calculate the Hausner ratio (Hr). Results Mathematical models evidenced a strong influence of bacitracin amount and air jet pressure on the yield and span. However, a non linear influence on the yield was observed. The dmv was mainly influenced by air jet pressure and the interactions of air jet pressure/time and time/amount of powder. The predictivity of the built model was successfully validated. The maximum desirability was obtained micronizing 200 mg of bacitracin at 1 bar for 120 minutes. In these conditions, the yield was about 70% with a dmv of 5.35 μm and a span of 0.96. On the contrary, working at the same conditions, capreomycin powder was not efficiently micronized, with only minor particle fragmentation as confirmed by SEM. This outcome was explained by the different morphology of the two powders. In fact, bacitracin powder particles showed an irregular shape and a Hr of 1.2864, while capreomycin powder particles were spherical with a smooth surface and a Hr of 1.0997. Capreomycin flowability was therefore higher than that of bacitracin, explaining its unsuccessful micronization. Conclusion Powder particle morphology and Hr showed a strong influence on the efficiency of the jet milling process.

Effect of particle shape on the air jet milling process efficiency.

SCHOUBBEN, Aurelie Marie Madeleine;GIOVAGNOLI, Stefano;BLASI, PAOLO;RICCI, Maurizio
2012

Abstract

Purpose To assess the influence of powder particle shape on the micronization efficiency using PilotMill-zero. Methods A 23 factorial design was used to individuate the best working conditions to produce inhalable bacitracin and capreomycin powders using a PilotMill-zero (Food Pharma Systems®, Italy). Air jet pressure, milling time, and powder amount were the investigated factors, while maximum desirability was intended as the smallest mean volume diameter (dmv) and span, and the highest yield. Powders were characterized in terms of particle dimensions and morphology (SEM) before and after micronization. Powder bulk and tap density were also determined to calculate the Hausner ratio (Hr). Results Mathematical models evidenced a strong influence of bacitracin amount and air jet pressure on the yield and span. However, a non linear influence on the yield was observed. The dmv was mainly influenced by air jet pressure and the interactions of air jet pressure/time and time/amount of powder. The predictivity of the built model was successfully validated. The maximum desirability was obtained micronizing 200 mg of bacitracin at 1 bar for 120 minutes. In these conditions, the yield was about 70% with a dmv of 5.35 μm and a span of 0.96. On the contrary, working at the same conditions, capreomycin powder was not efficiently micronized, with only minor particle fragmentation as confirmed by SEM. This outcome was explained by the different morphology of the two powders. In fact, bacitracin powder particles showed an irregular shape and a Hr of 1.2864, while capreomycin powder particles were spherical with a smooth surface and a Hr of 1.0997. Capreomycin flowability was therefore higher than that of bacitracin, explaining its unsuccessful micronization. Conclusion Powder particle morphology and Hr showed a strong influence on the efficiency of the jet milling process.
2012
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/1009867
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact