Effect of carrier on dry micropowder inhaler deposition in vitro

Key words: 
• dry powder inhaler, salbutamal /
• carrier, spray drying /
•  /

Abstract: OBJECTIVE To research the effect of carrier on dries micropowder inhaler(DMPI) deposition in vitro, and select the suitable carrier and the forming method (FM) for inhalers. METHODS DMPI prepared by spray drying techniques(SDT) with the aqueous solution of drug(salbutamal) and carrier (lactose or mannitol) and physical mixing techniques (PMT) after drug and carrier spray drying respectively. DMPI were aerosolized by Cyclo-haler and their mode of deposition in lung was evaluated in vitro using a twin impinger(TI). RESULTS Dramatically improved inhalation properties of the DMPI with carrier mannitol by SDT,i. e. a two-fold increase in delivery to deep lung, were found in vitro compared with the DMPI by PMT. But the inhalation properties didn't change after adding 2% poloxamer. Improved inhalation was also found with carrier lactose after adding 2% poloxamer but no significant difference with SDT or PMT. CONCLUSION An ideal DMPI could obtained by SDT using carrier mannitol.