Proliposome powder or tablets for generating inhalable liposomes using a medical nebulizer

Purpose The aim of this study was to develop and compare proliposome powder and proliposome tablet formulations for drug delivery from a Pari-LC Sprint nebulizer. Methods Proliposome powders were prepared by the slurry method and sorbitol or mannitol carbohydrate carrier were used in a 1:10 and 1:15 w/w lipid phase to carrier ratio. Beclometasone dipropionate (BDP; 2 mol%) was incorporated in the lipid phase. Proliposome powders were compressed into tablets, and liposomes were generated from proliposome powders or tablets within the nebulizer reservoir for subsequent aerosolization. Results Comparatively, shorter sputtering times were reported for the tablet formulations (approximate to < 2.7 +/- 0.45 min), indicating uniform aerosolization. Post-nebulization, liposomes size was larger in the nebulizer reservoir in the range of 7.79 +/- 0.48 mu m-9.73 +/- 1.53 mu m for both powder and tablet formulations as compared to freshly prepared liposomes (5.38 +/- 0.73 mu m-5.85 +/- 0.86 mu m), suggesting liposome aggregation/fusion in the nebulizer's reservoir. All formulations exhibited more than 80% mass output regardless of formulation type, but greater BDP proportions (circa 50%) were delivered to the Two-stage Impinger when tablet formulations were used. Moreover, the nebulized droplet median size and size distribution were lower for all tablet formulations in comparison to the powder formulations. Proliposome tablet and powdered formulations demonstrated the ability to generate vesicles that sustained the release of BDP. Conclusion Overall, this study showed that proliposome tablets could be disintegrated within a Pari-LC Sprint nebulizer to generate inhalable aerosol, with high drug output and hence can be manufactured on large scale to overcome the storage problems associated with powder formulations.

Automated summary

This study aimed to develop and compare proliposome powder and proliposome tablet formulations for drug delivery from a Pari-LC Sprint nebulizer. The tablet formulations showed shorter sputtering times and higher drug output compared to powder formulations. Liposomes size was larger in the nebulizer reservoir, indicating aggregation/fusion, and all formulations exhibited more than 80% mass output.