Influence of Formulation and Preparation Process on Ambroxol Hydrochloride Dry Powder Inhalation Characteristics and Aerosolization Properties

Spray drying tenofovir loaded mucoadhesive and pH-sensitive microspheres intended for HIV prevention

PURPOSE

To develop spray dried mucoadhesive and pH-sensitive microspheres (MS) based on polymethacrylate salt intended for vaginal delivery of tenofovir (a model HIV microbicide) and assess their critical biological responses.

METHODS

The formulation variables and process parameters are screened and optimized using a 2(4-1) fractional factorial design. The MS are characterized for size, zeta potential, yield, encapsulation efficiency, Carr's index, drug loading, in vitro release, cytotoxicity, inflammatory responses and mucoadhesion.

RESULTS

The optimal MS formulation has an average size of 4.73μm, zeta potential of -26.3mV, 68.9% yield, encapsulation efficiency of 88.7%, Carr's index of 28.3 and drug loading of 2% (w/w). The MS formulation release 91.7% of its payload in the presence of simulated human semen. At a concentration of 1mg/ml, the MS are noncytotoxic to vaginal endocervical/epithelial cells and Lactobacillus crispatus when compared to control media. There is also no statistically significant level of inflammatory cytokine (IL1-α, IL-1β, IL-6, IL-8, and IP-10) release triggered by these MS. Their percent mucoadhesion is 2-fold higher than that of 1% HEC gel formulation.

CONCLUSION

These data suggest the promise of using such MS as an alternative controlled microbicide delivery template by intravaginal route for HIV prevention.

Development of an inhalation chamber and a dry powder inhaler device for administration of pulmonary medication in animal model

CONTEXT

Pulmonary route of administration is becoming more popular for drug delivery in pulmonary tract and lungs for local and systemic actions.

OBJECTIVE

A dry powder inhaler (DPI) for delivery of dry powder and a nose-only inhalation chamber for small animals that can be used with nebuliser/DPI were designed.

MATERIALS AND METHODS

The inhalation chamber was made with a polypropylene-rectangular box and centrifuge tubes. DPI was made of a polypropylene tube. Micronized voriconazole and voriconazole solution were used for DPI and nebulizer, respectively, for both in vitro and in vivo studies.

RESULTS

In vitro drug deposition from nebulizer was found to be 11-26% w/w and that from DPI was 42 to 57% w/w depending on experimental set up. Uniform deposition across all the inhalation ports was observed irrespective of the methods. Respirable fraction (RF) varied from 34 to 73% in case of nebulizer and from 47 to 54% in case of DPI. In vivo deposition of voriconazole in lungs was found to be 80-130 µg/g of lung tissue in case of DPI and 40-68 µg/g of lung tissue in case of using nebulizer.

DISCUSSION

DPI designed was efficient in fluidizing powder bed and dispensing dry powder for inhalation. The inhalation chamber designed was efficient in uniformly distributing drug in various inhalation ports of the chamber.

CONCLUSIONS

The DPI and inhalation chamber designed can be successfully used for inhalation study with multiple animals especially mice.

Analysis of process parameters affecting spray-dried oily core nanocapsules using factorial design

The purpose of this work was to optimize the process parameters required for the production of spray-dried oily core nanocapsules (NCs) with targeted size and drug yield using a two-level four-factor fractional factorial experimental design (FFED). The coded process parameters chosen were inlet temperature (X(1)), feed flow rate (X(2)), atomizing air flow (X(3)), and aspiration rate (X(4)). The produced NCs were characterized for size, yield, morphology, and powder flowability by dynamic light scattering, electron microscope, Carr's index, and Hausner ratio measurement, respectively. The mean size of produced NCs ranged from 129.5 to 444.8 nm, with yield varying from 14.1% to 31.1%. The statistical analysis indicated an adequate model fit in predicting the effect of process parameters affecting yield. Predicted condition for maximum yield was: inlet temperature 140°C, atomizing air flow 600 L/h, feed flow rate 0.18 L/h, and aspiration air flow set at 100%, which led to a yield of 30.8%. The morphological analysis showed the existence of oily core and spherical nanostructure. The results from powder flowability analysis indicated average Carr's index and Hausner ratio of 42.77% and 1.76, respectively. Spray-dried oily core NCs with size lower than 200 nm were successfully produced, and the FFED proved to be an effective approach in predicting the production of spray-dried NCs of targeted yield.