The Forgotten Material: Gelatin-Based Inhalable Microcapsules Formulated By A Simple Ionic Complex Approach As A Platform For Controlled Pulmonary Drug Delivery
Beatriz Behrend-Keim1, Almendra Castro-Muñoz1, Tania F. Bahamondez-Canas 1,2, & Daniel Moraga-Espinoza1,2
1 Escuela de Química y Farmacia, Universidad de Valparaíso, Gran Bretaña 1093, Playa Ancha, Valparaíso, Región de Valparaíso 2340000, Chile
2 Centro de Investigación Farmacopea Chilena, Universidad de Valparaíso, Gran Bretaña 1093, Playa Ancha, Valparaíso, Región de Valparaíso 2340000, Chile
Summary
Formulating pulmonary controlled-release formulations is highly desirable when treating chronic diseases such as COPD and Asthma. However, a limited number of excipients are approved for inhalation. The following study presents a promising strategy that provides a matrix for controlling the release of anionic drugs using gelatin as the core of the encapsulation process for dry powder formulations. The ionic interaction between this biodegradable polymer and the drugs allows for controlling the diffusion rate of the drug while presenting swelling properties that could help to avoid macrophage patrolling and early clearance from the lung. Overall, the decrease in the drug release rate was minor, considering the expected. However, the time necessary to reach maximum concentration was three times higher compared to the drug without the presence of gelatin.
On the other hand, the particle swelling increases by tenfold in five minutes while presenting a good aerodynamic performance with 70 % of FPF. Even though these results are favorable, a more comprehensive study is required to understand the mechanism behind the ionic interaction between the polymer and the drug. However, this can be the start of developing a new generation of controlled-release formulations.
Key Message
The ionic complex approach allowed for the formulation of gelatin microcapsules capable of reducing the diffusion rate of sodium cromoglycate (SC) more efficiently. Positively charged gelatin microcapsules could interact with SC while rapidly swelling. This characteristic shows potential for increasing the residence time of the formulation by avoiding macrophage uptake.