Improving Atorvastatin Release from Polyelectrolyte Complex-Based Hydrogels Using Freeze-Drying: Formulation and Pharmaceutical Assessment of a Novel Delivery System for Oral Candidiasis Treatment

Atorvastatin calcium, an antifungal agent, has the potential to be repositioned/repurposed to combat the increasing antimicrobial resistance. However, one of the most crucial issues in developing atorvastatin calcium-loaded products with a topical antifungal effect is achieving the optimal release and dissolution rates of this statin to produce the desired therapeutic effect. In this paper, we report on the development and pharmaceutical assessment of hydrogels composed of low-molecular-weight chitosan, tragacanth, and xanthan gum/pectin/κ-carrageenan as potential drug carriers for atorvastatin calcium for buccal delivery. Multidirectional analysis of the carriers with regard to their drug-release profiles and mucoadhesive, antimicrobial, and cytotoxic properties was accompanied by an evaluation of the freeze-drying process used to improve the hydrogels' applicability. Using differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques, the role of lyophilization in enhancing atorvastatin calcium delivery from polyelectrolyte complex-based matrices via drug amorphization was demonstrated. The freeze-dried hydrogels had significantly improved release and dissolution rates for the amorphic statin. Therefore, there is great potential for the use of lyophilization in the design of polyelectrolyte complex-based semi-solids in usable dosage forms for numerous crystalline and poorly water-soluble active substances.