Development and In Vivo Evaluation of a Novel Vitamin D3 Oral Spray Delivery System

Developing drugs that are highly selective to host tissues but are the least toxic remains one of the most difficult challenges in cancer treatment. Recent studies have shown that tumor cells from a variety of sources can express vitamin D3 receptors and that the response to vitamin D3 and its analogs is prone to growth arrest and cell death. However, conventional vitamin D3 drug formulations lack dose control and cannot target specific cells or tissues. The aim of this study was to prepare vitamin D3 nanospray for inhalation delivery route. This study evaluated the physical properties of the formulation (particle size distribution and biological stability), the total number of sprays per bottle, the spray volume per spray, and the loading variance of the spray. The optimized vitamin D3 spray formula is easy to spray, has fewer drips, and has a fast drying time. It can be stored for 3 months at 37 ± 2 °C temperature, 75 ± 5% relative humidity, and away from light, and can maintain biological stability. This study showed that compared with traditional nasal sprays, the spray has a larger fan angle (82.1 degrees) and beam width (104.88 mm), more symmetrical spray on both sides of the spray column, a faster coverage of the administration site, and a wider range, which is suitable for inhalation delivery routes.