Search Results (3)

Background: Spray drying, whilst a popularly employed technique for powder formulations, has limited applications for large-scale proliposome manufacture. Objectives: Thus, the aim of this study was to investigate spray drying parameters, such as inlet temperature (80, 120, 160, and 200 °C), airflow rate (357, 473, and 601 L/h) and pump feed rate (5, 15, and 25%), for individual carbohydrate carriers (trehalose, lactose monohydrate (LMH), and mannitol) for 24 spray-dried (SD) formulations (F1–F24). Methods: Following optimization, the SD parameters were trialed on proliposome formulations based on the same carriers and named as spray-dried proliposome (SDP) formulations. Drug delivery of the formulations was assessed using a dry powder inhaler (DPI) in combination with a next-generation impactor (NGI). Results: Upon analysis, formulations F6 (SD-mannitol), F15 (SD-trehalose), and F20 (SD-LMH) demonstrated high production yields (84.01 ± 3.25, 72.55 ± 5.42, and 70.03 ± 3.39%, respectively), small particle sizes (2.96 ± 1.42, 4.55 ± 0.46, and 5.16 ± 1.32 µm, respectively) and low moisture contents (0.25 ± 0.03, 3.76 ± 0.75, and 1.99 ± 0.77%). These SD optimized parameters were then employed for SDP formulations employing dimyristoly phosphatidylcholine (DMPC) as a phospholipid and beclomethasone dipropionate (BDP) as the model drug. Upon spray drying, SDP-mannitol provided the highest production yield (82.45%) and smallest particle size (2.64 µm), as well as high entrapment efficiency (98%) and a high fine particle dose, fine particle fraction, and respirable fraction (285.81 µg, 56.84%, 86.44%, respectively). Conclusions: The study results are a promising step in the optimization of the large-scale manufacture of proliposome formulations and highlight the versatility of the instrument and variability of formulation properties with respect to the carriers employed for targeting the pulmonary system using dry powder inhalers. Full article

Tumor hypoxia (oxygen deficiency) is a major contributor to radiotherapy resistance. Ultrasound-sensitive microbubbles containing oxygen have been explored as a mechanism for overcoming tumor hypoxia locally prior to radiotherapy. Previously, our group demonstrated the ability to encapsulate and deliver a pharmacological inhibitor of tumor mitochondrial respiration (lonidamine (LND)), which resulted in ultrasound-sensitive microbubbles loaded with O₂ and LND providing prolonged oxygenation relative to oxygenated microbubbles alone. This follow-up study aimed to evaluate the therapeutic response to radiation following the administration of oxygen microbubbles combined with tumor mitochondrial respiration inhibitors in a head and neck squamous cell carcinoma (HNSCC) tumor model. The influences of different radiation dose rates and treatment combinations were also explored. The results demonstrated that the co-delivery of O₂ and LND successfully sensitized HNSCC tumors to radiation, and this was also enhanced with oral metformin, significantly slowing tumor growth relative to unsensitized controls (p < 0.01). Microbubble sensitization was also shown to improve overall animal survival. Importantly, effects were found to be radiation dose-rate-dependent, reflecting the transient nature of tumor oxygenation. Full article

In this work, 13 jet nebulizers, some of which in different configurations, were investigated in order to identify the biopharmaceutical constraints related to the quality attributes of the medicinal products, which affect their safety, efficiency, compliance, and effectiveness. The aerosolization parameters, including the aerosol output, aerosol output rate, mass median aerodynamic diameter, and fine particle fraction, were determined according to the European Standard EN 13544-1, using sodium fluoride as a reference formulation. A comparison between the aerosol output nebulization time and the fine particle fraction displayed a correlation between the aerosol quality and the nebulization rate. Indeed, the quality of the nebulization significantly increased when the rate of aerosol emission was reduced. Moreover, the performance of the nebulizers was analyzed in terms of respirable delivered dose and respirable dose delivery rate, which characterize nebulization as the rate and amount of respirable product that could be deposited into the lungs. Depending on which of these two latter parameters was used, the nebulizers showed different performances. The differences, in terms of the rate and amount of delivered aerosol, could provide relevant information for the appropriate choice of nebulizer as a function of drug product, therapy, and patient characteristics. Full article