RESUMO
In this review, an extensive analysis of dry powder inhalers (DPIs) is offered, focusing on their characteristics, formulation, stability, and manufacturing. The advantages of pulmonary delivery were investigated, as well as the significance of the particle size in drug deposition. The preparation of DPI formulations was also comprehensively explored, including physico-chemical characterization of powders, powder processing techniques, and formulation considerations. In addition to manufacturing procedures, testing methods were also discussed, providing insights into the development and evaluation of DPI formulations. This review also explores the design basics and critical attributes specific to DPIs, highlighting the significance of their optimization to achieve an effective inhalation therapy. Additionally, the morphology and stability of 3 DPI capsules (Spiriva, Braltus, and Onbrez) were investigated, offering valuable insights into the properties of these formulations. Altogether, these findings contribute to a deeper understanding of DPIs and their development, performance, and optimization of inhalation dosage forms.
RESUMO
Bioconjugation is an emerging field in the food and pharmaceutical industry. Due to its biocompatibility and high ligand binding capacity, albumin is widely used in modern drug delivery systems. However, the protein is sensitive to environmental stresses; albumin conjugates, on the other hand, have improved functional properties. Biopolymers are gaining interest due to their biodegradability and safety, compared to synthetic polymers. In this study, albumin-biopolymer bioconjugates were prepared by nonenzymatic Maillard reaction at 60 °C and 80% relative humidity. This nonenzymatic conjugation takes place between reducing sugars and available amino groups of a protein in certain conditions. The optimal molar ratio and time for the conjugation were studied by several investigation methods, including circular dichroism and fluorescence spectroscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and determination of available amino groups with ortho-phthaldialdehyde (OPA) assay. All of the measurements provided evidence for the covalent bonding of albumin and biopolymers, resulting in bioconjugates. Based on the results, a higher molar ratio and longer time are necessary to complete the reaction with the available amino groups. However, the optimal parameters are specific to each given biopolymer. The rheological behavior of the conjugates is characteristic of the initial biopolymer, which can be useful in drug development. Moreover, both the physical characteristics of albumin and the solubility-improving capacity were enhanced. Therefore, the potential use of albumin-biopolymer bioconjugates in the pharmaceutical industry could be considered.
RESUMO
Due to their light consistency and good spreadability, aqueous foams are considered as convenient and highly accepted drug carrier systems that are of great importance in the field of topical drug delivery. The production of a stable, easy to dose, preferably environmentally harmless foam formulation is challenging. Therefore, foam characterisation requires a complex approach: several tests are to be performed throughout the formulation. Our study primarily aims to investigate the quality attributes of propellant-free foam-forming additives. Throughout the research, we focused on acquiring knowledge about the properties of pharmaceutical excipients suitable for foam formulations and their effect on foam characteristics. Not only were the relative foam density, actuated foam weight and the foam collapse tendencies studied, but also the initial liquid properties. Along with surface tension determination, bubble-forming experiments were carried out. The bubble size and rate of formation, standardised by using a texture analyser, were followed by image analysis. Analysing the bubble-forming properties of dilute surfactant solutions allows assumptions on the properties of foam formed from the more concentrated solutions. The size and number of bubbles in the produced foams are related to the kinetics of single bubble formation. For comparison, commercially available medicated foams were studied.
