Microspherical Particles of Solid Dispersion of Polyvinylpyrrolidone K29-32 for Inhalation Administration

Electrohydrodynamic atomisation driven design and engineering of opportunistic particulate systems for applications in drug delivery, therapeutics and pharmaceutics

Electrohydrodynamic atomisation (EHDA) technologies have evolved significantly over the past decade; branching into several established and emerging healthcare remits through timely advances in the engineering sciences and tailored conceptual process designs. More specifically for pharmaceutical and drug delivery spheres, electrospraying (ES) has presented itself as a high value technique enabling a plethora of different particulate structures. However, when coupled with novel formulations (e.g. co-flows) and innovative device aspects (e.g., materials and dimensions), core characteristics of particulates are manipulated and engineered specifically to deliver an application driven need, which is currently lacking, ranging from imaging and targeted delivery to controlled release and sensing. This demonstrates the holistic nature of these emerging technologies; which is often overlooked. Parametric driven control during particle engineering via the ES method yields opportunistic properties when compared to conventional methods, albeit at ambient conditions (e.g., temperature and pressure), making this extremely valuable for sensitive biologics and molecules of interest. Furthermore, several processing (e.g., flow rate, applied voltage and working distance) and solution (e.g., polymer concentration, electrical conductivity and surface tension) parameters impact ES modes and greatly influence the production of resulting particles. The formation of a steady cone-jet and subsequent atomisation during ES fabricates particles demonstrating monodispersity (or near monodispersed), narrow particle size distributions and smooth or textured morphologies; all of which are successfully incorporated in a one-step process. By following a controlled ES regime, tailored particles with various intricate structures (hollow microspheres, nanocups, Janus and cell-mimicking nanoparticles) can also be engineered through process head modifications central to the ES technique (single-needle spraying, coaxial, multi-needle and needleless approaches). Thus, intricate formulation design, set-up and combinatorial engineering of the EHDA process delivers particulate structures with a multitude of applications in tissue engineering, theranostics, bioresponsive systems as well as drug dosage forms for specific delivery to diseased or target tissues. This advanced technology has great potential to be implemented commercially, particularly on the industrial scale for several unmet pharmaceutical and medical challenges and needs. This review focuses on key seminal developments, ending with future perspectives addressing obstacles that need to be addressed for future advancement.

Assessment and Development of the Antifungal Agent Caspofungin for Aerosolized Pulmonary Delivery

Invasive Pulmonary Aspergillosis (IPA) and Pneumocystis jiroveci Pneumonia (PCP) are serious fungal pulmonary diseases for immunocompromised patients. The brand name drug CANCIDAS^® (Caspofungin acetate for injection) is FDA approved to treat IPA, but is only 40% effective. Efficacious drug levels at the lung infection site are not achieved by systemic administration. Increasing the dose leads to toxicity. The objective, here, is to reformulate caspofungin for aerosolization to high drug concentration by lung targeted delivery and avoid systemic distribution. Described in this paper is a new, room temperature-stable formulation that meets these goals. The in vitro antifungal activity, solid state and reconstituted stability, and aerosol properties of the new formulation are presented. In addition, pharmacokinetic parameters and tissue distribution data are determined from nose-only inhalation studies in rats. Plasma and tissue samples were analyzed by High Performance Liquid Chromatography-tandem Mass Spectrometry (HPLC-MS-MS). Inhaled drug concentrations for caspofungin Active Pharmaceutical Ingredient (API), and the new formulation, were compared at the same dose. In the lungs, the parameters C_max and Area Under Curve (AUC) showed a 70%, and 60%, respective increase in drug deposition for the new formulation without significant systemic distribution. Moreover, the calculated pharmacodynamic indices suggest an improvement in efficacy. These findings warrant further animal toxicology studies and human clinical trials, with inhaled caspofungin, for treating IPA.

Amorphous solid dispersion dry powder for pulmonary drug delivery: Advantages and challenges

Amorphous solid dispersion (ASD) is commonly used in pharmaceutical industry. It has been mainly employed to enhance the oral bioavailability of poorly water-soluble drugs that belong to class II and IV of the biopharmaceutical classification system but has showed promise in other areas of pharmaceutical research. In this review, the potential and limitations of ASD dry powder for inhalation are discussed. ASD powder for inhalation (ASD-IP) is commonly prepared by spray drying technique. The physicochemical characteristics of ASD-IP could be tailored to achieve effective lung deposition. ASD-IP could also attain rapid dissolution behavior to achieve therapeutically effective concentration either locally or systemically before particle clearance in the lung. The key challenges of using ASD powder for inhalation include the possible chemical and/or physical instability of the amorphous phase during manufacturing and in vivo, and the moisture and temperature sensitivity of ASD-IP that affects its storage stability.