Activation of diacetyldapsone and a preliminary evaluation of a cyclodextrin-diacetyldapsone complex in cultured lung cells

Cyclodextrin-based nanosponges as promising carriers for active pharmaceutical ingredient

Effective drug distribution at the intended or particular location is a critical issue that researchers are now dealing. Nanosponges have significantly increased in importance in medication delivery using nanotechnology in recent years. An important step toward solving these problems has been the development of nanosponges. Recently created and proposed for use in drug delivery, nanosponge is a unique type of hyper-crosslinked polymer-based colloidal structures made up of solid nanoparticles with colloidal carriers. Nanosponges are solid porous particles that may hold pharmaceuticals and other actives in their nanocavities. They can be made into dosage forms for oral, parenteral, topical, or inhalation use. The targeted distribution of drugs in a regulated manner is greatly aided by nanosponge. The utilization of nanosponges, their benefits, their production processes, the polymers they are made of, and their characterization have all been covered in this review article.

Spray-Freeze Drying: a Suitable Method for Aerosol Delivery of Antibodies in the Presence of Trehalose and Cyclodextrins

We aimed to prepare spray-freeze-dried powder of IgG considering physicochemical stability and aerodynamic aspects. Spray-freeze drying (SFD) exposes proteins to various stresses which should be compensated by suitable stabilizers. The competence of cyclodextrins (CDs), namely beta-cyclodextrin (βCD) and hydroxypropyl βCD (HPβCD), at very low concentrations, was investigated in the presence of separate mannitol- and trehalose-based formulations. Spray-freeze-dried preparations were quantified in terms of monomer recovery and conformation by size exclusion chromatography (SEC-HPLC) and Fourier transform infrared (FTIR) spectroscopy, respectively. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were employed to identify the thermal characteristics of powders. Particle morphology was visualized by scanning electron microscopy (SEM). Aerodynamic behavior of powders was checked through an Anderson cascade impactor (ACI). Although all formulations protected antibody from aggregation during the SFD process (aggregation < 1%), mannitol-containing ones failed upon the storage (19.54% in the worst case). Trehalose-HPβCD incomparably preserved the formulation with fine particle fraction (FPF) of 51.29%. Crystallization of mannitol resulted in IgG destabilization upon storage. Although employed concentration of CDs is too low (less than 50:1 molar ratio to protein), they successfully served as stabilizing agents in SFD with perfect improvement in aerosol functionality. Graphical Abstract ᅟ.

Chlorin p6as a fluorescent probe for the investigation of surfactant–cyclodextrin interactions

Cyclodextrins (CD) are often proposed as potential vehicles in targeted drug delivery. However, if the membrane structure is disrupted by CD, then it cannot be considered to be a good drug delivery vehicle. When an extrinsic fluorescence probe is used to monitor such interactions, there are no less than three possible equilibria that can operate simultaneously: surfactant-cyclodextrin, surfactant-fluorophore and cyclodextrin-fluorophore. The fluorescence intensity/lifetime might be affected by all these and so, the results depend strongly on the fluorophore used as well as the nature of the surfactant. This aspect highlights the importance of the suitability of the fluorescence probe to be used to study complicated systems and interaction. In the present work, chlorin p6, prepared from chlorophyll from spinach leaves, has been used as the fluorescence probe to investigate the interaction between alpha-CD and beta-CD with the neutral surfactants Triton X 100 (TX 100) and cetyl trimethyl ammonium bromide (CTAB). The fluorophore is found to be a sensitive one for the study of the interaction of alpha, beta and gamma-CD with the surfactants TX 100 and CTAB. It is found that contrary to earlier reports, a complex between alpha-CD and TX 100 is formed, even though the binding constant is not very high. This observation can be obtained with chlorin p6, which does not bind to the CDs, but not with a fluorophore, which binds to the CD as well and thus complicates the situation as the binding with CD is stronger than that between TX 100 and alpha-CD as compared to that between TNS and CD.

Cyclodextrins in drug delivery

Cyclodextrins are a family of cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic central cavity. Cyclodextrin molecules are relatively large with a number of hydrogen donors and acceptors and, thus, in general they do not permeate lipophilic membranes. In the pharmaceutical industry cyclodextrins have mainly been used as complexing agents to increase aqueous solubility of poorly soluble drugs, and to increase their bioavailability and stability. Studies in both humans and animals have shown that cyclodextrins can be used to improve drug delivery from almost any type of drug formulation. However, the addition of cyclodextrins to existing formulations without further optimisation will seldom result in acceptable outcome. Currently there are approximately 30 different pharmaceutical products worldwide containing drug/cyclodextrin complexes on the market.

Pulmonary deposition of a budesonide/gamma-cyclodextrin complex in vitro

Cyclodextrins (CDs) may be potential excipients in inhalation powders; e.g., to increase drug stability, dissolution rate and bioavailability, or to decrease local irritation of an inhaled drug. The aim of this study was to investigate the effect of CD complexation on the pulmonary deposition of drugs. Studies were performed by using novel Taifun multi-dose dry powder inhalers and budesonide as a model compound. A precipitation method was developed to prepare solid budesonide/gamma-CD complexes. Inhalation powders containing either budesonide/gamma-CD complexes (15 microg/dose; complex:carrier ratio 1:15) or budesonide (10 microg/dose and 100 microg/dose; drug:carrier ratio 1:159 and 1:15, respectively) with a lactose carrier, were prepared by dry mixing. The in vitro pulmonary depositions of budesonide and budesonide/gamma-CD complexes were determined initially and after 1 month's storage (40 degrees C, 75% RH) using an Andersen cascade impactor. The respirable fraction (RF) of the budesonide/gamma-CD complex was 35% initially and 31% after storage. The RF of budesonide was 35% (10 microg/dose) and 45% (100 microg/dose) initially, and 31% (10 microg/dose) and 51% (100 microg/dose) after storage, respectively. In conclusion, CDs may be used in inhalation powders to improve pharmaceutical and biopharmaceutical properties of drugs without lowering their pulmonary deposition.