Enhancing Biopharmaceutical Attributes of Khellin by Amorphous Binary Solid Dispersions

Molecular interactions of niclosamide with hydroxyethyl cellulose in binary and ternary amorphous solid dispersions for synergistic enhancement of water solubility and oral pharmacokinetics in rats

The cellulose-based polymers are extensively employed in oral formulations for addressing ADMET issues of API. Herein, we report the synergistic effect of hydroxyethyl cellulose in solubility/dissolution enhancement of BCS class II, anthelmintic drug niclosamide. The low solubility and poor oral bioavailability are the primary reasons for its high daily dose. The amorphous solid dispersions (ASDs) developed herein demonstrated reproducible solubility and dissolution enhancement in smaller-to-pilot batches. The significant boost in niclosamide solubility in HEC-based binary SD was rationalized as a result of intermolecular H-bonding as indicated by in-silico studies and further supported by characterization data. HEC is plausibly inhibiting the precipitation of drug and thereby enabling high dissolution and permeation across the membrane. The comparative oral pharmacokinetics in Wistar rats at 25 mg/kg provided 4.4-fold higher plasma exposure of niclosamide in SD formulation SB-ASD-N2 over the plain drug. The results presented herein warrant validation of this ASD under clinical settings. Teaser Amorphous solid dispersions of niclosamide.

Preparation and Evaluation of Siderol Amorphous Solid Dispersions: Selection of Suitable Matrix/Carrier

The present study investigates the preparation of amorphous solid dispersions (ASD) for the ent-kaurane diterpenoid siderol (SDR). Initially, evaluation of the pure drug (isolated from Sideritis scardica) revealed that the API is a non-stable glass former, and hence the selection of a suitable ASD's matrix/carrier needs special attention. For this reason, four commonly used polymers and copolymers, namely poly(vinylpyrrolidone), copovidone, hydroxypropyl cellulose, and Soluplus® (SOL), were screened via film casting and crystal growth rate measurements. Amongst them, SOL showed the highest SDR's crystal growth rate reduction, and, since it was also miscible with the drug, it was selected for further testing. In this direction, SDR-SOL ASDs were successfully prepared via melt-quench cooling. These formulations showed full API amorphization, while good physical stability (i.e., a stable SDR amorphous dispersions) were obtained after storage for several months. Finally, evaluation of molecular interactions (with the aid of ATR-FTIR spectroscopy) showed strong H-bonds between SOL and SDR, while the use of molecular dynamics (MD) simulations unraveled the nature of these interactions. Therefore, based on the findings of the present work, SOL seems to be an appropriate matrix/carrier for the preparation of SDR ASDs, although further studies are needed in order to explore its full potentials.

Analytical Methods for Furanochromone Natural Product, Khellin and Its Inspired Drug Candidates, Amiodarone and Sodium Cromoglycate

Khellin is the key furanocoumarin of Ammi visnaga L. (Lam.) that exhibits various biological properties. This unique natural product has inspired the discovery of two first-in-class drugs, amiodarone and sodium cromoglycate. A wide range of analytical methods were generated while translating khellin scaffold into clinically used drugs; however, they have never been reviewed and critically assessed. The present review aims to review and evaluate the analytical techniques for the natural products, khellin, visnagin, and their inspired drugs, amiodarone and sodium cromoglycate. High-performance liquid chromatography (HPLC) is the extensively used technique in most analytical methods reported for these compounds; however, other techniques including the fluorimetry, luminescence spectrophotometry, potentiometry, voltammetry, FT-Raman spectroscopy, and ELISA were also employed. The review will be helpful for further basic and translational research on furanochromone and related scaffolds.

Design, Characterization, and Evaluation of Diosmetin-Loaded Solid Self-microemulsifying Drug Delivery System Prepared by Electrospray for Improved Bioavailability

Diosmetin (DIOS) is a functional compound with poor water solubility, bad permeability, and crystal form. Self-microemulsifying drug delivery system (SMEDDS) was an effective formulation to overcome these shortcomings. In this study, liquid SMEDDS was prepared using Capmul® MCM C8 EP/NF, Cremophor EL, and PEG 400 (2:5.6:2.4, w/w/w) as excipients. Then, the novel technology of electrospray solidified liquid SMEDDS and prepared solid SMEDDS for inhibiting crystallization. Polyvinyl pyrrolidone (PVP) was used as carrier to construct DIOS-loaded solid SMEDDS, with polyethylene oxide (PEO) contributing to the formation of regular sphere in the process of spinning. The particle size of solid SMEDDS (194 ± 5 nm) was much bigger than of liquid SMEDDS (25 ± 1 nm), while DIOS-loaded solid SMEDDS showed greater dissolution rates in pH 1.2 and pH 6.8 media through in vitro drug release study. The solid nanoparticles were smooth and uniform from the graph of a scanning electron microscope (SEM). The graph of a transmission electron microscope (TEM) showed that small droplets were loaded in the matrix. Furthermore, DIOS was encapsulated by matrix in amorphous state via differential scanning calorimetry (DSC) and attenuated total reflection Fourier transform infrared (ATR-FTIR). The crystalline of DIOS was not formed in solid SMEDDS due to the characteristic peaks of DIOS disappeared in X-ray diffraction (XRD) pattern. Therefore, the oral bioavailability of DIOS improved significantly compared with liquid SMEDDS (4.27-fold). Hence, solid SMEDDS could improve the solubility and bioavailability of DIOS, through transfer of the state of crystalline to amorphous by electrospray technology.

Stabilizing Effect of Soluplus on Erlotinib Metastable Crystal Form in Microparticles and Amorphous Solid Dispersions

Microparticles (MPs) and amorphous solid dispersions (SDs) are effective methods to improve the dissolution of insoluble drugs. However, stability is a concern for these two high-energy systems, resulting from high surface area and amorphous polymorph, respectively. As an amphiphilic polymer, Soluplus (SOL) is usually used as a carrier in SDs. In this study, erlotinib microparticles (ERL MPs) and erlotinib solid dispersions (ERL SDs) were prepared with SOL by bottom-up technology and solvent evaporation. The solid-state properties of ERL MPs and ERL SDs were characterized by Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). The ERL MPs existed in a metastable crystal form A while the ERL SDs existed in an amorphous state. Fourier transform infrared spectroscopy (FT-IR) showed that there was a hydrogen bond interaction between the N-H group of ERL and the carbonyl group of SOL in ERL MPs and SDs. The dissolution profiles of ERL SDs and ERL MPs were improved significantly. ERL MPs showed better stability than ERL SDs in accelerated stability test. The discrepant stabilizing effects of polymer SOL in two systems may provide effective ideas for solubilization of insoluble drugs and the stability of drugs after recrystallization.