Application of diethylene glycol monoethyl ether in solubilization of poorly water-soluble drugs

Development of Solid Lipid Nanoparticles for Controlled Amiodarone Delivery

In various drug delivery systems, solid lipid nanoparticles are dominantly lipid-based nanocarriers. Amiodarone hydrochloride is an antiarrhythmic agent used to treat severe rhythm disturbances. It has variable and hard-to-predict absorption in the gastrointestinal tract because of its low solubility and high permeability. The aims of this study were to improve its solubility by encapsulating amiodarone into solid lipid nanoparticles using two excipients-Compritol® 888 ATO (pellets) (C888) as a lipid matrix and Transcutol® (T) as a surfactant. Six types of amiodarone-loaded solid lipid nanoparticles (AMD-SLNs) were obtained using a hot homogenization technique followed by ultrasonication with varying sonication parameters. AMD-SLNs were characterized by their size distribution, polydispersity index, zeta potential, entrapment efficiency, and drug loading. Based on the initial evaluation of the entrapment efficiency, only three solid lipid nanoparticle formulations (P1, P3, and P5) were further tested. They were evaluated through scanning electron microscopy, Fourier-transform infrared spectrometry, near-infrared spectrometry, thermogravimetry, differential scanning calorimetry, and in vitro dissolution tests. The P5 formulation showed optimum pharmaco-technical properties, and it had the greatest potential to be used in oral pharmaceutical products for the controlled delivery of amiodarone.

Enhancing solubility and bioavailability of coenzyme Q10: formulation of solid dispersions using Soluplus® as a carrier

Improving the aqueous solubility of poorly soluble compounds have been a major issue in the pharmaceutical industry. In the present study, binary amorphous solid dispersions (SDs) of Coenzyme Q10 (CoQ₁₀), a biopharmaceutics classification system (BCS) II compound and Soluplus^® were prepared to enhance the solubility and pharmacokinetic properties compared to crystalline CoQ₁₀. SDs were prepared with different ratios of CoQ₁₀ and Soluplus^® (1:3, 1:5, and 1:7) using spray drying technology, and the physicochemical properties of the SDs were evaluated. X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy suggested the conversion of the crystalline form of CoQ₁₀ to a binary amorphous system in the SDs. Fourier transform infrared spectroscopy revealed no potential interactions between CoQ₁₀ and Soluplus^®. The solubility of the optimal SD formulation (SD 1:7) was approximately 9000-fold higher than that of crystalline CoQ_10, and the increment was Soluplus^® concentration dependent. As a result, optimized SD 1:7 also showed significantly enhanced dissolution rate where maximum drug release was observed within 30 min in two different dissolution media. Moreover, in contrast to crystalline CoQ_10, CoQ₁₀ SDs showed improved pharmacokinetic parameters. Thus, the SD 1:7 formulation is expected to improve biopharmaceutical properties and therapeutic efficacy of CoQ₁₀.

Formulation of water-dispersible hydrophobic compound nanocomplexes with polypeptides via a supramolecular approach using a high-speed vibration milling technique

Polypeptides were used to solubilize functional hydrophobic molecules via a high-speed vibrational milling method.

Application of supercritical fluid technology for solid dispersion to enhance solubility and bioavailability of poorly water-soluble drugs

Many new chemical entities (NCEs) have been discovered with the development of the pharmaceutical industry. However, the main disadvantage of these drugs is their low aqueous solubility, which results in poor bioavailability, posing a challenge for pharmaceutical scientists in the field of drug development. Solid dispersion (SD) technology is one of the most successful techniques used to resolve these problems. SD has been widely used to improve the solubility and bioavailability of poorly water-soluble drugs using several methods such as melting, supercritical fluid (SCF), solvent evaporation, spray drying, hot-melt extrusion, and freeze-drying. Among them, SCF with carbon dioxide (CO₂) has recently attracted great attention owing to its enhanced dissolution and bioavailability with non-toxic, economical, non-polluting, and high-efficiency properties. Compared with the conventional methods using organic solvents in the preparation of the formulation (solvent evaporation method), SCF used CO₂ to replace the organic solvent with high pressure to avoid the limitation of solvent residues. The solubility of a substance in CO₂ plays an important role in the success of the formulation. In the present review, the various processes involved in SCF technology, application of SCF to prepare SD, and future perspectives of SCF are described.

Preparation and Characterization of Fenofibrate Microparticles with Surface-Active Additives: Application of a Supercritical Fluid-Assisted Spray-Drying Process

In this study, supercritical fluid-assisted spray-drying (SA-SD) was applied to achieve the micronization of fenofibrate particles possessing surface-active additives, such as d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), sucrose mono palmitate (Sucroester 15), and polyoxyethylene 52 stearate (Myrj 52), to improve the pharmacokinetic and pharmacodynamic properties of fenofibrate. For comparison, the same formulation was prepared using a spray-drying (SD) process, and then both methods were compared. The SA-SD process resulted in a significantly smaller mean particle size (approximately 2 μm) compared to that of unprocessed fenofibrate (approximately 20 μm) and SD-processed particles (approximately 40 μm). There was no significant difference in the effect on the particle size reduction among the selected surface-active additives. The microcomposite particles prepared with surface-active additives using SA-SD exhibited remarkable enhancement in their dissolution rate due to the synergistic effect of comparably moderate wettability improvement and significant particle size reduction. In contrast, the SD samples with the surface-active additives exhibited a decrease in dissolution rate compared to that of the unprocessed fenofibrate due to the absence of particle size reduction, although wettability was greatly improved. The results of zeta potential and XPS analyses indicated that the surface-active additive coverage on the surface layer of the SD-processed particles with a better wettability was higher than that of the SA-SD-processed composite particles. Additionally, after rapid depletion of hydrophilic additives that were excessively distributed on the surfaces of SD-processed particles, the creation of a surface layer rich in poorly water-soluble fenofibrate resulted in a decrease in the dissolution rate. In contrast, the surface-active molecules were dispersed homogeneously throughout the particle matrix in the SA-SD-processed microparticles. Furthermore, improved pharmacokinetic and pharmacodynamic characteristics were observed for the SA-SD-processed fenofibrate microparticles compared to those for the SD-processed fenofibrate particles. Therefore, the SA-SD process incorporating surface-active additives can efficiently micronize poorly water-soluble drugs and optimize their physicochemical and biopharmaceutical characteristics.

Pharmaceutical Applications of Supercritical Fluid Extraction of Emulsions for Micro-/Nanoparticle Formation

Micro-/nanoparticle formulations containing drugs with or without various biocompatible excipients are widely used in the pharmaceutical field to improve the physicochemical and clinical properties of the final drug product. Among the various micro-/nanoparticle production technologies, emulsion-based particle formation is the most widely used because of its unique advantages such as uniform generation of spherical small particles and higher encapsulation efficiency (EE). For this emulsion-based micro-/nanoparticle technology, one of the most important factors is the extraction efficiency associated with the fast removal of the organic solvent. In consideration of this, a technology called supercritical fluid extraction of emulsions (SFEE) that uses the unique mass transfer mechanism and solvent power of a supercritical fluid (SCF) has been proposed to overcome the shortcomings of several conventional technologies such as solvent evaporation, extraction, and spray drying. This review article presents the main aspects of SFEE technology for the preparation of micro-/nanoparticles by focusing on its pharmaceutical applications, which have been organized and classified according to several types of drug delivery systems and active pharmaceutical ingredients. It was definitely confirmed that SFEE can be applied in a variety of drugs from water-soluble to poorly water-soluble. In addition, it has advantages such as low organic solvent residual, high EE, desirable release control, better particle size control, and agglomeration prevention through efficient and fast solvent removal compared to conventional micro-/nanoparticle technologies. Therefore, this review will be a good resource for determining the applicability of SFEE to obtain better pharmaceutical quality when researchers in related fields want to select a suitable manufacturing process for preparing desired micro-/nanoparticle drug delivery systems containing their active material.

Enhanced Bioavailability of AC1497, a Novel Anticancer Drug Candidate, via a Self-Nanoemulsifying Drug Delivery System

AC1497 is an effective dual inhibitor of malate dehydrogenase 1 and 2 targeting cancer metabolism. However, its poor aqueous solubility results in low bioavailability, limiting its clinical development. This study was conducted to develop an effective self-nanoemulsifying drug delivery system (SNEDDS) of AC1497 to improve its oral absorption. Based on the solubility of AC1497 in various oils, surfactants, and cosurfactants, Capryol 90, Kolliphor RH40, and Transcutol HP were selected as the components of SNEDDS. After testing various weight ratios of Capryol 90 (20–30%), Kolliphor RH40 (35–70%), and Transcutol HP (10–35%), SNEDDS-F4 containing 20% Capryol 90, 45% Kolliphor RH40, and 35% Transcutol HP was identified as an optimal SNEDDS with a narrow size distribution (17.8 ± 0.36 nm) and high encapsulation efficiency (93.6 ± 2.28%). Drug release from SNEDDS-F4 was rapid, with approximately 80% of AC1497 release in 10 min while the dissolution of the drug powder was minimal (<2%). Furthermore, SNEDDS-F4 significantly improved the oral absorption of AC1497 in rats. The maximum plasma concentration and area under the plasma concentration–time curve of AC1497 were, respectively 6.82- and 3.14-fold higher for SNEDDS-F4 than for the drug powder. In conclusion, SNEDDS-F4 with Capryol 90, Kolliphor RH40, and Transcutol HP (20:45:35, w/w) effectively improves the solubility and oral absorption of AC1497.

In-air particle generation by on-chip electrohydrodynamics

Electrohydrodynamic atomization has been emerging as a powerful approach for respiratory treatment, including the generation and delivery of micro/nanoparticles as carriers for drugs and antigens. In this work, we present a new conceptual design in which two nozzles facilitate dual electrospray coexisting with ionic wind at chamfered tips by a direct current power source. Experimental results by a prototype have demonstrated the capability of simultaneously generating-and-delivering a stream of charged reduced particles. The concept can be beneficial to pulmonary nano-medicine delivery since the mist of nanoparticles is migrated without any restriction of either the collector or the assistance of external flow, but is pretty simple in designing and manufacturing devices.

Experimental measurement - correlation of solubility and dissolution thermodynamics study of itraconazole in pure monosolvents at various temperatures

The information about the solubility and thermodynamic properties of solution is important for pharmaceutically important processes, formulation development, and further theoretical studies. In the present study, the solid-liquid equilibrium (solubility) for itraconazole (ITC) was determined experimentally in 14 monosolvents at temperatures between 293.15 K and 318.15 K under pressure of 0.1 MPa. The mole fraction solubilities were found to increase with increasing temperatures and followed inverse trend with the polarity of selected solvents. Besides, KAT-LSER analysis was performed to study the effect of solvent. The results revealed that the solute-solvent interaction (43.94%) was much higher than that of solvent-solvent interaction (16.59%). Thermodynamic based models like van't Hoff equation, modified Apelblat equation, Buchowski-Ksiazaczak equation, and polynomial empirical equation were applied to fit and correlate the experimental solubilities. Overall relative average deviation (RAD) and overall root-mean square deviation (104×RMSD) were observed to be minimum with the empirical polynomial equation and attained the values of 0.0033 and 0.0047, respectively. Furthermore, theoretical ideal solubilities, activity coefficients, and thermodynamic properties of dissolution including molar enthalpy, molar entropy, molar Gibbs free energy, and excess enthalpy were estimated. Ideal solubilities were projected considerably higher than experimental solubilities at each studied temperature. Thermodynamic properties of dissolution indicated that the dissolution was not a spontaneous process; observed to be endothermic (ΔH0soln>0) and enthalpy driven (ΔS0soln>0). Such solid-liquid equilibrium data of ITC will be of immense help in process and formulation development in pharmaceutical sciences.

Solubility Determination of c-Met Inhibitor in Solvent Mixtures and Mathematical Modeling to Develop Nanosuspension Formulation

The solubility and dissolution thermodynamics of new c-Met inhibitor, ABN401, were determined in eleven solvents and Transcutol^® HP-water mixture (TWM) from 298.15 to 318.15 K. The experimental solubilities were validated using five mathematical models, namely modified Apelblat, van't Hoff, Buchowski-Ksiazaczak λh, Yalkowsky, and Jouyban-Acree van't Hoff models. The experimental results were correlated and utilized further to investigate the feasibility of nanosuspension formation using liquid anti-solvent precipitation. Thermodynamic solubility of ABN401 increased significantly with the increase in temperature and maximum solubility was obtained with Transcutol^® HP while low solubility in was obtained water. An activity coefficient study indicated that high molecular interaction was observed in ABN401-Transcutol^® HP (THP). The solubility increased proportionately as the mole fraction of Transcutol^® HP increased in TWM, which was also supported by a solvent effect study. The result suggested endothermic and entropy-driven dissolution. Based on the solubility, nanosuspension was designed with Transcutol^® HP as solvent, and water as anti-solvent. The mean particle size of nanosuspension decreased to 43.05 nm when the mole fraction of ABN401 in THP, and mole fraction of ABN401 in TWM mixture were decreased to 0.04 and 0.1. The ultrasonicated nanosuspension appeared to give comparatively higher dissolution than micronized nanosuspension and provide a candidate formulation for in vivo purposes.

Enhanced Oral Bioavailability of Resveratrol by Using Neutralized Eudragit E Solid Dispersion Prepared via Spray Drying

In this study, we designed amorphous solid dispersions based on Eudragit E/HCl (neutralized Eudragit E using hydrochloric acid) to maximize the dissolution of trans-resveratrol. Solid-state characterization of amorphous solid dispersions of trans-resveratrol was performed using powder X-ray diffraction, scanning electron microscopy, and particle size measurements. In addition, an in vitro dissolution study and an in vivo pharmacokinetic study in rats were carried out. Among the tested polymers, Eudragit E/HCl was the most effective solid dispersion for the solubilization of trans-resveratrol. Eudragit E/HCl significantly inhibited the precipitation of trans-resveratrol in a pH 1.2 dissolution medium in a dose-dependent manner. The amorphous Eudragit E/HCl solid dispersion at a trans-resveratrol/polymer ratio of 10/90 exhibited a high degree of supersaturation without trans-resveratrol precipitation for at least 48 h by the formation of Eudragit E/HCl micelles. In rats, the absolute oral bioavailability (F%) of trans-resveratrol from Eudragit E/HCl solid dispersion (10/90) was estimated to be 40%. Therefore, trans-resveratrol-loaded Eudragit E/HCl solid dispersions prepared by spray drying offer a promising formulation strategy with high oral bioavailability for developing high-quality health supplements, nutraceutical, and pharmaceutical products.

Pharmacokinetic analysis of two different doses of simvastatin following oral administration in dogs

Simvastatin, used orally to treat hyperlipidemia, exhibits highly variable pharmacokinetics (PKs) in humans. The aim of this study was to investigate simvastatin PKs using noncompartmental analysis and population PK models following a single oral administration of two doses (20 and 80 mg) in dogs. Forty beagle dogs were randomly divided into two groups corresponding to the two doses. Blood samples were collected from each group according to the assigned schedule after oral administration. The plasma concentration of simvastatin was determined using liquid chromatography-tandem mass spectrometry. The area under the curve and maximum concentration of simvastatin increased in a dose-dependent manner with high variability. A two-compartment model with first-order absorption (K_a  = 1.83 hr^-1 ) and first-order elimination (clearance [CL/F] = 292 L/h; volume of distribution in the central compartment [V_c /F] = 1506 L) well described the PKs of simvastatin in dogs. Large variability in the PKs of simvastatin was quantitated via modeling approaches, allowing the differentiation of between-subject variability (144.8 CV% for K_a ; 94.7 CV% for CL/F; 97.5 CV% for V_c /F) and residual variability (62.7%). These findings will help facilitate the development of an optimal dose regimen of simvastatin in canines with hypercholesterolemia and may be useful in developing novel formulations.

Comparative study between high-pressure homogenisation and Shirasu porous glass membrane technique in sildenafil base-loaded solid SNEDDS: Effects on physicochemical properties and in vivo characteristics

The purpose of this study was to compare two types of emulsification techniques in a solid self-nanoemulsifying drug delivery system (SNEDDS); high-pressure homogenisation (HPH) and Shirasu porous glass membrane (SPG). Those two emulsification processes enhanced the solubility, dissolution and oral bioavailability of poorly water-soluble sildenafil base (SB) by producing fine and well-dispersed nanoemulsion droplet. The liquid SNEDDS consisting of Labrasol/Transcutol HP/coconut oil at the weight of 72/18/10, gave the smallest emulsion droplet size among the prepared liquid SNEDDS formulations. Then, the SB-loaded liquid SNEDDS was dissolved in the deionised water and applied to HPH or SPG techniques. Aerosil 200 was suspended as a mesoporous carrier and spray-dried, producing an SB-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of each emulsification process were compared to the solid SNEDDS fabricated without any treatment of additional emulsification. Moreover, the physicochemical properties of all formulations were compared. The crystalline state of the drug in all products was converted to the amorphous state. The solid SNEDDS, subjected to HPH technique, provided fine and well-dispersed nanoemulsion. Additionally, it increasingly improved the drug solubility and dissolution as compared to the others, including SB powder, non-treated (NT) and SPG. Furthermore, it gave improved C_max and increased AUC compared to SB powder and SPG, indicating HPH enhanced the oral bioavailability of SB the most. Thus, this solid SNEDDS with HPH would be strongly suggested as an oral SB-loaded pharmaceutical product.

Current Status of Supersaturable Self-Emulsifying Drug Delivery Systems

Self-emulsifying drug delivery systems (SEDDSs) are a vital strategy to enhance the bioavailability (BA) of formulations of poorly water-soluble compounds. However, these formulations have certain limitations, including in vivo drug precipitation, poor in vitro in vivo correlation due to a lack of predictive in vitro tests, issues in handling of liquid formulation, and physico-chemical instability of drug and/or vehicle components. To overcome these limitations, which restrict the potential usage of such systems, the supersaturable SEDDSs (su-SEDDSs) have gained attention based on the fact that the inclusion of precipitation inhibitors (PIs) within SEDDSs helps maintain drug supersaturation after dispersion and digestion in the gastrointestinal tract. This improves the BA of drugs and reduces the variability of exposure. In addition, the formulation of solid su-SEDDSs has helped to overcome disadvantages of liquid or capsule dosage form. This review article discusses, in detail, the current status of su-SEDDSs that overcome the limitations of conventional SEDDSs. It discusses the definition and range of su-SEDDSs, the principle mechanisms underlying precipitation inhibition and enhanced in vivo absorption, drug application cases, biorelevance in vitro digestion models, and the development of liquid su-SEDDSs to solid dosage forms. This review also describes the effects of various physiological factors and the potential interactions between PIs and lipid, lipase or lipid digested products on the in vivo performance of su-SEDDSs. In particular, several considerations relating to the properties of PIs are discussed from various perspectives.

Development of a Resveratrol Nanosuspension Using the Antisolvent Precipitation Method without Solvent Removal, Based on a Quality by Design (QbD) Approach

The purpose of this study was to develop a resveratrol nanosuspension with enhanced oral bioavailability, based on an understanding of the formulation and process parameters of nanosuspensions and using a quality by design (QbD) approach. Particularly, the antisolvent method, which requires no solvent removal and no heating, is newly applied to prepare resveratrol nanosuspension. To ensure the quality of the resveratrol nanosuspensions, a quality target product profile (QTPP) was defined. The particle size (z-average, d90), zeta potential, and drug content parameters affecting the QTPP were selected as critical quality attributes (CQAs). The optimum composition obtained using a 3-factor, 3-level Box-Behnken design was as follows: polyvinylpyrrolidone vinyl acetate (10 mg/mL), polyvinylpyrrolidone K12 (5 mg/mL), sodium lauryl sulfate (1 mg/mL), and diethylene glycol monoethyl ether (DEGEE, 5% v/v) at a resveratrol concentration of 5 mg/mL. The initial particle size (z-average) was 46.3 nm and the zeta potential was -38.02 mV. The robustness of the antisolvent process using the optimized composition conditions was ensured by a full factorial design. The dissolution rate of the optimized resveratrol nanosuspension was significantly greater than that of the resveratrol raw material. An in vivo pharmacokinetic study in rats showed that the area under the plasma concentration versus time curve (AUC0-12h) and the maximum plasma concentration (Cmax) respectively, than those of the resveratrol raw material. Therefore, the prepara values of the resveratrol nanosuspension were approximately 1.6- and 5.7-fold higher,tion of a resveratrol nanosuspension using the QbD approach may be an effective strategy for the development of a new dosage form of resveratrol, with enhanced oral bioavailability.