Development and Characterization of Celecoxib Solid Self-nanoemulsifying Drug Delivery Systems (S-SNEDDS) Prepared Using Novel Cellulose-Based Microparticles as Adsorptive Carriers

Development of a Carvedilol-Loaded Solid Self-Nanoemulsifying System with Increased Solubility and Bioavailability Using Mesoporous Silica Nanoparticles

This study developed a solid self-nanoemulsifying drug delivery system (S-SNEDDS) to improve the oral bioavailability of poorly soluble carvedilol using mesoporous silica nanoparticles (MSNs). The liquid self-nanoemulsifying drug delivery system (L-SNEDDS) consisted of carvedilol, Peceol, Tween 80, and Labrasol in a weight ratio of 10:25:50:25. The liquid SNEDDS was suspended in MSN at various ratios and spray-dried to produce S-SNEDDS. The emulsion size, PDI, solubility, and dissolution of various ratios of MSN were evaluated to make the optimal S-SNEDDS. The optimal S-SNEDDS, manufactured using a ratio of MSN to L-SNEDDS 1000 at 500, formed a nanoemulsion and achieved efficient supersaturation compared to carvedilol alone, which significantly improved drug solubility (approximately 400 times), dissolution (approximately 5.7 times at 60 min), area under the curve (AUC) (21.7 times), and maximum plasma concentration (Cmax) (15.7 times). In addition, the physicochemical properties of the optimal S-SNEDDS were evaluated by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), particle size, and scanning electron microscopy (SEM) images. S-SNEDDS showed a smaller particle size than MSN alone, and the crystalline drug was transformed into an amorphous substance, resulting in encapsulation in MSN. These results suggest that MSN can be a novel biocompatible carrier contributing to a safer and more effective delivery system.

Optimization of Glibenclamide Loaded Thermoresponsive SNEDDS Using Design of Experiment Approach: Paving the Way to Enhance Pharmaceutical Applicability

Thermoresponsive self-nanoemulsifying drug delivery systems (T-SNEDDS) offer a promising solution to the limitations of conventional SNEDDS formulations. Liquid SNEDDS are expected to enhance drug solubility; however, they are susceptible to leakage during storage. Even though solid SNEDDS offers a solution to this storage instability, they introduce new challenges, namely increased total dosage and potential for drug trapping within the formulation. The invented T-SNEDDS was used to overcome these limitations and improve the dissolution of glibenclamide (GBC). Solubility and transmittance studies were performed to select a suitable oil and surfactant. Design of Experiments (DoE) software was used to study the impact of propylene glycol and Poloxamer 188 concentrations on measured responses (liquefying temperature, liquefying time, and GBC solubility). The optimized formulation was subjected to an in vitro dissolution study. The optimized T-SNEDDS consisted of Kolliphor EL and Imwitor 308 as surfactants and oil. The optimized propylene glycol and Poloxamer 188 concentrations were 13.7 and 7.9% w/w, respectively. It exhibited a liquefying temperature of 35.0 °C, a liquefying time of 119 s, and a GBC solubility of 5.51 mg/g. In vitro dissolution study showed that optimized T-SNEDDS exhibited 98.8% dissolution efficiency compared with 2.5% for raw drugs. This study presents a promising approach to enhance pharmaceutical applicability by resolving the limitations of traditional SNEDDS.

Comparison of two self-nanoemulsifying drug delivery systems using different solidification techniques for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

In this study, we aimed to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) and a solid self-nanoemulsifying granule system (S-SNEGS) to enhance the solubility and oral bioavailability of celecoxib. This process involved the preparation of a liquid SNEDDS (L-SNEDDS) and its subsequent solidification into a S-SNEDDS and a S-SNEGS. The L-SNEDDS consisted of celecoxib (drug), Captex® 355 (Captex; oil), Tween® 80 (Tween 80; surfactant) and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS; cosurfactant) in a weight ratio of 3.5:25:60:15 to produce the smallest nanoemulsion droplet size. The S-SNEDDS and S-SNEGS were prepared with L-SNEDDS/Ca-silicate/Avicel PH 101 in a weight ratio of 103.5:50:0 using a spray dryer and 103.5:50:100 using a fluid bed granulator, respectively. We compared the two novel developed systems and celecoxib powder based on their solubility, dissolution rate, physicochemical properties, flow properties and oral bioavailability in rats. S-SNEGS showed a significant improvement in solubility and dissolution rate compared to S-SNEDDS and celecoxib powder. Both systems had been converted from crystalline drug to amorphous form. Furthermore, S-SNEGS exhibited a significantly reduced angle of repose, compressibility index and Hausner ratio than S-SNEDDS, suggesting that S-SNEGS was significantly superior in flow properties. Compared to S-SNEDDS and celecoxib powder, S-SNEGS increased the oral bioavailability (AUC value) in rats by 1.3 and 4.5-fold, respectively. Therefore, S-SNEGS wolud be recommended as a solid self-nanoemulsifying system suitable for poorly water-soluble celecoxib.

Modification of microenvironmental pH of nanoparticles for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

This study aimed to develop a novel pH-modified nanoparticle with improved solubility and oral bioavailability of poorly water-soluble celecoxib by modifying the microenvironmental pH. After assessing the impact of hydrophilic polymers, surfactants and alkaline pH modifiers on the drug solubility, copovidone, sodium lauryl sulfate (SLS) and meglumine were chosen. The optimal formulation of solvent-evaporated, surface-attached and pH-modified nanoparticles composed of celecoxib/copovidone/SLS/meglumine at weight ratios of 1:1:0.2:0, 1:0.375:1.125:0 and 1:1:1:0.2:0.02, respectively, were manufactured using spray drying technique. Their physicochemical characteristics, solubility, dissolution and pharmacokinetics in rats were evaluated compared to the celecoxib powder. The solvent-evaporated and pH-modified nanoparticles converted a crystalline to an amorphous drug, resulting in a spherical shape with a reduced particle size compared to celecoxib powder. However, the surface-attached nanoparticles with insignificant particle size exhibited the unchangeable crystalline drug. All of them gave significantly higher solubility, dissolution, and oral bioavailability than celecoxib powder. Among them, the pH-modified nanoparticles demonstrated the most significant improvement in solubility (approximately 1600-fold) and oral bioavailability (approximately 4-fold) compared to the drug powder owing to the alkaline microenvironment formation effect of meglumine and the conversion to the amorphous drug. Thus, the pH-modified nanoparticle system would be a promising strategy for improving the solubility and oral bioavailability of poorly water-soluble and weakly acidic celecoxib.

Impact of carrier hydrophilicity on solid self nano-emulsifying drug delivery system and self nano-emulsifying granule system

The purpose of this study was to investigate the impact of carrier hydrophilicity on solid self nano-emulsifying drug delivery system (SNEDDS) and self nano-emulsifying granule system (SEGS). The mesoporous calcium silicate (Ca-silicate) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were utilised as hydrophobic carrier and hydrophilic carrier, respectively. The liquid SNEDDS formulation, composed of Tween80/Kollipohr EL/corn oil (35/50/15%) with 31% (w/w) dexibuprofen, was spray-dried and fluid-bed granulated together with Avicel using Ca-silicate or HP- β-CD as a solid carrier, producing four different solid SNEDDS and SEGS formulations. Unlike the Ca-silicate-based systems, spherical shape and aggregated particles were shown in HP-β-CD-based solid SNEDDS and SEGS, respectively. Molecular interaction was detected between Ca-silicate and the drug; though, none was shown between HP-β-CD and the drug. Each system prepared with either carrier gave no significant differences in micromeritic properties, crystallinity, droplet morphology, size, dissolution and oral bioavailability in rats. However, the HP-β-CD-based system more significantly improved the drug solubility than did the Ca-silicate-based system. Therefore, both carriers hardly affected the properties of both solid SNEDDS and SEGS; though, there were differences in the aspect of appearance, molecular interaction and solubility.

Biology of cyclooxygenase-2: An application in depression therapeutics

Depressive Disorder is a common mood disorder or affective disorder that is dominated by depressed mood. It is characterized by a high incidence and recurrence. The onset of depression is related to genetic, biological and psychosocial factors. However, the pathogenesis is still unclear. In recent years, there has been an increasing amount of research on the inflammatory hypothesis of depression, in which cyclo-oxygen-ase 2 (COX-2), a pro-inflammatory cytokine, is closely associated with depression. A variety of chemical drugs and natural products have been found to exert therapeutic effects by modulating COX-2 levels. This paper summarizes the relationship between COX-2 and depression in terms of neuroinflammation, intestinal flora, neurotransmitters, HPA axis, mitochondrial dysfunction and hippocampal neuronal damage, which can provide a reference for further preventive control, clinical treatment and scientific research on depression.