Nisoldipine dissolution profile enhancement by supercritical carbon dioxide impregnation technique with fumed silica

β-Cyclodextrin metal-organic framework as a green carrier to improve the dissolution, bioavailability, and liver protective effect of luteolin

The incidence of acetaminophen-induced liver injury has increased, but effective prevention methods are limited. Although luteolin has hepatoprotective activity, its low solubility and bioavailability limit its applications. Cyclodextrin metal-organic frameworks (CD-MOFs) possess 3D-network structures and large inner cavities, which make them excellent carriers of poorly soluble drugs. In this study, we used CD-MOFs as carriers to improve the dissolution of luteolin and assessed their antioxidant activity, bioavailability, and hepatoprotective effects. Luteolin was loaded into β-CD-MOF, γ-CD-MOF, β-CD, and γ-CD, and characterized by powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TGA). Our results showed that luteolin-β-CD-MOF was the most stable. The main driving forces were hydrogen bonds and van der Waals forces, as determined by molecular simulation. The loading capacity of luteolin-β-CD-MOF was 14.67 wt%. Compared to raw luteolin, luteolin-β-CD-MOF exhibited a 4.50-fold increase in dissolution and increased antioxidant activity in vitro. Luteolin-β-CD-MOF increased the bioavailability of luteolin by approximately 4.04- and 11.07-fold in healthy rats and liver injured rats induced by acetaminophen in vivo, respectively. As determined by biochemical analysis, luteolin-β-CD-MOF exhibited a better hepatoprotective effect than raw luteolin in rats with acetaminophen-induced liver injury. This study provides a new approach for preventing acetaminophen-mediated liver damage.

Dissolution Improvement of Progesterone and Testosterone via Impregnation on Mesoporous Silica Using Supercritical Carbon Dioxide

Progesterone (PRG) and testosterone (TST) were impregnated on mesoporous silica (ExP) particles via supercritical carbon dioxide (scCO2) processing at various pressures (10–18 MPa), temperatures (308.2–328.2 K), and time (30–360 min). The impact of a co-solvent on the impregnation was also studied at the best determined pressure and temperature. The properties of the drug embedded in silica particles were analysed via gas chromatography (GC), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and nitrogen adsorption. An impregnation of 1 to 82 mg/g for PRG and 0.1 to 16 mg/g for TST was obtained depending on the processing parameters. There was a significant effect of pressure, time, and co-solvent on the impregnation efficiency. Generally, an increase in time and pressure plus the use of co-solvent led to an improvement in drug adsorption. Conversely, a rise in temperature resulted in lower impregnation of both TST and PRG on ExP. There was a substantial increase in the dissolution rate (> 90% drug release within the first 2 min) of both TST and PRG impregnated in silica particles when compared to the unprocessed drugs. This dissolution enhancement was attributed to the amorphisation of both drugs due to their adsorption on mesoporous silica.

Graphical Abstract

Application of commercially available mesoporous silica for drug dissolution enhancement in oral drug delivery

Due to the high number of poorly water-soluble active pharmaceutical ingredients, oral drug delivery development has become challenging. One of the strategies to enhance drug solubility and to achieve high oral bioavailability is to formulate such compounds into amorphous solid dispersions. In recent years, porous materials have been investigated as possible carriers into which a drug can be adsorbed, such as mesoporous silica, in particular. Unlike the ordered mesoporous network of silica, non-ordered silica already has a "generally regarded as safe" status, and is already used as an excipient in pharmaceutical and cosmetic products. Thus, it is reasonable to expect that products that contain solid dispersions with non-ordered carriers will reach the market sooner and more easily than those with ordered mesoporous carriers. The emphasis of this review is therefore on non-ordered commercially available mesoporous silica and the progress that has been made in development of the use of these materials for improved dissolution rates in oral drug delivery. First, a thorough categorisation of the drug loading methods is presented, followed by discussion on the most important characteristics of solid dispersions (i.e., physical state, stability, drug release). Finally, manufacturability and production of a final solid dosage form are considered.

Application of Fumed Silica as a Support during Oxidative Desulfurization

Here, a hydrophilic fumed silica (F-SiO₂) was used as a support, and we place phosphotungstic acid (HPW) onto the F-SiO₂ via a simple impregnation method normally used to prepare a HPW/F-SiO₂ catalyst, which is used in oxidative desulfurization processes. A number of characterization analyses were used, such as X-ray diffraction, Fourier transform infrared, and Transmission electron microscopy, to prove that the HPW catalyst was homogeneously distributed on the F-SiO₂. The structural parameters of the catalyst and the support were tested with Brunauer-Emmett-Teller, and it was confirmed that the catalyst is a mesoporous material. Energy-dispersive spectrometry was used to characterize the distribution of the active component distribution. Catalytic performance was investigated using the catalytic oxidative desulfurization process. During optimal conditions, the removal effect of dibenzothiophene (DBT) in simulated oil can reach 100%. After 13 cycles, catalytic activity is still high, and the DBT conversion can still attain 95.362%.

Polymeric behavior evaluation of PVP K30-poloxamer binary carrier for solid dispersed nisoldipine by experimental design

CONTEXT

High melting point polymeric carrier without plasticizer is unacceptable for solid dispersion (SD) by melting method. Combined polymer-plasticizer carrier significantly affects drug solubility and tableting property of SD.

OBJECTIVE

To evaluate and optimize the combined effect of a binary carrier consisting PVP K30 and poloxamer 188, on nisoldipine solubility and tensile strength of amorphous SD compact (SD_compact) by experimental design.

MATERIALS AND METHODS

SD of nisoldpine (SD_nisol) was prepared by melt mixing with different PVP K30 and poloxamer amount. A 3² factorial design was employed using nisoldipine solubility and tensile strength of SD_compact as response variables. Statistical optimization by design expert software, and SD_nisol characterization using ATR FTIR, DSC and microscopy were done.

RESULTS

PVP K30:poloxamer, at a ratio of 3.73:6.63, was selected as the optimized combination of binary polymeric carrier resulting nisoldipine solubility of 115 μg/mL and tensile strength of 1.19 N/m².

DISCUSSION

PVP K30 had significant positive effect on both responses. Increase in poloxamer concentration after a certain level decreased nisoldipine solubility and tensile strength of SD_compact.

CONCLUSION

An optimized PVP K30-poloxamer binary composition for SD carrier was developed. Tensile strength of SD_compact can be considered as a response for experimental design to optimize SD.