Preparation, characterisation, and pharmacodynamic study of myricetin pH-sensitive liposomes.

AIMS: Myricetin (MYR) was incorporated into pH-sensitive liposomes in order to improve its bioavailability and anti-hyperuricemic activity. METHODS: The MYR pH-sensitive liposomes (MYR liposomes) were prepared using thin film dispersion method, and assessed by particle size (PS), polydispersed index (PDI), zeta potential (ZP), encapsulation efficiency, drug loading, and in vitro release rate. Pharmacokinetics and anti-hyperuricemic activities were also evaluated. RESULTS: The PS, PDI, ZP, encapsulation efficiency, and drug loading of MYR liposomes were 184.34 ± 1.05 nm, 0.215 ± 0.005, -38.46 ± 0.30 mV, 83.42 ± 1.07%w/w, and 6.20 ± 0.31%w/w, respectively. The release rate of MYR liposomes was higher than free MYR, wherein the cumulative value responded to pH. Besides, the Cmax of MYR liposomes was 4.92 ± 0.20 µg/mL. The level of uric acid in the M-L-H group (200 mg/kg) was reduced by 54.74%w/v in comparison with the model group. CONCLUSION: MYR liposomes exhibited pH sensitivity and could potentially enhance the oral bioavailability and anti-hyperuricemic efficacy of MYR.

Isolation, Purification of Phenolic Glycoside 1 from Moringa oleifera Seeds and Formulation of Its Liposome Delivery System.

In this study, N, N '-bis {4- [(α-L- rhamnosyloxy) benzyl]} thiourea (PG-1), a phenolic glycoside compound was purified from Moringa seed. The PG-1 has attracted extensive attention due to its anti-cancer, antioxidant, anti-inflammatory and hypoglycemic properties. However, some of its physicochemical properties such as oral bioavailability has not been studied. Herein, a highly purified PG-1 was extracted and incorporated in multiple layered liposomes (PG-1-L) to avoid its burst release and enhance oral bioavailability. After appropriate characterization, it was discovered that the obtained PG-1-L was stable, homogeneous and well dispersed with the average particle size being 89.26 ± 0.23 nm. Importantly, the in vitro release and in vivo oral bioavailability of PG-1-L were significantly improved compared with PG-1. In addition, MTT results showed that compared with the free PG-1, PG-1-L displayed obvious inhibitory effect on the HepG2 cells, while the inhibitory effect on healthy non-malignant 3T6 and LO-2 cells was not significant, indicating that PG-1-L had high safety. In conclusion, PG-1-L can be used as a promising delivery system and an ideal novel approach to improve the oral bioavailability and anticancer activity of PG-1.

Enhanced oral bioavailability of capsaicin-loaded microencapsulation complex via electrospray technology: Preparation, in vitro and in vivo evaluation.

The purpose of this work was to fabricate the microencapsulation of capsaicin using electrospray technology and polyvinylpyrrolidone (PVP) K30 as a carrier. The morphological characteristics of capsaicin-PVP electrosprayed microencapsulation complex under different processing parameters were observed by scanning electron microscope (SEM), while the best process was determined, wherein it comprised of 10 KV (voltage), 0.8 ml·h-1 (solution flow rate), 0.9 mm (the inner diameter of the needle), and 10 cm (receiving distance). The X-ray diffraction results of the electrosprayed complex showed that capsaicin was present in the carrier in an amorphous form. The drug release properties of capsaicin powder and electrosprayed complex in different media were investigated. The results showed that in vitro release rates of the capsaicin complex in different media were much higher than that of capsaicin powder, with correspondingly improved bioavailability, defined by intravenous and oral dosing in rats in vivo, for the electrosprayed complex compared to that of capsacin powder. The dose absorbed of the electrosprayed complex was 2.2-fold that of the capsaicin powder. In short, electrospray technology can be used to prepare capsaicin-loaded electrosprayed microencapsulation complex. This technique can improve the solubility and bioavailability of capsaicin, and provide a new idea for the solubilization of other insoluble drugs.

Enhancing Anticancer Efficacy of Formononetin Microspheres via Microfluidic Fabrication.

Formononetin is a flavonoid compound with anti-tumor and anti-inflammatory properties. However, its low solubility limits its clinical use. We employed microfluidic technology to prepare formononetin-loaded PLGA-PEGDA microspheres (Degradable polymer PLGA, Crosslinking agent PEGDA), which can encapsulate and release drugs in a controlled manner. We optimized and characterized the microspheres, and evaluated their antitumor effects. The microspheres had uniform size, high drug loading efficiency, high encapsulation efficiency, and stable release for 35 days. They also inhibited the proliferation, migration, and apoptosis. The antitumor mechanism involved the induction of reactive oxygen species and modulation of Bcl-2 family proteins. These findings suggested that formononetin-loaded PLGA-PEGDA microspheres, created using microfluidic technology, could be a novel drug delivery system that can overcome the limitations of formononetin and enhance its antitumor activity.

Microfluidic Generation of Near-Infrared Photothermal Vitexin/ICG Liposome with Amplified Photodynamic Therapy.

Glioma, in which a malignant tumor cell occurs in neural mesenchymal cells, has a rapid progression and poor prognosis, which is still far from desirable in clinical treatments. We developed a lab-on-a-chip (LOC) device for the rapid and efficient preparation of vitexin/indocyanine green (ICG) liposomes. Vitexin could be released from liposome to kill cancer cell, which can potentially improve the glioma therapeutic effect and reduce the treatment time through synergistic photodynamic/photothermal therapies (PDT/PTT). The vitexin/ICG liposome was fabricated via LOC and its physicochemical property and release in vitro were evaluated. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and live/dead staining were used to examine the enhanced antitumor effect of vitexin/ICG liposome in cooperation with PDT/PTT, while the related mechanism was explored by flow cytometry and western blot. The results were as follows: (1) The prepared vitexin/ICG liposome was smaller in size, homogenous in particle size distribution with significant low polydispersity index (PDI), and enhanced cumulative release in vitro. (2) We found that the formulated liposome presented strong cancer cell inhibition and suppression of its migration in a dose-dependent manner. (3) Further mechanistic studies showed that liposome combined with near-infrared irradiation could significantly upregulate levels of B cell lymphoma 2-associated X (Bax) protein and decrease B cell lymphoma 2 (Bcl-2) at protein levels. The vitexin/ICG liposomes prepared based on a simple LOC platform can effectively enhance the solubility of insoluble drugs, and the combined effect of PTT/PDT can effectively increase their antitumor effect, which provides a simple and valid method for the clinical translation of liposomes.

Preparation, in vitro and in vivo evaluation of pinocembrin-loaded TPGS modified liposomes with enhanced bioavailability and antihyperglycemic activity.

PURPOSE: To prepare polyethylene glycol succinate-vitamin E modified pinocembrin (PCB)-loaded liposomes (PCBT-liposomes) and evaluate PCBT-liposomal pharmacokinetics and antihyperglycemic activity. SIGNIFICANCE: The novel PCBT-liposomes demonstrated a promising application prospect as a nano drug carrier for future research. METHODS: Thin film dispersion was used to prepare PCBT-liposomes. We measured a series of characterization, followed by in vitro cumulative release, in vivo pharmacokinetic study, and antihyperglycemic activity evaluation. RESULTS: PCBT-liposomes displayed spherical and bilayered nanoparticles with mean particle size (roughly 92 nm), negative zeta potential (about -26.650 mV), high drug encapsulation efficiency (87.32 ± 1.34%) and good storage (at 4 or 25 °C) stability during 48 h after hydration. The cumulative release rate of PCBT-liposomes was markedly higher than free PCB in four different pH media. In vivo investigation showed that PCBT-liposomes could obviously improve oral bioavailability of PCB by 1.96 times, whereas the Cmax, MRT0-t, and T1/2 of PCBT-liposomes were roughly 1.700 ± 0.139 µg·mL-1, 12.695 ± 1.647 h, and 14.244 h, respectively. In terms of biochemical analysis, aspartate amino-transferase (AST), alanine amino-transferase (ALT), interleukin-1 (IL-1), and tumor necrosis factor-α (TNF-α) concentrations in serum of diabetic mice were respectively decreased 28.28%, 17.23%, 17.77%, and 8.08% after PCBT-liposomal treatment. CONCLUSION: These results show PCBT-liposomal preparation as an excellent nano-carrier which has the potential to improve water solubility, bioavailability, and antihyperglycemic activity of PCB, amid broadening the application of PCB in the clinical settings.

Pinocembrin polymeric micellar drug delivery system: preparation, characterisation and anti-hyperuricemic activity evaluation.

Aim: Hydrophobic pinocembrin (PCB) was incorporated into a new nano-drug delivery system to enhance solubility, bioavailability and anti-hyperuricemic activity of the drug.Methods: We fabricated PCB loaded polymeric micelles (PCB-FPM) by thin film dispersion method and appropriately determined their physical characteristics. The oral relative bioavailability and anti-hyperuricemic activity of PCB-FPM and free PCB were observed.Results: The optimum particle size of the micelles was 19.90 ± 0.93 nm. PCB-FPM exhibited great stability within 18 days, coupled with lower cytotoxicity and higher biocompatibility. Moreover, the percent cumulative release of PCB-FPM was much higher than free PCB in the dissolution media. The oral bioavailability of PCB-FPM was increased by 2.61 times compared with free PCB. Uric acid (UA) level of rats was reduced in PCB-FPM group (200 mg/kg) by 78.82% comparable to the model control.Conclusion: PCB-FPM may become an ideal strategy to increase oral in-vivo availability and anti-hyperuricemic activity of PCB.

Improved intestinal absorption and oral bioavailability of astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles: preparation, in vitro evaluation, and pharmacokinetics in rats.

BACKGROUND: Astaxanthin (ASTA) is a kind of food-derived active ingredient (FDAI) with antioxidant and antidiabetic functions. It is nontoxic but its poor solubility and low bioavailability hinder its application in the food industry. In this study, a novel carrier, polyethylene glycol-grafted chitosan (PEG-g-CS) was applied to enhance the bioavailability of astaxanthin. It encapsulated astaxanthin completely by solvent evaporation to manufacture astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles (ASTA-PEG-g-CS) nanoparticles to improve absorption. RESULTS: The ASTA-PEG-g-CS nanoparticles were spherical, with a particle size below 200 nm and a ζ potential of about -26 mV. Polyethylene glycol-grafted chitosan can encapsulate astaxanthin well, and the encapsulated astaxanthin was released rapidly - in 15 min in an in vitro release study. In a rat single-pass intestinal perfusion study, a low concentration of ASTA-PEG-g-CS nanoparticle (0.2 µg mL-1 ) was better absorbed in the intestine. In particular, the jejunum could absorb most astaxanthin without a change in the concentration. An in vivo release study also demonstrated that ASTA-PEG-g-CS nanoparticles enhanced oral bioavailability significantly. CONCLUSION: This novel carrier, PEG-g-CS, provided a simple way to encapsulate food, which improved the bioavailability of hydrophobic ingredients. © 2021 Society of Chemical Industry.

Hyperoside-loaded TPGs/mPEG-PDLLA self-assembled polymeric micelles: preparation, characterization and in vitro/in vivo evaluation.

Hyperoside (Hyp) self-assembled polymeric micelles (Hyp-PMs) were purposely developed to enhance aqueous solubility, in vivo availability and anti-oxidative effect of Hyp. In preparing Hyp-PMs, we employed the thin film dispersion method with the micelles consisting of TPGs and mPEG2000-PDLLA3000. The particle size, polydispersity index and zeta potential of Hyp-PMs were 67.42 ± 1.44 nm, 0.229 ± 0.015 and -18.67 ± 0.576 mV, respectively, coupled with high encapsulation efficiency （EE）of 90.63 ± 1.45% and drug loading (DL) of 6.97 ± 1.56%. Furthermore, the value of critical micelle concentration (CMC) was quite low, which indicated good stability and improved self-assembly ability of Hyp-PMs. Also, trend of in vitro Hyp release from Hyp-PMs demonstrated enhanced solubility of Hyp. Similarly, in comparison with free Hyp, oral bioavailability of Hyp-PMs was improved (about 8 folds) whilst half-life of Hyp-PMs was extended (about 3 folds). In vitro anti-oxidative effect showed obvious strong scavenging DPPH capability of Hyp-PMs, which may be attributed to its smaller size and better solubility. Altogether, Hyp-PMs may serve as a possible strategy to potentially enhance aqueous solubility, bioavailability and anti-oxidative effect of Hyp, which may play a key role in Hyp application in the pharmaceutical industries.

Preparation of Pinocembrin-Loaded F127/MPEG-PDLLA Polymer Micelles and Anti-Osteoporotic Activity.

Pinocembrin (PCB) is 5,7-dihydroxyl flavanone and has multiple pharmacological activities, namely, anti-inflammation, anti-osteoporotic, and so on. However, low water solubility and bioavailability have hindered its application. Herein, we aimed to increase its bioavailability through preparation of F127/MPEG-PDLLA polymer micelles (PCB-M). We characterized the micelles through appropriate attributes such as analysis of particle size (PS), polydispersity (PDI), transmission electron microscopic (TEM) image, stability test, and evaluation of in vitro release of drug. After physical characterization, the respective PS, PDI, and entrapment efficiency (EE) of PCB-M were estimated to be 27.63 ± 0.17 nm, 0.055 ± 0.02, and 90.53 ± 0.01%. Fluorescence probe method was employed to measure critical micelle concentration (CMC) of PCB-M, we observed CMC was low, thereby suggesting that PCB-M had good stability. In vitro release analysis indicated that the rate of cumulative PCB release from PCB-M was greater than 90% in each medium compared with free PCB, which was less than 40%, thus pointing to a significantly improved solubility of PCB. In vivo pharmacokinetic results showed that oral biological availability of PCB-M increased 5.3 folds comparable to free PCB. The effects of PCB on osteoblasts and ALP activities were investigated; subsequently, zebrafish osteoporotic model was established with prednisolone to study the anti-osteoporotic effects of PCB and PCB-M. The results showed that PCB improved osteoporosis with PCB-M being more effective than free PCB. Finally, PCB-M can be used as a promising method to improve the solubility of PCB, while the bioavailability and anti-osteoporotic effect of PCB could be improved, thus laying a foundation for clinical use in the future.

Improved oral bioavailability, cellular uptake, and cytotoxic activity of zingerone via nano-micelles drug delivery system.

Herein, a nano-micelle drug delivery system was developed to orally improved zingerone's bioavailability and its antitumor effect. Indeed, zingerone-loaded d-α-tocopheryl polyethylene glycol succinate micelles (ZTMs) were effectively prepared, characterised and assessed. The ZTMs had diameter, polydispersity index, and zeta potential of 50.62 ± 0.25 nm, 0.168 ± 0.006, and -28.07 ± 0.33 mV, respectively, coupled with a high entrapment efficiency (m/m, %) were 94.71 ± 2.02. The release rate of ZTMs in three media was significantly greater than that of free zingerone. Intriguingly, results obtained from pharmacokinetic studies showed that the oral bioavailability of the ZTMs was enhanced by 5.10 times in comparison with the free zingerone. Further, the half inhibitory concentration (IC50) of ZTMs and free zingerone was 7.56 µg/ml and 14.30 µg/ml, respectively, on HepG2 cells. Hence, ZTMs may be used as a potential approach to enrich the solubility, bioavailability, and concomitant anti-proliferative effect of zingerone in vitro.

Enhanced oral bioavailability of self-assembling curcumin-vitamin E prodrug-nanoparticles by co-nanoprecipitation with vitamin E TPGS.

Curcumin (CUR), a nontoxic natural compound with potent antitumor activity, was limited in clinical application due to its insolubility and exceedingly low bioavailability. In this study, a novel prodrug-nanoparticle (CSSV/TPGS-NPs) self-assembled by co-nanoprecipitation of CUR-s-s-vitamin E conjugate and d-alpha-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) was prepared in attempt to solve aforementioned obstacles. CSSV/TPGS-NPs showed smaller sizes and better stability compared with that of CUR-s-s-vitamin E conjugate prodrug-nanoparticles (CSSV-NPs). Significantly, the absorption constant and effective permeability of CSSV/TPGS-NPs in different intestinal tracts increased 1.31-2.78 times and 1.81-6.95 times than that of CUR suspension, respectively. Pharmacokinetic study in Sprague-Dawley (SD) rats demonstrated that orally administered CSSV/TPGS-NPs displayed a prolonged plasma circulation with 8.06-fold increase in relative bioavailability compared to that of the CUR suspension. Altogether, conjugation of hydrophobic native CUR with vitamin E to form CSSV/TPGS-NPs is a promising technology for sustained and controlled drug delivery of CUR with improved oral bioavailability in vivo.

Preparation and in vitro/in vivo evaluation of 6-Gingerol TPGS/PEG-PCL polymeric micelles.

6-Gingerol, an active herbal ingredient of ginger has various bioactivities such as anti-neurodegenerative disease, anti-inflammatory and so on. The aim of the present study was to enhance the oral bioavailability and brain distribution of 6-Gingerol via polymeric micelles. A polymeric micelles drug delivery system of 6-Gingerol consisting of D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) and Poly (ethylene glycol)-poly (ε-caprolactone) (PEG-PCL) was prepared via solvent injection method. The developed 6-Gingerol-loaded TPGS/PEG-PCL micelles (6-GTPMs) were characterized based on particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE), drug loading (DL) and in vitro release profile. The pharmacokinetics and tissue distribution studies were also evaluated. The nanoformulation produced a particle size of 73.24 ± 2.84 nm with acceptable PDI (0.129 ± 0.03), zeta potential (-2.74 ± 0.92 mV), DL (4.64%) and EE (79.68%). The in vitro release profile showed that the 6-GTPMs enhanced the solubility of 6-Gingerol, while the pharmaceutical analysis in rats indicated that 6-GTPMs significantly improved the oral bioavailability of 6-Gingerol (about 3 folds) in circulation. The 6-GTPMs exhibited remarkable brain targetability in the tissue distribution analysis. Collectively, a 6-Gingerol polymeric micelle with enhanced oral bioavailability coupled with excellent brain distribution was successfully developed.

Preparation and evaluation of isoliquiritigenin-loaded F127/P123 polymeric micelles.

Isoliquiritigenin (ISL) possesses a variety of pharmacological activities amid poor solubility in water which has restricted its clinical application. In this study, isoliquiritigenin-loaded F127/P123 polymeric micelles (ISL-FPM) were successfully prepared and evaluated in vitro and in vivo. The particle size, polydispersity index, and zeta potential of the selected formulation were 20.12 ± 0.72 nm, 0.183 ± 0.046, and -38.31 ± 0.33 mV, respectively, coupled with high encapsulation efficiency of 93.76 ± 0.31%. Drug-loading test showed the solubility of ISL after formulating into micelles was 232 times higher than its intrinsic solubility. Moreover, critical micelle concentration (CMC) was tested with fluorescence probe method and turned out to be quite low, which implied high stability of ISL-FPM. Release profile in HCl (pH 1.2), double distilled water, and PBS (pH 7.4) of ISL-FPM reached over 80%, while free ISL was around 40%. Pharmacokinetic research revealed that formulated ISL-FPM significantly increased bioavailability by nearly 2.23-fold compared to free ISL. According to the results of in vitro antioxidant activity, scavenging DPPH activity of ISL was significantly strengthened when it was loaded into polymeric micelles. Altogether, ISL-FPM can act as a promising approach to improve solubility as well as enhance bioavailability and antioxidant activity of ISL.

Anti-hyperuricemic property of 6-shogaol via self-micro emulsifying drug delivery system in model rats: formulation design, in vitro and in vivo evaluation.

The prevalence of hyperuricemia is relatively high worldwide, and a great number of patients are suffering from its complications. 6-shogaol, an alkylphenol compound purified from the root of ginger (Zingiber officinale Roscoe), has been proved to possess diverse pharmacological activities. However, its poor aqueous solubility usually leads to low bioavailability, and further clinical applications will be greatly discounted. The current study aimed to formulate a 6-shogaol-loaded-Self Microemulsifying Drug Delivery System (SMEDDS) to amend low aqueous solubility and bioavailability orally, as well as, potentiate the hyperuricemic activity of the 6-shogaol. SMEDDS was developed with central composite design established on a two system components viz., 18.62% W/W ethyl oleate (oil phase) and ratio of tween 80 (surfactant) to PEG 400 (co-surfactant) (1.73:1, W/W). Based on quadratic model, the navigation of the design space could generate spherically-shaped and homogenous droplets with respective mean particle diameter, polydispersity and of 20.00 ± 0.26 nm and 0.18 ± 0.02. The 6-shogaol-SMEDDS showed significant elevation of cumulative release compared with the free 6-shogaol and more importantly a 571.18% increment in the relative oral bioavailability of the drug. The predominant accumulation of 6-shogaol-SMEDDS in the liver suggested hepatic-targeting potentiality of the drug. Oral administration of 6-shogaol-SMEDDS in hyperuricemic rats also significantly decreased uric acid level and xanthine oxidase activity. Histological studies confirmed formulation groups indeed could provide better protection of kidney than free drug groups. Collectively, these findings indicated that the SMEDDS hold much promise in enhancing the oral delivery and therapeutic efficacy of 6-shogaol.

Preparation, optimization, and pharmacokinetic study of nanoliposomes loaded with triacylglycerol-bound punicic acid for increased antihepatotoxic activity.

Punicic acid of pomegranate oil (PAP) has gained heightened interest due to several health benefits, such as anticarcinogenic, antidiabetic, and antiatherosclerotic properties. However, these bioactivities have been hampered by chemical instability, poor water solubility, rapid metabolism, and low bioavailability of PAP. Therefore, this study was aimed at optimizing the liposomal formulation of Triacylglycerol-bound punicic acid with its regioisomers (TPAR) for improved oral bioavailability and increased hepatoprotection through antioxidation and anti-inflammation. Herein, the optimized TPAR nanoliposome (TPAR-NL) was developed using thin-film dispersion method and subsequently characterized with appropriate indices. The optimized TPAR-NL produced fairly stable spherical nanoparticles (˂ 200 nm) with encapsulation efficiency (%EE) of 85.77%, as well as enhanced in vitro release and improved oral bioavailability. The TPAR-NL exhibited profound antihepatotoxic effect in mice pretreated with carbon tetrachloride (CCl4 ) via reduction of serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels compared with free TPAR. The TPAR-loaded liposome also significantly reduced oxidative stress by increasing superoxide dismutase and glutathione levels while lowering malonaldehyde concentration compared with the free TPAR. The TPAR-LNF further exhibited remarkable anti-inflammatory activity compared with the free drug via inhibition of interleukin-6 and tumor necrosis factor-alpha generation. Thus, the developed nanoliposomes potentiated the antihepatotoxic activity of TPAR via antioxidation and anti-inflammation.

Preparation and Characterization of Syringic Acid-Loaded TPGS Liposome with Enhanced Oral Bioavailability and In Vivo Antioxidant Efficiency.

In this study, syringic acid-loaded TPGS liposome (SA-TPGS-Ls) was successfully prepared to improve oral bioavailability of syringic acid (SA). SA is a natural and notable antioxidant activity compound with its limited bioavailability ascribable to its poor aqueous solubility and fast elimination. Recently, TPGS has become a perfect molecular biomaterial in developing several carrier systems with sustained, controlled, and targeted the drug delivery. SA-TPGS-Ls was prepared via thin-film dispersion method and characterized in terms of particle size, stability, morphology, and encapsulation efficiency (EE). The results showed that SA-TPGS-Ls had regular spherical-shaped nanoparticles with EE of 96.48 ± 0.76%. The pharmacokinetic studies demonstrated a delayed MRT and prolonged t1/2, while relative oral bioavailability increased by 2.8 times. Tissue distribution showed that SA-TPGS-Ls maintained liver drug concentration while delayed elimination was also observed in the kidney. In CCl4-induced hepatotoxicity study, the activities of hepatic T-AOC, GSH-Px, CAT, GSH, and SOD were greatly elevated, while serum biological markers ALT, AST, and AKP were reduced after treatment of mice with SA-TPGS-Ls. Histopathological studies confirmed that SA-TPGS-Ls could remarkably improve the status of hepatic tissues. Collectively, SA-TPGS-Ls significantly improved the drug encapsulation efficiency, stability coupled with bioavailability of SA, hence increasing in vivo antioxidant activity of the drug.

Enhancement of Oral Bioavailability and Anti-hyperuricemic Activity of Isoliquiritigenin via Self-Microemulsifying Drug Delivery System.

The aim of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) for enhancement of the oral bioavailability of isoliquiritigenin (ISL) as well as evaluate its in vivo anti-hyperuricemic effect in rats. The ISL-loaded self-microemulsifying drug delivery system (ISL-SMEDDS) was comprised of ethyl oleate (EO, oil phase), Tween 80 (surfactant), and PEG 400 (co-surfactant). The ISL-SMEDDS exhibited an acceptable narrow size distribution (44.78 ± 0.35 nm), negative zeta potential (- 10.67 ± 0.86 mV), and high encapsulation efficiency (98.17 ± 0.24%). The in vitro release study indicated that the release rates of the formulation were obviously higher in different release media (HCl, pH 1.2; PBS, pH 6.8; double-distilled water, pH 7.0) compared with the ISL solution. The oral bioavailability of the ISL-SMEDDS was enhanced by 4.71 times in comparison with the free ISL solution. More importantly, ISL-SMEDDS significantly reduced uric acid level by inhibiting xanthine oxidase (XOD) activity in the model rats. Collectively, the prepared ISL-SMEDDS proved to be potential carriers for enhancing the solubility and oral bioavailability of ISL, as well as ameliorating its anti-hyperuricemic effect.

Self-Micro-Emulsifying Controlled Release of Eugenol Pellets: Preparation, In vitro/In vivo Investigation in Beagle Dogs.

This report aimed to formulate self-micro-emulsifying (SMEDDS) controlled-release pellets delivery system to improve aqueous solubility and in vivo availability of eugenol, a main constituent of clove oil with multiple pharmacological activities. The optimal formulation of eugenol-SMEDDS was eugenol: ethyl oleate: cremophor EL: 1, 2-propylene glycol at the ratio of 5:5:12:8. The SMEDDS were observed under transmission electron microscopy (TEM), and the size distribution was measured with dynamic laser light scatting (DLS). The particle size, index of dispersity (PDI), and zeta potential (Z-potential) were 68.8 ± 0.1 nm, 0.285 ± 0.031, and - 11.62 ± 0.63 mV, respectively. Eugenol-SMEDDS exhibited substantial increased in vitro dissolution compared with the free eugenol. The eugenol-SMEDDS sustained-release pellets (eugenol-SMEDDS-SR pellets) comprising of eugenol-SMEDDS, hydroxypropyl methylcellulose (HPMC), microcrystalline cellulose (MCC), and ethyl cellulose (EC) coats were obtained via extrusion spheronization technique. Consequently, the obtained pellets observed under scanning electron microscopy (SEM) showed spherical shape with smooth surface, desirable drug loading capacity (7.18 ± 0.17%), greater stability, and controlled release. Meanwhile, the oral test showed that bioavailability of eugenol in pellets was highly improved 23.6-fold to the free eugenol. Overall, these results suggested that the improvement of the oral bioavailability of eugenol-SMEDDS-SR could be due to the successful incorporation of the drug into SMEDDS.

Enhanced Solubility and Bioavailability of Naringenin via Liposomal Nanoformulation: Preparation and In Vitro and In Vivo Evaluations.

This study was aimed at preparing orally administered naringenin-loaded liposome for pharmacokinetic and tissue distribution studies in animal models. The liposomal system, consisting of phospholipid, cholesterol, sodium cholate, and isopropyl myristate, was prepared using the thin-film hydration method. Physicochemical characterization of naringenin-loaded liposome such as particle size, zeta potential, and encapsulation efficiency produced 70.53 ± 1.71 nm, -37.4 ± 7.3 mV, and 72.2 ± 0.8%, respectively. The in vitro release profile of naringenin from the formulation in three different media (HCl solution, pH 1.2; acetate buffer solution, pH 4.5; phosphate buffer solution, pH 6.8) was significantly higher than the free drug. The in vivo studies also revealed an increase in AUC of the naringenin-loaded liposome from 16648.48 to 223754.0 ng·mL-1 h as compared with the free naringenin. Thus, approximately 13.44-fold increase in relative bioavailability was observed in mice after oral administration. The tissue distribution further showed that the formulation was very predominant in the liver. These findings therefore indicated that the liposomal formulation significantly improved the solubility and oral bioavailability of naringenin, thus leading to wider clinical applications.