Nanocrystal Formulation to Enhance Oral Absorption of Silybin: Preparation, In Vitro Evaluations, and Pharmacokinetic Evaluations in Rats and Healthy Human Subjects.

Despite the various therapeutic benefits and high tolerance of orally administered silybin, poor water-solubility can be the main restrictive physicochemical feature, which results in low oral bioavailability in the absorption. A milk thistle nanocrystal formulation (HM40) was prepared using a modified wet-milling method. Comprehensive characterization was performed to determine the physical morphology, crystallinity, and physicochemical properties. The long-term stability was evaluated over 24 months. In vitro silybin release was assessed at pH 1.2 for 2 h, followed by pH 6.8 for 4 h. Finally, in vivo pharmacokinetic studies were conducted in rats and healthy human volunteers. HM40 exhibited a nanocrystal structure maintaining crystallinity and enhanced the solubility and dissolution of silybin compared to that of the raw material. The stability over 24 months revealed consistent surface morphology, particle size, silybin content, and solubility. In vitro release profiles indicated a significant increase in the silybin release from HM40. In vivo pharmacokinetic studies demonstrated that HM40 showed 2.61- and 1.51-fold higher oral bioavailability in rats and humans, respectively, than that of the reference capsule. HM40 formulation presents a stable and promising approach for the oral delivery of poorly water-soluble silybin, with the potential for use in pharmaceutical formulations containing milk thistle.

Bioanalysis of lanreotide in dog plasma using liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study of beagle dogs after single subcutaneous injection.

Lanreotide is similar to a naturally occurring hormone, somatostatin; thus, it may be used to treat acromegaly or metastatic gastroenteropancreatic neuroendocrine tumours. Here, a bioanalytical method coupling ultra-performance liquid chromatography with tandem mass spectrometry to quantify lanreotide and an internal standard (IS) was developed and validated in dog plasma. The plasma samples were extracted using typical protein precipitation processes. The analyte and internal standard were separated on Phenomenex Kinetex® C18 with 0.1% formic acid and acetonitrile in the mobile phase at a flow rate of 0.4 mL/min. The fragmentation of precursor ions to product ions was optimized at m/z 548.8 â†’ 170.0 for lanreotide [M + 2H]2+ and 472.2 â†’ 436.2 for IS [M + H]+. The peak retention times of lanreotide and IS were 1.09 min and 1.22 min, respectively. The calibration curve samples in dog plasma ranged from 0.3 to 1000 ng/mL and showed good linearity, with a correlation coefficient of r2=0.9996. The lower limit of quantitation was 0.3 ng/mL. The intra- and inter-day precision (relative standard deviation) values for each quality control level were < 9.7 % and < 9.3 %, respectively; intra- and inter-day accuracy were < 109.3% and < 110.4%, respectively. Lanreotide in dog plasma was stable in various conditions. The maximum plasma concentration of lanreotide in male beagle dogs after subcutaneous injection of Somatuline® (lanreotide) Autogel 120 mg was 88.1 ng/mL. The half-life (T1/2) of lanreotide in beagle dogs was long, approximately 198.6 h; the area under the plasma-concentration curve from 0 to 840 h (day 35) was 6,995 ng⋅h/mL. This novel quantification method using UPLC-MS/MS was successfully applied to the pharmacokinetic analysis of lanreotide in dog plasma. The results will assist future studies of drug formulation and repurposing.

Identification of engine oil-derived ash nanoparticles and ash formation process for a gasoline direct-injection engine.

Engine oil-derived ash particles emitted from internal combustion (IC) engines are unwanted by-products, after oil is involved in in-cylinder combustion process. Since they typically come out together with particulate emissions, no detail has been reported about their early-stage particles other than agglomerated particles loaded on aftertreatment catalysts and filters. To better understand ash formation process during the combustion process, differently formulated engine oils were dosed into a fuel system of a gasoline direct injection (GDI) engine that produces low soot mass emissions at normal operating conditions to increase the chances to find stand-alone ash particles separated from soot aggregates in the sub-20-nm size range. In addition to them, ash/soot aggregates in the larger size range were examined using scanning transmission electron microscopy (STEM)-X-ray electron dispersive spectroscopy (XEDS) to present elemental information at different sizes of particles from various oil formulations. The STEM-XEDS results showed that regardless of formulated oil type and particle size, Ca, P and C were always contained, while Zn was occasionally found on relatively large particles, suggesting that these elements get together from an early stage of particle formation. The S, Ca and P K-edge X-ray absorption near edge structure (XANES) analyses were performed for bulk soot containing raw ash. The linear combination approach & cross-checking among XANES results proposed that Ca5(OH)(PO4)2, Ca3(PO4)2 and Zn3(PO4)2 are potentially major chemical compounds in raw ash particles, when combined with the STEM-XEDS results. Despite many reports that CaSO4 is a major ash chemical when ash found in DPF/GFP systems was examined, it was observed to be rarely present in raw ashes using the S K-edge XANES analysis, suggesting ash transformation.

Estimation of an Appropriate Human Dose of Boesenbergia pandurata Extracts Based on Allometric Scaling Data of Panduratin A in Mice, Rats, and Dogs.

It can be difficult to identify health/functional foods that exert therapeutic benefits for alleviating gingivitis and periodontitis. Recently, extracts of Boesenbergia pandurata (Roxb.), which is a tropical plant, have shown promising inhibitory activity against lipopolysaccharide-induced periodontitis. As a result, a clinical trial is being planned to assess utility of B. pandurata (Roxb.) extracts for promoting oral health; this study was designed to determine an appropriate human dose of the extracts for the trial. Pharmacokinetic studies of panduratin A, which is an active substance in fingerroot, were carried out in mice, rats, and dogs after oral administration of the extracts. The clearance data for each species were used to estimate clearance in humans through allometric scaling based on the maximum lifespan potential, and a daily dose providing sufficient anti-periodontitis activity was estimated for use in the clinical trial. The findings indicated that allometric scaling is a reasonable approach that is relatively free of safety issues and can be used to determine doses of substances for incorporation into health/functional foods appropriate for humans.

Inhibitory Effects of Standardized Boesenbergia pandurata Extract and Its Active Compound Panduratin A on Lipopolysaccharide-Induced Periodontal Inflammation and Alveolar Bone Loss in Rats.

Periodontitis, an inflammatory disease of the gingival tissue, triggered by microbial-derived elements, such as lipopolysaccharide (LPS), collapses the periodontal tissues and resorbs the alveolar bone. This study evaluated the inhibitory effects of standardized Boesenbergia pandurata extract (BPE) and panduratin A (PAN) on periodontitis-induced inflammation and alveolar bone loss. Sprague-Dawley rats with LPS-induced periodontitis were orally administered BPE (50 and 200 mg/kg/day) and PAN (20 mg/kg/day) for 8 days. Histological analysis revealed that BPE- and PAN-administered groups showed decreased cell infiltration and alveolar bone resorption. Furthermore, the BPE and PAN significantly alleviated the mRNA and protein expression levels of nuclear factor kappa B (NF-κB), interleukin-1ß, matrix metalloproteinase (MMP)-2, and MMP-8. BPE and PAN also inhibited the expression of nuclear factor of activated T cells, cytoplasmic 1, c-Fos, and ostoclastogenesis-related enzymes, including cathepsin K and tartrate-resistant acid phosphatase (ALP). BPE and PAN not only upregulated the osteoblastogenesis-associated markers, such as collagen type I (COL1A1) and ALP, but also increased the ratio of osteoprotegerin to receptor activator of NF-κB ligand. Collectively, BPE and PAN efficiently prevent destruction of periodontal tissues and stimulating the loss of alveolar bone tissues, strongly indicative of their potential as natural antiperiodontitis agents.

Effect of Korean Red Ginseng extracts on drug-drug interactions.

BACKGROUND: Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications. METHODS: We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses. RESULTS: The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1'-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner. CONCLUSION: Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.

C1q/TNF-α-Related Protein 1 (CTRP1) Maintains Blood Pressure Under Dehydration Conditions.

RATIONALE: Circulating CTRP1 (C1q/TNF-α [tumor necrosis factor-α]-related protein 1) levels are increased in hypertensive patients compared with those in healthy subjects. Nonetheless, little is known about the molecular and physiological function of CTRP1 in blood pressure (BP) regulation. OBJECTIVE: To investigate the physiological/pathophysiological role of CTRP1 in BP regulation. METHODS AND RESULTS: CTRP1 production was increased to maintain normotension under dehydration conditions, and this function was impaired in inducible CTRP1 KO (knockout) mice (CTRP1 ΔCAG). The increase in CTRP1 under dehydration conditions was mediated by glucocorticoids, and the antagonist mifepristone prevented the increase in CTRP1 and attenuated BP recovery. Treatment with a synthetic glucocorticoid increased the transcription, translation, and secretion of CTRP1 from skeletal muscle cells. Functionally, CTRP1 increases BP through the stimulation of the AT1R (Ang II [angiotensin II] receptor 1)-Rho (Ras homolog gene family)/ROCK (Rho kinase)-signaling pathway to induce vasoconstriction. CTRP1 promoted AT1R plasma membrane trafficking through phosphorylation of AKT and AKT substrate of 160 kDa (AS160). In addition, the administration of an AT1R blocker, losartan, recovered the hypertensive phenotype of CTRP1 TG (transgenic) mice. CONCLUSIONS: For the first time, we provide evidence that CTRP1 contributes to the regulation of BP homeostasis by preventing dehydration-induced hypotension.

HPLC-MS/MS analysis of mesupron and its application to a pharmacokinetic study in rats.

Mesupron, the first-in-class inhibitor of urokinase-type plasminogen activator (uPA) is known to regulate cell proliferation and migration, and is under investigation for the treatment of metastatic breast cancer. In this study, a quantification method was developed for the determination of mesupron in rat plasma using liquid chromatography with a tandem mass spectrometry (LC-MS/MS). After protein precipitation with acetonitrile including itraconazole (internal standard, IS), the analytes were chromatographed on a reversed phased column with a mobile phase of acetonitrile and water (7:3, v/v, including 0.1% formic acid). The ion transitions of the precursor to the product ion were principally protonated ion [M+H]+ at m/z 630.4→398.3 for mesupron and 705.2→392.1 for the IS. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods This method was successfully applied to a pharmacokinetic study of mesupron after intravenous administration in rats.

Characterization and pharmacokinetic study of itraconazole solid dispersions prepared by solvent-controlled precipitation and spray-dry methods.

OBJECTIVES: Solid dispersion formulations have attracted attention to improve solubility and bioavailability of water-insoluble drugs. In this study, the variation of solubility and bioavailability by different preparation methods were studied using itraconazole (ITZ) solid dispersions. METHODS: Itraconazole solid dispersions were prepared by a solvent-controlled precipitation method (SCPM) using HPMCAS-LF, HCl antisolvent or a spray-drying method (SDM) for comparison. Dissolution tests by pH transition and pharmacokinetic study using male Sprague Dawley rats were conducted. KEY FINDINGS: Itraconazole solid dispersion dissolution tests by pH transition exhibited better dissolution compared to naive ITZ, limited dissolution in acidic conditions and a burst release at neutral pH. The ITZ solid dispersions by SCPM indicated a smaller-sized particle dispersion, limited dissolution at acidic pH and a higher release at neutral pH compared to those by SDM, suggesting that the increased protonation of anionic polymers and HPMCAS-LF by acidic antisolvent could form a tighter hydrophobic aggregation with ITZ in solid dispersions. ITZ solid dispersion prepared by SCPM also showed improved ITZ absorption in male Sprague Dawley rats compared to SDM and naïve ITZ. CONCLUSIONS: This study suggests that the SCPM method can be widely used for solid dispersion preparations due to improved dissolution and PK profile.

Determination of panduratin A in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study.

Although panduratin A, a chalcone derivative isolated from the rhizome of Kaempferia pandurata Roxb., represents a variety of pharmacological activities, no validated method for determination of panduratin A levels in biological samples is yet available. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of panduratin A in rat plasma. After simple protein precipitation with methanol including flufenamic acid (internal standard, IS), the analytes were chromatographed on a reversed-phased column with a mobile phase of distilled water and acetonitrile including 2% of formic acid (2:8, v/v). The ion transitions of the precursor to the product ion were principally deprotonated ions [M-H]- at m/z 405.2→165.9 for panduratin A and 280.1→236.0 for the IS. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor the plasma concentrations of panduratin A following oral administration in rats.

Quantitative determination of xanthorrhizol in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study.

Although xanthorrhizol, a sesquiterpenoid oil isolated from the rhizoma of Curcuma xanthorrhiza Roxb. known as Java turmeric, represents a variety of pharmacological activities, to date, there have been no validated determination methods of xanthorrhizol in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of xanthorrhizol in rat plasma. After simple protein precipitation with acetonitrile including diclofenac (internal standard, IS), the analytes were chromatographed on a reversed-phased column with a mobile phase of 20mM ammonium acetate aqueous solution and acetonitrile (20:80, v/v). The ion transitions of the precursor to the product ion were principally deprotonated ions [M-H]- at m/z 216.9→132.8 for xanthorrhizol and 296.1→251.7 for the IS. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of xanthorrhizol over time following intravenous administration in rats.