Pharmacokinetic Evaluation of the CYP3A4 and CYP2C9 Drug-Drug Interaction of Avacopan in 2 Open-Label Studies in Healthy Participants.

Avacopan, a complement 5a receptor (C5aR) antagonist approved for treating severe active antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, was evaluated in 2 clinical drug-drug interaction studies. The studies assessed the impact of avacopan on the pharmacokinetics (PK) of CYP3A4 substrates midazolam and simvastatin and CYP2C9 substrate celecoxib, and the influence of CYP3A4 inhibitor itraconazole and inducer rifampin on the PKs of avacopan. The results indicated that twice-daily oral administration of 30 mg of avacopan increased the area under the curve (AUC) of midazolam by 1.81-fold and celecoxib by 1.15-fold when administered without food, and twice-daily oral administration of 30 or 60 mg of avacopan increased the AUC of simvastatin by approximately 2.6-3.5-fold and the AUC of the active metabolite ß-hydroxy-simvastatin acid by approximately 1.4-1.7-fold when co-administered with food. Furthermore, the AUC of avacopan increased by approximately 2.19-fold when co-administered with itraconazole and decreased by approximately 13.5-fold when co-administered with rifampin. These findings provide critical insights into the potential drug-drug interactions involving avacopan, which could have significant implications for patient care and treatment planning. (NCT06207682).

A Drug-Drug Interaction Study to Evaluate the Impact of Simvastatin and Itraconazole on Erlotinib Pharmacokinetics in Rats by UPLC-MS/MS.

Aim: The goal of our study was to investigate the effects of single-dose simvastatin and itraconazole application on the pharmacokinetics of erlotinib in rats. Methods: Twenty-one male Sprague-Dawley rats were randomly divided into 3 groups, including erlotinib combined with simvastatin, erlotinib combined with itraconazole and erlotinib alone groups. The rats were given a single dose of 2 mg/kg simvastatin, 15 mg/kg itraconazole or 0.5% sodium carboxymethyl cellulose followed by 12 mg/kg erlotinib. The concentration of erlotinib in rat plasma was determined by UPLC-MS/MS. As internal standard, tinidazole was used for chromatographic analysis on the Kinetex C18 column (100×2.1 mm, 2.6 µm). Results: Erlotinib was validated in the calibration range of 5-1000 ng/mL. The lower limit of quantification (LLOQ) was 5 ng/mL. The inter- and intra-day precisions for erlotinib were less than 10.56%, and the accuracies were in the range of 98.61-104.99%. The validated UPLC-MS/MS method was successfully applied to this study. Compared with the erlotinib alone group, the values of AUC0-t, AUC0-∞, Cmax, Vz/F and t1/2 in the simvastatin group showed no statistical differences among pharmacokinetic parameters (P>0.05). However, the values of AUC0-t, AUC0-∞ and Cmax, in the itraconazole group were approximately 1.32-fold, 1.32-fold and 1.34-fold higher, and the CL/F was lower than those in the erlotinib alone group; the difference was statistically significant (P<0.05). Conclusion: Simvastatin had no significant effect on the pharmacokinetics of erlotinib, whereas co-administration of itraconazole considerably increased the exposure of erlotinib. Therefore, we should pay more attention to the potential drug-drug interaction to ensure safety in cancer patient treatment.

Association of cytochromes P450 3A4*22 and 3A5*3 genotypes and polymorphism with response to simvastatin in hypercholesterolemia patients.

BACKGROUNDS: Inter-individual variability in response to statin was mainly due to genetic differences. This study aimed to investigate the association of CYP3A4*22 (rs35599367), CYP3A5*3 (rs776746) single nucleotide polymorphism (SNP) with response to simvastatin in hypercholesterolemia patients conducted at King Abdulaziz University hospital (KAUH) in Jeddah, Saudi Arabia. PATIENTS AND METHODS: A total of 274 participants were registered in the current study. Hypercholesterolemic patients taking simvastatin 20 mg (n = 148) and control subjects (n = 126) were tested for rs35599367 and rs776746 genotypes using Custom Taqman ® Assay Probes. Response to simvastatin in these patients was assessed by determination of low density lipoprotein (LDL-C), total cholesterol (TC) and by measuring statin plasma levels using Liquid Chromatography-Mass Spectrometry (LC-MS). RESULTS: None of the participants carried a homozygous CYP3A4*22 mutant genotype, while 12 (4.4%) individuals had a heterozygous genotype and 262 (95.6%) had a wild homozygous genotype. The CYP3A5*3 allele was detected in the homozygous mutant form in 16 (5.8%) individuals, while 74 (27.0%) individuals carried the heterozygous genotype and 184 (67.2%) carried the wildtype homozygous genotype. Of the patient group, 15 (11%) were classified as intermediate metabolizers (IMs) and 133 (89%) as extensive metabolizers (EMs). Plasma simvastatin concentrations for the combined CYP3A4/5 genotypes were significantly (P<0.05) higher in the IMs group than in the EMs group. TC and plasma LDL-C levels were also significantly (P<0.05) higher in IMs than in EMs. CONCLUSION: The present study showed associations between CYP3A4*22 (rs35599367) and CYP3A5*3 (rs776746) SNP combination genotypes with response to statins in hypercholesterolemia. Patients who had either a mutant homozygous allele for CYP3A5*3 or mutant homozygous and heterozygous alleles for CYP3A4*22 showed increased response to lower TC and LDL-C levels.

Genomewide Association Study of Simvastatin Pharmacokinetics.

We investigated genetic determinants of single-dose simvastatin pharmacokinetics in a prospective study of 170 subjects and a retrospective cohort of 59 healthy volunteers. In a microarray-based genomewide association study with the prospective data, the SLCO1B1 c.521T>C (p.Val174Ala, rs4149056) single nucleotide variation showed the strongest, genomewide significant association with the area under the plasma simvastatin acid concentration-time curve (AUC; P = 6.0 × 10-10 ). Meta-analysis with the retrospective cohort strengthened the association (P = 1.6 × 10-17 ). In a stepwise linear regression candidate gene analysis among all 229 participants, SLCO1B1 c.521T>C (P = 1.9 × 10-13 ) and CYP3A4 c.664T>C (p.Ser222Pro, rs55785340, CYP3A4*2, P = 0.023) were associated with increased simvastatin acid AUC. Moreover, the SLCO1B1 c.463C>A (p.Pro155Thr, rs11045819, P = 7.2 × 10-6 ) and c.1929A>C (p.Leu643Phe, rs34671512, P = 5.3 × 10-4 ) variants associated with decreased simvastatin acid AUC. Based on these results and the literature, we classified the volunteers into genotype-predicted OATP1B1 and CYP3A4 phenotype groups. Compared with the normal OATP1B1 function group, simvastatin acid AUC was 273% larger in the poor (90% confidence interval (CI), 137%, 488%; P = 3.1 × 10-6 ), 40% larger in the decreased (90% CI, 8%, 83%; P = 0.036), and 67% smaller in the highly increased function group (90% CI, 46%, 80%; P = 2.4 × 10-4 ). Intermediate CYP3A4 metabolizers (i.e., heterozygous carriers of either CYP3A4*2 or CYP3A4*22 (rs35599367)), had 87% (90% CI, 39%, 152%, P = 6.4 × 10-4 ) larger simvastatin acid AUC than normal metabolizers. These data suggest that in addition to no function SLCO1B1 variants, increased function SLCO1B1 variants and reduced function CYP3A4 variants may affect the pharmacokinetics, efficacy, and safety of simvastatin. Care is warranted if simvastatin is prescribed to patients carrying decreased function SLCO1B1 or CYP3A4 alleles.

Effect of Roxadustat on the Pharmacokinetics of Simvastatin, Rosuvastatin, and Atorvastatin in Healthy Subjects: Results From 3 Phase 1, Open-Label, 1-Sequence, Crossover Studies.

Roxadustat inhibits breast cancer resistance protein and organic anion transporting polypeptide 1B1, which can affect coadministered statin concentrations. Three open-label, 1-sequence crossover phase 1 studies in healthy subjects were conducted to assess effects from steady-state 200-mg roxadustat on pharmacokinetics and tolerability of 40-mg simvastatin (CL-0537 and CL-0541), 40-mg atorvastatin (CL-0538), or 10-mg rosuvastatin (CL-0537). Statins were dosed concomitantly with roxadustat in 28 (CL-0537) and 24 (CL-0538) healthy subjects, resulting in increases of maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from the time of dosing extrapolated to infinity (AUCinf ) 1.87- and 1.75-fold for simvastatin, 2.76- and 1.85-fold for simvastatin acid, 4.47- and 2.93-fold for rosuvastatin, and 1.34- and 1.96-fold for atorvastatin, respectively. Additionally, simvastatin dosed 2 hours before, and 4 and 10 hours after roxadustat in 28 (CL-0541) healthy subjects, resulted in increases of Cmax and AUCinf 2.32- to 3.10-fold and 1.56- to 1.74-fold for simvastatin and 2.34- to 5.98-fold and 1.89- to 3.42-fold for simvastatin acid, respectively. These increases were not attenuated by time-separated statin dosing. No clinically relevant differences were observed for terminal elimination half-life. Concomitant 200-mg roxadustat and a statin was generally well tolerated during the study period. Roxadustat effects on statin Cmax and AUCinf were statin and administration time dependent. When coadministered with roxadustat, statin-associated adverse reactions and the need for statin dose reduction should be evaluated.

Simvastatin induced ferroptosis for triple-negative breast cancer therapy.

Triple-negative breast cancer (TNBC), a management of aggressive breast cancer, remains an unmet medical challenge. Although a wave of efforts had spurred to design novel therapeutic method of TNBC, unpredictable prognosis with lacking effective therapeutic targets along with the resistance to apoptosis seriously limited survival benefits. Ferroptosis is a non-apoptotic form of cell death that is induced by excessive lipid peroxidation, which provide an innovative way to combat cancer. Emerging evidence suggests that ferroptosis plays an important role in the treatment of TNBC cells. Herein, a novel ferroptosis nanomedicine was prepared by loading simvastatin (SIM), a ferroptosis drug, into zwitterionic polymer coated magnetic nanoparticles (Fe3O4@PCBMA) to improve the therapeutic effect of TNBC. The as-obtained Fe3O4@PCBMA-SIM nanoparticles demonstrated more cytotoxicity against MDA-MB-231 than MCF-7 due to the higher expression of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), which demonstrated that statins could effectively kill TNBC. Further experiments showed that SIM could inhibit the expression of HMGCR to downregulate the mevalonate (MVA) pathway and glutathione peroxidase 4 (GPX4), thereby inducing cancer cell ferroptosis. What's more, PCBMA endows Fe3O4@PCBMA longer blood circulation performance to enhance their accumulation at tumor sites. Given that Fe3O4 have proven for clinical applications by the U.S. Food and Drug Administration (FDA) and SIM could induce cancer cell ferroptosis, the developed Fe3O4@PCBMA-SIM nanosystem would have great potential in clinics for overcoming the drug resistance brought about by apoptotic drugs to cancer cells.

Preparation and characterization of poly (lactic-co-glycolic acid) nanofibers containing simvastatin coated with hyaluronic acid for using in periodontal tissue engineering.

Periodontal diseases can lead to soft tissue defects. Tissue engineering can provide functional replacements for damaged tissues. Recently, electrospun nanofibers have attracted great interest for tissue engineering and drug delivery applications. This has been revealed that statins exhibit positive impacts on the proliferation and regeneration of periodontal tissues. Electrospun simvastatin loaded poly (lactic-co-glycolic acid) (SIM-PLGA-NF) were prepared using electrospinning technique. Optimal conditions for preparation of SIM-PLGA-NF (PLGA concentration of 30 wt%, voltage of 15 kV, and flow rate of 1.5 ml h-1 ) were identified using a 23 factorial design. The optimized SIM-PLGA-NFs (diameter of 640.2 ± 32.5 nm and simvastatin entrapment efficacy of 99.6 ± 1.5%) were surface modified with 1% w/v hyaluronic acid solution (1%HA- SIM-PLGA-NF) to improve their compatibility with fibroblasts and potential application as a periodontal tissue engineering scaffold. HA-SIM-PLGA NFs were analyzed using SEM, FTIR, and XRD. 1%HA-SIM-PLGA-NF had uniform, bead-free and interwoven morphology, which is similar to the extracellular matrix. The mechanical performance of SIM-PLGA-NFs and release profile of simvastatin from these nanofibers have been also greatly improved after coating with HA. In vitro cellular tests showed that the proliferation, adhesion, and differentiation of fibroblast cells positively enhanced on the surface of 1%HA- SIM-PLGA-NF. These results demonstrate the potential application of 1%HA-SIM-PLGA-NFs as a scaffold for periodontal tissue engineering.

Baicalein inhibits the pharmacokinetics of simvastatin in rats via regulating the activity of CYP3A4.

CONTEXT: Baicalein and simvastatin possess similar pharmacological activities and indications. The risk of their co-administration was unclear. OBJECTIVE: The interaction between baicalein and simvastatin was investigated to provide reference and guidance for the clinical application of the combination of these two drugs. MATERIALS AND METHODS: The pharmacokinetics of simvastatin was investigated in Sprague-Dawley rats (n = 6). The rats were pre-treated with 20 mg/kg baicalein for 10 days and then administrated with 40 mg/kg simvastatin. The single administration of simvastatin was set as the control group. The rat liver microsomes were employed to assess the metabolic stability and the effect of baicalein on the activity of CYP3A4. RESULTS: Baicalein significantly increased the AUC(0-t) (2018.58 ± 483.11 vs. 653.05 ± 160.10 µg/L × h) and Cmax (173.69 ± 35.49 vs. 85.63 ± 13.28 µg/L) of simvastatin. The t1/2 of simvastatin was prolonged by baicalein in vivo and in vitro. The metabolic stability of simvastatin was also improved by the co-administration of baicalein. Baicalein showed an inhibitory effect on the activity of CYP3A4 with the IC50 value of 12.03 µM, which is responsible for the metabolism of simvastatin. DISCUSSION AND CONCLUSION: The co-administration of baicalein and simvastatin may induce drug-drug interaction through inhibiting CYP3A4. The dose of baicalein and simvastatin should be adjusted when they are co-administrated.

Combination of Phospholipid Complex and Matrix Dispersion.

Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs. This work was undertaken to fabricate simvastatin-phospholipid complex (SIM-PLC)-loaded matrix dispersion (SIM-PLC-MD) using Soluplus® as carrier material, to augment dispersibility and dissolution of SIM-PLC without altering complexation between simvastatin (SIM) and phospholipid. SIM-PLC and SIM-PLC-MD were prepared using solvent evaporation and discontinuous solvent evaporation techniques, respectively. The successful complexation was substantiated by FTIR method. Besides, PXRD and SEM studies disclosed the absence of crystallinity of SIM in both SIM-PLC and SIM-PLC-MD. The TEM analysis monitored the self-assembly of SIM-PLC and SIM-PLC-MD into colloidal structures, which could be correlated with redispersion in GIT fluids upon oral administration. The considerable increase in hydrophilicity of SIM-PLC-MD and SIM-PLC as evident from partition coefficient experiment can further be correlated with their remarkably improved solubility profiles in the following pattern: SIM-PLC-MD˃SIM-PLC˃SIM. Correspondingly, improved dispersibility of SIM-PLC-MD in comparison to SIM-PLC can be accountable for accelerated dissolution rate by 2.53-fold and 1.5-fold in pH 1.2 and 6.8 conditions, respectively. The oral pharmacokinetic evaluation in Sprague Dawley (SD) rats revealed 3.19-fold enhancement in oral bioavailability of SIM through SIM-PLC-MD when compared with plain SIM, whereas 1.83-fold increment was observed in the case of SIM-PLC. Finally, the efficacy experimentation in SD rats revealed that SIM-PLC-MD significantly reduced triglycerides and cholesterol levels in comparison to SIM and SIM-PLC. These outcomes suggest that a matrix dispersion strategy improves oral bioavailability and hypolipidemic activity of SIM.

Fixed Dose Single Tablet Formulation with Differential Release of Amlodipine Besylate and Simvastatin and Its Pharmacokinetic Profile: QbD and Risk Assessment Approach.

PURPOSE: A differential release fixed dose matrix tablet of amlodipine besylate (AML-B) and simvastatin (SIM) was formulated to enhance patient compliance. MATERIAL AND METHOD: In the first phase, release controlling parameters of AML-B and SIM granules were identified and in the second phase a fixed dose AML-B and SIM tablet formulation was prepared and optimized for a differential release of the drugs using a quality by design (QbD) and risk assessment approach. A validated HPLC method was employed for simultaneous determination of AML-B and SIM for FDC formulation. A pharmacokinetics of the above drugs was studied in healthy dogs in the third phase. RESULTS: In QbD-based optimized formulation, Eudragit® RSPO-dicalcium phosphate (DCP) blend controlled the release of AML-B over 8 h, though this diffusion-controlled release assumed first order kinetics. DCP and Eudragit® RS 100 also retarded release of SIM causing SIM release over 8 h after AML-B release from the optimized FDC tablet formulation. The HPLC retention times of AML-B and SIM were 2.10 and 15.52 min, respectively. Linearity for AML-B was 5.0-50 ng/mL and 0.01-2.0 µg/mL for SIM with percent recoveries of 92.85-101.53% and 94.51-117.75% for AML-B and SIM. AUC0-∞ of AML-B was increased 3 fold, while AUC0-∞ of SIM was decreased 2 fold. The tmax values for AML-B and SIM were 12 and 6 h, respectively. AML-B was absorbed without any lag time (tlag) while tlag was 6.33 ± 0.81 h for SIM, thus met the study objective. CONCLUSION: The pharmacokinetic study showed an immediate absorption of AML-B while that of SIM was withheld for 6 h, close to the desired delay time of 8 h.

Thermoresponsive Hydrogel-Based Local Delivery of Simvastatin for the Treatment of Periodontitis.

Except for routine scaling and root planing, there are few effective nonsurgical therapeutic interventions for periodontitis and associated alveolar bone loss. Simvastatin (SIM), one of the 3-hydroxy-3-methylglutaryl-cosenzyme A reductase inhibitors, which is known for its capacity as a lipid-lowering medication, has been proven to be an effective anti-inflammatory and bone anabolic agent that has shown promising benefits in mitigating periodontal bone loss. The local delivery of SIM into the periodontal pocket, however, has been challenging due to SIM's poor water solubility and its lack of osteotropicity. To overcome these issues, we report a novel SIM formulation of a thermoresponsive, osteotropic, injectable hydrogel (PF127) based on pyrophosphorolated pluronic F127 (F127-PPi). After mixing F127-PPi with F127 at a 1:1 ratio, the resulting PF127 was used to dissolve free SIM to generate the SIM-loaded formulation. The thermoresponsive hydrogel's rheologic behavior, erosion and SIM release kinetics, osteotropic property, and biocompatibility were evaluated in vitro. The therapeutic efficacy of SIM-loaded PF127 hydrogel on periodontal bone preservation and inflammation resolution was validated in a ligature-induced periodontitis rat model. Given that SIM is already an approved medication for hyperlipidemia, the data presented here support the translational potential of the SIM-loaded PF127 hydrogel for better clinical management of periodontitis and associated pathologies.

A safety, tolerability, and pharmacokinetic study of a novel simvastatin silica-lipid hybrid formulation in healthy male participants.

Simvastatin (SIM) is a commonly used cholesterol-lowering drug that can reduce the risk of major cardiovascular events. However, due to its poor intrinsic water solubility, the drug is poorly absorbed from the gastrointestinal tract and exhibits a low oral bioavailability of approximately 5%. The aim of this study was to fabricate and optimize SIM encapsulated silica-lipid hybrids (SLH) as a solid-state lipid-based formulation to enhance absorption and bioavailability during a human in vivo pharmacokinetic study. SLH formulations were formulated by spray drying a submicron emulsion with either Aerosil® 300 fumed silica nanoparticles (SLH-A) or Syloid® 244 amorphous micronized silica (SLH-B). A cross-over, double-blinded study design was implemented to evaluate the performance of SLH formulations compared with a commercially available formulation in 12 healthy male participants after oral administration under fasting conditions. SLH formulations enhanced the bioavailability of SIM up to 1.6-fold and more importantly the active simvastatin acid (SIMA), 3.5-fold when compared with an equivalent dose of commercial formulation. The results demonstrate that the porous nanostructure of SLH impact systemic SIM and SIMA concentrations and may serve as a novel approach to enhance the bioavailability of specifically the parent or metabolite. No significant difference was observed in exposure when SLH formulations were administered at 10 mg in comparison with 20 mg of the commercial formulation, suggesting the potential for dose reduction. The study indicated that SLH formulations were safe and well-tolerated when administered to healthy males, confirming the commercial potential of SLH to enhance the bioavailability of poorly water-soluble drugs. Graphical abstract.

Drug-Drug Interaction Surveillance Study: Comparing Self-Controlled Designs in Five Empirical Examples in Real-World Data.

Self-controlled designs, specifically the case-crossover (CCO) and the self-controlled case series (SCCS), are increasingly utilized to generate real-world evidence (RWE) on drug-drug interactions (DDIs). Although these designs share the advantages and limitations of within-individual comparison, they also have design-specific assumptions. It is not known to what extent the differences in assumptions lead to different results in RWE DDI analyses. Using a nationwide US commercial healthcare insurance database (2006-2016), we compared the CCO and SCCS designs, as they are implemented in DDI studies, within five DDI-outcome examples: (1) simvastatin + clarithromycin and muscle-related toxicity; (2) atorvastatin + valsartan, and muscle-related toxicity; and (3-5) dabigatran + P-glycoprotein inhibitor (clarithromycin, amiodarone, and verapamil) and bleeding. Analyses were conducted within person-time exposed to the object drug (statins and dabigatran) and adjusted for bias associated with the inhibiting drugs via control groups of individuals unexposed to the object drug. The designs yielded similar estimates in most examples, with SCCS displaying better statistical efficiency. With both designs, results varied across sensitivity analyses, particularly in CCO analyses with small number of exposed individuals. Analyses in controls revealed substantial bias that may be differential across DDI-exposed and control individuals. Thus, both designs showed no association between amiodarone or verapamil and bleeding in dabigatran-exposed but revealed strong positive associations in controls. Overall, bias adjustment via a control group had a larger impact on results than the choice of a design, highlighting the importance and challenges of appropriate control group selection for adequate bias control in self-controlled analyses of DDIs.

Physiologically Based Precision Dosing Approach for Drug-Drug-Gene Interactions: A Simvastatin Network Analysis.

Drug-drug interactions (DDIs) and drug-gene interactions (DGIs) are well known mediators for adverse drug reactions (ADRs), which are among the leading causes of death in many countries. Because physiologically based pharmacokinetic (PBPK) modeling has demonstrated to be a valuable tool to improve pharmacotherapy affected by DDIs or DGIs, it might also be useful for precision dosing in extensive interaction network scenarios. The presented work proposes a novel approach to extend the prediction capabilities of PBPK modeling to complex drug-drug-gene interaction (DDGI) scenarios. Here, a whole-body PBPK network of simvastatin was established, including three polymorphisms (SLCO1B1 (rs4149056), ABCG2 (rs2231142), and CYP3A5 (rs776746)) and four perpetrator drugs (clarithromycin, gemfibrozil, itraconazole, and rifampicin). Exhaustive network simulations were performed and ranked to optimize 10,368 DDGI scenarios based on an exposure marker cost function. The derived dose recommendations were translated in a digital decision support system, which is available at simvastatin.precisiondosing.de. Although the network covers only a fraction of possible simvastatin DDGIs, it provides guidance on how PBPK modeling could be used to individualize pharmacotherapy in the future. Furthermore, the network model is easily extendable to cover additional DDGIs. Overall, the presented work is a first step toward a vision on comprehensive precision dosing based on PBPK models in daily clinical practice, where it could drastically reduce the risk of ADRs.

Hyaluronic acid-coated polymeric micelles with hydrogen peroxide scavenging to encapsulate statins for alleviating atherosclerosis.

Inflammation and oxidative stress are two major factors that are involved in the pathogenesis of atherosclerosis. A smart drug delivery system that responds to the oxidative microenvironment of atherosclerotic plaques was constructed in the present study. Simvastatin (SIM)-loaded biodegradable polymeric micelles were constructed from hyaluronic acid (HA)-coated poly(ethylene glycol)-poly(tyrosine-ethyl oxalyl) (PEG-Ptyr-EO) for the purpose of simultaneously inhibiting macrophages and decreasing the level of reactive oxygen species (ROS) to treat atherosclerosis. HA coating endows the micelle system the ability of targeting CD44-positive inflammatory macrophages. Owing to the ROS-responsive nature of PEG-Ptyr-EO, the micelles can not only be degraded by enzymes, but also consumes ROS by itself at the pathologic sites, upon which the accumulation of pro-inflammatory macrophages is effectively suppressed and oxidative stress is alleviated. Consequently, the cellular uptake experiment demonstrated that SIM-loaded HA-coated micelles can be effectively internalized by LPS-induced RAW264.7 cells and showed high cytotoxicity against the cells, but low cytotoxicity against LO2 cells. In mouse models of atherosclerosis, intravenously SIM-loaded HA-coated micelles can effectively reduce plaque content of cholesterol, resulting in remarkable therapeutic effects. In conclusion, the SIM-loaded micelle system provides a promising and innovative option against atherosclerosis.

Simvastatin-Nicotinamide Co-Crystals: Formation, Pharmaceutical Characterization and in vivo Profile.

PURPOSE: To enhance the solubility and dissolution profile of simvastatin (SIM) through co-crystallization with varying ratios of nicotinamide (NIC) using various co-methods. MATERIALS AND METHODS: Twelve SIM:NIC co-crystal formulations (F01-F12) were prepared using dry grinding, slurry, liquid-assisted grinding, and solvent-evaporation methods, and their properties compared. Optimized formulations were selected on the basis of dissolution profiles and solubility for in vivo studies. The angle of repose, Carr Index and Hausner ratio were calculated to evaluate flow properties. Differential light scattering (DLS) was used to estimate particle-size distribution. Scanning electron microscopy (SEM) was employed to evaluate surface morphology. Thermal analyses and Fourier-transform infrared (FTIR) spectroscopy were used to determine the ranges of thermal stability and physical interaction of formulated co-crystals. X-ray powder diffraction (XPD) spectroscopy was used to determine the crystalline nature. Solubility and dissolution studies were undertaken to determine in vitro drug-release behaviors. RESULTS: Micromeritic analyses revealed the good flow properties of formulated co-crystals. DLS showed the particle size of co-crystals to be in the nanometer range. SEM revealed that the co-crystals were regular cubes. Thermal studies showed the stability of co-crystals at >300°C. FTIR spectroscopy revealed minor shifts of various peaks. XPD spectroscopy demonstrated co-crystal formation. The formulations exhibited an improved dissolution profile with marked improvements in solubility. In vivo studies showed a 2.4-fold increase in Cmax whereas total AUC(0-∞) was increased 4.75-fold as compared with that of SIM tablets. CONCLUSION: Co-crystallization with NIC improved the solubility and dissolution profile and, hence, the bioavailability of the poorly water-soluble drug SIM.

Enhancing the Hypolipidemic Effect of Simvastatin in Poloxamer-Induced Hyperlipidemic Rats via Liquisolid Approach: Pharmacokinetic and Pharmacodynamic Evaluation.

This study aimed to enhance the dissolution of simvastatin (SMV) through its formulation in liquisolid tablets (LSTs) to improve its bioavailability and hypolipidemic activity after oral administration. SMV-LSTs were optimized using Box-Behnken design to maximize the rate and extent of SMV dissolution. The optimized SMV-LST was evaluated for pharmacokinetic parameters and potential hypolipidemic activity on induced hyperlipidemic rats. The dissolution parameters revealed a shortening of mean dissolution time from 10.99 to 6.82 min, increasing of dissolution rate during the first 10 min from 1253.15 to 1667.31 µg/min, and enhancing of dissolution efficiency after 60 min from 71.92 to 86.93% for SMV-LSTs versus the commercial SMV tablets. The obtained data reflected an improvement in the relative bioavailability of SMV with 148.232% which was confirmed by the significant reduction of the levels of circulating total cholesterol, triglycerides that reached the normal level after 12 h. In particular, the optimized SMV-LSTs reduced serum low-density lipoproteins (LDL) by 44.6% which was significantly different from the commercial SMV tablets. In contrast, the level of serum high-density lipoprotein (HDL) was significantly augmented after 4 h in rats treated with the optimized SMV-LSTs by 47.6%. Finally, the optimized SMV-LSTs showed a significant lower atherosclerotic index value which could maximize its potential in decreasing the risk of coronary disease and atherosclerosis. Overall enhancement in pharmacokinetics and pharmacodynamics in comparison with the commercial tablets confers the potential of the liquisolid approach as a promising alternative for improved oral bioavailability, hypolipidemic, and cardioprotective effects of SMV. Graphical abstract.

Chronopharmacology of simvastatin on hyperlipidaemia in high-fat diet-fed obese mice.

The chronopharmacology refers to the utilization of physiological circadian rhythms to optimize the administration time of drugs, thus increasing their efficacy and safety, or reducing adverse effects. Simvastatin is one of the most widely prescribed drugs for the treatment of hypercholesterolaemia, hyperlipidemia and coronary artery disease. There are conflicting statements regarding the timing of simvastatin administration, and convincing experimental evidence remains unavailable. Thus, we aimed to examine whether different administration times would influence the efficacy of simvastatin. High-fat diet-fed mice were treated with simvastatin at zeitgeber time 1 (ZT1) or ZT13, respectively, for nine weeks. Simvastatin showed robust anti-hypercholesterolaemia and anti-hyperlipidemia effects on these obese mice, regardless of administration time. However, simvastatin administrated at ZT13, compared to ZT1, was more functional for decreasing serum levels of total cholesterol, triglycerides, non-esterified free fatty acids and LDL cholesterol, as well as improving liver pathological characteristics. In terms of possible mechanisms, we found that simvastatin did not alter the expression of hepatic circadian clock gene in vivo, although it failed to change the period, phase and amplitude of oscillation patterns in Per2::Luc U2OS and Bmal1::Luc U2OS cells in vitro. In contrast, simvastatin regulated the expression of Hmgcr, Mdr1 and Slco2b1 in a circadian manner, which potentially contributed to the chronopharmacological function of the drug. Taken together, we provide solid evidence to suggest that different administration times affect the lipid-lowering effects of simvastatin.

Enhancing the oral bioavailability of simvastatin with silica-lipid hybrid particles: The effect of supersaturation and silica geometry.

Silica-lipid hybrid (SLH) microparticles are a solidified lipid-based drug delivery system under investigation for their aptitude to enhance the oral bioavailability of poorly water-soluble drugs. The cholesterol-lowering agent, simvastatin (SIM), is poorly water-soluble and undergoes extensive first pass metabolism, resulting in a low oral bioavailability of approximately 5%. Hence, the current pre-clinical studies investigated the application of SLH technology to SIM with a supersaturation approach, aiming to enhance bioavailability and drug loading capacity. Additionally, the effect of silica was explored by evaluating the performance of SLH fabricated with silica of different particle geometries. SLH microparticles with supersaturated SIM loading levels ranging from 100% to 400% above the equilibrium solubility were successfully fabricated using either Aerosil® 300 or Syloid® 244 silica. All SLH formulations existed as white free-flowing powders, consisting of spherical porous microparticles for Aerosil® 300, and aggregated irregular microparticles for Syloid® 244. During in vitro dissolution in pH 7.0 media, the SLH formulations performed up to 4.4-fold greater than pure SIM powder. Furthermore, in vivo oral pharmacokinetics in male Sprague-Dawley rats revealed that the SLH formulations enhanced the oral bioavailability of SIM up to 6.1-fold and 2.9-fold, in comparison to pure SIM powder and a commercially available formulation (Simvastatin Sandoz®), respectively. The greatest in vivo performance enhancement was observed for the SLH formulation manufactured with Syloid® 244 silica with a supersaturation level of 200%. SLH technology demonstrated to be a successful formulation strategy to significantly improve the oral bioavailability of SIM in rodents and therefore, has a strong potential to also improve the oral bioavailability of SIM in humans.

Effects of multidose simvastatin co-administration on pharmacokinetic profile of apatinib in rats by UPLC-MS/MS.

Apatinib, a small molecule anti-angiogenic tyrosine kinase inhibitor is used extensively to treat advanced gastric cancer and simvastatin (SV) is often co-prescribed to treat cardiovascular disease in cancer patients. As both apatinib and SV are metabolized primarily by cytochrome P450 variant CYP3A4, they are likely to interact. Therefore, the potential effect of SV co-administration on pharmacokinetics of apatinib in Sprague-Dawley male rats is demonstrated for the first time.Sixteen rats were randomly divided into two groups (n = 8), 2 mg/kg SV orally co-administrated for seven days (group B) and the corresponding control group (group A). Apatinib concentrations of rat plasma samples were detected by ultra-performance liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were calculated using non compartmental methods.Co-administration of SV for seven days significantly increased area under curve (AUC(0-t)), AUC(0-∞) and maximum plasma concentration of apatinib by 2.4-, 2.4-, and 2.7-fold, respectively while decreasing apparent volume of distribution and clearance by 81.7 and 73.9%, respectively.These findings suggest that concomitant administration of SV with 7 days may have inhibited the metabolism of apatinib in rats.