Optimization of atorvastatin and quercetin-loaded solid lipid nanoparticles using Box-Behnken design.

Aim: The study explores the synergistic potential of atorvastatin (ATR) and quercetin (QUER)- loaded solid lipid nanoparticles (SLN) in combating breast cancer. Materials & methods: SLNs were synthesized using a high-shear homogenization method and optimized using Box-Behnken design. The SLNs were characterized and evaluated for their in vitro anticancer activity. Results: The optimized SLN exhibited narrow size distribution (PDI = 0.338 ± 0.034), a particle size of 72.5 ± 6.5 nm, higher entrapment efficiency (<90%), sustained release and spherical surface particles. The in vitro cytotoxicity studies showed a significant reduction in IC50 values on MDA-MB-231 cell lines. Conclusion: We report a novel strategy of repurposing well-known drugs and encapsulating them into SLNs as a promising drug-delivery system against breast cancer.

[Box: see text].

Unveiling Impurities: A Comprehensive RP-HPLC Method for Accurate Atorvastatin Impurity Analysis in Pharmaceuticals Using an Accuracy Profile Approach.

BACKGROUND: Accurate determination of active pharmaceutical ingredients and impurities is essential for ensuring the safety and effectiveness of medications. This study focuses on the validation of a high-performance liquid chromatography (HPLC) method for quantifying atorvastatin and its impurities, addressing a critical aspect of pharmaceutical analysis. OBJECTIVE: The primary objective is to conduct a comprehensive validation study for the HPLC method, covering specificity assessment, response function establishment, and a detailed analysis of precision, trueness, and tolerance intervals. The emphasis is on demonstrating the method's precision, accuracy, and stability-indicating capabilities across various concentrations and compounds. METHODS: The HPLC method is validated through rigorous assessments, including specificity, response function establishment, and analyses of precision, trueness, and tolerance intervals. Induced degradation experiments are conducted to explore atorvastatin's behavior under extreme conditions. Insights into the compound's synthesis and degradation pathways are provided through a proposed mechanism for intramolecular esterification. RESULTS: The results affirm the precision, accuracy, and stability-indicating capabilities of the validated HPLC method. The method effectively differentiates between atorvastatin and its impurities, showcasing its suitability for pharmaceutical quality control. CONCLUSIONS: The validated HPLC method emerges as a robust and reliable tool for atorvastatin analysis, contributing significantly to pharmaceutical research and quality control. Its application ensures the safety and efficacy of medications, reinforcing its role in pharmaceutical analysis. HIGHLIGHTS: This study not only validates a crucial HPLC method for atorvastatin analysis but also provides insights into the compound's behavior under extreme conditions and its synthesis and degradation pathways. The validated method serves as a cornerstone in pharmaceutical research and quality control, ensuring medication safety and efficacy.

Synthesis of zero valent copper/iron nanoparticles using Piper betle leaves for the removal of pharmaceutical contaminant atorvastatin.

In this study, bimetallic Cu-Fe nanoparticles were synthesized using the green approach with Piper betle leaves, and the removal efficiency of one of the pharmaceutical compounds, Atorvastatin, was investigated. UV, SEM, FTIR, EDAX, particle size, and zeta potential measurements were used to confirm nanoparticle fabrication. The removal efficiency of Atorvastatin (10 mg/L) by bimetallic Cu-Fe nanoparticles was 67% with a contact time of 30 min at pH 4, the adsorbent dosage of 0.2 g/L, and stirring at 100 rpm. Piper betle bimetallic Cu-Fe nanoparticles have demonstrated excellent stability, reusability, and durability, even after being reused five times. Furthermore, the synthesized bimetallic Cu-Fe nanoparticles demonstrated remarkable antimicrobial properties against gram-negative strains such as Escherichia coli and Klebsiella pneumoniae, gram-positive strains such as Staphylococcus aureus and Bacillus subtilis, and fungi such as Aspergillus niger. In addition, the antioxidant properties of the synthesized bimetallic Cu-Fe nanoparticles were assessed using the DPPH radical scavenging assay. The results indicated that the nanoparticles had good antioxidant activity. Thus, using Piper betle extract to make Cu-Fe nanoparticles made the procedure less expensive, chemical-free, and environmentally friendly, and the synthesized bimetallic Cu-Fe nanoparticles helped remove the pharmaceutical compound Atorvastatin from wastewater.

Design, optimization and characterization of atorvastatin loaded chitosan-based polyelectrolyte complex nanoparticles based transdermal patch.

AIM: Atorvastatin (ATO) loaded chitosan-based polyelectrolyte complex nanoparticles (PECN) incorporated transdermal patch was developed to enhance its skin permeability and bioavailability. METHODOLOGY: The ATO loaded PECN were prepared by ionic gelation method and optimized by Box-Behnken design. The optimized batches were evaluated for physicochemical characteristics, in vitro, ex vivo, cell line and stability studies. The optimized ATO-PECN were incorporated into transdermal patches by solvent evaporation method and evaluated for their physicochemical properties, ex vivo skin permeation, in vivo pharmacokinetics and stability study. RESULTS: The optimized batch of ATO-PECN had average size of 219.2 ± 5.98 nm with 82.68 ± 2.63 % entrapment and 25.41 ± 3.29 mV zeta potential. ATO-PECN showed sustained drug release and higher skin permeation. The cell line study showed that ATO-PECN increased the cell permeability of ATO as compared to ATO suspension. ATO-PECN loaded transdermal patch showed higher skin permeation. The in vivo pharmacokinetic study revealed that the ATO-PECN transdermal patch showed significant (p < 0.05) increase in pharmacokinetic parameters as compared to marketed oral tablet, confirming enhancement in bioavailability of ATO. CONCLUSIONS: The results of the present work concluded that the ATO-PECN loaded transdermal patch is a promising novel drug delivery system for poorly bioavailable drugs.

3D printed scaffolds as delivery devices for nanocrystals: A proof of concept loading Atorvastatin with enhanced properties for sublingual route of administration.

Increasing the solubility of drugs is a recurrent objective of pharmaceutical research, and one of the most widespread strategies today is the formulation of nanocrystals (NCs). Beyond the many advantages of formulating NCs, their incorporation into solid dosage forms remains a challenge that limits their use. In this work, we set out to load Atorvastatin NCs (ATV-NCs) in a delivery device by combining 3D scaffolds with an "in situ" loading method such as freeze-drying. When comparing two infill patterns for the scaffolds at two different percentages, the one with the highest NCs load was chosen (Gyroid 20 % infill pattern, 13.8 ± 0.5 mg). Colloidal stability studies of NCs suggest instability in acidic media, and therefore, the system is postulated for use as a sublingual device, potentially bypassing stomach and hepatic first-pass effects. An ad hoc dissolution device was developed to mimic the release of actives. The nanometric size and properties acquired in the process were maintained, mainly in the dissolution rate and speed, achieving 100 % dissolution of the content in 180 s. Based on these results, the proof of concept represents an innovative approach to converting NCs suspensions into solid dosage forms.

Hybrid Microneedle-Mediated Transdermal Delivery of Atorvastatin Calcium-Loaded Polymeric Micelles for Hyperlipidemia Therapy.

Hyperlipidemia has been a huge challenge to global health, leading to the cardiovascular disease, hypertension, and diabetes. Atorvastatin calcium (AC), a widely prescribed drug for hyperlipidemia, faces huge challenges with oral administration due to poor water solubility and hepatic first-pass effects, resulting in low therapeutic efficacy. In this work, we designed and developed a hybrid microneedle (MN) patch system constructed with soluble poly(vinyl alcohol) (PVA) and AC-loaded polymeric micelles (AC@PMs) for transdermal delivery of AC to enhance the hyperlipidemia therapy. We first prepared various AC@PM formulations self-assembled from mPEG-PLA and mPEG-PLA-PEG block copolymers using a dialysis method and evaluated the physicochemical properties in combination with experiment skills and dissipative particle dynamics (DPD) simulations. Then, we encapsulated the AC@PMs into the PVA MN patch using a micromold filling method, followed by characterizing the performances, especially the structural stability, mechanical performance, and biosafety. After conducting in vivo experiments using a hyperlipidemic rat model, our findings revealed that the hybrid microneedle-mediated administration exhibited superior therapeutic efficacy when compared to oral delivery methods. In summary, we have successfully developed a hybrid microneedle (MN) patch system that holds promising potential for the efficient transdermal delivery of hydrophobic drugs.

Assessing the structural stability and drug encapsulation efficiency of poly(ethylene glycol)-poly(L-lactic acid) nanoparticles loaded with atorvastatin calcium: Based on dissipative particle dynamics.

Block polymer micelles have been proven highly biocompatible and effective in improving drug utilization for delivering atorvastatin calcium. Therefore, it is of great significance to measure the stability of drug-loading nano micelles from the perspective of block polymer molecular sequence design, which would provide theoretical guidance for subsequent clinical applications. This study aims to investigate the structural stability of drug-loading micelles formed by two diblock/triblock polymers with various block sequences through coarse-grained dissipative particle dynamics (DPD) simulations. From the perspectives of the binding strength of poly(L-lactic acid) (PLLA) and polyethylene glycol (PEG) in nanoparticles, hydrophilic bead surface coverage, and the morphological alteration of nanoparticles induced by shear force, the ratio of hydrophilic/hydrophobic sequence length has been observed to affect the stability of nanoparticles. We have found that for diblock polymers, PEG3kda-PLLA2kda has the best stability (corresponding hydrophilic coverage ratio is 0.832), while PEG4kda-PLLA5kda has the worst (coverage ratio 0.578). For triblock polymers, PEG4kda-PLLA2kda-PEG4kda has the best stability (0.838), while PEG4kda-PLLA5kda-PEG4kda possesses the worst performance (0.731), and the average performance on stability is better than nanoparticles composed of diblock polymers.

Non-lamellar lyotropic liquid crystalline nanoparticles as nanocarriers for enhanced drug encapsulation of atorvastatin calcium and proanthocyanidins.

Atorvastatin calcium (ATV) and proanthocyanidins (PAC) have a strong antioxidant activity, that can benefit to reduce the atherosclerotic plaque progression. Unfortunately, the bioavailability of ATV is greatly reduced due to its limited drug solubility while the PAC drug is unstable upon exposure to the atmospheric oxygen. Herein, the lyotropic liquid crystalline nanoparticles (LLCNPs) constructed by a binary mixture of soy phosphatidylcholine (SPC) and citric acid ester of monoglyceride (citrem) at different weight ratios were used to encapsulate the hydrophobic ATV and hydrophilic PAC. The LLCNPs were further characterized by small-angle X-ray scattering and dynamic light scattering. Depending on the lipid composition, the systems have a size range of 140-190 nm and were able to encapsulate both drugs in the range of 90-100%. Upon increasing the citrem content of drug-loaded LLCNPs, the hexosomes (H2) was completely transformed to an emulsified inverse micellar (L2). The optimum encapsulation efficiency (EE) of ATV and PAC were obtained in citrem/SPC weight ratio 4:1 (L2) and 1:1 (H2), respectively. There was a substantial change in the mean size and PDI of the nanoparticles upon 30 days of storage with the ATV-loaded LLCNPs exhibiting greater colloidal instability than PAC-loaded LLCNPs. The biphasic released pattern (burst released at the initial stage followed by the sustained released at the later stage) was perceived in ATV formulation, while the burst drug released pattern was observed in PAC formulations that could be attributed by its internal H2 structure. Interestingly, the cytokine studies showed that the PAC-LLCNPs promisingly up regulate the expressions of tumor necrosis factor-alpha (TNF-α) better than the drug-free and ATV-loaded LLCNPs samples. The structural tunability of citrem/SPC nanoparticles and their effect on physicochemical characteristic, biological activities and potential as an alternative drug delivery platform in the treatment of atherosclerosis are discussed.

Significant progress in improving Atorvastatin dissolution rate: Physicochemical characterization and stability assessment of self-dispersible Atorvastatin/Tween 80® nanocrystals formulated through wet milling and freeze-drying.

Atorvastatin (ATV) is a first-line drug for the treatment of hyperlipidemia. This drug presents biopharmaceutical problems, partly due to its low solubility and dissolution rate. In this work, nanocrystals of ATV stabilized with Tween 80® were designed by wet milling. A full factorial design was applied to optimize the process. Additionally, a cryoprotectant agent (maltodextrin, MTX) was identified, which allowed maintaining the properties of the nanocrystals after lyophilization. The storage stability of the nanocrystals was demonstrated for six months in different conditions. The obtained nanocrystal powder was characterized using SEM, EDXS, TEM, DSC, TGA, FT-IR, and XRD, showing the presence of irregular crystals with semi-amorphous characteristics, likely due to the particle collision process. Based on the reduction in particle size and the decrease in drug crystallinity, a significant increase in water and phosphate buffer (pH 6.8) solubility by 4 and 6 times, respectively, was observed. On the other hand, a noticeable increase in the dissolution rate was observed, with 90 % of the drug dissolved within 60 min of study, compared to 30 % of the drug dissolved within 12 h in the case of the untreated drug or the physical mixture of components. Based on these results, it can be concluded that the nano-milling of Atorvastatin stabilized with Tween 80® is a promising strategy for developing new formulations with improved biopharmaceutical properties of this widely used drug.

A novel circular RNA, circSQSTM1, protects the endothelial function in atherosclerosis.

A novel circRNA named circSQSTM1 (hsa_circRNA_075320) was screened out in atorvastatin (ATV) stimulated endothelial cells (ECs) by our group. Considering the anti-atherosclerotic function of ATV, we hypothesized the circSQSTM1 could protect ECs functions in AS progression. The effects of circSQSTM1 on ECs inflammation, oxidative stress and autophagy were measured by qRT-PCR, Western blotting, monocyte-endothelial adhesion assay, dichloro-dihydro-fluorescein diacetate and mCherry-GFP-LC3 labeling. A luciferase reporter assay, RNA immunoprecipitation, MS2-tagging system and fluorescence in situ hybridization were performed to identify the biological functions of circSQSTM1. The partial left carotid artery ligation model and atherosclerosis model were established to analyze the effects of circSQSTM1 on atherosclerosis progression in vivo. Our results revealed that ATV induced the accumulation of circSQSTM1 in ECs via suppressing m6A modified degradation. In the cytoplasm, circSQSTM1 could relieve Sirt1 by competitively sponging miR-23b-3p. In the nucleus, circSQSTM1 directly interacts with eIF4A3 and promoting the efficient nuclear export of FOXO1 mRNA, which encodes FOXO1 transcription factor to directly activate Sirt1 promoter activity. Hence, circSQSTM1 reduced inflammation, inhibited oxidative stress and promoted autophagy by upregulating Sirt1 in ECs. Moreover, circSQSTM1 overexpression in ECs attenuated the progression of atherosclerosis in ApoE-/- mice. Taken together, the unique noncoding RNA known as circSQSTM1 took a protective role to the ECs in atherosclerosis.

Inhibition of Methamphetamine-Induced Cytotoxicity in the U87-Cell Line by Atorvastatin-Conjugated Carbon Nanotubes.

In biological systems, carbon nanotubes can enhance the biological effects of drugs and reduce their side effects. Methamphetamine (METH) is a stimulant drug that induces cell death in various cell types, primarily neural cells. On the other hand, specific doses of atorvastatin (ATO) can stimulate cell growth and inhibit cell death in different cell lines. This study aimed to investigate the improvement effect of ATO@single-walled carbon nanotube (SWCNT) on METH-induced cell cytotoxicity in the U87 glioblastoma cell line. In this study, cells were cultured in 10 mM of METH during the cell treatment with 0-10 nM of ATO and ATO@SWCNT. The conjugated drugs to SWCNT as Van der Waals were detected using field emission scanning electron microscopy, Fourier transform-infrared spectroscopy, and other analyses. Then, the in vitro proliferating of ATO@SWCNT was explored against glioblastoma cells compared to pure ATO. This examine was performed using methyl thiazole tetrazolium approach, terminal deoxynucleotidyl transferase deoxy uridine-triphosphate nick end labeling assay, caspase-3 method, lactate dehydrogenase assay, and RH-123 assay with 10 mM METH. The results obtained from transmission electron microscopy analysis showed the average size of 50 nm for ATO@SWCNT. This study indicated that U87 cells, which were exposed to METH and suffered cell death, were severely reduced in the presence of ATO, especially ATO@SWCNT (for its anti-apoptotic effect), but they survived. This study suggests that ATO, which was primarily used to reduce blood lipids, can significantly reduce brain cell death. The findings of this study indicate that by using SWCNT, more drugs can reach the target cells. This method reduces the total amount of required medication and shows a more beneficial therapeutic effect.

Establishment of an in vitro safety assessment model for lipid-lowering drugs using same-origin human pluripotent stem cell-derived cardiomyocytes and endothelial cells.

Cardiovascular safety assessment is vital for drug development, yet human cardiovascular cell models are lacking. In vitro mass-generated human pluripotent stem cell (hPSC)-derived cardiovascular cells are a suitable cell model for preclinical cardiovascular safety evaluations. In this study, we established a preclinical toxicology model using same-origin hPSC-differentiated cardiomyocytes (hPSC-CMs) and endothelial cells (hPSC-ECs). For validation of this cell model, alirocumab, a human antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), was selected as an emerging safe lipid-lowering drug; atorvastatin, a common statin (the most effective type of lipid-lowering drug), was used as a drug with reported side effects at high concentrations, while doxorubicin was chosen as a positive cardiotoxic drug. The cytotoxicity of these drugs was assessed using CCK8, ATP, and lactate dehydrogenase release assays at 24, 48, and 72 h. The influences of these drugs on cardiomyocyte electrophysiology were detected using the patch-clamp technique, while their effects on endothelial function were determined by tube formation and Dil-acetylated low-density lipoprotein (Dil-Ac-LDL) uptake assays. We showed that alirocumab did not affect the cell viability or cardiomyocyte electrophysiology in agreement with the clinical results. Atorvastatin (5-50 µM) dose-dependently decreased cardiovascular cell viability over time, and at a high concentration (50 µM, ~100 times the normal peak serum concentration in clinic), it affected the action potentials of hPSC-CMs and damaged tube formation and Dil-Ac-LDL uptake of hPSC-ECs. The results demonstrate that the established same-origin hPSC-derived cardiovascular cell model can be used to evaluate lipid-lowering drug safety in cardiovascular cells and allow highly accurate preclinical assessment of potential drugs.

Atorvastatin Ester Regulates Lipid Metabolism in Hyperlipidemia Rats via the PPAR-signaling Pathway and HMGCR Expression in the Liver.

Atorvastatin ester (Ate) is a structural trim of atorvastatin that can regulate hyperlipidemia. The purpose of this study was to evaluate the lipid-lowering effect of Ate. Male Sprague Dawley (SD) rats were fed a high-fat diet for seven months and used as a hyperlipidemia model. The lipid level and liver function of the hyperlipidemia rats were studied by the levels of TG, TC, LDL, HDL, ALT, and AST in serum after intragastric administration with different doses of Ate. HE staining was used to observe the pathological changes of the rat liver and gastrocnemius muscle. The lipid deposits in the liver of rats were observed by staining with ORO. The genes in the rat liver were sequenced by RNA-sequencing. The results of the RNA-sequencing were further examined by qRT-PCR and western blotting. Biochemical test results indicated that Ate could obviously improve the metabolic disorder and reduce both the ALT and AST levels in serum of the hyperlipidemia rats. Pathological results showed that Ate could improve HFD-induced lipid deposition and had no muscle toxicity. The RNA-sequencing results suggested that Ate affected liver lipid metabolism and cholesterol, metabolism in the hyperlipidemia-model rats may vary via the PPAR-signaling pathway. The western blotting and qRT-PCR results demonstrated the Ate-regulated lipid metabolism in the hyperlipidemia model through the PPAR-signaling pathway and HMGCR expression. In brief, Ate can significantly regulate the blood lipid level of the model rats, which may be achieved by regulating the PPAR-signaling pathway and HMGCR gene expression.

In vitro study on the potential fungicidal effects of atorvastatin in combination with some azole drugs against multidrug resistant Candida albicans.

The resistance of Candida albicans to azole drugs represents a great global challenge. This study investigates the potential fungicidal effects of atorvastatin (ATO) combinations with fluconazole (FLU), itraconazole (ITR), ketoconazole (KET) and voriconazole (VOR) against thirty-four multidrug-resistant (MDR) C. albicans using checkerboard and time-kill methods. Results showed that 94.12% of these isolates were MDR to ≥ two azole drugs, whereas 5.88% of them were susceptible to azole drugs. The tested isolates exhibited high resistance rates to FLU (58.82%), ITR (52.94%), VOR (47.06%) and KET (35.29%), whereas only three representative (8.82%) isolates were resistant to all tested azoles. Remarkably, the inhibition zones of these isolates were increased at least twofold with the presence of ATO, which interacted in a synergistic (FIC index ≤ 0.5) manner with tested azoles. In silico docking study of ATO and the four azole drugs were performed against the Lanosterol 14-alpha demethylase enzyme (ERG11) of C. albicans. Results showed that the mechanism of action of ATO against C. albicans is similar to that of azole compounds, with a docking score (-4.901) lower than azole drugs (≥5.0) due to the formation a single H-bond with Asp 225 and a pi-pi interaction with Thr 229. Importantly, ATO combinations with ITR, VOR and KET achieved fungicidal effects (≥ 3 Log10 cfu/ml reduction) against the representative isolates, whereas a fungistatic effect (≤ 3 Log10 cfu/ml reduction) was observed with FLU combination. Thus, the combination of ATO with azole drugs could be promising options for treating C. albicans infection.

Identifying FDA-approved drugs with multimodal properties against COVID-19 using a data-driven approach and a lung organoid model of SARS-CoV-2 entry.

BACKGROUND: Vaccination programs have been launched worldwide to halt the spread of COVID-19. However, the identification of existing, safe compounds with combined treatment and prophylactic properties would be beneficial to individuals who are waiting to be vaccinated, particularly in less economically developed countries, where vaccine availability may be initially limited. METHODS: We used a data-driven approach, combining results from the screening of a large transcriptomic database (L1000) and molecular docking analyses, with in vitro tests using a lung organoid model of SARS-CoV-2 entry, to identify drugs with putative multimodal properties against COVID-19. RESULTS: Out of thousands of FDA-approved drugs considered, we observed that atorvastatin was the most promising candidate, as its effects negatively correlated with the transcriptional changes associated with infection. Atorvastatin was further predicted to bind to SARS-CoV-2's main protease and RNA-dependent RNA polymerase, and was shown to inhibit viral entry in our lung organoid model. CONCLUSIONS: Small clinical studies reported that general statin use, and specifically, atorvastatin use, are associated with protective effects against COVID-19. Our study corroborrates these findings and supports the investigation of atorvastatin in larger clinical studies. Ultimately, our framework demonstrates one promising way to fast-track the identification of compounds for COVID-19, which could similarly be applied when tackling future pandemics.

[18F]Atorvastatin Pharmacokinetics and Biodistribution in Healthy Female and Male Rats.

Statins are 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors that are widely used to prevent cardiovascular diseases. However, a series of pleiotropic mechanisms have been associated with statins, particularly with atorvastatin. Therefore, the assessment of [18F]atorvastatin kinetics with positron emission tomography (PET) may elucidate the mechanism of action of statins and the impact of sexual dimorphism, which is one of the most debated interindividual variations influencing the therapeutic efficacy. [18F]Atorvastatin was synthesized via a previously optimized 18F-deoxyfluorination strategy, used for preclinical PET studies in female and male Wistar rats (n = 7 for both groups), and for subsequent ex vivo biodistribution assessment. PET data were fitted to several pharmacokinetic models, which allowed for estimating relevant kinetic parameters. Both PET imaging and biodistribution studies showed negligible uptake of [18F]atorvastatin in all tissues compared with the primary target organ (liver), excretory pathways (kidneys and small intestine), and stomach. Uptake of [18F]atorvastatin was 38 ± 3% higher in the female liver than in the male liver. The irreversible 2-tissue compartment model showed the best fit to describe [18F]atorvastatin kinetics in the liver. A strong correlation (R2 > 0.93) between quantitative Ki (the radiotracer's unidirectional net rate of influx between compartments) and semi-quantitative liver's SUV (standard uptake value), measured between 40 to 90 min, showed potential to use the latter parameter, which circumvents the need for blood sampling as a surrogate of Ki for monitoring [18F]atorvastatin uptake. Preclinical assays showed faster uptake and clearance for female rats compared to males, seemingly related to a higher efficiency for exchanges between the arterial input and the hepatic tissue. Due to the slow [18F]atorvastatin kinetics, equilibrium between the liver and plasma concentration was not reached during the time frame studied, making it difficult to obtain sufficient and accurate kinetic information to quantitatively characterize the radiotracer pharmacokinetics over time. Nevertheless, the reported results suggest that the SUV can potentially be used as a simplified measure, provided all scans are performed at the same time point. Preclinical PET-studies with [18F]atorvastatin showed faster uptake and clearance in female compared to male rats, apparently related to higher efficiency for exchange between arterial blood and hepatic tissue.

Assessing the Interactions of Statins with Human Adenylate Kinase Isoenzyme 1: Fluorescence and Enzyme Kinetic Studies.

Statins are the most effective cholesterol-lowering drugs. They also exert many pleiotropic effects, including anti-cancer and cardio- and neuro-protective. Numerous nano-sized drug delivery systems were developed to enhance the therapeutic potential of statins. Studies on possible interactions between statins and human proteins could provide a deeper insight into the pleiotropic and adverse effects of these drugs. Adenylate kinase (AK) was found to regulate HDL endocytosis, cellular metabolism, cardiovascular function and neurodegeneration. In this work, we investigated interactions between human adenylate kinase isoenzyme 1 (hAK1) and atorvastatin (AVS), fluvastatin (FVS), pravastatin (PVS), rosuvastatin (RVS) and simvastatin (SVS) with fluorescence spectroscopy. The tested statins quenched the intrinsic fluorescence of hAK1 by creating stable hAK1-statin complexes with the binding constants of the order of 104 M-1. The enzyme kinetic studies revealed that statins inhibited hAK1 with significantly different efficiencies, in a noncompetitive manner. Simvastatin inhibited hAK1 with the highest yield comparable to that reported for diadenosine pentaphosphate, the only known hAK1 inhibitor. The determined AK sensitivity to statins differed markedly between short and long type AKs, suggesting an essential role of the LID domain in the AK inhibition. Our studies might open new horizons for the development of new modulators of short type AKs.

Formulation of Gelucire®-Based Solid Dispersions of Atorvastatin Calcium: In Vitro Dissolution and In Vivo Bioavailability Study.

Atorvastatin (ATV) is a poorly water-soluble drug that exhibits poor oral bioavailability. Therefore, present research was designed to develop ATV solid dispersions (SDs) to enhance the solubility, drug release, and oral bioavailability. Various SDs of ATV were formulated by conventional and microwave-induced melting methods using Gelucire®48/16 as a carrier. The formulated SDs were characterized for different physicochemical characterizations, drug release, and oral bioavailability studies. The results obtained from the different physicochemical characterization indicate the molecular dispersion of ATV within various SDs. The drug polymer interaction results showed no interaction between ATV and used carrier. There was marked enhancement in the solubility (1.95-9.32 folds) was observed for ATV in prepared SDs as compare to pure ATV. The drug content was found to be in the range of 96.19% ± 2.14% to 98.34% ± 1.32%. The drug release results revealed significant enhancement in ATV release from prepared SDs compared to the pure drug and the marketed tablets. The formulation F8 showed high dissolution performance (% DE30 value of 80.65 ± 3.05) among the other formulations. Optimized Gelucire®48/16-based SDs formulation suggested improved oral absorption of atorvastatin as evidenced with improved pharmacokinetic parameters (Cmax 2864.33 ± 573.86 ng/ml; AUC0-t 5594.95 ± 623.3 ng/h ml) as compared to ATV suspension (Cmax 317.82 ± 63.56 ng/ml; AUC0-t 573.94 ± 398.9 ng/h ml) and marketed tablets (Cmax 852.72 ± 42.63 ng/ml; 4837.4 ± 174.7 ng/h ml). Conclusively, solid dispersion-based oral formulation of atorvastatin could be a promising approach for enhanced drug solubilization, dissolution, and subsequently improved absorption.

Co-processing of Atorvastatin and Ezetimibe for Enhanced Dissolution Rate: In Vitro and In Vivo Correlation.

Development of fixed dose combinations is growing and many of these drug combinations are being legally marketed. However, the development of these requires careful investigation of possible physicochemical changes during co-processing. This requires investigation of the effect of co-processing of drug combination in absence of excipients to maximize the chance of interaction (if any). Accordingly, the aim was to investigate the effect of co-processing of ezetimibe and atorvastatin on drugs dissolution rate. The objective was extended to in vitro in vivo correlation. Drugs were subjected to wet co-processing in presence of ethanol after being mixed at different ratios. The prepared formulations were characterized using FTIR spectroscopy, X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, and in vitro dissolution testing. These investigations proved the possibility of eutectic system formation after drugs co-processing. This was reflected on drugs dissolution rate which was significantly enhanced at dose ratio and 2:1 atorvastatin:ezetimibe molar ratio compared to the corresponding pure drugs. In vivo antihyperlipidemic effects of the co-processed drugs were monitored in albino mice which were subjected to hyperlipidemia induction using poloxamer 407. The results showed significant enhancement in pharmacological activity as revealed from pronounced reduction in cholesterol level in mice administering the co-processed form of both drugs. Besides, histopathological examinations of the liver showed marked decrease in hepatic vacuolation. In conclusion, co-processing of atorvastatin with ezetimibe resulted in beneficial eutexia which hastened the dissolution rate and pharmacological effects of both drugs.Graphical abstract.

Pharmacokinetics and Pharmacodynamic Herb-Drug Interaction of Piperine with Atorvastatin in Rats.

Herbals that are widely consumed as therapeutic alternatives to conventional drugs for cardiovascular diseases, may lead to herb-drug interactions (HDIs). Atorvastatin (ATR) is drug of choice for hyperlipidemia and is extensively metabolized through CYP3A4 enzyme. Thus, we postulate that concomitant administration of ATR with piperine (PIP, potent inhibitor of CYP3A4 enzyme)/ridayarishta (RID, cardiotonic herbal formulations containing PIP) may lead to potential HDI. A simple, accurate, sensitive high-performance liquid chromatography-photodiode array detection method using Kromasil-100 C18 column, mobile phase acetonitrile: 30 mM phosphate buffer (55:45 v/v) pH 4.5 with flow rate gradient programming was developed to study the potential HDI in rats. Method was found to be linear (2-100 ng/mL) with Lower Limit of Detection (LLOD) 2 ng/mL. The precision (%CV < 15%), accuracy (-1.0 to -10% R.E) with recoveries above 90% from rat plasma of ATR and IS were obtained. The pharmacokinetic (PK) interactions studies on co-administration of ATR (8.4 mg/kg, p.o.) with PIP (35 mg/kg, p.o.), demonstrated a threefold increase in Cmax of ATR (P < 0.01) with significant increase in AUC0-t/AUC0-∞ compared to ATR alone indicating potential PK-HDI. However co-administration of RID (4.2 mL/kg, p.o.) showed less significant changes (P > 0.05) indicating low HDI. The pharmacodynamic effects/interactions study (TritonX-100 induced hyperlipidemic model in rats) suggested no significant alterations in the lipid profile on co-administration of PIP/RID with ATR, indicating that there may be no significant pharmacodynamic interactions.