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.

Effect of atorvastatin calcium plus clopidogrel in the treatment of patients with transient ischemic attacks and its effect on blood lipids and platelets

OBJECTIVE

To explore the clinical effect of atorvastatin calcium combined with clopidogrel in the treatment of patients with transient ischemic attacks (TIAs) and its effect on blood lipids and platelets.

METHODS

Low-density lipoprotein cholesterol (LDL-C)], platelet-related parameters [prothrombin time (PT), activated partial thromboplastin time (APTT), platelet count (PLT)], incidence of cerebral infarction, and adverse reactions.

RESULTS

The clinical outcomes of the experimental group patients were significantly better than those of the control group patients (p < 0.05). The experimental group exhibited notably lower levels of TG, TC, and LDL-C compared to the control group (p < 0.05). Platelet-related indices-PT, APTT, and PLT-showed no significant differences between groups before and after treatment (p > 0.05). The incidence of cerebral infarction was notably lower in the experimental group (p < 0.005), while the occurrence of adverse reactions showed no significant difference between groups (p > 0.05).

CONCLUSION

Atorvastatin calcium combined with clopidogrel demonstrates a positive impact on individuals with TIAs by significantly lowering levels of LDL, total cholesterol, and triglycerides. However, it is noteworthy that platelet-related indices did not exhibit significant differences between the experimental and control groups. While the observed improvements in blood lipids are attributed to the effects of atorvastatin, the combination with clopidogrel did not show a substantial influence on platelet-related parameters. Thus, the overall therapeutic impact, particularly on platelet-related indices, may require further investigation and clarification. Despite these nuances, our findings suggest potential benefits in reducing the risk of adverse reactions and cerebral infarction, supporting the consideration of this approach for wider clinical use.

Effects of atorvastatin in suppressing pulmonary vascular remodeling in rats with chronic obstructive pulmonary disease

OBJECTIVE

To investigate the effects of atorvastatin calcium on pulmonary vascular remodeling, the authors explored the regulatory mechanism of Histone Deacetylation Enzyme-2 (HDAC2) in rats with Chronic Obstructive Pulmonary Disease (COPD), and provided a new direction for drug treatment in the progression of vascular remodeling.

METHODS

Eighteen female SD rats were randomly divided into control (Group S1), COPD (Group S2), and atorvastatin calcium + COPD (Group S3) groups. A COPD rat model was established by passive smoking and intratracheal injection of Lipopolysaccharide (LPS). Haematoxylin and eosin staining and Victoria Blue + Van Gibson staining were used to observe pathological changes in the lung tissue. The pulmonary vascular inflammation score was calculated, and the degree of pulmonary vascular remodeling was evaluated. The ratio of Muscular Arteries in lung tissue (MA%), the ratio of the vessel Wall Area to the vessel total area (WA%), and the ratio of the vessel Wall Thickness to the vascular outer diameter (WT%) were measured using imaging software. The expression of HDAC2 was measured using western blotting, ELISA (Enzyme-Linked Immunosorbent Assay), and qPCR (Real-time PCR).

RESULTS

Compared with the control group, the degree of pulmonary vascular inflammation and pulmonary vascular remodeling increased in rats with COPD. The WT%, WA%, and lung inflammation scores increased significantly; the expression of HDAC2 and HDAC2mRNA in the serum and lung tissue decreased, and the level of Vascular Endothelial Growth Factor (VEGF) in the lung tissues increased (p < 0.05). Compared with the COPD group, the lung tissues from rats in the atorvastatin group had fewer inflammatory cells, and the vascular pathological changes were significantly relieved. The WT%, WA%, and lung inflammation scores decreased significantly; the expression of HDAC2 and HDAC2mRNA in the serum and lung tissues increased, and the level of VEGF in the lung tissues decreased (p < 0.05).

CONCLUSION

The present study revealed that atorvastatin calcium could regulate the contents and expression of HDAC2 in serum and lung tissues and inhibit the production of VEGF, thereby regulating pulmonary vascular remodeling in a rat model with COPD.

Development and validation of an eco-friendly HPLC-UV method for determination of atorvastatin and vitamin D3 in pure form and pharmaceutical formulation

Statin-associated muscle symptoms are considered as obvious adverse effects of prolonged statin therapy such as myopathy, myalgia, and rhabdomyolysis. These side effects are associated with vitamin D₃ deficiency and can be adjusted by amendment of serum vitamin D₃ level. Green chemistry aims to decrease the harmful effects of analytical procedures. Here we have developed a green and eco-friendly HPLC method for the determination of atorvastatin calcium and vitamin D₃. The two drugs were separated in less than 10 min on Symmetry column C₁₈ (100 × 4.6 mm, 3.5 µm) using a mixture consisting of 0.1% ortho-phosphoric acid (OPA) (pH = 2.16) and ethanol as the mobile phase in gradient manner. We have used Green Analytical Procedure Index (GAPI) tools and the Analytical GREEnness Metric Approach (AGREE) for assessment of the greenness of our proposed method. The method proved linearity over concentration ranges of (5-40) and (1-8) µg/ml with low limit of detection of 0.475 and 0.041 µg/ml for atorvastatin calcium and vitamin D₃ respectively. The method was successfully validated in accordance with ICH instructions and utilized for determination of the drugs of interest either in pure form or in their pharmaceuticals.

Optimization of a solidified micelle formulation for enhanced oral bioavailability of atorvastatin calcium using statistical experimental design

To enhance the oral bioavailability of atorvastatin calcium (ATV), a novel solidified micelle (S-micelle) was developed. Two surfactants, Gelucire 48/16 (G48) and Tween 20 (T20), were employed for micelle formation, and two solid carriers (SC), Florite PS-10 (FLO) and Vivapur 105 (VP105), were selected as solid carriers. The S-micelle was optimized using a Box-Behnken design with three independent variables, including G48:T20 (X₁, 1.8:1), SC:G48 + T20 (X₂, 0.65:1), and FLO:VP105 (X₃, 1.4:0.6), resulting in a droplet size (Y₁) of 198.4 nm, dissolution efficiency at 15 min in the pH 1.2 medium (Y₂) of 47.6%, Carr's index (Y₃) of 16.9, and total quantity (Y₄) of 562.5 mg. The optimized S-micelle resulted in good correlation showing percentage prediction values less than 10%. The optimized S-micelle formed a nanosized dispersion in the aqueous phase, with a higher dissolution rate than raw ATV and crushed Lipitor®. The optimized S-micelle improved the relative bioavailability of oral ATV (25 mg equivalent/kg) in rats by approximately 509% and 271% compared to raw ATV and crushed Lipitor^®, respectively. In conclusion, the optimized S-micelle possesses great potential for the development of solidified formulations for improved oral absorption of poorly water-soluble drugs.

A New method for simultaneous qualitative and quantitative determination of amlodipine besylate and atorvastatin calcium in bulk and pharmaceutical formulations using transmission FT-IR spectroscopy

A simple, precise, rapid, and eco-friendly FTIR spectrophotometric method was developed and validated for simultaneous analysis of amlodipine (AML) and atorvastatin (ATV) in drug combination preparations. Firstly, synthetic mixtures were made and scanned with FTIR instrument. Then the result spectra were converted automatically to absorbance spectra. The calibration model was made depending on Beer's law which relates concentration to absorbance. Two characteristic bands corresponding to the carbonyl group at 1708-1688 cm^-1 and 1660-1632 cm^-1 for AML and ATV, respectively, were selected for quantification. The absorbance of a series of standards was measured as the AUC of the chosen bands. Then, the calibration line was obtained by plotting the measured AUCs and the actual concentrations against each other. Validation tests were performed per ICH recommendations. Specificity was evaluated by the separation of APIs and excipients from marketed preparations by methanol. Then, the spectra of extracted excipients, APIs, and pharmaceutical samples were taken and overlapped. The selected peaks were specific and did not interfere with each other or other peaks from the excipients used in the tablet's matrix. Linearity for AML and ATV was in the range of 0.1-1% w/w with excellent coefficients of determination (R²), 0.998 and 0.999 for AML and ATV, respectively. The proposed analytical method was accurate and precious, as the RSD values were less than 2%. The proposed FTIR method was successfully applied to estimate the exact quantity of APIs in pharmaceutical samples. Recoveries were accepted in accordance with USP and were in the range of 94.62-100.6% and 98.175-101.06% for AML and ATV, respectively. Likewise, the acquired results were compared with the HPLC method. And the t- and F- tests were calculated and compared with the theoretical values, which indicate the similarity of results in both developed and reported methods.

Effect of nimodipine combined with atorvastatin calcium on microinflammation and oxidative stress levels in patients with cerebral vasospasm after subarachnoid hemorrhage

Objective

To evaluate the effect of nimodipine combined with atorvastatin calcium on the micro inflammation and oxidative stress levels in patients with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) and its clinical implications.

Methods

A total of 80 patients with CVS caused by SAH who had been admitted to Baoding First Central Hospital from August 2021 to August 2022 were selected and randomly divided into two groups. The control group underwent conventional symptomatic treatment, while the experimental group was administered nimodipine combined with atorvastatin calcium on the basis of conventional treatment. The changes in the micro inflammatory cytokines and oxidative stress factors in the two groups were compared, as well as the differences in clinical efficacy and incidence of adverse drug reactions.

Result

After treatment, the levels of inflammatory cytokines in the experimental group decreased more significantly than those in the control group (p=0.00). After treatment, the serum levels of oxidative stress factors were obviously higher in the experimental group than in the control group (p=0.00). After treatment, the total efficacy was 77.5% in the experimental group and 55% in the control group, and the difference was statistically significant (p=0.04).

Conclusions

Nimodipine combined with atorvastatin calcium could significantly improve the clinical symptoms in patients with CVS after SAH, which would be beneficial, safe, and effective for the patient's recovery.

Development and validation of a simple method for the determination of Atorvastatin calcium in pure and pharmaceutical formulations using spectrofluorimetry

A simple, accurate, precise, sensitive and selective spectrofluorimetric method was developed and validated for the determination of Atorvastatin calcium (ATV), an HMG-CoA reductase inhibitor, in its pure and tablet dosage form. The proposed method was based on direct measurement of the native fluorescence of ATV. Fluorescence analysis was accomplished by using an emission wavelength 385 nm after excitation at the wavelength of 270 nm in acetonitrile, without difficult preparation steps of the sample solution such as separation, extraction, pH adjustment or derivatization. All variables affecting the fluorescence intensity such as measurement time, temperature, and diluting solvent were investigated and optimized. Under the typical conditions, a validation study for linearity, range, accuracy, precision, selectivity and robustness of the proposed method was implemented according to ICH guidelines. The fluorescence intensity was linear over concentration range of (0.4-12) μg/ml (r = 0.9999), and the lower limits of detection and quantification were 0.079 and 0.24 μg/ml, respectively. Good accuracy and precision results were obtained through using the presented method with excellent mean recovery value 100.08 ± 0.32 which was in the acceptable range (98.0-102.0%), and RSD <2%, proving the precision of the developed method. Specificity was proved in the presence of excipients and Amlodipine besylate (AML) which encountered usually as combined drug with ATV. The developed method was successfully applied to the analysis of pharmaceuticals containing the mentioned drug with no interference from other drugs or dosage form additives, and the recoveries were in the range of 99.11 ± 0.75 to 100.89 ± 0.70. Furthermore, the obtained results were compared with reported HPLC method. Then, the t- and F- values were calculated and compared with the theoretical ones, which indicate good precision and high accuracy of the proposed method. Therefore, this method is valuable, reliable, and very suitable to be applied in routine quality control laboratories.

Process intensification of atorvastatin calcium crystallization for target polymorph development via continuous combined cooling and antisolvent crystallization using an oscillatory baffled crystallizer

In this paper, continuous crystallization of Atorvastatin calcium (ASC) using a continuous oscillatory baffled crystallizer (COBC) has been investigated. Like most API manufacturing, ASC is manufactured batchwise and the pure API is recovered via batch combined cooling and antisolvent crystallization (CCAC) process, which has the challenges of low productivity, wide crystal size distribution (CSD) and sometimes polymorphic form contamination. To overcome the limitations of the batch crystallization, continuous crystallization of ASC was studied in a NiTech (United Kingdom) DN15 COBC, manufactured by Alconbury Weston Ltd. (AWL, United Kingdom), with the aim to improve productivity and CSD of the desired polymorph. The COBC has the advantage of high heat transfer rates and improved mixing that significantly reduces the crystallization time. It also has the advantage of spatial temperature distribution and multiple addition ports to control supersaturation and hence the crystallization process. This work uses an array of process analytical technology (PAT) tools to assess key process parameters that affect the polymorphic outcome and CSD. Two parameters were found to have significant impact on the polymorph, they are ratio of solvent to antisolvent at the point of mixing of the two streams and presence of seeds. The splitting of antisolvent into two addition ports in the COBC was found to give the desired form. The CCAC of ASC in COBC was found to be -30-fold more productive than the batch CCAC process. The cycle time for generating 100 g of desired polymorphic form of ASC also significantly reduced from 22 h in batch process to 12 min in the COBC. The crystals obtained using a CCAC process in a COBC had a narrower CSD compared to that from a batch crystallization process.

Inhaled Atorvastatin Nanoparticles For Lung Cancer

BACKGROUND

Lung cancer is one of the main causes of mortality globally. This research paper aims at the development of an inhaled nanotechnology for lung cancer to deliver an atorvastatin calcium compound, for lung cancer, capable of reaching the tumor site directly via inhalation.

METHODS

Atorvastatin calcium micellar nanoparticles (ATO-NPs) encapsulated with Pluronic F-127 and polyvinyl alcohol (PVA) were manufactured utilizing the solvent and anti-solvent precipitation technique. The physicochemical features of the formulation were evaluated in terms of their physicochemical characteristics using Fourier transform infrared spectroscopy, differential scanning calorimetry, and dynamic light scattering. Additionally, the Andersen Cascade impactor was used at 15 L/minutes to assist in the aerosols performances of the formulation. The ATO-NPs formula's cell viability was tested in vitro using the A549 non-small cell lung cancer cell type.

RESULTS

Transmission electron microscopy was utilized to determine the ATO-NPs particle morphology, demonstrating a spherical shape with a smooth surface. The fine particle fraction of the aerosol produced was 62.70 ± 1.18%. This finding suggests that atorvastatin micellar nanoparticles are suitable for medication administration by inhalation with a wide particle size dispersion. Moreover, it was found in vitro that concentrations up to 21 µg/mL of the atorvastatin nanoparticles were safe and non-toxic on the cell model.

CONCLUSION

This study found that atorvastatin micellar nanoparticles for inhalation could potentially be used for lung cancer treatment.

Determination of arsenic, cadmium, mercury, lead and nickel as elemental impurities in atorvastatin calcium by inductively coupled mass spectrometer

Atorvastatin calcium is employed as front-line treatment for cardiovascular diseases. According to the international conference on harmonization (ICH) guideline ICH Q3D, elemental impurities can come into drug products from various sources. These elemental impurities do not have any therapeutic benefit to the end-user. On the contrary, it harms the normal physiological system. Class 1 elements like arsenic, cadmium, mercury, and lead are inorganic impurities that can cause toxic effects on the human body. Nickel was used as a catalyst during the synthesis process of atorvastatin calcium. It comes under the Class-2A, can cause toxicity to humans, and must be quantified. A simple, fast, reliable inductively coupled plasma mass spectrometric method for the estimation of elemental impurities like arsenic, cadmium, mercury, lead, and nickel in atorvastatin calcium by open sample digestion technique was developed and validated in accordance with ICH Q3D and USP < 232 > and USP <233 > general chapter. Internal standards like indium, terbium, thallium, bismuth and yttrium were used to correct the non-spectral interferences that were generated during analysis. Gold was added to all solutions as it preserves mercury by amalgamation. The system performance was evaluated every time my performing system suitability parameters. The limits for all the elements were fixed in accordance with ICH Q3D. The limit of detection and the limit of quantification for all the five elements were estimated. Method specificity was proven by checking for interferences due to the sample matrix and other elements. Linearity of each element in standards was established from 25% to 200% of sample concentration, and correlation coefficients were found to be not less than 0.999. The accuracy of the method was demonstrated at three spiking levels at 50%, 100%, and 150% of the J-value for all the elements. The recoveries for all elements at each level were within the range of 90-120%. Method precision was proved at 100% J-value. The relative standard deviation of all elements was less than 5%. It concludes that this newly developed and validated reliable inductively coupled plasma mass spectrometric method for estimating of elemental impurities like arsenic, cadmium, mercury, lead, and nickel in atorvastatin calcium was within the permitted limit and suitable for routine use.

Oleic acid-reinforced PEGylated polymethacrylate transdermal film with enhanced antidyslipidemic activity and bioavailability of atorvastatin: A mechanistic ex-vivo/in-vivo analysis

To enhance the poor bioavailability and extensive liver metabolism of atorvastatin calcium (ATC), we have developed an oleic acid-reinforced PEGylated polymethacrylate (OLA-PEG-E-RLPO) transdermal film as a convenient and alternative delivery system. The effect of varying levels of Eudragit RLPO, PEG 400, and oleic acid on the target product profile was optimized through Quality by Design (QbD) approach. The ATC-loaded OLA-PEG-E-RLPO transdermal films were evaluated in ex-vivo experiments using full thickness skin, utilizing Franz cell studies, and undergone in-vivo pharmacokinetics/pharmacodynamics (PK/PD) assessment, using poloxamer-induced dyslipidemic Sprague-Dawley rats. At 2 and 12 h, the optimized ATC films with a thickness of 0.79 mm showed permeation of 37.34% and 97.23% into the receptor compartment, respectively. Steady-state flux was 0.172 mg/cm²h, with 7.01 × 10^-4 cm/h permeability coefficient, and 0.713 × 10^-3 cm²/h diffusion coefficient. In-vivo PK results indicated that the absorption profiles (AUC_0-∞) of the optimized film in pre-treated group of animals were 8.6-fold and 2.8-fold greater than controls pre-treated with non-PEGylated non-oleic acid film and orally administered ATC, respectively. PD assessment of the lipid panel indicated that the lipid profile of the optimized film pre-treated group reached normal levels after 12 h, along with the significant enhancement over the non-PEGylated non-oleic acid film and the oral marketed tablet groups. The histopathological findings revealed near-normal hepatocyte structure for the optimized film pre-treated animal group. Our results further indicate that transdermal delivery films based on an optimized ATC-loaded OLA-PEG-E-RLPO were successfully developed and their assessment in both ex-vivo and in-vivo suggests enhanced permeability and improvement in bioavailability and antidyslipidemic activity of ATC. This approach can provide several advantages, especially during chronic administration of ATC, including improvement in patient compliance, therapeutic benefits, bioavailability, and feasibility for commercialization and as a platform for other drug classes.

Formulation and Evaluation of Atorvastatin Calcium-Poly-ε-Caprolactone Nanoparticles Loaded Ocular Inserts for Sustained Release and Antiinflammatory Efficacy

PURPOSE

The work was performed to investigate the feasibility of preparing ocular inserts loaded with Poly-ε-Caprolactone (PCL) nanoparticles as a sustained ocular delivery system.

METHODS

First, Atorvastatin Calcium-Poly-ε-Caprolactone (ATC-PCL) nanoparticles were prepared and characterized. Then, the optimized nanoparticles were loaded within inserts formulated with Methylcellulose (MC) and Polyvinyl Alcohol (PVA) by a solvent casting technique and evaluated physically, for in-vitro drug release profile. Finally, an in-vivo study was performed on the selected formulation to prove non-irritability and sustained ocular anti-inflammatory efficacy compared with free drug-loaded ocuserts.

RESULTS

The results revealed (ATC-PCL) nanoparticles prepared with 0.5% pluronic F127 were optimized with 181.72±3.6 nm particle size, 0.12±0.02 (PDI) analysis, -27.4± 0.69 mV zeta potential and 62.41%±4.7% entrapment efficiency. Nanoparticles loaded ocuserts manifested compatibility between drug and formulation polymers. Moreover, formulations complied with average weight 0.055±0.002 to 0.143±0.023 mg, and accepted pH. ATC-PCL nanoparticles loaded inserts prepared by 5% MC showed more sustained, prolonged in-vitro release over 24h. In-vivo study emphasized non-irritability, ocular anti-inflammatory effectiveness represented by smaller lid closure scores, and statistically significant lowering in PMN count after 3h.

CONCLUSION

These findings proposed a possibly simple, new and affordable price technique to prepare promising (ATC-PCL) nanoparticles loaded inserts to achieve sustained release with prolonged antiinflammatory efficacy.

Optimization of transdermal atorvastatin calcium - Loaded proniosomes: Restoring lipid profile and alleviating hepatotoxicity in poloxamer 407-induced hyperlipidemia

In an attempt to optimize the anti- hyperlipidemic effect and reduce statins induced hepatotoxicity, Atorvastatin Calcium (ATC) transdermal proniosomal gel (PNG) was developed. Different non-ionic surfactants (NISs) (Spans, Tweens, Cremophor RH 40 and Brij 52) were incorporated in the vesicle's lipid bilayer, in combination with lecithin. PNG formulae were characterized for encapsulation efficiency percent (% EE), vesicle size, polydispersity index (PDI) and zeta potential (ZP). Ex-vivo permeation study was performed using full thickness rat skin measuring drug flux and skin permeability coefficients. The pharmacodynamic performance of optimized transdermal ATC- PNG on both lipid profile and liver biomarkers was assessed and compared to oral ATC administration in poloxamer 407-induced hyperlipidemic rats. The liver tissues were subjected to histological examination as well. The results revealed nano-size range vesicles with relatively high ATC entrapment efficiency. Ex-vivo results demonstrated the permeation superiority of ATC proniosomes over free drug. Pharmacodynamic study revealed that transdermal administration of ATC- PNG succeeded in retaining the anti-hyperlipidemic efficacy of orally administered ATC without elevating liver biomarkers. The histological examination signified the role of optimized ATC-PNG in hindering statin- induced hepatocellular damage. The obtained results suggested a promising, easy-to-manufacture and effective ATC proniosomal gel for safe treatment of hyperlipidemia.

[Effects of Atorvastatin Calcium on the Survival of Ultra-long Dorsal Random Skin Flaps in Rats]

Objective

To investigate the effects of atorvastatin calcium (ATR) on the survival of ultra-long dorsal random skin flaps in rats.

Methods

Thirty SD rats were divided into five groups ( n=6) according to the random number table: normal saline control group (CON group), ATR 10 mg/kg group (P10 group), ATR 20 mg/kg group (P20 group), ATR 30 mg/kg group (P30 group), and ATR 40 mg/kg group (P40 group). After pretreatment with ATR or 0.9% saline for 3 days, an ultra-long dorsal random skin flaps with size of 8 cm×2 cm was made on the back of each rat and replanted in situ. After the operation, the ATR or saline treatment lasted for 3 d. Seven days after operation, the appearance of skin flaps was observed with naked eyes, the survival rate of skin flaps was calculated. The pathological changes in the surviving areas of skin flaps were observed by HE staining, the number of microvessels in skin flaps was observed by immunohistochemistry staining, the mRNA expressions of vascular endothelial growth factor ( VEGF) and basic fibroblast growth factor ( bFGF) were tested by quantitative real-time PCR, and the contents of superoxide dismutase, nitrogen monoxide and malonaldehyde were tested by enzyme linked immunosorbent assays (ELISA).

Results

On the 7 ^thday after operation, the skin flap of the CON group showed a large area of necrosis, and the necrotic part formed crusts. Crusts were hard and inelastic, and a large amount of tissue fluid exudated. The fascial layer showed dark purple. No exudation of tissue fluid was observed in the flaps of P10, P20, P30 and P40 groups. The scab shell fell off naturally and the fur grew normally. HE staining of CON group showed that a large number of inflammatory cell infiltration, epidermal loss and necrosis in skin flaps, but the pathological changes in skin flaps were significantly improved after treatment with ATR. Compared with the CON group, the survival rate of skin flaps, the number of microvessels in skin flaps and the levels of VEGF mRNA, bFGF mRNA, SOD, NO in skin flaps also increased with the dose of ATR, which reached a peak at 30 mg/kg ATR ( P<0.05). However, the level of MDA in skin flaps decreased with the dose of ATR, which reached the lowest at 30 mg/kg ATR ( P<0.05).

Conclusion

ATR can enhance the survival of ultra-long dorsal random skin flaps in rats, which may be related to promoting microangiogenesis and inhibiting inflammatory and oxidative stress.

An atorvastatin calcium and poly(L-lactide-co-caprolactone) core-shell nanofiber-covered stent to treat aneurysms and promote reendothelialization

Aneurysmal subarachnoid hemorrhage is a common complication caused by an intracranial aneurysm that can lead to hemorrhagic stroke, brain damage, and death. Knowing this clinical situation, the purpose of this study was to develop a controlled-release stent covered with a core-shell nanofiber mesh, fabricated by emulsion electrospinning, for the treatment of aneurysms. By encapsulating atorvastatin calcium (AtvCa) in the inner of poly (L-lactide-co-caprolactone) (PLCL) nanofibers, the release period of AtvCa was effectively extended. The morphology and inner structure of the core-shell nanofibers were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The release of AtvCa from the nanofiber system continued for more than ten weeks without a significant initial burst release. The nanofiber mesh structure degraded gradually but maintained its fiber morphology before neovascularization. The results of this study further elucidated the reendothelialization mechanism of AtvCa by analyzing the nitric oxide (NO) expression from seeded HUVECs. The in vivo studies demonstrated that the PLCL-AtvCa covered stents were capable of separating the aneurysm dome from the blood circulation, leading to the abolishment of the aneurysm. Moreover, the AtvCa controlled release promoted the in vitro proliferation of HUVECs on the nanofiber meshes, and the PLCL-AtvCa covered stents induced in vivo neovascularization. STATEMENT OF SIGNIFICANCE: Intracranial aneurysms are pathological dilatations of blood vessels that have developed an abnormally weak wall structure, thus prone to rupture. Covered stents had been demonstrated to be a method for the treatment of intracranial aneurysm. We prepared a controlled-release stent covered with a core-shell nanofiber mesh, fabricated by emulsion electrospinning, which encapsulated atorvastatin calcium in the inner portion of nanofibers. The results of this study further elucidated the reendothelialization mechanism of AtvCa by analyzing the nitric oxide (NO) expression from seeded HUVECs. The generated AtvCa-load covered stents separated the aneurysm dome from the blood circulation, and keep long-term patency of the parent artery. But also induced neovascularization, thus provide further protection against recurrence of aneurysms after nanofiber meshes degradation.

Boosting transdermal delivery of atorvastatin calcium via o/w nanoemulsifying system: Two-step optimization, ex vivo and in vivo evaluation

A nanoemulsion system was designed for Atorvastatin calcium (ATOR) transdermal delivery to overcome its poor bioavailability of (30%) resulting from the extensive first-pass effect and dissolution rate-limited in vivo absorption. Pseudo ternary phase diagrams were developed, and various NE formulae were prepared using oleic acid (OA), Tween 80 as surfactant and PEG 400 as cosurfactant, ethanol and limonene as permeation enhancers (PEs). NEs were characterized for morphology, droplet size, zeta potential and in vitro release. The optimized formulae were assessed for ex vivo transdermal permeation and in vivo pharmacodynamic/pharmacokinetic studies. Hypocholesterolemic effect after 7 days skin treatment was detected and compared to oral ATOR dispersion. Finally, blood plasma levels were measured for 24 h for rats received the selected transdermal NE and transdermal drug in OA. The obtained results suggested the low potentiality of NE systems in transdermal delivery of lipophilic drugs, only the addition of PEs is driving factor for increasing drug flux through full thickness rat skin. In the optimized formula, the presence of ethanol and PEG 400 disrupts SC lipids exhibiting rapid ex vivo release profile compared to other NEs and to ATOR in OA. In contrast, the optimized NE achieved a prolonged plasma profile. Transdermal NE was significantly more efficient than oral administration in lowering cholesterol plasma level and in increasing ATOR bioavailability. In conclusion, data revealed no correlation between ex vivo and in vivo studies explained by the collapse of the follicles in ex vivo skin permeation study, leaving only the lipoidal pathway for NE to pass through, thus only NE components, neither nanosizing nor other reported mechanisms, are the main influencing factors. In vivo experiments suggested that o/w NE changed ATOR pathway to follicular delivery leading to accumulation of NE in follicles and consequently a prolonged plasma profile.

Formulation and In Vitro Evaluation of Self Microemulsifying Drug Delivery System Containing Atorvastatin Calcium

OBJECTIVE

The aim of this study was to develop a new dosage form as an alternative to the classical tablet forms of atorvastatin calcium (AtrCa). The formulation strategy was to prepare an optimum self micro emulsifying drug delivery system (SMEDDS) to overcome the problem of low solubility of the active substance.

METHODS

In this study, pseudo ternary phase diagrams were plotted determined by the solubility studies. According to the solubility studies; oleic acid was used as the oil phase, Tween 20 and Span 80 were used as the surfactants and ethanol was used as the co-surfactant. SMEDDS formulations were characterized according to pH, electrical conductivity, density, refractive index, viscosity, emulsification time, dispersibility, robustness of dilution stability, droplet size, polidispersity index, zeta potential, transmittance %, cloud point, content quantification %, chemical and physical stability. The lipolysis study was conducted under fed and fasted conditions. In vitro release studies and kinetic evaluation were carried out. Permeability studies were also examined with Caco-2 cell culture.

RESULTS

The droplet size of the optimized formulation did not change significantly in different medias over the test time period. Improved SMEDDS formulation will progress steadily without precipitating along the gastrointestinal tract. Lipolysis studies showed that the oil solution had been exposed to high amount of lipolysis compared to the SMEDDS formulation. The release rate of AtrCa from AtrCa- SMEDDS formulation (93.8%, at 15 minutes) was found as increased when the results were compared with commercial tablet formulation and pure drug. The permeability value of AtrCa from AtrCa- SMEDDS formulation was found higher than pure AtrCa and commercial tablet formulation, approximately 9.94 and 1.64 times, respectively.

CONCLUSION

Thus, lipid-based SMEDDS formulation is a potential formulation candidate for lymphatic route in terms of the increased solubility of AtrCa.

Atorvastatin calcium inclusion complexation with polysaccharide arabinogalactan and saponin disodium glycyrrhizate for increasing of solubility and bioavailability

The aim of the present investigation was to enhance the solubility and dissolution of atorvastatin calcium (ATV), a poorly water-soluble drug with larch polysaccharide arabinogalactan (AG) and disodium glycyrrhizate (Na₂GA) as carriers of drug delivery systems for improving its bioavailability. The interactions of ATV with AG or Na₂GA were investigated by DSC, XRD, SEM, and NMR techniques. The molecular weights of supramolecular systems-inclusion complexes and micelles-which are the hosts for ATV molecules were measured. On the other hand, the rapid storage assay (+ 40 °C for 3 months) showed that the chemical stability of ATV/AG and ATV/Na₂GA complexes had been enhanced compared with pure ATV. In vitro drug release showed a significant increase in ATV's dissolution rate after formation of a complex with Na₂GA or AG. Pharmacokinetic tests in vivo on laboratory animals showed a significant increase in ATV's bioavailability after its introduction as a complex with Na₂GA or AG. Moreover, ATV/AG and ATV/Na₂GA complexes showed a more prominent decrease of total cholesterol (TC) level compared to net ATV. Therefore, the novel mechanochemically synthesized complexes of ATV with AG or Na₂GA as drug delivery systems might be potential and promising candidates for hypercholesterolemia treatment and deserved further researches.

Preparation, characterization, and in vitro/vivo evaluation of polymer-assisting formulation of atorvastatin calcium based on solid dispersion technique

Due to low solubility and bioavailability, atorvastatin calcium is confronted with challenge in conceiving appropriate formulation. Solid dispersion of atorvastatin calcium was prepared through the solvent evaporation method, with Poloxamer 188 as hydrophilic carriers. This formulation was then characterized by scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction and fourier transform infrared spectroscopy. Moreover, all these studies suggested the conversion of crystalline atorvastatin calcium. In addition, the drug solubility studies as well as dissolution rates compared with bulk drug and market tablets Lipitor were also examined. Furthermore, the study investigated the pharmacokinetics after oral administration of Lipitor and solid dispersion. And the AUC_0–8 h and C_max increased after taking ATC-P188 solid dispersion orally compared with that of Lipitor. All these could be demonstrated that ATC-P188 solid dispersions would be prospective means for enhancing higher oral bioavailability of ATC.

In vitro and in vivo evaluation of cyclodextrin-based nanosponges for enhancing oral bioavailability of atorvastatin calcium

The aim of this study was to explore the feasibility of complexing the poorly water-soluble drug atorvastatin calcium (AC) with β-cyclodextrin (β-CD) based nanosponges (NS), which offer advantages of improving dissolution rate and eventually oral bioavailability. Blank NS were fabricated at first by reacting β-CD with the cross-linker carbonyldiimidazole at different molar ratios (1:2, 1:4, and 1:8), then NS of highest solubilization extent for AC were complexed with AC. AC loaded NS (AC-NS) were characterized for various physicochemical properties. Pharmacokinetic, pharmacodynamics and histological finding of AC-NS were performed in rats. The prepared AC-NS showed particles size ranged from 408.7 ± 12.9 to 423 ± 15.9 nm while zeta potential values varied from -21.7 ± 0.90 to -22.7 ± 0.85 mV. The loading capacity varied from 17.9 ± 1.21 to 34.1 ± 1.16%. DSC, FT-IR, and PXRD studies confirmed the complexation of AC with NS and amorphous state of the drug in the complex. AC-NS displayed a biphasic release pattern with increase in the dissolution rate of AC as compared to plain AC. Oral administration of AC-NS (1:4 w/w, drug: NS) to rats led to 2.13-folds increase in the bioavailability as compared to AC suspension. Pharmacodynamics studies in rats with fatty liver revealed significant reduction (p < .05) in total cholesterol, triglyceride, LDL-C and increased level of beneficial HDL-C along with improvement in the associated liver steatosis as confirmed through photomicrographs of liver sections. In this study, we confirmed that complexation of AC with NS would be a viable approach for improving oral bioavailability and in vivo performance of AC.

Dissolution enhancement of atorvastatin calcium by co-grinding technique

Atorvastatin calcium (AC) is a BCS class II drug which shows poor bioavailability due to inadequate dissolution. Solid dispersions present a promising option to enhance the solubility of poorly soluble drugs. Co-grinding with hydrophilic excipients is an easy and economical technique to improve the solubility of poorly soluble drugs and is free from usage of organic solvents. The aim of the present study was to explore novel carrier VBP-1 (organosulphur compound) for formulating a solid dispersion by using a simple, commercially viable co-grinding technique to enhance the dissolution of AC and to develop an oral formulation of the same. Composition of the solid dispersion was optimized based on the release profile in pH 1.2 buffer. The optimized solid dispersion was further characterized for flow properties, DSC, FTIR spectroscopy, XRD, contact angle, SEM studies and release profile in phosphate buffer pH 6.8. The developed solid dispersion gave similar release profile as the innovator formulation (Lipitor® tablets) in both pH 1.2 buffer and phosphate buffer pH 6.8. The developed solid dispersion was formulated into hard gelatin capsules (size 3). The developed capsules were found to give similar release as the innovator formulation in both pH 1.2 buffer and phosphate buffer pH 6.8. The developed capsules were found to be stable for a period of 6 months. Anti-hyperlipidemic efficacy studies in rats showed higher reduction in cholesterol and triglyceride levels by the developed capsules in comparison to pure AC. In conclusion, novel carrier VBP-1 was successfully employed to enhance the dissolution of AC using co-grinding technique.

Atorvastatin Calcium Inhibits PDGF-ββ-Induced Proliferation and Migration of VSMCs Through the G0/G1 Cell Cycle Arrest and Suppression of Activated PDGFRβ-PI3K-Akt Signaling Cascade

BACKGROUND/AIMS

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is a hallmark of vascular lesions, such as atherosclerosis and restenosis. PDGF-ββ, an isoform of PDGF (platelet-derived growth factor), has been demonstrated to induce proliferation and migration of VSMCs. Atorvastatin calcium, a selective inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, has favorable protective effects on VSMCs. This study examined the effects of atorvastatin calcium on the proliferation and migration of PDGF-ββ-treated VSMCs, as well as its underlying mechanisms.

METHODS

MTT assays, Edu imaging, cell cycle analysis, wound healing assays, transwell migration assays, and western blot analysis were performed.

RESULTS

Atorvastatin calcium significantly inhibited cell proliferation, DNA synthesis and cell migration of PDGF-ββ-treated VSMCs. We demonstrated that atorvastatin calcium induced cell cycle arrest in the G0/G1 phase in response to PDGF-ββ stimulation and decreased the expression of G0/G1-specific regulatory proteins, including proliferating cell nuclear antigen (PCNA), CDK2, cyclin D1, cyclin E and CDK4 in PDGF-ββ-treated VSMCs. Moreover, pretreatment with atorvastatin calcium inhibited the PDGF-ββ-treated phosphorylation of PDGFRβ and Akt, whereas atorvastatin calcium did not affect the phosphorylation of PLC-γ1 or (ERK) 1/2.

CONCLUSION

Our data suggested that atorvastatin calcium inhibited abnormal proliferation and migration of VSMCs through G0/G1 cell cycle arrest and suppression of the PDGFRβ-Akt signaling cascade.

Reconstitutable spray dried ultra-fine dispersion as a robust platform for effective oral delivery of an antihyperlipidemic drug

The current article highlights the application of spray drying technique to produce an ultra-fine powder encapsulating the antihyperlipidemic drug, atorvastatin calcium (ATV). First, ATV was dissolved in an emulsion formulation, and different carriers (pectin, alginate, chitosan HCl and hydroxypropylmethyl cellulose) in two concentrations (1.5 and 3%) were added. Then, these carrier-containing formulations were subjected to spray drying, whereby ultra-fine ATV-loaded spray dried emulsions were produced (ATV-SDE). The optimum formulation; ATV-SDE7 containing 3% w/w pectin was selected showing an obviously enhanced dissolution profile compared to the other used polymers which could be attributed to its lower ability to swell in acidic medium, resulting in faster drug diffusion into release medium. Thus, ATV-SDE7 was subjected to further characterization including; DSC, XRPD, SEM and flowability properties. In-vivo studies were conducted using high-fat induced hyperlipidemic rats. The optimum formulation depicted normal lipid profile showing significant reduction in the measured parameters at the end of daily oral treatment, compared to ATV marketed tablets and control hyperlipidemic rats confirmed by normal liver sections upon histopathological examination. The superior lipid-lowering activity of ATV-SDE7 was not only due to the enhanced dissolution of ATV but also due to the presence of pectin which is capable of lowering both cholesterol and triglyceride serum levels. Hence, the present study suggests that the formulation strategy employing ultrafine redispersible spray dried emulsion with pectin as a carrier holds a promising approach for the development of a novel dosage form of enhanced antihyperlipidemic effect for ATV.

Comparison between Atorvastatin and Rosuvastatin in Renal Function Decline among Patients with Diabetes

BACKGROUND

Although the beneficial effects of statin treatment in dyslipidemia and atherosclerosis have been well studied, there is limited information regarding the renal effects of statins in diabetic nephropathy. We aimed to investigate whether, and which, statins affected renal function in Asian patients with diabetes.

METHODS

We enrolled 484 patients with diabetes who received statin treatment for more than 12 months. We included patients treated with moderate-intensity dose statin treatment (atorvastatin 10 to 20 mg/day or rosuvastatin 5 to 10 mg/day). The primary outcome was a change in estimated glomerular filtration rate (eGFR) during the 12-month statin treatment, and rapid renal decline was defined as a >3% reduction in eGFR in a 1-year period.

RESULTS

In both statin treatment groups, patients showed improved serum lipid levels and significantly reduced eGFRs (from 80.3 to 78.8 mL/min/1.73 m² for atorvastatin [P=0.012], from 79.1 to 76.1 mL/min/1.73 m² for rosuvastatin [P=0.001]). A more rapid eGFR decline was observed in the rosuvastatin group than in the atorvastatin group (48.7% vs. 38.6%, P=0.029). Multiple logistic regression analyses demonstrated more rapid renal function loss in the rosuvastatin group than in the atorvastatin group after adjustment for other confounding factors (odds ratio, 1.60; 95% confidence interval, 1.06 to 2.42).

CONCLUSION

These results suggest that a moderate-intensity dose of atorvastatin has fewer detrimental effects on renal function than that of rosuvastatin.

Compounding and stability evaluation of atorvastatin extemporaneous oral suspension using tablets or pure powder

Background

Statins are the first-line therapy for lowering high lipid levels. Atorvastatin calcium (AtC) is the most commonly prescribed statin. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase which converts HMG-CoA into mevalonic acid, a cholesterol precursor.

Objective

To compound and evaluate the stability of AtC suspension (0.4% w/v) using commercial tablets or pure AtC powder as the source of the active pharmaceutical ingredient.

Method

Several AtC suspension formulations were produced using commercial AtC tablets or AtC pure powder as the source of the active ingredient. The most suitable one in terms of general organoleptic properties and dissolution was selected for stability studies. For this purpose, samples of final suspensions were stored at room temperature and in the refrigerator. Assay, pH, organoleptic properties and microbial contamination were evaluated according to the USP specifications. High performance liquid chromatography was used for the analysis and quantification of AtC in the studied samples.

Results

The obtained suspension (S4) had good organoleptic properties. It showed complete dissolution of AtC within 30 min. However, the suspension prepared from crushed tablet (S_t4) showed a better dissolution profile than that prepared from pure powder (S_p4). The prepared formula had unchanged pH, which remained around 9.9. S_t and S_p formulas were both free from microbial contamination. Both products showed good stability within at least the period of use of the 100 mL AtC bottles.

Conclusions

AtC extemporaneous suspension was successfully prepared using tablets as a source of AtC or pure AtC powder. However, S_t4 had a better dissolution profile than S_p4. This study provides a solution for patients with swallowing difficulties or feeding tubes who are unable to take medicines in solid oral dosage forms. Community pharmacists can prepare the suspension using AtC tablets as the source of the active ingredient.

Transdermal delivery of atorvastatin calcium from novel nanovesicular systems using polyethylene glycol fatty acid esters: Ameliorated effect without liver toxicity in poloxamer 407-induced hyperlipidemic rats

CONTEXT

Atorvastatin calcium (ATV), a cholesterol-lowering agent, suffers from poor systemic availability (14%) after oral administration in addition to other side effects on the gastrointestinal tract, liver and muscle.

OBJECTIVE

The goal of the present investigation was to improve ATV bioavailability and overcome complications attendant with peroral administration by developing a new nanovesicular system encapsulating ATV for its delivery via the transdermal route.

METHODS

The vesicular systems were prepared by incorporating different polyethylene glycol fatty acid esters such as Labrasol, Cremophor EL, Gelucire 44/14 and Tween 80 as edge activators (EAs) in the lipid bilayer. The effect of the phosphatidylcholine (PC):EA molar ratio on the physicochemical properties of the vesicles was investigated. The pharmacokinetic studies of the optimized formulation were evaluated in rats. The optimized formulation was tested in poloxamer 407-induced hyperlipidemic rats. The plasma lipid profile, activity of liver enzymes, and oxidative stress parameters were measured using commercially available kits.

RESULTS

The results revealed high ATV entrapment efficiency (EE%) ranging from 55.62 to 83.91%. The formulations that contained Labrasol showed the highest EE%. The mean diameter of the vesicles was in the range of 186-583nm. T8 containing Gelucire 44/14 as an EA in the molar ratio of 15:1 (PC:EA) gave the smallest size and exhibited the best permeation parameters across the skin. The pharmacokinetic studies revealed that about three times statistically significant (p<0.05) improvement in bioavailability, after transdermal administration of nanotransfersomal ATV gel compared to oral ATV suspension. The transdermal vesicular system exhibited a significant decrease in plasma total cholesterol, triglycerides and LDL cholesterol comparable to oral ATV. Additionally, it lowered the malondialdehyde levels in plasma and abolished the increase in liver enzyme activity.

CONCLUSION

The results obtained suggest that the proposed transdermal vesicular system can serve as a promising alternative means for delivery of ATV.

Effect of two lipid-lowering strategies on high-density lipoprotein function and some HDL-related proteins: a randomized clinical trial

BACKGROUND

The influence of lipid-lowering therapy on high-density lipoprotein (HDL) is incompletely understood. We compared the effect of two lipid-lowering strategies on HDL functions and identified some HDL-related proteins.

METHODS

Thirty two patients were initially screened and HDLs of 21 patients were finally analyzed. Patients were randomized to receive atorvastatin 20 mg (n = 11) or atorvastatin 5 mg/ezetimibe 10 mg combination (n = 10) for 8 weeks. The cholesterol efflux capacity and other anti-inflammatory functions were assessed based on HDLs of the participants before and after treatment. Pre-specified HDL proteins of the same HDL samples were measured.

RESULTS

The post-treatment increase in cholesterol efflux capacities was similar between the groups (35.6% and 34.6% for mono-therapy and combination, respectively, p = 0.60). Changes in nitric oxide (NO) production, vascular cell adhesion molecule-1 (VCAM-1) expression, and reactive oxygen species (ROS) production were similar between the groups. The baseline cholesterol efflux capacity correlated positively with apolipoprotein (apo)A1 and C3, whereas apoA1 and apoC1 showed inverse associations with VCAM-1 expression. The changes in the cholesterol efflux capacity were positively correlated with multiple HDL proteins, especially apoA2.

CONCLUSIONS

Two regimens increased the cholesterol efflux capacity of HDL comparably. Multiple HDL proteins, not limited to apoA1, showed a correlation with HDL functions. These results indicate that conventional lipid therapy may have additional effects on HDL functions with changes in HDL proteins.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT02942602 .

The studies of PLGA nanoparticles loading atorvastatin calcium for oral administration in vitro and in vivo

A biodegradable poly(lactic-co-glycolic acid) loading atorvastatin calcium (AC) nanoparticles (AC-PLGA-NPs) were prepared by probe ultrasonication and evaporation method aiming at improving the oral bioavailability of AC. The effects of experimental parameters, including stabilizer species, stabilizer concentration and pH of aqueous phase, on particle size were also evaluated. The resultant nanoparticles were in spherical shape with an average diameter of 174.7 nm and a narrow particle size distribution. And the drug loading and encapsulation efficiency were about 8% and 71%, respectively. The particle size and polydispersion were almost unchanged in 10 days. The release curves of AC-PLGA-NPs in vitro displaying sustained release characteristics indicated that its release mechanisms were matrix erosion and diffusion. The pharmacokinetic study in vivo revealed that the C_max and AUC_0-∞ of AC-PLGA-NPs in rats were nearly 3.7-fold and 4.7-fold higher than that of pure atorvastatin calcium suspension. Our results demonstrated that the delivery of AC-PLGA-NPs could be a promising approach for the oral delivery of AC for enhanced bioavailability.

Atorvastatin solid dispersion for bioavailability enhancement

Atorvastatin calcium is a lipid-lowering agent. It has approximately 15% of bioavailability, remaining amount of drug showed adverse effect which is undesirable for patients. The objective of the study was to enhance the solubility and a dissolution profile of the atorvastatin (AT) calcium. Solid dispersion (SD) is a technique which enhances the solubility and a dissolution profile of poorly soluble drug. Various methods are being used for SDs such as microwave irradiation fusion, kneading, solvent evaporation, fusion, and dropping method. The authors have used here conventional fusion method using PEG 4000 as a hydrophilic carrier. The solubility of pure drug, physical mixture using PEG 4000 (1:3), and SD in phosphate buffer solutions (pH 6.8) was found to be 55.33 ± 0.66, 81.89 ± 2.35, and 93.66 ± 1.35, respectively. Fourier transform infrared and differential scanning calorimetry study showed the significant peak shift of drug in SD. It indicated that the nature of drug had been changed from crystalline form to amorphous form due to conversion into SD formulation. The dissolution rate was significantly increased when the drug polyethylene glycol 4000 ratio was 1:3. The mean cumulative percentage drugs release from pure drug, physical mixture, marketed tablet, and SD at 1 h was 28.92 ± 1.66%, 55.26 ± 0.95%, 72.16 ± 1.33%, and 91.66 ± 1.65%, respectively. It was concluded that the solubility and dissolution profile of SD of AT calcium showed the enhancement of solubility and dissolution when compared with marketed preparations.

New Chemometrics Mode Based on Adjacent Data Points' Differences for the Simultaneous Determination of Clopidogrel, Atorvastatin, and Aspirin in their Combined Ternary Drug Formulation

A new method is proposed for the analysis of a ternary mixture composed of clopidogrel, atorvastatin, and aspirin without prior separation steps. The method combines the advantages of the mean centering of ratio spectra and derivative spectrophotometric methods. It is based on using the difference between adjacent data points in the absorbance spectra. The principal advantage of this method is the use of absorbance data, and not derivative data; hence the signal-to-noise ratio is not diminished. The mathematical explanation of the procedure is illustrated. Beer’s law was valid in the concentration range 0.3–35 μg.mL^-1 for CLOP, 0.5–30 μg.mL^-1 for ATOR, and 1–40 μg.mL^-1 for ASP. Mean recoveries were obtained as 100.2, 100.1, and 100.2% for CLOP, ATOR, and ASP, respectively, in the prepared synthetic mixtures. The method has been successfully applied to the simultaneous determination of ternary mixtures of aspirin, clopidogrel bisulphate, and atorvastatin calcium. The analytical characteristics of the method were calculated. The results showed that the new method is simple, rapid, accurate, and precise.

Cost-effectiveness analysis of low density lipoprotein cholesterol-lowering therapy in hypertensive patients with type 2 diabetes in Korea: single-pill regimen (amlodipine/atorvastatin) versus double-pill regimen (amlodipine+atorvastatin)

OBJECTIVES

Single-pill combination therapy (amlodipine/atorvastatin) might be more effective than double-pill therapy (amlodipine+atorvastatin) in patients with diabetes and concomitant hypertension requiring statin therapy. We compared the cost-effectiveness of a single-pill with that of double-pill for control of low density lipoprotein cholesterol (LDL-C) levels, with the ultimate goal of cardiovascular disease prevention, in these patients using a cost-effectiveness analysis model that considered medication adherence.

METHODS

Effectiveness was defined as the percentage (%) attainment of target LDL-C levels (<100 mg/dL) based on adherence for each therapy. Adherence was defined as compliance to medication (≥80% proportion of days covered). A systematic review of the literature was conducted to determine the proportion of patients who were adherent and target goal attainment based on adherence level. The annual medication costs were based on the adherence levels for each regimen. The average cost-effectiveness ratio (ACER) was calculated as the cost per % attainment of the target LDL-C level.

RESULTS

The ACER for the single-pill regimen was lower than for the double-pill regimen (4,123 vs. 6,062 Korean won per 1% achievement of target goal). Compared with the double-pill, the medication costs were approximately 32% lower with the single-pill.

CONCLUSION

A single-pill for reductions in LDL-C is cost-effective compared with double-pill in hypertensive patients with type 2 diabetes.

Spectrophotometric and TLC-densitometric methods for the simultaneous determination of Ezetimibe and Atorvastatin calcium

Three sensitive methods were developed for simultaneous determination of Ezetimibe (EZB) and Atorvastatin calcium (ATVC) in binary mixtures. First derivative (D¹) spectrophotometry was employed for simultaneous determination of EZB (223.8 nm) and ATVC (233.0 nm) with a mean percentage recovery of 100.23 ± 1.62 and 99.58 ± 0.84, respectively. Linearity ranges were 10.00–30.00 μg mL⁻¹ and 10.00–35.00 μg mL⁻¹, respectively. Isosbestic point (IS) spectrophotometry, in conjunction with second derivative (D²) spectrophotometry was employed for analysis of the same mixture. Total concentration was determined at IS, 224.6 nm and 238.6 nm over a concentration range of 10.00–35.00 μg mL⁻¹ and 5.00–30.00 μg mL⁻¹, respectively. ATVC concentration was determined using D² at 313.0 nm (10.00–35.00 μg mL⁻¹) with a mean recovery percentage of 99.72 ± 1.36, while EZB was determined mathematically at 224.6 nm (99.75 ± 1.43) and 238.6 nm (99.80 ± 0.95). TLC-densitometry was employed for the determination of the same mixture; 0.10–0.60 μg band⁻¹ for both drugs. Separation was carried out on silica gel plates using diethyl ether–ethyl acetate (7:3 v/v). EZB and ATVC were resolved with R_f values of 0.78 and 0.13. Determination was carried out at 254.0 nm with a mean percentage recovery of 99.77 ± 1.30 and 99.86 ± 0.97, respectively. Methods were validated according to ICH guidelines and successfully applied for analysis of bulk powder and pharmaceutical formulations. Results were statistically compared to a reported method and no significant difference was noticed regarding accuracy and precision.

Stress Degradation Behavior of Atorvastatin Calcium and Development of a Suitable Stability-Indicating LC Method for the Determination of Atorvastatin, its Related Impurities, and its Degradation Products

A rapid, reversed-phase liquid chromatographic method was developed for the quantitative determination of Atorvastatin calcium, its related substances (12 impurities), and degradation impurities in bulk drugs. The chromatographic separation was achieved on a Zorbax Bonus-RP column by employing a gradient elution with water–acetonitrile–trifluoroacetic acid as the mobile phase in a shorter run time of 25 min. The flow rate was 1.0 mL/min and the detection wavelength was 245 nm. The drug substance was subjected to stress studies such as hydrolysis, oxidation, photolysis, and thermal degradation, and considerable degradation was observed in acidic hydrolysis, oxidative, thermal, and photolytic stress conditions. The formed degradation products were reported and were well-resolved from the Atorvastatin and its related substances. The stressed samples were quantified against a qualified reference standard and the mass balance was found to be close to 99.5% (w/w) when the response of the degradant was considered to be equal to the analyte (i.e. Atorvastatin), which demonstrates the stability-indicating capability of the method. The method was validated in agreement with ICH requirements. The method developed here was single and shorter (25 min method for the determination of all 12 related impurities of Atorvastatin and its degradation products), with clearly better resolution and higher sensitivity than the European (85 min method for the determination of six impurities) and United States pharmacopeia (115 min and 55 min, two different methods for the determination of six related substances).

Enhanced Bioavailability and Dissolution of Atorvastatin Calcium from Floating Microcapsules using Minimum Additives

Atorvastatin calcium, a lipid-lowering drug, is much less bioavailable because of reduced solubility in acidic media. Multiple-unit floating microcapsules of Atorvastatin calcium (ATC) were developed to expand the gastric residence time of the drug, as ATC has maximum rate of absorption in the upper GI tract. Floating microcapsules were prepared by Emulsion-solvent evaporation technique through incorporation of dioctyl sodium sulphosuccinate (DSS) as a dissolution enhancer. The microcapsules were assessed for shape, size, drug entrapment efficiency, stability and in-vitro drug dissolution rate and were subjected to SEM, DSC and PXRD studies. The ATC-loaded floating microcapsules were spherical in shape and had the particle size of about 28.10 μm and drug-loading efficiency of about 96.55 %. The floating microspheres containing DSS had significantly higher drug dissolution rates than those without DSS. The best formulation, AT4, consisting of Ethyl cellulose, DSS and Poly Ox®, had a maximum drug dissolution rate of 97.86 %, as compared to Storvas 80 mg (Ranbaxy Ltd, as a reference) which had a rate of only 54% during a period of 12 h in acidic media. A pharmacokinetic study performed on albino rabbits illustrates that the bioavailability of AT4 floating microcapsules significantly increased to nearly 1.7 times that of Storvas 80 mg. The present study indicates that the use of multi-unit floating microcapsules for delivery of ATC can improve its bioavailability.

Stability Indicating RP-HPLC Estimation of Atorvastatin Calcium and Amlodipine Besylate in Pharmaceutical Formulations

A simple, specific, accurate and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of atorvastatin calcium and amlodipine besylate in tablet dosage forms. A phenomenex Gemini C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.02 M potassium dihydrogen phosphate:acetonitrile:methanol (30:10:60, v/v/v) adjusted to pH 4 using ortho phosphoric acid was used. The flow rate was 1.0 ml/min and effluents were monitored at 240 nm. The retention times of atorvastatin calcium and amlodipine besylate were 11.6 min and 4.5 min, respectively. The calibration curves were linear in the concentration range of 0.08-20 μg/ml for atorvastatin calcium and 0.1-20 μg/ml for amlodipine besylate. Atorvastatin calcium and amlodipine besylate stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time values. The proposed method was validated and successfully applied to the estimation of atorvastatin calcium and amlodipine besylate in combined tablet dosage forms.

A validated densitometric method for analysis of atorvastatin calcium and metoprolol tartarate as bulk drugs and in combined capsule dosage forms

A simple, accurate and precise high-performance thin-layer chromatographic method has been developed for the estimation of Atorvastatin Calcium and Metoprolol Tartarate simultaneously from a capsule dosage form. The method employed Silica gel 60F _254sprecoated plates as stationary phase and a mixture of Chloroform: Methanol: Glacial acetic acid (dil.) :: (9:1.5:0.2 ml %v/v) as mobile phase. Densitometric scanning was performed at 220 nm using Camag TLC scanner 3. The method was linear in the drug concentrations’ range of 500 to 2500 ng/spot for Atorvastatin Calcium, also for Metoprolol Tartarate with correlation coefficient of 0.984 for Atorvastatin Calcium and 0.995 for Metoprolol Tartarate respectively. The retention factor for Atorvastatin Calcium was 0.45 ± 0.04 and for Metoprolol Tartarate was 0.25 ± 0.02. The method was validated as per ICH (International Conference on Harmonisation) Guidelines, proving its utility in estimation of Atorvastatin Calcium and Metoprolol Tartarate in combined dosage form.