Fast Analysis of Statins in Pharmaceuticals by MEKC

Critical analysis of analytical techniques developed for statins in biological fluids, environmental and fermentation samples

Statins are the most prescribed drug for regulating the high cholesterol level in the blood, which can lead to severe complications, such as cardiovascular diseases and other health complications. A wide range of analytical techniques have been employed for the quantification of statins from various origins, including fermentation derived (lovastatin, pravastatin, and compactin), semi-synthetic (simvastatin), and synthetic (atorvastatin, rosuvastatin, and fluvastatin) routes. The presence of more than one structural form and structural analogue generated in the biosynthesis pathway, as well as reaction intermediates and macromolecules in the clinical sample, complicates the quantification of statins. Furthermore, significant concentrations of statins in environmental samples pose serious health and ecology hazards, and estimating statins in those diluted samples is extremely difficult. On the other hand, the: cost, accurate estimation of the desired one from other structural forms, sample complexity, time, limits of detection and quantification, were major criteria distinguishing the usability of each technique. As a result, the current manuscript focuses on analytical techniques such as molecular spectroscopy (normal and derivatives UV-Visible spectrophotometer), chromatography (TLC, HP-TLC, HPLC, GC, swing column, micellar, and supercritical fluid), mass spectroscopy (HPLC-MS/MS and GC-MS/MS), sequential flow injection, capillary electrophoresis, and cyclic voltammetry, as well as their: optimal operating conditions, limits of detection and quantification, advancements, and limitations. Furthermore, various online and offline sample preparations (precipitation, solid phase extraction, liquid-liquid extraction, and micellar extraction) have been highlighted as an essential pretreatment technique to avoid the interference caused by structural analogues and other macromolecules. The greener and more sustainable concepts used in analytical approaches for the quantification statins are also highlighted with current advancements.

Shear Stress and ROS Dual-Responsive RBC-Hitchhiking Nanoparticles for Atherosclerosis Therapy

Atherosclerosis (AS), a leading cause of death worldwide, is a chronic inflammatory disease rich in lipids and reactive oxygen species (ROS) within plaques. Therefore, lowering lipid and ROS levels is effective in treating AS and reducing AS-induced mortality. In this study, an intelligent biomimetic drug delivery system that specifically responded to both shear stress and ROS microenvironment was developed, consisting of red blood cells (RBCs) and cross-linked polyethyleneimine nanoparticles (SA PEI) loaded with a lipid-lowering drug simvastatin acid (SA), and RBCs were self-assembled with SA PEI to obtain biresponsive SA PEI@RBCs for the treatment of AS. SA PEI could achieve sustained release of SA in response to ROS and reduce ROS and lipid levels to achieve the purpose of treating AS. Shear stress model experiments showed that SA PEI@RBCs could respond to the high shear stress level (100 dynes/cm2) at plaques, realizing the desorption and enrichment of SA PEI and improving the therapeutic efficiency of SA PEI@RBCs. In vitro and in vivo experiments have confirmed that SA PEI@RBCs exhibits better in vivo safety and therapeutic efficacy than SA PEI and free SA. Therefore, shaping SA PEI@RBCs into a biomimetic drug delivery system with dual sensitivity to ROS and shear stress is an effective strategy and treatment to facilitate their delivery into plaques.

Stepwise optimization and sensitivity improvement of green micellar electrokinetic chromatography method to simultaneously determine some fluoroquinolones and glucocorticoids present in various binary ophthalmic formulations

A sensitive micellar electrokinetic chromatography method is presented to simultaneously quantify ofloxacin, gatifloxacin, dexamethasone sodium phosphate and prednisolone acetate. The method has the advantages of being rapid, accurate, reproducible, ecologically acceptable and sensitive. The electrophoretic separation utilized 20 mm borate buffer as background electrolyte with pH 10.0 ± 0.1 and 50 mm sodium dodecyl sulfate as a micelle forming molecule. A capillary tube (50 μm i.d., 33 cm) of fused silica was used and on-column diode array detection at 243 nm for dexamethasone sodium phosphate and prednisolone acetate, and 290 nm for ofloxacin and gatifloxacin. Various factors were optimized such as the background electrolyte (type, concentration and pH), addition of sodium dodecyl sulfate and its concentration, detection wavelength, applied voltage and injection parameters. The studied drugs were efficiently separated in 6.2 min, at 20 kV with high resolution. The greenness of the method was estimated using an eco-scale tool and the presented method was found to have excellent green characteristics. The method was validated in conformance with International Conference on Harmonization guidelines, with acceptable accuracy, precision and selectivity. The suggested method can be employed for the economic analysis of the four drugs in dissimilar binary combinations of eye drops saving solvents and chemicals.

Development and validation of a green RP-HPLC method for the analysis of rosuvastatin: a step towards making liquid chromatography environmentally benign

The purpose of this study was to formulate and validate a new green high-performance liquid chromatography-ultraviolet (HPLC)-UV method for quick quantification of rosuvastatin calcium (ROC) in standard drugs. The results showed a combination of ethanol:methanol:ethyl acetate (6:3:1 v/v) at a rate of 1.0 ml/min to be the best for identifying ROC and its separation from its breakdown products. The identification of ROC was achieved using a NUCLEODUR 150 mm×4.6 mm RP C8 column packed using 5 μm filler as the stationary phase and detection was performed at 254 nm. The technique developed was checked for linearity, selectivity, accuracy, precision, robustness and sensitivity as well as specificity. The usefulness of the proposed process was confirmed by analyzing ROC in a prepared self-nanoemulsifying drug delivery system (SNEDDS) and over-the-counter products. The amount of ROC in SNEDDS was found to be 98.38%. The HPLC-UV system we developed effectively determined the ROC peak along with its breakdown products which confirmed the stability-indicating property of the projected system. The system could also be used to compare the solubility of rosuvastatin nanoparticles in standard drugs. These outcomes indicated that the developed HPLC could be effectively used for the regular investigation of ROC in standard drugs, various pharmaceutical formulations and drug release samples.

Comparison of the elution characteristics of individual forms of lovastatin in both isocratic and gradient modes and HPLC-PDA method development for pure and fermentation-derived lovastatin

The elution characteristics of lovastatin were studied by varying the composition of mobile phase in both isocratic and gradient elution modes to comprehend the role of organic modifier and acidifier on the overall analysis time and retention time of individual forms of lovastatin. Acetonitrile has influenced on the overall analysis time, whereas the acidifier determines the retention time of hydroxy acid form of lovastatin and the retention time gap between the individual forms. A combination of acetonitrile and 0.1% trifluoroacetic acid (TFA) (60:40, v/v) in isocratic elution mode eluted both hydroxy acid and lactone forms of lovastatin at 4.5 and 5.4 min, respectively. This appears to be a better approach for the separation of pharmaceutical and clinical lovastatin samples. At isocratic elution mode, a mixture of acetonitrile and either 0.05% TFA or 0.1% H₃PO₄ of 60:40 (v/v) has eluted both hydroxy acid and lactone forms of lovastatin at 10 ± 0.5 and 17 ± 0.5 min, respectively. This is suitable for the fermentation-derived samples or for the complex mixtures of structural analogs. The fermentation broth (pH not adjusted) extracted with ethyl acetate at a ratio of 1:1 (v/v) at 60°C for 30 min was the optimal extraction condition for lovastatin.

Pravastatin sodium

Pravastatin sodium is an [HMG-CoA] reductase inhibitor and is a lipid-regulating drug. This monograph includes the description of the drug: nomenclature, formulae, elemental composition, solubility, appearance, and partition coefficient. The uses and the methods that have been reported for the synthesis of this drug are described. The physical methods that were used to characterize the drug are the X-ray powder diffraction pattern, thermal methods, melting point, and differential scanning calorimetry. This chapter also contains the following spectra of the drug: the ultraviolet spectrum, the vibrational spectrum, the nuclear magnetic resonance spectra, and the mass spectrum. The compendial methods of analysis include the British Pharmacopoeia and the United States Pharmacopoeia methods. Other methods of analysis that are included in this profile are spectrophotometric, electrochemical, polarographic, voltammetric and chromatographic, and immunoassay methods. The chapter also contains the pharmacokinetics, metabolism, stability, and articles that reviewed pravastatin sodium manufacturing, characterization, and analysis. One hundred and sixty-two references are listed at the end of this comprehensive profile.

Development of a rapid LC/DAD/FLD/MS(n) method for the simultaneous determination of monacolins and citrinin in red fermented rice products

Red fermented rice is used worldwide by many patients as an alternative therapy for hyperlipidemia; however, the discovery of a toxic fermentation byproduct, citrinin, causes much controversy about the safety of red mold rice products. A new and fast high-performance liquid chromatography method was developed and validated for simultaneous determination of cholesterol-lowering compounds monacolin K (lovastatin), monacolin K hydroxy acid, and other monacolins present in red fermented rice as well as nephrotoxic mycotoxin citrinin in a single run using connected diode array and fluorescence and mass spectrometric detectors. The proposed method was successfully applied for the analysis of red fermented rice food samples and various dietary supplements also containing other natural lipid-lowering agents. The deviations between label content and levels of active compounds found in investigated samples as well as high batch-to-batch variation found in one product indicate that the regular quality control of red fermented rice products is of great importance.

MEKC as a powerful growing analytical technique

This review summarizes the principle and the developments in MEKC in terms of separation power, sensitivity, and detection approaches more than 25 years after its appearance. Newly used surfactants are mentioned. Classical and new sample concentration techniques in MEKC are described. The different detection approaches in MEKC with advantages, limitations, and future prospects are also discussed. This review highlights the wider application of MEKC in different analytical fields. Various recent selected applications of this technique in different analytical fields are reported.