Development of validated HPLC-UV method for simultaneous determination of Metformin, Amlodipine, Glibenclamide and Atorvastatin in human plasma and application to protein binding studies

Simultaneous Determination of Glibenclamide and Silymarin Released from Chitosan Microparticles by HPLC-ESI-MS Technique: Method Development and Validation

The study aim was to develop and validate a high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC-ESI-MS) method to simultaneously determine glibenclamide (Gli) and silymarin (Sil) released from chitosan (CS) microparticles in aqueous solutions. The CS microparticles were synthesized using an ionic gelation method, and their morphology, swelling degree, encapsulation efficiency and active substance release were investigated. Gli and Sil were loaded in different concentrations, and their identification and quantification were performed using the HPLC-ESI-MS method, which was further validated. The drugs’ characteristic m/z was found in the higher intensity of retention time (Rt) (Gli, 8.909 min; Sil A, 5.41 min; and Sil B, 5.66 min). The method selectivity and precision are very good, and the blank solution proved no interference. The linearity of the answer function is very good for Sil A (R² = 1), Sil B (R² = 0.9998) and Gli (R² = 0.9991). For Gli, we obtained a limit of detection (LOD) = 0.038 mg/mL and limit of quantification (LOQ) = 1.275 mg/mL; for Sil A, a LOD = 0.285 mg/mL and LOQ = 0.95 mg/mL; and for Sil B, a LOD = 0.045 mg/mL and LOQ = 0.15 mg/mL. A high-resolution HPLC-ESI-MS method was developed and validated, which allowed the simultaneous determination of Gli and Sil loaded in CS microparticles, in a concentration range of 0.025–1 mg/mL.

Enhancing Atorvastatin In Vivo Oral Bioavailability in the Presence of Inflammatory Bowel Disease and Irritable Bowel Syndrome Using Supercritical Fluid Technology Guided by wbPBPK Modeling in Rat and Human

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are common disorders that can change the body's physiology and drugs pharmacokinetics. Solid dispersion (SD) preparation using supercritical fluid technology (SFT) has many advantages. Our study aimed to explore the effect of IBS and IBD on atorvastatin (ATV) pharmacokinetics, enhance ATV oral bioavailability (BCS II drug) using SFT, and analyze drug-disease-formulation interaction using a whole-body physiologically based pharmacokinetic (wbPBPK) model in rat and human. A novel ATV formulation was prepared using SFT and characterized in vitro and in vivo in healthy, IBS, and IBD rats. The resulting ATV plasma levels were analyzed using a combination of conventional and wbPBPK approaches. The novel formulation increased ATV solubility by 20-fold and resulted in a zero-order release of up to 95%. Both IBS and IBD increased ATV exposure after oral and intravenous administration by more than 30%. The novel SFT formulation increased ATV bioavailability by 28, 14, and 18% in control, IBD, and IBD rat groups and resulted in more consistent exposure as compared to raw ATV solution. Higher improvements in ATV bioavailability of more than 2-fold upon receiving the novel SFT formulation were predicted by the human wbPBPK model as compared to receiving the conventional tablets. Finally, the established wbPBPK model could describe ATV ADME in the presence of IBS and IBD after oral administration of raw ATV and using the novel SFT formula and can help scale the optimized ATV dosing regimens in the presence of IBS and IBD from rats to humans.

A review on liquid chromatographic methods for the bioanalysis of atorvastatin

Background

The unsatisfied clinical need has encouraged the development and validation of bioanalytical procedures for the quantification of drugs in biological samples because the monitoring of drug concentrations helps in personalizing the patient’s pharmacotherapy, assessing the adherence to therapy, and is also extensively useful for pharmacokinetics and drug-drug interactions studies.

Main Body

The present review aimed to provide insightful information about the various liquid chromatographic methods developed till 2019 for the analysis and quantification of atorvastatin, its metabolites, and co-administered drugs in the various biological matrices like the serum, plasma, and urine with special emphasis on sample preparation techniques applied before chromatographic analysis along with different chromatographic conditions and their validation data. A total of 88 published papers that have used liquid chromatography techniques to quantify atorvastatin in biological fluids are included in the study. Out of the total reported liquid chromatographic methods, 34% used UV spectrophotometer as a detector, and 55% used MS/MS as a detector. Whereas 38% of them used protein precipitation procedure, 33% applied liquid-liquid extraction approach, and 12% employed solid-phase extraction technique for sample preparation.

Conclusion

In the last decade, numerous bioanalytical procedures have been developed for the quantification of atorvastatin in different biological samples using liquid chromatographic techniques. Moreover, advancement in technology developed several new and advanced sample preparation approaches like dispersive liquid-liquid extraction, microextraction by packed sorbent, which have high recovery rates than conventional procedures. Thus, the summarized review may be consulted as an informative tool to support the optimization of new bioanalytical methods for the quantification of atorvastatin.

Comparative Study of Different Derivative Spectrophotometric Techniques for the Analysis and Separation of Metformin, Empagliflozin, and Glimepiride

Background:

In some cases, lifestyle changes are not enough to keep type 2 diabetes under control, so there are several medications that may help. Metformin can lower your blood sugar levels, Glimepiride makes more insulin, whereas Empagliflozin prevents the kidneys from reabsorbing sugar into the blood and sending it out in the urine.

Methods:

Mean centering, double divisor, ratio spectra-zero crossing, and successive derivative were applied for the estimation of metformin, empagliflozin, and glimepiride respectively, in their prepared laboratory mixtures and in pharmaceutical tablets, without prior chemical separation. The absorption spectra of the mentioned drugs were recorded in the range of 200-400nm.

Results:

These methods were linear over concentration ranges of 1.0-10, 2.5-30, and 1.0-10 μgmL-1 of metformin, empagliflozin, and glimepiride respectively. Mean centering for metformin was measured at 234 and 248 nm, while empagliflozin and glimepiride had amplitude values at 276 and 262 nm, respectively. The derivative of double divisor was measured at 234, 278, and 288 nm for metformin, empagliflozin and glimepiride, respectively. The ratio of spectra-zero crossing was quantified at amplitude values of the analytical signal at 234 and 274 nm for metformin and empagliflozin, respectively, whereas glimepiride was determined at 242 and 286 nm. The successive ratio of metformin, empagliflozin, and glimepiride was determined at 284, 242, and 266 nm, respectively.

Conclusion:

The methods are validated according to the ICH guidelines where accuracy, precision and repeatability are found to be within the acceptable limit. The methods were studied and optimized. Upon validation linearity, precision, accuracy, LOD, LOQ and selectivity were proved to be operative for the analysis of specified drugs in pharmaceutical dosage configuration. Statistical illustration was done between the suggested methods with the reported methods with consideration to accuracy and precision. No significant difference was found by student’s t-test, F-test and one-way ANOVA.

Analytical and Bioanalytical Techniques for the Quantification of the Calcium Channel Blocker - Amlodipine: A Critical Review

Hypertension is a condition in which blood pressure is elevated to an extent where benefit is obtained from blood pressure lowering. The risk of complications is proportional to the level that blood pressure raises. Calcium channel blockers are a class of compounds used in the treatment of hypertension. The dihydropyridine (DHP) group, a subclass of the calcium channel blocker works almost exclusively on L-type calcium channels in the peripheral arterioles and reduce blood pressure by reducing total peripheral resistant. Long acting DHP is preferred because they are more convenient for patients and avoid the large fluctuations in plasma drug concentration which are associated with side effects. Amlodipine is the most distinct DHP and the most popular. The drug was patented in the year 1986 and its commercial sale began by 1990. The current article provides a state of art about the analytical and bioanalytical techniques available for the quantification of drug as a single entity and in combined pharmaceutical formulations between 1989 and 2019.

A Sensitive HPTLC Method for the Estimation of Glibenclamide, Rosiglitazone Maleate and Metformin Hydrochloride from a Multicomponent Dosage Form

A sensitive, rapid and cost-effective method based on HPTLC with UV detection was developed for the quantitation of Glibenclamide (GLIBEN), Rosiglitazone maleate (ROSI) and Metformin hydrochloride (MET) from a combined dosage form. Pre-coated RP-18 F254s aluminum sheets were used as the stationary phase. Methanol–tetrahydrofuran–water–glacial acetic acid (16: 3.6: 4: 0.4, v/v) used as the mobile phase, along with chamber saturation of 10 min offered an optimum migration (Rf = 0.54, 0.62 and 0.80 for GLIBEN, ROSI and MET, respectively). TLC Scanner 3 was used for densitometric evaluation of the chromatograms. DigiStore 2 Documentation System with winCATS software version 1.4.10 was used for the quantitation and photodocumentation. The LOD for GLIBEN, ROSI and MET was found to be 80 ng, 80 ng and 48 ng, respectively. Moreover, the LOQ was 200 ng, 200 ng and 120 ng for GLIBEN, ROSI and MET, respectively. The method was linear for GLIBEN (r = 0.9991), ROSI (r = 0.9993) and MET (r = 0.9988) within the tested range (200–1000, 200–1000 and 120–600 ng/band, respectively). The method was found to be precise and accurate for all the three drugs. The method was applied for the analysis of Triglucored tablets, and it proved to be a reliable quality control tool for the routine analysis of GLIBEN, ROSI and MET in a combined dosage form.

Development and Validation of an RP-HPLC Method for Determination of Atorvastatin and its Hydroxyl Metabolites in Human Plasma

Background:

Atorvastatin (AT) belongs to cholesterol-lowering agents, commonly used in patients with an increased risk of cardiovascular disease. The drug, as well as its hydroxyl metabolites, exhibit pharmacological activity, and their plasma levels may be helpful in the assessment of the therapeutic effectiveness.

Objective:

Development and validation of a fast and reproducible RP-HPLC method with UV detection for the simultaneous determination of atorvastatin and its active metabolites, para-hydroxy-atorvastatin (p-OH-AT) and ortho-hydroxy-atorvastatin (o-OH-AT) in human plasma.

Methods:

Optimal conditions of chromatographic separation of the analytes, as well as rosuvastatin, chosen as an internal standard, were studied. The absorbance of the compounds was measured at λ=248 nm. Validation of the method was performed. The usefulness of the method was confirmed for determination of the analytes in plasma of patients treated with the drug.

Results:

Total peak separation was achieved at LiChrospher 100 RP-18 column with a mobile phase composed of methanol and water (1:1,v:v) and a flow rate of 1.2 ml/min. The method was linear in the ranges of 0.025 - 1.0 μg/ml for AT, o-OH-AT and p-OH-AT. Intra- and inter-assay precision expressed as relative standard deviation was ≤13% for AT, ≤12% for p-OH-AT and ≤11% for o-OH-AT. Intraand inter-day accuracy of the method, expressed as a relative error, was ≤15%.

Conclusion:

The elaborated HPLC method is specific, repeatable, reproducible, adequately accurate and precise and fulfills the validation requirements for the bioanalytical method. The method was successfully applied for analysis of atorvastatin and its o-hydroxy metabolite in plasma of patients treated with the drug.