Method development for quantitative determination of seven statins including four active metabolites by means of high-resolution tandem mass spectrometry applicable for adherence testing and therapeutic drug monitoring.

Background Statins are used to treat and prevent cardiovascular diseases (CVDs) by reducing the total serum cholesterol concentration. Unfortunately, dose-related side effects and sub-optimal response, attributed to non-adherence amongst others, were described. Therefore, a fast and sensitive liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) method for adherence testing and therapeutic drug monitoring of all currently marketed statins and their active metabolites in human blood plasma should be developed, validated and tested for applicability. Methods Atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin, as well as ortho- and para-hydroxy-atorvastatin, lovastatin hydroxy acid and simvastatin hydroxy acid were included and several internal standards (IS) tested. Validation was performed according to the guideline of the European Medicines Agency including selectivity, carry-over, accuracy, precision, matrix effects, dilution integrity and analyte stability. Finally, applicability was tested using 14 patient samples submitted for regular toxicological analysis. Results Due to an analytical interference of atorvastatin-d5, diazepam-d5 and pentobarbital-d5 were chosen as IS for positive and negative ionization mode, respectively. All statins and metabolites fulfilled the validation acceptance criteria except for fluvastatin, which could not be quantified reliably and reproducibly, most probably due to instability. Analyses of human plasma samples revealed concentrations of statins and metabolites below the reference plasma concentrations in the case of eight patients. However, nothing was known concerning patients' adherence and time between intake and sampling. Conclusions An LC-HRMS/MS method for identification and quantification of atorvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin and four active metabolites was successfully developed and applicability demonstrated.

Combining Multiple Treatment Comparisons with Personalized Patient Preferences: A Randomized Trial of an Interactive Platform for Statin Treatment Selection.

BACKGROUND: Patients and clinicians are often required to make tradeoffs between the relative benefits and harms of multiple treatment options. Combining network meta-analysis results with user preferences can be useful when choosing among several treatment alternatives. OBJECTIVE: Using cholesterol-lowering statin drugs as a case study, we aimed to determine whether an interactive web-based platform that combines network meta-analysis findings with patient preferences had an effect on the decision-making process in a general population sample. METHOD: This was a pilot parallel randomized controlled trial. We used Amazon's Mechanical Turk to recruit adults residing in the United States. A total of 349 participants were randomly allocated to view either the interactive tool (intervention) or a series of bar charts (control). The primary endpoint was decisional conflict, and secondary endpoints included decision self-efficacy, preparation for decision making, and the overall ranking of statins. RESULTS: A total of 258 participants completed the trial and were included in the analysis. On the primary outcome, participants randomized to the interactive tool had significantly lower levels of decisional conflict than those in the control group (difference, -8.53; 95% confidence interval [CI], -12.96 to -4.11 on a 100-point scale; P = 0.001). They also appeared to have higher levels of preparation for decision making (difference, 4.19; 95% CI, -0.24 to 8.63 on a 100-point scale; P = 0.031). No difference was found for decision self-efficacy, although groups were statistically significantly different in how they ranked different statins. CONCLUSION: The findings of our proof-of-concept evaluation suggest that an interactive web-based tool combining published clinical evidence with individual preferences can reduce decisional conflict and better prepare individuals for decision making.

PHARMACEUTICAL QUALITY OF GENERIC ATORVASTATIN PRODUCTS COMPARED WITH THE INNOVATOR PRODUCT: A NEED FOR REVISING PRICING POLICY IN PALESTINE.

Atorvastatin reduces morbidity and mortality due to cardiovascular events. This study was conducted to assess the prices and pharmaceutical quality of innovator atorvastatin 20 mg with its locally available generics in Palestine and to assess the suitability of their interchangeability. The prices of innovator and generic atorvastatin 20 mg were determined and compared. Innovator atorvastatin and four generic products were tested for their pharmaceutical quality. Tablets were tested for their drug contents, weight uniformity, hardness, disintegration and dissolution. Three out of four generics were less expensive than the innovator. Pharmaceutical quality assessments were satisfactory and within limits for all atorvastatin tested products. The average weight ranged from 206.6 ± 8.40 to 330 ± 3.92 mg and the %RSDs were within the permitted limits as per USP. Tablet hardness ranged from 102 ± 1.41 to 197.4 ± 6.88 kg and drug contents ranged from 92.2% to 105.3%. All products disintegrated within permitted time limits and showed very rapid dissolution. Products released more than 85% of their drug contents in less than 15 min. Our results showed that all tested innovator and generic atorvastatin products were of good pharmaceutical quality. Despite the lack of in vivo evaluation, our results indicate that these products are equivalent in vitro. Considering the in vitro release characteristics, these products might be used interchangeably. However, regulatory authorities permit the use of in vitro data in establishing similarity between immediate release oral dosage forms containing biopharmaceutical classification system class I and III drugs only.

Isolation of oxidative degradation products of atorvastatin with supercritical fluid chromatography.

The isolation of four oxidative degradation products of atorvastatin using preparative high-performance liquid chromatography applying at least two chromatographic steps is known from the literature. In this paper it is shown that the same four impurities could be isolated from similarly prepared mixtures in only one step using supercritical fluid chromatography. The methods for separation were developed and optimized. The preparation of the mixtures was altered in such a way as to enhance the concentration of desired impurities. Appropriate solvents were applied for collection of separated impurities in order to prevent degradation. The structures of the isolated impurities were confirmed and their purity determined. The preparative supercritical fluid chromatography has proven to be superior to preparative HPLC regarding achieved purity of standards applying fewer chromatographic as well as isolation steps.