Systematic development of a bioanalytical UPLC-MS/MS method for estimation of risperidone and its active metabolite in long-acting microsphere formulation in rat plasma

Relationship between clinical efficacy and plasma concentration-dose ratio of risperidone in patients with schizophrenia

This study aimed to retrospectively explore the relationship between clinical efficacy and plasma concentration-dose ratio of risperidone (RIS) in 252 patients with schizophrenia taking RIS orally. After the same dose of RIS treatment, the plasma concentration of RIS/9-hydroxyrisperidone (9-OH-RIS), the total plasma concentration of RIS, and the ratio of the steady-state plasma concentration to the daily dose of the total active product (C/D) showed individual difference. The RIS plasma concentration was significantly higher in patients taking high doses than those taking lower doses ( P  = 0.003). There was a statistically significant difference in C/D ratio between males and females ( P  = 0.003). There were significant differences in ratio of C/D and the total plasma concentration of RIS between patients under 60 years and over 60 years ( P  = 0.016; P  = 0.005). Logistic regression analysis showed that the therapeutic effect and adverse reactions of RIS were correlated with the ratio of C/D in patients with schizophrenia ( P  = 0.038; P  < 0.001). It has been suggested that the importance of monitoring of the plasma concentration of RIS in patients with schizophrenia and the ratio of C/D may be used as the reference for RIS personalized treatment.

Development and Validation of a Novel UHPLC-MS/MS Method for the Quantification of Plinabulin in Plasma and Its Application in a Pharmacokinetic Study with Leukopenic Rats

Plinabulin, a new antitumor drug developed from marine natural products that targets microtubules in cancer cells, is currently being tested in a phase III clinical study. Plinabulin has been clinically proven to be effective on leukopenia. However, to our knowledge, there are no reports investigating the pharmacokinetics of plinabulin in individuals with leukopenia and healthy individuals. In this study, we developed a rapid and sensitive UHPLC-MS/MS method for the detection of plinabulin for the first time. Using a novel cyclophosphamide-induced leukopenia model, we investigated the differences in the pharmacokinetic characteristics of plinabulin between rats with leukopenia and normal rats. Plinabulin and propranolol (IS) peaks were separated by gradient elution for a total run time of 5 min. The methodological validation showed a good accuracy (101.96-109.42%) and precision (RSD ≤ 5.37%) with the lower limit of quantification at 0.5 ng/mL. The recovery of plinabulin was between 91.99% and 109.75% (RSD ≤ 7.92%). The values of the area under the plasma concentration-time curve (AUC0-t) for leukopenia groups and control groups at doses of 0.5 mg/kg, 1 mg/kg, and 3 mg/kg were 148.89 ± 78.74 h·μg/L and 121.75 ± 31.56 h·μg/L; 318.15 ± 40.00 h·μg/L and 272.06 ± 42.85 h·μg/L; and 1432.43 ± 197.47 h·μg/L and 1337.12 ± 193.56 h·μg/L; respectively. The half-lives (t1/2s) of plinabulin were 0.49-0.72 h for leukopenia groups and 0.39-0.70 h for control groups at three doses, and the clearance rates (CLs) of plinabulin were 2.13-3.87 L/h/kg for leukopenia groups and 2.29-4.23 L/h/kg for control groups. Pharmacokinetic results showed that there was no significant pharmacokinetic difference between the normal group and the leukopenia group. Based on the power model, plinabulin exhibits a lack of dose proportionality over the dose range of 0.5-3 mg/kg after intravenous administration. This study provides guidance for the development of plinabulin as a potential candidate for the treatment of chemotherapy-induced leukopenia.

Analytical Method Development for 19 Alkyl Halides as Potential Genotoxic Impurities by Analytical Quality by Design

Major issues in the pharmaceutical industry involve efficient risk management and control strategies of potential genotoxic impurities (PGIs). As a result, the development of an appropriate method to control these impurities is required. An optimally sensitive and simultaneous analytical method using gas chromatography with a mass spectrometry detector (GC–MS) was developed for 19 alkyl halides determined to be PGIs. These 19 alkyl halides were selected from 144 alkyl halides through an in silico study utilizing quantitative structure–activity relationship (Q-SAR) approaches via expert knowledge rule-based software and statistical-based software. The analytical quality by design (QbD) approach was adopted for the development of a sensitive and robust analytical method for PGIs. A limited number of literature studies have reviewed the analytical QbD approach in the PGI method development using GC–MS as the analytical instrument. A GC equipped with a single quadrupole mass spectrometry detector (MSD) and VF-624 ms capillary column was used. The developed method was validated in terms of specificity, the limit of detection, quantitation, linearity, accuracy, and precision, according to the ICH Q2 guideline.

Application of the "Method Operable Design Region" (MODR) approach for the development of a UHPLC method for the assay and purity determination of risperidone in risperidone drug substance and other formulations

To understand the role of analytics in drug development, regulatory bodies also started using the approach of Quality by Design (QbD) during analytical method developments. The present study deals with the development of the "Method Operable Design Region" for assay and purity determination of risperidone in risperidone drug substance and formulations usingy UHPLC. Five different column chemistries, five different pH buffers, oven temperatures from 25 to 45°C, and different organic modifier composition, column lengths and flow rates were studied and statistically evaluated using Fusion QbD software. The final method parameters were selected by performing multivariable changes in a single run and evaluated using the Monte Carlo simulation approach. The uniqueness of this method is that it is mass compatible, a total of 10 peaks are separated within a short run time of 12.0 min and it uses a "Platforming approach", which means the use of a single method for testing the drug substance, different strengths of a drug product and different formulations. The same method can be also used for the determination of the preservative (benzoic acid) in risperidone 1 mg/ml oral solution. The use of the QbD approach is aligned with the US Pharmacopeia <1220>, BP supplementary chapter 2022 and the International Conference on Harmonization Q14 guidelines for life cycle management of analytical methods.

UPLC-MS/MS Method Validation for Estimation of Resveratrol in Rat Skin from Liposphere Gel Formulation and Its Application to Dermatokinetic Studies in Rats

For the quantification of resveratrol (RV) in the Wistar rat skin, an ultra-performance liquid chromatography-mass spectrometric (UPLC-MS/MS) method was developed and validated on ACQUITY UPLC BEH C18 column (1.7 μm). The mobile phase ratio of methanol (A) and 2% formic acid (B) (ratio 10: 90% v/v, 80: 20 v/v) at isocratic elution with flow rate 0.3 mL/min, and run time 3 min was used for analysis. In addition, the use of multiple reaction monitoring (MRM)/ES+ mode to detect the analytes and to track parents to daughter ion transition of 229.17 > 107.04 m/z (time scan 3 min, retention time 1.48) for RV and curcumin as an internal standard shows 369.16 > 176.93m/z (scan time is 2.80 min, retention time is 1.11), respectively. Linearity was observed in the range of 2.5 to 2,000 ng/mL (R2 = 0.987). Precision and accuracy on rat skin were within the acceptability range (RE%: ±15; RSD%: ±15). Moreover, it showed a good percentage recovery and found within acceptance limit 90-110%. Lower limit of detection and quantitation for the method observed to be 2.5 and 20 ng.mL-1, respectively. Method application indicated successful determination of dermatokinetics parameters of RV from lipospheres gel and suspension in the rats.

Development and validation of a new UPLC-MS/MS method for quantification of ganoderic acid-A loaded nanolipidic carrier in rat plasma and application to pharmacokinetic studies

A systematic methodology was used to quantify ganoderic acid-A (GA-A) loaded nano-lipid carriers (NLC) in rat plasma using UPLC-MS/MS. Separation of the analyte was achieved using ACQUITY UPLC BEH C₁₈ column (1.7 µm) and mobile phase as water containing 0.1% Acetonitrile (40: 60% v/v) at a flow rate of 0.4 mL·min^-1. The analyte was detected using MRM mode to track precursor-to-product ion transitions of 515.37 → 285.31 m/z (time scan of 2 min) for GA-A, and 175.11 → 115.08 m/z (time scan of 4 min) for ascorbic acid as an internal standard (IS), respectively. The developed method was validated for linearity, accuracy, within and between day precisions, limit of quantification and recovery of the analyte. The results indicated intra and inter-day consistency and precision values were found to be within the acceptance limit for the plasma samples. The method applicability for determination of pharmacokinetic parameters of GA-A was assessed after oral administration of free GA-A solution and GA-A-loaded NLC, which indicated significant difference (p < 0.05) in the rate and extent of absorption parameters of GA-A from the NLC formulation vis-à-vis the plain solution. Overall, the studies construed successful development and application of UPLC-MS/MS method for estimation of GA-A in the lipidic formulation.