Accuracy Profile Theory for the Validation of an LC–MS-MS Method for the Determination of Risperidone and 9-Hydroxyrisperidone in Human Plasma

[Design and application of special solid phase extraction column for three cannabinol compounds in hemp]

大麻中的主要成分大麻二酚(CBD)、大麻酚(CBN)和Δ9-四氢大麻酚(Δ9-THC)的含量决定了其性质和应用。在液相色谱分析中,由于大麻提取液中含有较多杂质,需要净化。该文基于大麻中CBD、CBN和Δ9-THC的结构特征及样品基质组成,根据中性氧化铝、硅酸镁和石墨化炭黑的不同表面特征,考察了这3种吸附剂对大麻提取液中叶绿素、多糖、高级脂肪酸酯及重金属离子的去除率和对3种大麻酚的回收率,确定了3种吸附剂的用量分别为1.80 g、0.15 g、0.05 g混合装填成的2 g/6 mL小柱为3种大麻酚类化合物测定的专用固相萃取柱。该小柱对大麻乙酸乙酯-甲醇提取液样品中CBD、CBN和Δ9-THC的回收率分别为98.9%, 95.7%和99.2%,对叶黄素、叶绿素a和叶绿素b的去除率分别为96.3%、99.2%和95.5%,对总糖的去除率为98.5%,对脂肪酸甘油酯的去除率为96.9%,对重金属离子的平均去除率为85.4%。优化了色谱分析条件,采用Eclipse Plus C18色谱柱(50 mm×2.1 mm, 1.8 μm),在1%乙酸水溶液-乙腈(30:70, v/v)流动相条件下等度洗脱,流速为0.5 mL/min,柱温为30 ℃,检测波长为210 nm,进样量为1 μL,在10 min内可完成样品分析。方法学考察表明,在0.5~50 mg/L范围内,CBD、CBN和Δ9-THC的液相色谱峰面积与其质量浓度呈良好的线性关系,相关系数(R²)分别为0.9983、0.9995和0.9981,检出限分别为0.45 μg/L、0.53 μg/L和0.38 μg/L,加标回收率为90.3%~97.0%、93.7%~95.6%、90.8%~96.1%,相对标准偏差(RSD)分别为2.2%~6.1%、4.1%~8.0%、2.4%~4.8%。研究结果表明,该文以中性氧化铝、硅酸镁和石墨化炭黑制作的复合型大麻酚类成分测定专用固相萃取柱在大麻植物中3种酚类化合物的测定中具有净化杂质、防止色谱柱污染的功能。由于大麻不同部位的化学成分存在差异,在后续的研究中,还要进一步考察小柱对其他杂质的去除情况,使得制备的固相萃取小柱更具有普适性。

Perspectives on updates, clarifications and controversies in chromatographic assay guidance for bioanalytical method validation from major regulatory agencies and organizations

Bioanalysis, a key supporting function for generating data for pre-clinical and clinical studies in drug development, is under the regulation of local agencies as well as global organizations to ensure the data integrity and quality in submission. As major regulatory agencies and organizations, the US Food and Drug Administration, the European Medicines Agency and the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use have been updating their industry guidance for bioanalytical method validation, to keep up with the development new modalities, technologies and regulations. This article summarizes the recent updates and any clarifications and controversies triggered by those updates. Perspectives and recommendations are given based on our own experience as well as commonly accepted practice in the bioanalytical community.

Impact of CYP2D6 Polymorphism on Steady-State Plasma Levels of Risperidone and 9-Hydroxyrisperidone in Thai Children and Adolescents with Autism Spectrum Disorder

OBJECTIVE

The purpose of this study was to investigate the influence of CYP2D6 gene polymorphisms on plasma concentrations of risperidone and its metabolite in Thai children and adolescents with autism spectrum disorder (ASD).

METHODS

All 97 autism spectrum disorder patients included in this study had been receiving risperidone at least for 1 month. The CYP2D6 genotypes were determined by real-time polymerase chain reaction (PCR)-based allelic discrimination for CYP2D6*4, *10, and *41 alleles. Plasma concentrations of risperidone and 9-hydroxyrisperidone were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Among the 97 patients, the most important nonfunctional alleles (CYP2D6*4 and *5) were detected, whereas the most common allele was CYP2D6*10 (55.9%). CYP2D6 genotyping revealed 90 (92.78%) patients to be extensive metabolizers (EM) and 7 (7.22%) to be intermediate metabolizers (IM). Plasma levels of risperidone were significantly higher in individuals with CYP2D6*5/*10 (p = 0.02), CYP2D6*10/*10 (p = 0.04), and CYP2D6*10/*41 (p = 0.04). Additionally, the plasma concentration of risperidone/9-OH risperidone ratio in patients with a CYP2D6 activity score of 0.5 were significantly higher than those with a CYP2D6 activity score of 2 (p = 0.04). Conversely, no significant influence was found among CYP2D6 polymorphisms, plasma concentrations of 9-hydroxyrisperidone, and the total active moiety.

CONCLUSIONS

This is the first study to investigate the effects of CYP2D6 genetic polymorphisms on the plasma concentrations of risperidone in Thai children with ASD. The findings indicate that CYP2D6 polymorphisms affect the plasma concentrations of risperidone and the risperidone/9-hydroxyrisperidone ratio. Genetic screening for CYP2D6 polymorphisms could help to predict unexpected adverse events caused by the higher plasma concentration of risperidone.

Development and Validation of Liquid Chromatography/Tandem Mass Spectrometry Analysis for Therapeutic Drug Monitoring of Risperidone and 9-Hydroxyrisperidone in Pediatric Patients with Autism Spectrum Disorders

BACKGROUND

Risperidone (RIS) is a widely used atypical antipsychotic drug. We developed and validated a sensitive and accurate LC-MS/MS method, which requires a small-volume of plasma and small-volume injection for measurement of RIS levels in ASD pediatric patients. We also investigated the relationship between RIS levels and RIS dosages, including prolactin levels.

METHOD

Blood samples were processed by protein precipitation extraction. Only 1 μl of sample was injected. Plasma samples were separated on a C18 column (4.6 cm × 50 mm; 1.8 μm particle size). Detection was by MS-MS with an analytical run time of 6 min.

RESULTS

The inter-day accuracy of RIS was 101.33-107.68% and 95.24-103.67% for 9-OH-RIS. The inter-day precision of RIS was ≤7.27% CV and ≤7.41% CV for 9-OH-RIS. The extraction recovery of RIS and 9-OH-RIS were 95.01 ± 7.31-112.62 ± 7.50% and 90.27 ± 11.15-114.00 ± 10.35%, respectively. This method was applied in the therapeutic drug monitoring of ASD pediatric patients. Higher RIS dosage has a tendency to produce higher RIS plasma levels. The high RIS plasma levels have a tendency to produce hyperprolactinemia.

CONCLUSION

The determination of RIS in individual patients might be clinically useful for monitoring and prediction of treatment response.

Detection of CYP2D6 polymorphism using Luminex xTAG technology in autism spectrum disorder: CYP2D6 activity score and its association with risperidone levels

CYP2D6 is involved in the biotransformation of a large number of drugs, including risperidone. This study was designed to detect CYP2D6 polymorphisms with a Luminex assay, including assessment the relationship of CYP2D6 polymorphisms and risperidone plasma concentration in autism spectrum disorder children (ASD) treated with risperidone. All 84 ASD patients included in this study had been receiving risperidone at least for 1 month. The CYP2D6 genotypes were determined by Luminex assay. Plasma concentrations of risperidone and 9-hydroxyrisperidone were measured using LC/MS/MS. Among the 84 patients, there were 46 (55.42%) classified as EM, 33 (39.76%) as IM, and 4(4.82%) as UM. The plasma concentration of risperidone and risperidone/9-hydroxyrisperidone ratio in the patients were significant differences among the CYP2D6 predicted phenotype group (P = 0.001 and P < 0.0001 respectively). Moreover, the plasma concentration of risperidone and risperidone/9-hydroxyrisperidone ratio in the patients with CYP2D6 activity score 0.5 were significantly higher than those with the CYP2D6 activity score 2.0 (P = 0.004 and P = 0.002 respectively). These findings suggested that the determination of the accurate CYP2D6 genotype-predicted phenotype is essential in the clinical setting and individualization of drug therapy. The use of the Luminex assay for detection of CYP2D6 polymorphisms could help us more accurately identify an individual's CYP2D6 phenotype.

Use of the Charge Transfer Reactions for the Spectrophotometric Determination of Risperidone in Pure and in Dosage Forms

The aim of study was to develop and validate two simple, sensitive, and extraction-free spectrophotometric methods for the estimation of risperidone in both pure and pharmaceutical preparations. They are based on the charge transfer complexation reactions between risperidone (RSP) as n-electron donor and p-chloranilic acid (p-CA) in method A and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in method B as π-acceptors. In method A, RSP reacts with p-CA in methanol to produce a bright pink-colored chromogen measured at 530 nm whereas, in method B, RSP reacts with DDQ in dichloromethane to form orange-colored complex with a maximum absorption at 460 nm. Beer's law was obeyed in the concentration range of 0-25 and 0-50 μg/mL with molar absorptivity of 1.29 × 10(4) and 0.48 × 10(4) L/moL/cm for RSP in methods A and B, respectively. The effects of variables such as reagents, time, and stability of the charge transfer complexes were investigated to optimize the procedures. The proposed methods have been successfully applied to the determination of RSP in pharmaceutical formulations. Results indicate that the methods are accurate, precise, and reproducible (relative standard deviation <2 %).