Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay

Abstract

A selective and sensitive competitive enzyme-linked immunosorbent assay (ELISA) method was developed and validated for the quantification of erlotinib in 50 µL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity (6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib.

A Microwave-Enhanced Synthesis and Biological Evaluation of N-Aryl‑5,6,7,8‑tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-amines

“…General Compound 1 (1.78 g, 10 mmol) and DMF-DMA (3.57 g, 30 mmol) were added into a 1-necked 20 mL pressure tube, and then the mixture was subjected to microwave irradiation (CEM Explorer Hybrid, USA, 100 W, 200 psi, 78 °C) for 5 min. After the reaction, the DMF-DMA was evaporated in vacuum and the crude compound was re-crystallized from ethyl acetate to give the target compound of 2.29 g (9.80 Preparation of N-aryl- 5,6,7,8-tetrahydrobenzo [4,5]thieno [2,3-…”

“…N-Phenyl- 5,6,7,8-tetrahydrobenzo [4,5]thieno [2,3-d] At first, the cytotoxic activities of target compounds 3a-x were determined against A549, CT26 and HepG2 cell lines in vitro according to MTT assay with Erlotinib as the positive control at 25 μM. Then, the selected compounds, which have better cytotoxic effects compared to Erlotinib (at 25 μM), were subsequently severally selected to investigate the IC 50 values of cytotoxic activity against three tumor cell lines tested at six concentrations (3.125, 6.25, 12.5, 25, 50 and 100 μM).…”

“…In investigation, we found the presence of several marketed anticancer drugs such as gefitinib I (Iressa™), 1 vandetanib II (Caprelsa™), 2 lapatinib III (Tykerb™), 3 erlotinib IV (Tarceva™), 4 tandutinib V (MLN518) (phase II clinical trials) 5 and icotinib VI (Conmana™) 6 ( Figure 1), which have a quinazoline nucleus, the thieno [2,3-d]pyrimidine core can be considered a bioisostere of this quinazoline core. 7 In literatures, [8][9][10] thieno[2,3-d]pyrimidin-4-amine derivatives exhibit a broad range of biological and pharmacological activities associated with their heterocyclic scaffold and have been widely used in the medical field.…”

“…In these compounds, compounds VIII and IX exhibited most effects, with IC 50 values of 0.18 and 0.16 μM, respectively. Abbas et al 20 synthesized two series of new tetrahydrobenzo [4,5] thieno [2,3-d] activity. According to the results, compound X was found to have the highest cytotoxic activity against breast MCF-7 with IC 50 = 15.01 μM, and XI showed to be the most active one to inhibit human hepatocellular liver carcinoma cell line (HepG2) with IC 50 = 1.29 μM.…”

“…Subsequently, compounds 3a-x (Scheme 1) were obtained. In this study, two questions would be solved: (i) a series of N-aryl-5,6,7,8-tetra hydrobenzo [4,5]thieno [2,3-d]pyrimidin-4-amines (3a-x) were obtained with the aid of microwave irradiation technology ( Figure 5); (ii) the cytotoxic activity of synthesized compounds were evaluated against A549, murine BALB/c spontaneous colon adenocarcinoma cell line (CT26), and HepG2.…”