Miniaturized chromatographic systems for radiochemical purity evaluation of 131I-Ferulic acid as a new candidate in nuclear medicine applications

Recently, the anticancer activity of ferulic acid (FA) which is a caffeic acid derivative has been reported. Therefore, in this study FA was radiocaped with ¹³¹I^- to explore its potential as a tumor targeting agent. The radiolabeling process was carried out via electrophilic substitution reaction. The factors affecting labeling yield were optimized and the radiochemical purity (RCP) was assessed by various analytical techniques including paper chromatography (PC), thin layer chromatography (TLC), instant thin layer chromatography (ITLC), paper electrophoresis (PE) and high-performance liquid chromatography (HPLC). The RCP assay was extended to the utilization of miniaturized techniques including miniaturized PC (mini-PC), mini-TLC and mini-column chromatography (silica, sephadex-G25). Validation of mini-TLC, as one of ¹³¹I-FA RCP assay methods, was done according to ICH guidelines. Biodistribution studies of ¹³¹I-FA were performed on Ehrlich solid tumor bearing mice at various time points (5, 30, 60, 120 and 240 min), post injection. The radiolabeling yield of ¹³¹I-FA was 96.23 ± 0.45% and the miniaturized chromatographic systems showed high efficacy in RCP evaluation comparable to the conventional ones. Mini-TLC was proved to be specific, accurate, precise and linear. The tumor uptake of ¹³¹I-FA in solid tumor bearing mice was 4.35 ± 0.41 ID/g at 60 min with 2.79 as a tumor/muscle ratio. Consequently, ¹³¹I-FA could be used as a tumor targeting agent for nuclear medicine applications and the fast reaction monitoring could be achieved using miniaturized chromatographic techniques.

Nanoparticle-Mediated Dual Targeting: An Approach for Enhanced Baicalin Delivery to the Liver

In this study, water-soluble chitosan lactate (CL) was reacted with lactobionic acid (LA), a disaccharide with remarkable affinity to hepatic asialoglycoprotein (ASGP) receptors, to form dual liver-targeting LA-modified-CL polymer for site-specific drug delivery to the liver. The synthesized polymer was used to encapsulate baicalin (BA), a promising bioactive flavonoid with pH-dependent solubility, into ultrahigh drug-loaded nanoparticles (NPs) via the ionic gelation method. The successful chemical conjugation of LA with CL was tested and the formulated drug-loaded LA-modified-CL-NPs were assessed in terms of particle size (PS), encapsulation efficiency (EE) and zeta potential (ZP) using full factorial design. The in vivo biodistribution and pharmacokinetics of the designed NPs were assessed using ^99mTc-radiolabeled BA following oral administration to mice and results were compared to ^99mTc-BA-loaded-LA-free-NPs and ^99mTc-BA solution as controls. Results showed that the chemical modification of CL with LA was successfully achieved and the method of preparation of the optimized NPs was very efficient in encapsulating BA into nearly spherical particles with an extremely high EE exceeding 90%. The optimized BA-loaded-LA-modified-CL-NPs showed an average PS of 490 nm, EE of 93.7% and ZP of 48.1 mV. Oral administration of ^99mTc-BA-loaded-LA-modified-CL-NPs showed a remarkable increase in BA delivery to the liver over ^99mTc-BA-loaded-LA-free-CL-NPs and ^99mTc-BA oral solution. The mean area under the curve (AUC_0-24) estimates from liver data were determined to be 11-fold and 26-fold higher from ^99mTc-BA-loaded-LA-modified-CL-NPs relative to ^99mTc-BA-loaded-LA-free-CL-NPs and ^99mTc-BA solution respectively. In conclusion, the outcome of this study highlights the great potential of using LA-modified-CL-NPs for the ultrahigh encapsulation of therapeutic molecules with pH-dependent/poor water-solubility and for targeting the liver.

The purity identification and radiolabeling of α-mangostin with technetium-99m

Alpha-mangostin (AM) is a natural compound that has the greatest activity in breast cancer. Radiolabeling AM with technetium-99 m (Tc-99m) has a function as breast cancer radiotracer. This study is aimed to identify the purity of Tc-99m-labeled AM. The identification method was conducted by a validated radio-high-performance liquid chromatography (HPLC) to confirm the chemical purity of the compound when the thin layer of chromatography and paper chromatography were used to find out the radiochemical purity (RCP). The validated radio-HPLC method obtained was C18 column with methanol:water (90:10) as the mobile phase and ultraviolet (243 nm) tandem radioactive detector (Gabi Star). The result showed that the RCP was 70.6% ± 2.87%. The analytical method met the validation criteria according to ICH Q2 (R1); thus, it could be applied in the identification. Unfortunately, the ^99mTc-AM identification using radio-HPLC showed that the expected complex was not yet formed perfectly because of chemical impurities.