Thermal Inkjet System to Enable Picoliter Dispense of Pharmaceutical Compounds

Abstract

A system designed to dispense small-molecule compounds dissolved in Dimethyl Sulfoxide (DMSO) into ANSI-standard wellplates has been developed by Hewlett Packard (HP). This system, based on HP's Scalable Printing Technology (SPT), includes a disposable TIJ (thermal inkjet) dispensehead cassette designed specifically for the jetting of DMSO. Each cassette uses open 7μL reservoirs that allow a researcher to load fluid directly into the dispenseheads. The system also includes an instrument that drives the dispenseheads and moves wellplates below the fixed cassette. The system finally includes software designed to specify the amount of fluid dispensed into each well, rendering complicated experiments to be simple to both design and execute.Picoliter-dispense technology is particularly suited for the creation of direct compound titrations in well plates commonly used for dose-response experiments. Advantages over traditional serial dilution techniques include a reduction of carry over and accumulated error, an improvement in precision, and a reduction in compound usage. Additionally, the HP system enables a simpler workflow and makes finely-spaced dosages practical.This paper describes key features of the HP system and performance data from pharmaceutical beta sites. It also describes the advantages of a TIJ-based compound-dispensing system relative to existing pipette-based or PIJ (piezo inkjet)-based systems. Finally, it describes some of the advantages of using a non-contact Digital Dispenser in this application.