From compressibility to structural investigation of sodium dodecyl sulphate — Part 1: Powder and tablet physico-chemical characteristics

As a part of a study on detergent tablets, investigations were carried out to elucidate the compression behavior of a powdered surfactant, sodium dodecyl sulphate (SDS), based on a comparison with the main component of the formulation, i.e. the chorine provider (DCCNa). The compacted SDS exhibited poor cohesion as well as delayed dissolution whatever the compression pressure. The microscopic observations and the mercury porosimetry measurements both demonstrated that a residual porosity existed in the tablets but the dissolution times were always long. A modification of SDS in contact with water, forming a structure like a gel, probably occurred, inducing the closing of the pores and thereby limiting the water intrusion into the tablets.

Compression behavior of SDS and DCCNa (main component of a detergent formulation) was investigated. Whatever the compression pressure, compacted SDS exhibited poor cohesion, and delayed dissolution even if a residual porosity existed in the tablets. A modification of SDS in contact with water, forming a gel-like structure, probably occurred, inducing the closing of the pores and thereby limiting the water intrusion into the tablets.Onion peel-like structure of SDS particlesFigure optionsDownload as PowerPoint slide