Abstract
Sodium lauryl sulfate (SLS) is an anionic surfactant widely used in pharmaceutical research as a dissolution enhancer for poorly soluble drugs. When SLS was used in ritonavir (RTV) tablet formulation to improve wetting, dissolution of RTV was surprisingly deteriorated in acidic media. To understand this unexpected phenomenon, a systematic investigation, including solubility determination, intrinsic dissolution rate measurement, dissolution in an artificial stomach and duodenum apparatus, and solid-state characterization, revealed the formation of a poorly soluble salt, [RTV 2+ ][LS − ] 2 , in an acidic environment. Solubilization of the poorly soluble RTV salt was observed when the concentration of SLS exceeded the critical micelle concentration. Thus, precipitation of [RTV 2+ ][LS − ] 2 at a low pH and in presence of a low SLS concentration can lead to deteriorated bioavailability. This unintended negative effect on dissolution should be carefully considered when using SLS in a tablet formulation of a basic drug that can be ionized in gastric fluid.
Original language | English (US) |
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Pages (from-to) | 516-524 |
Number of pages | 9 |
Journal | Journal of Pharmaceutical Sciences |
Volume | 108 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2019 |
Bibliographical note
Funding Information:Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. The authors also thank the Chinese Scholarship Council for partial financial support to Y.G.
Funding Information:
Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. The authors also thank the Chinese Scholarship Council for partial financial support to Y.G.
Publisher Copyright:
© 2019 American Pharmacists Association®
Keywords
- dissolution
- pH
- precipitation
- ritonavir
- salt
- sodium lauryl sulfate