Effects of Added Surfactant on Swelling and Molecular Transport in Drug-Loaded Tablets Based on Hydrophobically Modified Poly(acrylic acid)
Author
Summary, in English
A combination of NMR chemical shift imaging and self-diffusion experiments is shown to give a detailed molecular picture of the events that occur when tablets of hydrophobically modified poly(acrylic acid) loaded with a drug (griseofulvin) swell in water in the presence or absence of surfactant (sodium octylbenzenesulfonate). The hydrophobic substituents on the polymer bind and trap the surfactant molecules in mixed micelles, leading to a slow effective surfactant transport that occurs via a small fraction of individually dissolved surfactant molecules in the water domain. Because of the efficient binding of surfactant, the penetrating water is found to diffuse past the penetrating surfactant into the polymer matrix, pushing the surfactant front outward as the matrix swells. The added surfactant has little effect on the transport of drug because both undissolved solid drug and surfactant-solubilized drug function as reservoirs that essentially follow the polymer as it swells. However, the added surfactant nevertheless has a strong indirect effect on the release of griseofulvin, through the effect of the surfactant on the solubility and erosion of the polymer matrix. The surfactant effectively solubilizes the hydrophobically modified polymer, making it fully miscible with water, leading to a more pronounced swelling and a slower erosion of the polymer matrix.
Department/s
- Physical Chemistry
- Department of Food Technology, Engineering and Nutrition
- Division of Food and Pharma
- Biotechnology (M.Sc.Eng.)
Publishing year
2014
Language
English
Pages
9757-9767
Publication/Series
The Journal of Physical Chemistry Part B
Volume
118
Issue
32
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Physical Chemistry
- Food Engineering
Status
Published
ISBN/ISSN/Other
- ISSN: 1520-5207