On the solubilization properties of surfactant-polymer complexes

Area of Science:

• Physical Chemistry
• Colloid Science
• Pharmaceutical Sciences

Background:

• Sodium dodecyl sulphate (SDS) is a common anionic surfactant used for solubilizing poorly soluble compounds.
• Polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) are widely used polymers in various formulations.
• The interaction between surfactants and polymers can significantly alter solution properties, including solubilization capacity.

Purpose of the Study:

• To investigate the effect of PEG and PVP on the solubilization power of SDS.
• To determine how these polymer additives influence the solubilization of model drug compounds (riboflavin, khellin, and p-hydroxybenzoates).

Main Methods:

• Preparation of SDS solutions with varying concentrations of PEG or PVP.
• Measurement of the solubilization capacity of these mixed systems for specific model compounds.
• Analysis of the influence of polymer and surfactant concentrations on solubilization.

Main Results:

• PEG and PVP generally decrease the solubilization of riboflavin and khellin by SDS, with effects varying by concentration.
• Solubilization of propyl p-hydroxybenzoate by SDS is reduced by PEG/PVP, inversely proportional to surfactant concentration.
• Conversely, PEG and PVP enhance SDS-mediated solubilization of methyl and butyl p-hydroxybenzoate, with concentration-dependent effects.

Conclusions:

• The presence of PEG and PVP significantly modifies the solubilization behavior of SDS towards different compounds.
• The impact of polymers on SDS solubilization is compound-specific and concentration-dependent.
• These findings are crucial for optimizing formulations involving SDS and polymers for drug delivery and other applications.