Characterization of physiochemical and biological properties of an insulin/lauryl sulfate complex formed by hydrophobic ion pairing

Enhanced bioavailability of poorly absorbed hydrophilic compounds through drug complex/in situ gelling formulation

“…The result indicates that the positively charged RWJ-445167 can be stoichiometrically ion-paired with the negatively charged SLS. The precipitation phenomenon observed in the study is in agreement with the findings reported previously that the negatively charged surfactants form a complex precipitate with basic compounds at appropriate conditions (Dai and Dong, 2007;Hegg, 1979;Matsuura et al, 1993;Yoo et al, 2001). After reaching the stoichiometric molar ratio (SLS/RWJ-445167; 1:1), addition of an excessive amount of SLS into RWJ-445167 solution decreased the turbidity of the solution.…”

“…Furthermore, the formation of the RWJ-445167/lauryl sulfate complex was investigated by isothermal titration calorimetry (ITC) and FTIR. ITC results confirmed a stoichiometric binding ratio of SLS to RWJ-445167 in the complex formation (data not shown), and FTIR results suggest that it is the sulfate group in SLS that binds to RWJ-445167 in the complex formation as suggested by previous studies (Dai and Dong, 2007). In this study, we believe that amidine group of RWJ-445167 is …”

Structural Modification of Proteins and Peptides

“…Dai et al, Koul et al, Sun et al prepared insulin hydrophobic ion paired complex using different anionic surfactants like sodium lauryl sulphate, surfoplex, sodium deoxycholate and sodium oleate respectively in 1: 6 ratio (drug : surfactant). [49][50][51][52] The hydrophobic ion paired complex so formed has new properties like increase solubility and partitioning in 1-octanol, retained complex tertiary and secondary structures of insulin. In-vivo activity of insulin is similar to free insulin.…”

Wide-angle X-ray scattering as a probe for insulin denaturation

“…The resultant spectra are smoothed with a seven-point Savitsky Golay smooth function to remove the noise [32][33][34]. After area normalization, the second-derivative spectra are obtained using the derivative function of Origin software Version 6.0.…”