title: Thermal gelation of aqueous hydroxypropylmethylcellulose solutions with SDS and hydrophobic drug particles.
abstract: The thermal gelation of hydroxypropylmethylcellulose (HPMC) solutions has been studied as a function of sodium dodecyl sulfate (SDS) concentration with and without griseofulvin, a model particulate BCS Class II drug by rheological measurements of gelation temperature (Tgel), steady-state viscosity (η) at 25 °C, and ζ-potential. Polymer adsorption on the drug was demonstrated by a decrease in η and potential in the absence of SDS. Griseofulvin had a synergistic effect on gelation which was attributed to an effective spanning of associated hydrophobic polymeric regions through interactions with the adsorbed polymer. Adding SDS offsets this effect on Tgel shielding hydrophobic interactions. Higher SDS concentrations had no effect on the particles surface as evidenced by constant ζ-potential and Tgel. Yet, polymeric chains are saturated and larger surfactant aggregates account for the increase in viscosity. Understanding the gelation mechanism and complex interactions of HPMC with surfactants and drugs is necessary for the design of pharmaceutical products and optimization of their performance properties.
authors: Department of Chemical Engineering, University of Puerto Rico, Mayagüez, PO Box 9000, Mayagüez, Puerto Rico 00680, Puerto Rico. Electronic address: aldo.acevedo@upr.edu.
authors: Aldo
authors: A
authors: Acevedo
authors: Department of Food Science, Rutgers University, New Brunswick, NJ 08901, United States.
authors: Paul
authors: P
authors: Takhistov
authors: Department of Chemical Engineering, University of Puerto Rico, Mayagüez, PO Box 9000, Mayagüez, Puerto Rico 00680, Puerto Rico.
authors: Carlos Pinzón
authors: CP
authors: de la Rosa
authors: Department of Chemical Engineering, University of Puerto Rico, Mayagüez, PO Box 9000, Mayagüez, Puerto Rico 00680, Puerto Rico.
authors: Vivian
authors: V
authors: Florián
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry; D005782:Gels; D006118:Griseofulvin / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012212:Rheology; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D014783:Viscosity
chemical_list: D000935:Antifungal Agents; D005782:Gels; D004364:Pharmaceutical Preparations; D006118:Griseofulvin; D012967:Sodium Dodecyl Sulfate; D065347:Hypromellose Derivatives; D008747:Methylcellulose
keywords: Gels; Rheology; Surfactants