Effect of sucrose on phase behavior of aqueous phase/polyoxyethylene sorbitan fatty acid ester (Tween xx)/vegetable oil systems and food nano-emulsification using low-energy methods

In Situ Swelling Formulation of Glycerol-Monooleate-Derived Lyotropic Liquid Crystals Proposed for Local Vaginal Application

Hydrogels have been extensively investigated to identify innovative formulations that can fulfill all the necessary purposes to improve local vaginal therapy through the mucosa. Herein, we propose in situ-forming lyotropic liquid crystals (LLCs) derived from a cheap and GRAS (generally recognized as safe) ingredient as an intravaginal delivery system. The system consists of a precursor solution loaded with sertaconazole nitrate as a model drug, which is able to easily swell in a stable three-dimensional structure by absorbing simulated vaginal fluid. Under polarized light microscopy the precursor solution and the formed phase of LLCs showed the typical textures belonging to anisotropic and an isotropic mesophases, respectively. A deep rheological investigation by Kinexus^® Pro proved the stability and strength of the cubic phase, as well as its potential in mucoadhesion. In vitro degradation studies showed a slow matrix erosion, consistent with data obtained from lipophilic drug release studies in simulated vaginal fluid. Therefore, the suggested cubic phase based on lyotropic liquid crystals could represent a valid proposal as a vaginal drug delivery system due to its characteristics of resistance, adhesion and the possibility of providing a slow and controlled release of drugs directly at the administration site.

Inhibitory effect of sixteen pharmaceutical excipients on six major organic cation and anion uptake transporters

To date, relatively little is known about the interactions of pharmaceutical excipients with hepatic and renal drug uptake transporters. The present study was designed to systematically evaluate the effects of 16 commonly consumed excipients on human organic cation transporter 1 and 2 (hOCT1 and hOCT2), human organic anion transporter 1 and 3 (hOAT1 and hOAT3) and human organic anion transporting polypeptide 1B1 and 1B3 (hOATP1B1 and hOATP1B3). The inhibitory effects and mechanisms of excipients on transporters were investigated using in vitro uptake studies, cell viability assays, concentration-dependent studies, and the Lineweaver-Burk plot method. Triton X-100 is a non-competitive inhibitor for all six transporters. Tween 20 inhibits hOCT2, hOAT1, hOAT3, and hOATP1B3 in a mixed way, whereas it competitively inhibits hOATP1B1. The inhibition of Tween 80 is competitive for hOCT2, non-competitive for hOATP1B1 and hOATP1B3, and mixed for hOAT1 and hOAT3. Concentration-dependent studies identify Triton X-100 as a strong inhibitor of hOCT1 and hOCT2 with IC₅₀ values of 20.1 and 4.54 μg/mL, respectively. Additionally, Triton X-100, Tween 20, and Tween 80 strongly inhibit hOAT3 with IC₅₀ values ≤31.0 μg/mL. The present study is significant in understanding the excipient-drug interactions and provides valuable information for excipient selection in drug development.

Effect of Alcohols on the Phase Behavior and Emulsification of a Sucrose Fatty Acid Ester/Water/Edible Oil System

The effect of alcohols (ethanol, 1-propanol, propylene glycol, glycerin, sucrose) on the phase behavior and emulsification of sucrose stearic acid ester (SSE)/water/edible vegetable oil (EVO) systems was investigated. Adding sucrose, propylene glycol, and glycerin narrowed the oil-separated two-phase region in the phase diagram of the SSE/water/EVO systems, whereas adding ethanol and 1-propanol expanded the oil-separated two-phase region. Changing the course of emulsification in the phase diagram showed that the size of the oil-droplet particle typically decreased in a system with a narrowed oil-separated region. The emulsification properties of the systems varied with respect to changes in the phase diagram. The microstructure of the systems was examined using small-angle X-ray scattering, and the ability to retain the oil in the lamellar structure of the SSEs was suggested as an important role in emulsification, because the mechanism of the systems was the same as that for the liquid crystal emulsification method.