Skip to Content
Merck
  • Non-destructive monitoring of creaming of oil-in-water emulsion-based formulations using magnetic resonance imaging.

Non-destructive monitoring of creaming of oil-in-water emulsion-based formulations using magnetic resonance imaging.

Drug development and industrial pharmacy (2013-05-02)
Yoshinori Onuki, Akihiro Horita, Hideto Kuribayashi, Yoshihide Okuno, Yasuko Obata, Kozo Takayama
ABSTRACT

A non-destructive method for monitoring creaming of emulsion-based formulations is in great demand because it allows us to understand fully their instability mechanisms. This study was aimed at demonstrating the usefulness of magnetic resonance (MR) techniques, including MR imaging (MRI) and MR spectroscopy (MRS), for evaluating the physicochemical stability of emulsion-based formulations. Emulsions that are applicable as the base of practical skin creams were used as test samples. Substantial creaming was developed by centrifugation, which was then monitored by MRI. The creaming oil droplet layer and aqueous phase were clearly distinguished by quantitative MRI by measuring T1 and the apparent diffusion coefficient. Components in a selected volume in the emulsions could be analyzed using MRS. Then, model emulsions having different hydrophilic-lipophilic balance (HLB) values were tested, and the optimal HLB value for a stable dispersion was determined. In addition, the MRI examination enables the detection of creaming occurring in a polyethylene tube, which is commonly used for commercial products, without losing any image quality. These findings strongly indicate that MR techniques are powerful tools to evaluate the physicochemical stability of emulsion-based formulations. This study will make a great contribution to the development and quality control of emulsion-based formulations.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
1-Hexadecanol, ≥99%
Sigma-Aldrich
1-Hexadecanol, ReagentPlus®, 99%
Sigma-Aldrich
1-Hexadecanol, 95%
USP
Cetyl alcohol, United States Pharmacopeia (USP) Reference Standard
Stearic acid, European Pharmacopoeia (EP) Reference Standard
Supelco
Cetyl Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Stearic Acid, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Stearic acid, analytical standard
Sigma-Aldrich
Stearic acid, ≥95%, FCC, FG
Sigma-Aldrich
Stearic acid, Grade I, ≥98.5% (capillary GC)
USP
Stearic acid, United States Pharmacopeia (USP) Reference Standard
Supelco
Cetyl alcohol, analytical standard
Sigma-Aldrich
Stearic acid, reagent grade, 95%
Cetyl alcohol, European Pharmacopoeia (EP) Reference Standard
Supelco
Stearic acid, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland