Effect of the Addition of Oxybenzone or Octyl-Methoxycinnamate on Particle Size of Submicron Emulsions

• Published in: Drug development and industrial pharmacy Vol. 26; no. 3; pp. 349 - 356
• Main Authors: Marti-Mestres, Gilberte, Nielloud, Françoise, Fortuné, Renée, Fernandez, Cormarie, Maillols, Hélène
• Format: Journal Article
• Language: English
• Published: Colchester Informa UK Ltd 01.01.2000; Taylor & Francis
• Subjects: Benzophenones - chemistry; Biological and medical sciences; Cinnamates - chemistry; Drug Stability; Emulsions - chemistry; General pharmacology; Medical sciences; Mixture design; Oils - chemistry; Particle Size; PCS; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Solubility; Submicron emulsion; Sunscreen; Sunscreening Agents - chemistry; Surface-Active Agents - chemistry; Particle size; Structure stability; Pharmaceutical technology; Oil water emulsion; Cream; Vehicle(excipient); Solubility; Oxybenzone; Drug adjuvant; Surfactant; Paraffin; Particle size distribution; Coconut oil; Myristic acid; Formulation; Dosage form; Sunscreen product; Physicochemical properties; Physical structure
• ISSN: 0363-9045; 1520-5762
• DOI: 10.1081/DDC-100100364

The formulation of sunscreen products requires understanding of the solubilization of these products in different vehicles to obtain aesthetic preparations and to evaluate long-term stability. For this study, two different ultraviolet (UV) filters were selected: oxybenzone (powder) and octyl-methoxycinnamate (liquid). First, the solubility of these UV filters was tested using a three-component simplex-centroid design strategy. The mixtures were prepared with three oily phases used in this field of cosmetics: liquid paraffin, isopropyl myristate, and coconut oil. A phase diagram method was used to carry out a systematic study of submicron oil-in-water emulsions. Phase diagrams were produced by diluting fixed binary mixtures with water. The surfactant consisted of polyoxyethylene-20-sorbitan monostearate sorbitan monostearate (50 50, w w). The oily phase contained equal quantities of each oil studied. From this water surfactant oil ternary system, we selected two reference emulsions with receptively 75 5 20 and 68 7 25 proportions. Photon correlation spectroscopy (PCS) was used to investigate the influence of these two UV filters at several concentrations on droplet size and distribution of the oil droplets in the material. All emulsions were stored and checked every month for 6 months.