title: Drug-excipient compatibility studies in binary mixtures of avobenzone.
abstract: During preformulation studies of cosmetic/pharmaceutical products, thermal analysis techniques are very useful to detect physical or chemical incompatibilities between the active and the excipients of interest that might interfere with safety and/or efficacy of the final product. Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of avobenzone with some currently used cosmetic excipients. In the first phase of the study, DSC was used as a tool to detect any interaction. Based on the DSC results alone, cetearyl alcohol, isopropyl myristate, propylparaben, diethylhexyl syringylidene malonate, caprylic capric triglyceride, butylated hydroxytoluene (BHT), glycerin, cetearyl alcohol/ceteareth 20, cetearyl alcohol/sodium lauryl sulfate/sodium cetearyl sulfate, and paraffinum liquidum exhibit interaction with avobenzone. Stressed binary mixtures (stored at 50°C for 15 days) of avobenzone and excipients were evaluated by high-performance liquid chromatography. Binary mixtures were further investigated by infrared (IR) spectroscopy. Based on DSC, isothermal stress testing, and fourier transform infrared results; avobenzone is incompatible with caprylic capric triglyceride, propylparaben, and BHT.
authors.affiliation: Cátedra de Control de Calidad de Medicamentos (R.C., Y.K.H., M.A.R., A.S.) and Departamento Química Orgánica (L.R.O.), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Ciudad de Buenos Aires, Argentina.
authors.forename: Rita
authors.initials: R
authors.lastname: Ceresole
authors.forename: Yong K
authors.initials: YK
authors.lastname: Han
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rosasco
authors.forename: Liliana R
authors.initials: LR
authors.lastname: Orelli
authors.forename: Adriana
authors.initials: A
authors.lastname: Segall
mesh_terms: D002084:Butylated Hydroxytoluene / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002210:Caprylates / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004344:Drug Incompatibility; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry*; D006801:Humans; D010226:Parabens / Q000737:chemistry*; D011427:Propiophenones / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013473:Sunscreening Agents / Q000737:chemistry*; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry
chemical_list: D002210:Caprylates; D005079:Excipients; D010226:Parabens; D011427:Propiophenones; D013473:Sunscreening Agents; D014280:Triglycerides; D002084:Butylated Hydroxytoluene; C049935:avobenzone; C006068:propylparaben