Thermal analysis of lipoic acid and evaluation of the compatibility with excipients

MOYANO, MA; BROUSSALIS A.M.; SEGALL, AI

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

SPRINGER

Lugar: Amsterdam; Año: 2010 p. 631 - 637

1388-6150

Abstract Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of lipoic acid with some currently employed 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, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy. Keywords Compatibility study Differential scanning calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR calorimetry Lipoic acid HPLC IR Compatibility study Differential scanning calorimetry Lipoic acid HPLC IR Lipoic acid HPLC IR Introduction