Investigationsonon alkanediolsasas alternative preservativesininaa nonionic hydrophilic cream

Abstract

Alkanediols are often used as alternative antimicrobial preservatives for dermal formulations, e.g., hydrophilic creams. These substances show an antimicrobial effect due to theiformulations, e.g., hydrophilic creams. These substances show an antimicrobial effect due to amphiphilic structure. At the same time, their amphiphilic behavior enables various interactiontheir amphiphilic structure. At the same time, their amphiphilic behavior enables various interactions with the cream base itself. Therefore, the effect of four different alkanediols, namely 1,2-pentanediolwith the cream base itself. Therefore, the effect of four different alkanediols, namely 1,2-pentanediol, 2-methyl-2,4-pentanediol (hexylene glycol), 1,2-hexanediol, and 1,2-octanediol on the physica2-methyl-2,4-pentanediol (hexylene glycol), 1,2-hexanediol, and 1,2-octanediol on the physical stability stability of a nonionic hydrophilic cream was investigated. Further, the incorporation of the of a nonionic hydrophilic cream was investigated. Further, the incorporation of the alkanediols alkanediols into lamellar structures of the cream was evaluated using differential scanning into lamellar structures of the cream was evaluated using differential scanning calorimetry (DSC) calorimetry (DSC) and small-angle X-ray scattering (SAXS) measurements. The interaction with the and small-angle X-ray scattering (SAXS) measurements. The interaction with the mixed crystals mixed crystals of the cream was found to increase with raising alkyl chain length of the added of alkanediol. the cream was As a found result, to consistency increase with and raising stability alkyl of chain the cream length are of the slightly added impaired. alkanediol. A test As a foresult, efficacy consistency of antimicrobial and stability preservation of the cream according are slightly to the impaired. European A Pharmacopoeia test for efficacy (Ph.Eur.) of antimicrobial revealed preservation that the antimicrobial according activity to the European is directly Pharmacopoeia linked to the length (Ph.Eur.) of the revealed alkyl chain that of the the antimicrobial alkanediols. 2activity Methyl-2,4-pentanediol is directly linked to differs the length from of both the findings. alkyl chain This of compound the alkanediols. has non-vicinal 2-Methyl-2,4-pentanediol hydroxy groupdiffers which from result both in findings. a reduced This amphiphilicity compound has compared non-vicinal to hydroxy the others. groups Consequently, which result it in has a reduced a smalleamphiphilicity impact on the compared colloidal structure to the others. of the Consequently, cream and shows it has a comparatively smaller impact low on the antimicrobial colloidal structure activityof the cream and shows a comparatively low antimicrobial activity.