The effect of alkanediols on the release of triamcinolone acetonide from semisolid dosage forms

Alkanediols are frequently used as alternative antimicrobial preservatives for dermal formulations. However, these substances can also have an influence on the biopharmaceutical properties of the applied preparations. Therefore, the influence 2-methyl-2,4-pentanediol, 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol on the release of triamcinolone acetonide (TAA) from four different commonly used semi-solid vehicles was investigated. In addition, the solubility of TAA in aqueous alkanediol solutions was evaluated. It was observed that its solubility increases as a function of chain length of the alkanediol, with exception of 1,2-octanediol. This can be related to the corresponding solubility parameters. Despite alkanediols increase the aqueous solubility of TAA, polarization microscopic images revealed that a significant amount of the drug is present in the suspended state in all formulations. Therefore, TAA release was proportional to the square root of time, indicating Higuchi kinetic. Alkanediols modify the release of TAA depending on the used base. The addition of alkanediols to the hydrogel formulation result in a slightly augmented release rate of the drug with increasing chain length of the added alkanediol. In contrast, alkanediols having longer chain lengths diminish the TAA release rate from all tested creams. Consequently, TAA release revealed to be partially inequivalent upon the addition of alkanediols.

Automated summary

Alkanediols such as 2-methyl-2,4-pentanediol, 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol can affect the release of triamcinolone acetonide from dermal formulations by influencing solubility and drug suspension. The addition of alkanediols alters the drug release rate, with longer chain lengths increasing solubility and release rate, but also causing drug suspension. The release of triamcinolone acetonide exhibits a Higuchi kinetic pattern in the presence of alkanediols.