Sorbitol incompatibilities

The compatibility of sorbitol in various solid [49,50] and solution [45-47] formulations has been investigated. In a study conducted using DSC as a stability screening tool, sorbitol was found to be incompatible with salbutanol sulfate [49] and cephalexin [50]. Sorbitol has been found to be... 

Parabens are approved for use in oral solution and suspensions at a concentration of 0.015% to 0.2% w/v. Due to their low solubility, the sodium salts of parabens are often used in aqueous formulations. The parabens are most effective in the pH range of 2 to 6, and their antimicrobial activity decreases with increasing pH. Additionally, they are very unstable at pH 8 or above in solution. Methyl paraben has also demonstrated incompatibility with sorbitol and may show some discoloration in the presence of iron. The absorption of methylparaben by plastics has been reported with the amount absorbed being dependent upon the type of plastic and vehicle. However, no absorption has been reported for low density polyethylene (LDPE) or high density polyethylene (HDPE) containers. Certain coloring agents such as yellow iron oxide, ultramarine blue, and aluminum silicate can extensively absorb ethyl paraben in simple aqueous systems, thus reducing its preservative efficacy. 

Incompatibilities with other substances, such as bentonite, magnesium trisilicate, talc, tragacanth, " sodium alginate, " essential oils, " sorbitol, and atropine, " have been reported. It also reacts with various sugars and related sugar alcohols. ... 

Clear antiperspirants have become popular because they leave no visible residue.They are not always formulated through a microemulsion route. Clear sticks can be based on dibenzylidene sorbitol acetal (DBSA) gelling agent and zirconium or glycine-complexed aluminum chlorhydrate antiperspirant actives that are soluble in propylene glycol without water. An alternative route is to closely match the refractive indices of the oil and water phases so a clear product (not a microemulsion) results for an antiperspirant gel [20,23]. Clear deodorant sticks with the active ingredient triclosan can be solidified with sodium stearate, which is incompatible with antiperspirant active ingredients (aluminium chlorhydrates). 

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