Effect of essential oils, hydrating agents, and ethanol on hair removal efficiency of thioglycolates.

BACKGROUND: The required time for hair removal by chemical depilatories has always been a concern and depends on different parameters including permeation into the hair shaft. OBJECTIVES: In an attempt to improve this process, it was decided here to investigate the possibility of decreasing depilation time of thioglycolates, widely used depilatories, using penetration enhancers. METHODS: Urea, sodium dodecyl sulfate, dimethylsulfoxide (DMSO), ethanol (75 and 96%), NaCl, and peppermint and orange oils were used as penetration enhancers, and their effect on depilatory time of thioglycolates, represented as tear resistance time (TRT) of hair shaft under a constant tensile stress, was studied. The effects of temperature and hydration on TRT were also investigated. RESULTS: Results showed that ethanol (75%), DMSO, and peppermint oil (ethanolic solution) were able to significantly reduce TRT up to two times from about 6 to 3.5 min. Other enhancers were not able to change TRT. Results also revealed that increase in temperature from 20 to 37 °C reduces TRT by about 4 times. Hydration in boiling water also reduced TRT significantly about 1.5 times. CONCLUSIONS: Present results show that it is possible to reduce depilation time by penetration enhancers. Such improvement can increase users' compliance and might provide other advantages like decreased skin irritation.

Synthesis of a quaternary bis derivative of imipramine as a novel compound with potential anti-enuretic effect.

OBJECTIVES: Imipramine has been used for over four decades (early reports in 1960s) for the treatment of nocturnal enuresis, although the reason for its effect is not clear. Imipramine is a tertiary amine, which may act both in the periphery and/or pass through the blood-brain barrier (BBB) in unionized form and exhibit a central effect. Since imipramine has anti-cholinergic properties, some believe it may exert its anti-enuretic effect by affecting peripheral cholinergic receptors, i.e. its anti-enuretic effect may be due to peripheral anti-cholinergic properties, whereas others think it can pass through the BBB and interact with central nervous system (CNS) receptors. If the anti-enuretic effect of imipramine is due to its peripheral anti-cholinergic effects, its entrance into the CNS is unnecessary. Therefore, the synthesis of a form of imipramine that can exhibit peripheral anti-cholinergic effects but does not have CNS adverse effects would have a safer drug profile in this case. On the other hand, if the anti-enuretic effect of imipramine is primarily due to its action on the CNS, a form of imipramine that cannot pass through the BBB has no effect on nocturnal enuresis treatment and thus may help to clarify the mechanism of action of imipramine in nocturnal enuresis treatment. METHODS: This article describes the synthesis and evaluation of the anti-cholinergic effect of a new bis derivative of imipramine, which contains two imipramine units in its structure. KEY FINDINGS: The compound exhibited anti-cholinergic activity comparable with that of imipramine on isolated guinea pig ileum. CONCLUSIONS: Being a quaternary ammonium, this compound is not expected to be able to cross the BBB and thus would cause fewer CNS side effects.