Percutaneous penetration following use of hair dyes.

We assess the percutaneous penetration potential of two commercially distributed semipermanent hair dyes. Utilizing several solvent systems in conjunction with thin-layer chromatography (TLC), we found that the commercial formulations contained at least nine component chemicals. Eight adult volunteers had their hair dyed with these preparations and 24-hour urine specimens were collected daily for five days. The urine was lyophilized and extracted with diethyl ether under acid and alkaline conditions. The TLC of urine from four of the eight subjects, taken from one to four days after dyeing the hair, disclosed a purple spot. This spot, though not identified, was the same with both dye preparations. It is likely that these hair dyes not uncommonly penetrate the skin.

Structure--activity studies on tetrahydro- and hexahydrocannabinol derivatives.

A series of tetrahydro- and hexahydrocannabinol derivatives was prepared in which the substituents at position 9 were varied. These compounds were evaluated in mice for their effects on locomotor acitivty, body temperature, muscle tone, and analgesia. Depression of body temperature and locomotor function was demonstrated by several compounds, but all were devoid of any significant analgesic activity.

Tick repellents II: N-substituted azacyclopentanones and azacyclopentenones.

Several N-substituted azacyclopentanones and azacyclopentenones were synthesized and evaluated as repellents for the brown dog tick Rhipicephalus sanguineus. Several of these compounds were more effective in our test system than were the standard repellents, N,N-diethyl-m-toluamide and butopyranoxyl.

Topical mosquito repellents XI: carbamates derived from N,N'-disubstituted diamines.

Carbamates derived from various N,N'-disubstituted diamines were synthesized and evaluated as repellents for Aedes aegypti mosquitoes with an in vitro blood-feeding test system. Several compounds were more effective than diethyltoluamide.

Topical mosquito repellents XII: N-substituted ureas and cyclic ureas.

Various N-substituted urea and cyclic urea derivatives were synthesized and evaluated as repellents for Aedes aegypti mosquitoes with an in vitro blood-feeding test system. Several compounds were superior to diethyltoluamide.

Topical mosquito repellents XIII: Cyclic analogs of lactic acid.

Numerous cyclic analogs of lactic acid were synthesized to ascertain whether they might act as agonists of antagonists of lactic acid, a known attractant for mosquitoes. These compounds were evaluated with an in vitro blood-feeding test system and an in vivo cloth test. Two of the compounds in the blood-feeding test system showed biphasic results, acting as attractants at low concentrations and as repellents at higher concentrations. Several compounds (III, V, VII, and X) repelled Aedes aegypti mosquitoes in the blood-feeding test system. However, in the in vivo cloth test system, only III repelled the mosquitoes significantly.

Topical mosquito repellents VII: alkyl triethylene glycol monoethers.

Normal and branched-chain aliphatic monoethers of triethylene glycol are effective topical mosquito repellents. In terms of duration of protection, they are generally superior to the corresponding diethylene glycol analogs and some are superior to diethyltoluamide. The n-heptyl monoether of triethylene glycol affords double the protection time of diethyltoluamide under controlled laboratory conditions and appears to be a useful new mosquito repellent.

Influence of human skin surface lipids on protection time of topical mosquito repellent.

Skin surface lipids were extracted from volunteers who had been ranked according to the duration of protection from mosquitoes by diethyltoluamide. These lipids were analyzed by GLC-mass spectrometry for their fatty acid contents. Correlations were found between total skin lipid content and protection time of diethyltoluamide and between certain fatty acid concentrations in the skin lipids and the protection time of diethyltoluamide.

Mutagenic studies of aziridine derivatives derived from various diamines.

Various aziridine derivatives derived from diamines were studied in several biological systems to evaluate their effects on reproduction and as potential mutagens. Considerable variations in the biological activities of these compounds were seen among animal species and among the varied chemical structures. In general, mutagenic responses paralleled the antifertility effects in mice and houseflies and the anticancer effects in mice. The lack of an antifertility effect by N,N'-bis(aziridinylacetyl)-1,8-octamethylenediamine in the rat was quite unexpected in view of its chemosterilant activity in houseflies and mice.