Oral irritation characterization

Many varieties of red pepper, derived from plants of the genus Capsicum, are used in different cuisines around the world for their sensory properties of oral chemical "heat", volatile flavor and color. Determination of the degree of heat in a pepper sample has been a difficult problem for both sensory and instrumental analysts of flavor. Furthermore, the literature concerning the sensory physiology and perceptual responses of the "common chemical sense" (as defined later) has lagged behind other areas of study of the chemical senses. The purpose of this paper will be to review recent developments in two areas, the development of a standard method for sensory analysis of ground red pepper heat and the psychophysical characterization of observers responses to oral chemical Irritation induced by spice-derived compounds. 

However, since the act of sensation is an interaction of an observer with a stimulus, the two approaches often end up using similar methods (e.g., scaling) to provide similar information (e.g., observer response as a function of stimulus concentration). Because of this parallel orientation in methods, and because of the concurrent advances recently made in both areas, we have integrated results from the two fields in this paper. The first section will focus on psychophysical characterization of oral chemical irritants. The final section will discuss the development of a new sensory method for evaluation of ground red pepper heat. 

Antazoline is less active than most of the other anlihisla-minic drugs, but it is characterized by the lack of local irritation. The more soluble phosphate salt is applied topically to the eye in a 0.5% solution. The less soluble hydrochloride is given orally. In addition to its use as an antihistamine, antazxtline has more than iwice the local anesthetic potency of procaine and also exhibits anticholinergic actions. 

Trifluralin is classified as a Toxicity Category IV (practically nontoxic) agent for acute oral toxicity and dermal irritation and Toxicity Category III (slightly toxic) for acute dermal toxicity, acute inhalation toxicity, and eye irritation. Ocular irritation is characterized by increased lacrimation, photophobia, and redness. Conjunctivitis can continue for 5-7 days. 

The drug is less soluble than the eorresponding phosphate salt and is mostly administered orally. It is found to be less aetive than a host of other antihistaminics however, it has been duly characterized by its predominant absenee of local irritation. 

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