Tetrahydrozoline hydrochloride

Chemical Name 4,5-Dihydro-2-(1,2,3,4-tetrahydro-1-naphthalenyl)-1 H-imIdazole hydrochloride 

Trade Name Manufacturer Country Year Introduced 

A mixture of 540 grams (9.0 mols) of ethylenediamine, 270 grams (1.53 mois) of 1,2,3,4-tetrahydro-aipha-naphthoic acid, and 360 mi (4.32 mois) of concentrated hydrochloric acid was introduced into a two-liter, three-necked flask fitted with a thermometer, stirrer, and distillation takeoff. The mixture was distilled under a pressure of about 20 mm of mercury absolute until the temperature rose to 210°C. Thereafter, heating was continued under atmospheric pressure and when the temperature reached about 260°C, an exothermic reaction was initiated. The heat was then adjusted to maintain a reaction temperature of 275° to 280°C for 45 minutes and the mixture thereafter cooled to room temperature. 

900 ml of 4 N hydrochloric acid was added and the aqueous layer stirred with warming until a clear, brown solution resulted. This brown solution was made strongly alkaline with sodium hydroxide. The oil that separated solidified and was collected on a filter leaving filtrate A. The solid was dissolved in 370 ml of alcohol with warming, and the solution was treated with 130 ml of concentrated hydrochloric acid with stirring and cooling. This acidified mixture was diluted with 300 ml of ether and chilled. The solid salt was collected and dried and the filtrate concentrated to approximately 300 ml, diluted with 300 ml of ether and the salt which separated collected and dried. 

Filtrate A was extracted with ether, dried, acidified with alcoholic hydrogen chloride, and the salt which separated was collected and dried. There was thus obtained, when all the salt had been combined, 250 grams (69.3% of the theoretical yield) of 2-( 1,2,3,4-tetra-hydro-1-naphthyl)imidazoline hydrochloride, melting at 256° to 257°C. 

An additional 50 ml of methanol was added to the flask and then 22.2 grams (0.05 mol) of tetracycline, neutral form, was added portionwise intermittently with another 50 ml of methanol. A clear solution was maintained throughout the addition of the tetracycline. After addition of all of the tetracycline, the solution was a deep orange color and the temperature in the reaction flask was 35 C. 

One hour after addition of the tetracycline, the clear reaction solution was poured into 1,500 ml of chloroform. A yellow product separated and was collected on a coarse sintered glass filter and air dried. The tetracycline-metaphosphoric acid complex weighed about 10 grams, contained 7.34% of phosphorus and had a bioassay of 634 gammas per milligram. Solubility in water is 750 mg/ml. 

Sieger, G.M. Jr. and Weidenheimer, J.F. U.S. Patent 3,053,892 September 11, 1962 assigned to American Cyanamid Company 

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Naphazoline hydrochloride Tetrahydrozoline hydrochloride Long-acting... 

G. Puglisi, S. Sciuto, R. Chillemi, and S. Mandiafico, Simultaneous high-performance liquid chromatographic determination of antazoline phosphate and tetrahydrozoline hydrochloride in ophthalmic solution, J. Chromatogr., 569 165 (1986). 

Infra-red Spectrum. Principal peaks at wavenumbers 1600, 742, 1293, 1250, 763, 1500 (tetrahydrozoline hydrochloride, KBr disk). 

Octamylamine Hydrochloride Arecoline Hydrobromide Isosorbide Dinitrate Carbazochrome Carbamazepine Cyclobarbitone Dropropizine Hexobarbitone Methazolamide Procaine Thiacetazone Tetrahydrozoline Hydrochloride Carbromal Cotarnine Viloxazine Ketamine Methyldopa Nitrofurantoin Proxyphylline Nealbarbitone Nomifensine Quinalbarbitone Isoetharine Methyldopate Salbutamol Benzphetamine Methacholine Bromide Danthron Cropropamide Hexethal... 

Fig. 2 Disappearance profiles of (A) tetrahydrozoline hydrochloride and (B) chlorpheniramine maleate from rat nasal cavity after nasal administration of an o/w emulsion and an aqueous solution at pH 8. (From Ref. l)...

Tetrahydrozoline hydrochloride Long-acting Oxymetazoline hydrochloride Up to 12... 

TETRAHYDROZOLINE HYDROCHLORIDE (Collyrium Fresh, Murine Plus, Ocu-Drop, Soothe, Tyzine Pediatric, Visine)... 

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