Doxepin is a tricyclic antidepressant (TCA) used as a pill to treat major depressive disorder, anxiety disorders, chronic hives, and for short-term help with trouble remaining asleep after going to bed (a form of insomnia). As a cream it is used for short term treatment of itchiness due to atopic dermatitis or lichen simplex chronicus. The aim of the present study was to in vitro evaluate the antibacterial effects of doxepin using MIC, MBC and disk diffusion methods. The MIC and MBC was determined by dilution assay using different concentrations of doxepin on Bacillus subtilis and Pseudomonas aeruginosa. Disk diffusion assay were prepared under sterile conditions disks of drugs (three repeat for each concentration) containing three different doses (25, 50 and 150 µg) were prepared. MIC values of doxepin against Pseudomonas aeruginosa was 0.750 mg/ml, and MBC values was 4.5 mg/ml and MIC values of doxepin on Bacillus subtilis was 0.500 mg/ml, and MBC values was 4.5 mg/ml. The results obtained from disk diffusion assay supported that the doxepin has not antibacterial effect against Pseudomonas aeruginosa and Bacillus subtilis. It can be said that doxepin does not have antibiotic effect against gram negative and gram positive bacterial strain.

Food additives adding to food and some drinking to protect taste or improve its flavor and quality, it has been used for centuries to help ease processing, packaging, and storage. Food additives are classified as colors, antimicrobial agents, anti-fungal agents, and flavor enhancers. Antimicrobial agents including salts, sorbic acid, vinegar and calcium propionate are used in the products like salad dressings, margarine, cheese and pickled foods. Antioxidant agents such as vitamin C, vitamin E, BHT and BHA are using in the foods containing high fats. Food additives are significant in drinking and food manufacturing firms.