Disclosed herein is an eco-friendly, non-aqueous and stable antimicrobial solution composition comprising (a) about 0.1 to 20.0 wt % of a Tropolone; and (b) about 80.0 to 99.9 wt % of bio-derived 1,3-propanediol and/or bio-derived sorbitan caprylate. Also disclosed is a process for preparing and method of using the composition. The composition is stable for at least two years at room temperature and can be employed in the fields of cosmetic, toiletry, personal care, household, cleaning, disinfecting, food, beverages, enzyme formulations, feminine care products, foot care products, pet care products, food ingredients, paints, coatings, metal working fluids, nutrients for plants, construction and/or laundry products.