Biomaterial Database

New color reaction for determination of bacitracin in ophthalmic ointments. 1975

J Doulakas

A colorimetric method was developed for the rapid analysis of bacitracin in ophthalmic ointments. The method involves the oxidation of alpha-aminocarboxylic acid with sodium hypobromite in an alkaline medium and condensation of the resulting aldehyde with phloroglucinol in concentrated hydrochloric acid to yield a pink color which gives an absorbance maximum at 505 nm. The relationship between absorbance and the quantity of bacitracin reacted obeyed Beer's law over the 15-100-mug/ml concentration range studied, and the produced color was stable for several hours. Furthermore, the method, which can be applied directly to the aqueous dissolution sample, gave results comparable to the official microbiological analytical procedure. The standard deviation is equal to plus or minus 1.81%.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D009555	Ninhydrin	2,2-Dihydroxy-1H-indene-1,3-(2H)-dione. Reagent toxic to skin and mucus membranes. It is used in chemical assay for peptide bonds, i.e., protein determinations and has radiosensitizing properties.	Indantrione Monohydrate,Monohydrate, Indantrione
D009824	Ointments	Semisolid preparations used topically for protective emollient effects or as a vehicle for local administration of medications. Ointment bases are various mixtures of fats, waxes, animal and plant oils and solid and liquid hydrocarbons.	Ointment,Paste,Pastes,Salve,Unguent,Salves,Skin Ointment,Unguents,Ointment, Skin
D009883	Ophthalmic Solutions	Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.	Eye Drop,Eyedrop,Eyedrops,Ophthalmic Solution,Eye Drops,Drop, Eye,Drops, Eye,Solution, Ophthalmic,Solutions, Ophthalmic
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010696	Phloroglucinol	A trinitrobenzene derivative with antispasmodic properties that is used primarily as a laboratory reagent.	1,3,5-Benzenetriol,Benzene-1,3,5-triol,Spasfon-Lyoc,Spassirex
D001966	Bromine	A halogen with the atomic symbol Br, atomic number 35, and atomic weight 79.904. It is a volatile reddish-brown liquid that gives off suffocating vapors, is corrosive to the skin, and may cause severe gastroenteritis if ingested.	Bromine-79,Bromine 79
D002855	Chromatography, Thin Layer	Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Thin-Layer,Thin Layer Chromatography,Chromatographies, Thin Layer,Chromatographies, Thin-Layer,Thin Layer Chromatographies,Thin-Layer Chromatographies,Thin-Layer Chromatography
D003124	Colorimetry	Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations