A simple and rapid high-performance liquid chromatographic method for determining tobramycin in pharmaceutical formulations by direct UV detection

Abstract

Background:Tobramycin, an aminoglycoside antibiotic, is a polar pharmaceutical compound which lacks a UV absorbing chromophore. Due to the absence of a UV absorbing chromophore and high polar nature of this antibiotic, the analysis of such compounds becomes a major challenge.Objective:To overcome these problems, a novel method for the determination aminoglycoside tobramycin was developed and validated based on reversed-phase high-performance liquid chromatography (RP-HPLC) with UV detector.Materials and Methods:An isocratic mobile phase consists of buffer 0.05 M diammonium hydrogen phosphate, pH adjusted to 10.0 using tetramethyl ammonium hydroxide. Chromatography was carried out at 25°C on a Purosphere RP-8e, 250 mm × 4.6 mm, 5mm. The detection was carried out using variable wavelength UV-Vis detector set at 210 nm. The compounds were eluted isocratically at a steady flow rate of 1.0 mL/min.Result and Discussion:Tobramycin retention time was about 9.0 min with an asymmetry factor of 1.4. A logarithmic calibration curve was obtained from 0.47 to 0.71 mg/mL (r > 0.9998). Within-day %RSD was 0.29 (n = 6, 0.60 mg/mL) and between-day %RSD was 0.54 Specificity/ selectivity experiments revealed the absence of interference from excipients, recovery from spiked samples was between 99.0–100.0 percent.Conclusions:A HPLC method based on UV detection has been developed and validated for determination of tobramycin from ophthalmic solution. The method is simple, rapid, specific, accurate (error 0.80%), precise (RSD <2.0%) and linear (r2=0.9998). The described method is suitable for routine analysis and quality control of ophthalmic solution containing tobramycin.

Lipopolysaccharide-affinity copolymer senses the rapid motility of swarmer bacteria to trigger antimicrobial drug release

“…At each measurement time point (i.e., 20 min, 40 min, 80 min, 2 h, 4 h, 8 h, 24 h, 48 h and 96 h), the absorption spectrum of the supernatant after centrifugation (10,956 × g ) was measured using a UV–Vis absorption spectrometer. The absorbance of tobramycin at 210 nm was used to determine the concentration of the drug 37 . The cumulative amount of tobramycin released at a particular measurement time was determined by summing the amount measured at that time and the cumulative amount measured at the last measurement time.…”

Long-term stability of gentamicin sulfate-ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) solution for catheter locks

“…Therefore, 2.5 mL of gentamicin sulfate standard solution or ALS was then mixed with 0.5 mL of stock solution of derivatizing agent and 2.75 mL of methanol (final volume: 5.75 mL). Although usually derivatization was carried out at 60 °C constant temperature [20], [22], no heating was applied to gentamicin – OPA based solution, taking into account the lack of stability of such chemical reaction and the short half-life of reaction products, as reported elsewhere [23].…”

Analytical Methods for the Determination of Aminoglycosides Antibiotics by Chromatrographic Technique

“…Analysis was carried out by using Purosphere RP column. The detection was carried out using variable wavelength UV-Vis detector set at 210 nm [55].…”