Determination of aminoglycosides in pharmaceutical formulations--I. Thin-layer chromatography.

A simple, fast and reliable procedure for the determination of seven major aminoglycosides in commercial formulations (injections, capsules, eye drops, solutions and ointments) is presented. The aminoglycosides are separated on silica gel plates then located with ninhydrin and analysed in situ using a chromatogram spectrophotometer. Linearity tests, repeatability (relative standard deviation congruent to 3.5%) detection limits (60-200 ng) were satisfactory for all the compounds. Recovery data in pharmaceutical formulations (expressed as the percentage of the label claim) from thin-layer chromatography (TLC) and microbiological assays did not give any significant difference (P = 0.05); this result shows that TLC is a reliable method for the determination of aminoglycosides as the drug substance and in pharmaceutical formulations.