In this paper, chromatographic analysis of active substance olopatadine hydrochloride, which is used in eye drops as antihistaminic agent, and its impurity E isomer by hydrophilic interaction liquid chromatography (HILIC) and application of design of experiments (DoE) methodology are presented. In addition, benzalkonium chloride is very often used as a preservative in eye drops. Therefore, the evaluation of its chromatographic behavior in HILIC was carried out as well. In order to estimate chromatographic behavior and set optimal chromatographic conditions, DoE methodology was applied. After the selection of important chromatographic factors, Box-Behnken design was utilized, and on the basis of the obtained models factor effects were examined. Then, multi-objective robust optimization is performed aiming to obtain chromatographic conditions that comply with several quality criteria simultaneously: adequate and robust separation of critical peak pair and maximum retention of the first eluting peak. The optimal conditions are identified by using grid point search methodology. The experimental verification confirmed the adequacy of the defined optimal conditions. Finally, under optimal chromatographic conditions, the method was validated and applicability of the proposed method was confirmed.

Aim: An ultra pressure liquid chromatography (UPLC)/MS/MS method for vancomycin and teicoplanin determination in human plasma was developed in accordance with analytical quality by design (AQbD) concept and fully validated. Materials & methods: Chromatographic separation was performed on ACQUITY UPLC C18 charge surface hybrid (CSH) column (2.1 mm × 50 mm, 1.7 μm particle size) in gradient mode and the mobile phase consisted of 0.1% formic acid in water and pure acetonitrile. The experimental design methodology was used for the definition of optimal chromatographic and protein precipitation conditions. Results: The linearity ranges were 0.05–10 μg ml-1 for vancomycin and 0.5–200 μg ml-1 for total teicoplanin. The relative standard deviations for precision estimation were below 15% and the accuracy was within 85–115% for all quality control levels. Conclusion: The method was utilized for glycopeptide antibiotics bioanalysis.

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The proposed method was utilized for monitoring of olopatadine in human tear.

IzvodU savremenoj farmaceutskoj analizi neke farmaceutski aktivne supstance studije forsirane degradacije imaju veliki značaj jer se iz njih može dobiti veliki broj značajnih posataka o stabilnosti leka. U ovom radu, opisano je ispitivane stabilnosti olopatadin-hidrohlorida pod utcajem stres agenasa a u cilju dobijanja podataka o njegovoj stabilnosti. Za praćenje ponašanja olopatadin-hidrohlorida primenjena je metoda tečne hromatografije hidrofilnih interakcija (eng. Hidrophilic Interaction Liquid Chromatography -HILIC). Olopatadin-hidrohlorid izložen je dejstvu kiseline, baze, povišene temperature i oksidacionog sredstva, a stepen degradacije praćen je u definisanim vremenskim intervalima. Takođe, određena je i kinetika degradacije u cilju sticanja boljeg uvida u stabilnost supstance i njen mehanizam razgradnje. Definisani su red reakcije, konstanta brzine reakcije i poluvreme degradacije nakon izlaganja dejstvu kiseline, baze i oksidacionog sredstva.Ključne reči: olopatadin-hidrohlorid; studije forsirane degradacije; kinetika degradacije; tečna hromatografija hidrofilnih interakcija.