Development and validation of a high performance liquid chromatographic method for determination of cyclosporine-A from biodegradable intraocular implants

Abstract

An HPLC method was developed and validated aiming to quantify the cyclosporine-A incorporated into intraocular implants, released from them; and in direct contact with the degradation products of PLGA. The separation was carried out in isocratic mode using acetonitrile/water (70:30) as mobile phase, a C18 column at 80 ºC and UV detection at 210 nm. The method provided selectivity based on resolution among peaks. It was linear over the range of 2.5-40.0 µg/mL. The quantitation and detection limits were 0.8 and 1.2 µg/mL, respectively. The recovery was 101.8% and intra-day and inter-day precision was close to 2%

Development and Validation of a High Performance Liquid Chromatographic Method Determination of Zidovudine Encapsulated in PCL Nanoparticles

“…The linearity could be defined by the following equation "y = 30000x -9172.2", where y and x are the area and the concentration (μg/mL), respectively. The significance of the calibration curve intercept was tested and this parameter was not statistically significant (p > 0.05), which can be considered, consequently, that the curve passes through the origin (25). The correlation coefficient (r) was higher than 0.99, showing highly significant correlation between concentration and peak area.…”

Characterization and in vitro release of cyclosporine-A from poly(D,L-lactide-co-glycolide implants obtained by solvent/extraction evaporation

“…The microspheres were collected by centrifugation at 50 g, washed three times with double--distilled water and placed in a freezer under -80 o C. Afterwards the frozen solution was lyophilized for 24 h (Christ Alpha 1-2 LD, Bioblock Scientific, France).The encapsulation efficiency of CyA--PLGA microspheres was 57.5% ± 3.0, and this result was obtained using the HPLC method described subsequently. 30 The obtained microspheres were then moulded into rods using Teflon ® sheets heated on a hot plate from 100 to 120 °C in order to form CyA--loaded PLGA implants. According to the literature, the polymer and drug thermal stability was confirmed as no relevant alterations were detected in the system up to 200 °C based on the themogravimetric analysis performed.…”

“…The validation of the method has showed the absence of interference of the polymer with CyA retention time, discarding the risks of overestimation. 30…”

“…The amount of CyA in the PBS solution was detected and quantified by validated high performance liquid chromatographic method previously described. 30…”

Estudo farmacológico, eletrofisiológico, imunocitoquímico e morfológico da injeção intravítrea de aciclovir em coelhos

“…The representative linear equation was y = 213557169.88x + 896259.92, where y and x were area and concentration (g/mL), respectively. The significance of the intercept obtained in the calibration curve was tested and this parameter was not statistically significant (p > 0.05), consequently, it can be considered that the curve passes through the origin (Saliba et al 2011). The correlation coefficient (r) was higher than 0.99, showing highly significant correlation between concentration and peak area (Brazil 2003).…”