Prednisolone (PD) has been used in various disease and as various doses according to disease or body weight in pediatrics. Young children (≤5 years) who cannot able to take the tablet is prescribed with pulves, but the taste of PD is so bitter that they are difficulty in taking this medicine. And it is difficult to take precise doses because of the unequalization of distribution, loss of drug when it is distibuted with pulves. So in this study, we developed PD syrups for easiness, exactness of distribution and evaluated the stability of prednisolone syrups.
First, we made an preliminary experiments to evaluate the effect of exipients on the stability. We added EDTA (disodium edetate) to PD solutions (0.05%) and observed the slight changes of the contents. As a result, EDTA has an effect of stabilization. Besides, after added 40% sucrose and preservatives to PD solutions (0.05%), mixed each 10% glycerin, sorbitol, xylitol, propylene glycol (PG), and preserved for 6 days at 55℃, we analyzed the contents and compared the rate constant (k) and half-life (t_(1/2)). Because solutions added PG, glycerin is more stable, we observed the stability of the different concentrations of these exipients and established the appropriate concentrations of these exipients. We kept PD solutions containing citric acid for 7 days at 55℃ and evaluated the effect of the concentration of the citric acid. As a result, there is no difference less than 0.5% citric acid concentrations.
Second, through this preliminary experiments we designed the preliminary formulations. To examine the stability of formulations which is containing alcohol and is not, formulations containing alcohol (RP1, RP2) and formulations not containing alcohol (RP3, RP4) were stored for 4 weeks at 30, 40, 60℃ and was measured by a stability-indicating HPLC. And we plotted the Arrhenius-plot. All samples were analyed in duplicate on each week of analysis.
When extrapolated this straight line, we found that the shelf life (t_(90)%) of RPI was about 23.4 months, RP2 was about 2.5 months, RP3 was months and RP4 was about 7.4 months. We developed PD syrups successfully but thought that we hereafter would correct the bitter taste of prednisolone itself.
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