Effects of hydroxypropyl-β-cyclodextrin, gel and in situ gelling systems on the stability of hydrocortisone after gamma irradiation

This work investigated the potential of (2-hydroxy)propyl-β-cyclodextrin (HPβCD) to protect hydrocortisone against degradation by gamma radiation. Hydrocortisone stability was monitored after irradiation of aqueous solution in absence and presence of HPβCD. The study also monitored the stability after incorporation of hydrocortisone- HPβCD solution in carboxymethylcellulose gel, alginate-based and carbopol-based in situ gelling systems. Incorporation of HPβCD in hydrocortisone aqueous solution significantly increased the drug stability after gamma irradiation. The recovered chemical potency values of the drug in presence of HPβCD were significantly higher than those recovered after irradiation of drug solution in absence of HPβCD. Irradiation of the gel or in situ gelling systems containing HPβCD-drug solution resulted in a significant reduction in the viscosity with the recovered drug concentrations being similar to those recovered in absence of the gelling system. The study indicated the potential of HPβCD to protect hydrocortisone against gamma irradiation with no augmentation from the gel or gelling systems.