| The stability problems of cefazolin sodium ophthalmic solutions extemporaneously prepared in the hospital were a short shelf life(7 day) and frequently altered type of artificial tear solutions. Thus the effect of preservative contained in artificial tear on physicochemical stability of cefazolin extemporaneous eye drop is needed to benefit for drug selection in hospital. Objectives= This study purposes to study the effects of different preservatives in artificial tear on physical and chemical stability of cefazolin extemporaneous eye drop. Materials and methods =Extemporaneouscefazolineye drop (50 mg/mL) was prepared from cefazolinsodium powder for injection (1g) in SWFI. Cefazolin solution would be aliquated with the different commercial artificial tear; Lac -oph®(formulation 1),Opsil tears®(formulation 2) which contained banzalkonium chloride as preservative, whereas Natear®(formulation 3)contained sodium perborate as preservative. The storage temperatures for all formulations were kept at 4 °C and 30 °C and determined stability every 0, 7, 14 and 28 day either physical or chemical stability. Colour, pH, and odour were employed for physical stability. The percentage remaining drug were presented as chemical stability and calculated form cefazolin quantitative analysis by HPLC. Results= For physical stability, it showed that storage temperature slightly affected on pH of formulation within 21 days. However, there is no statistically significant for the alteration of pH (p>0.05, unpaired t-test). It also found that colour changes related to the odour alterations. It illustrated that colour and odour alterations were observed at day 7 especially at 30°C (pale-yellow to yellowish, and mildly smell to tang smell) and the intensity of alterations depended on storage duration. Interestingly, formulation 1 and 2 at 4 °C were found fairly colour and odouralterationsat day 14. Percentage remaining of drug indicated that storage temperature affected on chemical stability at day 14. At 30 oC (day 14),percentage of drug remain of formulation 1, 2, and 3 were 83.00 ± 0.57, 84.98 ± 8.09 and 79.69 ± 0.85 consecutively. As those results, it showed that the percentage of drug remain of formulation 1, 2, and 3 were not accepted from USP30NF25 (accepted concentration range for cefazolin sodium in ophthalmic solution ; 89.06-108.83 %). Thus Cefazolin extemporaneous eye drop should be kept at temperature 4 oC to prolong the stability. Natear® was suitable vehicle of the cefazolin extemporaneous eye drop preparation. However in further study the formulationshouldbe determined microbiological stability. |