Stability and antibacterial potency of ceftazidime and vancomycin eyedrops reconstituted in BSS® against Pseudomonas aeruginosa and Staphylococcus aureus

Purpose: We aimed to study the stability and the in vitro antibacterial potency of ceftazidime and vancomycin eyedrops against Pseudomonas aeruginosa and Staphylococcus aureus, respectively, under different storage temperatures and light conditions. Methods: Solutions of ceftazidime 50 mg/ml and vancomycin 50 mg/ml were prepared by reconstituting with balanced salt solution (BSS^®) and stored at 4 °C and at 24 °C with and without exposure to light. The minimum bactericidal concentrations against P. aeruginosa and S. aureus were measured to evaluate the antimicrobial potency over a 4‐week period. Changes in the pH values and physical characteristics of the solutions were recorded over the same period of time. Results: The antibacterial potency of ceftazidime decreased significantly from days 3 and 7 onwards at storage temperatures of 24 °C and 4 °C, respectively, but was not affected by light exposure. The pH value progressed from acidic to alkaline, peaking at day 3, in all solutions. The antibacterial potency of vancomycin remained stable during the 4‐week period, but its pH showed a slight progression from acidic to less acidic, in all solutions. Conclusions: Ceftazidime eyedrops in BSS^® appear to remain effective against P. aeruginosa for ≥ 7 days when stored at 4 °C, but were less effective when stored at 24 °C. Loss of antibacterial potency coincides with the appearance of visual and olfactory signs of degradation. The transient rise in pH at day 3 is a matter of possible concern, however, as it may affect patient tolerance. By contrast, vancomycin eyedrops in BSS^® can be safely used for ≥ 4 weeks, stored at either 4 °C or 24 °C.     

氟康唑滴眼液的制备及临床应用

目的：将氟康唑制成0．2％滴眼液,用于治疗真菌性角膜溃疡,观察其临床疗效。方法：以无菌方法配置成滴眼液,选用紫外分光光度计（uv -200）测定滴眼液含量,对21例真菌性角膜溃疡进行对照分组疗效观察。结果：氟康唑滴眼液制备,含量测定方法简便,可靠,结果准确,对真菌性角膜溃疡总有效率为95．2％。结论：氟康唑滴眼液是一种可供临床选用的真菌性角膜溃疡用药。     

Eyedrop‐Induced Allergy: Clinical Evaluation and Diagnostic Protocol

Abstract

Background.?In the last few years, adverse reactions to mydriatic eyedrops have been investigated. However, is not still available a standardized protocol, capable of identify the pathogenetic mechanism. In the light of these findings we have evaluated the reliability of a protocol with well established concentration of specific allergens. Methods.?The diagnostic method includes the application of patch test series Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali (GIRDCA), medicaments, corticosteroids, local anesthetics, main eyedrops' excipients, pure active principles and extemporaneous preparations with mydriatic eyewashes. At the same time, skin prick test with a solution of atropine sulfate at 1‰ and an intradermal test with injection of atropine at 0.01‰ were carried out. Results.?After patch tests were removed, we detected seven positiveness to the phenylephrine, two to the benzalkonium chloride, one to thiomersal, one to the ethylendiamine and one to the atropine sulfate 1‰. With intradermal tests we obtained three positiveness in patients who reported adverse reactions to atropine. Conclusions.?Our results show that phenylephrine is frequently responsible for allergic conjunctivitis (53.8%). In the case of atropine, even though the limited number of patients suggests to perform more extensive studies, it emerges that our diagnostic protocol is safe and might be able to screen allergic reactions in the field of ophthalmopathies.     

Contact allergy from tobramycin eyedrops

We report a patient with allergic conjunctivitis and blepharitis as a result of tobramycin eyedrops.     

氟康唑滴眼液的研制及质量控制

目的 :制备氟康唑滴眼液并控制其质量。方法 :采用高效液相色谱法测定滴眼液中氟康唑含量 ,依据《中国药典》对滴眼液进行质量控制。结果 :含量测定平均回收率为100 41 % ,RSD=0 54% (n=5)。结论 :该制剂处方合理 ,制备工艺简便 ,质量易于控制。     

A Comparison of Proparacaine and Tetracaine Eye Anesthetics

Objective : To compare two topical eye anesthetics, proparacaine and tetracaine, for pain of instillation and duration of activity.
Methods : Volunteers received both anesthetics in a prospective, randomized, double-masked protocol. The subjects were given one drop of a study solution in the lower lid fornix of the left eye. Immediately after receiving the medication, they rated the pain of instillation on a previously validated visual-analog pain scale. This procedure was then repeated in the right eye with the other study solution. Pain scales were quantified by making measurements to the nearest millimeter from the point of scale origin to the point marked by the patient. The time interval until return of the corneal blink reflex was determined using a cotton wisp. Pain scores and the time to return of corneal reflex were analyzed by the Sign test and Wilcoxon rank-sum test, respectively, with significance defined as p < 0.05.
Results : Twenty-three subjects were available for analysis. Twenty subjects reported proparacaine hurt less than tetracaine, two felt the pain was the same for the two agents, and only one reported that proparacaine was more painful. The mean pain score for tetracaine was 24 mm (100 mm maximum) higher than that for proparacaine (p < 0.0002). Proparacaine lasted 1.3 minutes longer than tetracaine, 10.7 minutes versus 9.4 minutes (p = 0.0001).
Conclusion : Proparacaine eye drops cause less pain than tetracaine eye drops upon instillation. Anesthesia from proparacaine lasts slightly longer. These properties make proparacaine preferable to tetracaine.