Comparison of 1% cyclosporine eye drops in olive oil and in linseed oil to treat experimentally-induced keratoconjunctivitis sicca in rabbits / Comparação da ciclosporina 1% em óleo de oliva e óleo de linhaça no tratamento da ceratoconjuntivite seca experimentalmente induzida em coelhos

ABSTRACTPurpose:To evaluate the effectiveness of topical 1% cyclosporine eye drops diluted in either of the two vehicles-olive and linseed oil-and that of the oils themselves in treating experimentally-induced keratoconjunctivitis sicca (KCS) in rabbits.Methods:KCS was induced in 25 New Zealand rabbits using 1% atropine sulfate eye drops for 7 days before treatment and throughout the treatment period (12 weeks). The rabbits were divided into five groups: one control (C) group without KCS induction and four treatment groups in which KCS was induced and treated topically with olive oil (O), linseed oil (L), cyclosporine in olive oil (CO), and cyclosporine in linseed oil (CL). The animals were evaluated using Schirmer tear test 1 (STT), the fluorescein test (FT), tear-film break-up time (TBUT), the rose bengal test (RBT), and histopathological analysis.Results:Values of STT and TBUT significantly decreased 1 week post-induction (p<0.05) and were similar to initial values after the 4th week of treatment, in all groups. After KCS induction, there was significantly less corneal damage in group L than in group CL, as assessed FT and RBT. Histopathology demonstrated that Groups L and CL presented less edema and corneal congestion. There was no significant difference in the goblet cell density (cells/mm2) between the groups (p=0.147).Conclusion:Cyclosporine diluted in olive oil or linseed oil was effective in the treatment of KCS, although it had better efficacy when diluted in linseed oil. Linseed oil presented better effectiveness, whether associated or not, than olive oil. These results may contribute to the creation of novel topical ophthalmic formulations for KCS treatment in future.

RESUMOObjetivo:Avaliar a eficácia do uso tópico do colírio de ciclosporina 1% em dois veículos, óleo de oliva e linhaça, e dos óleos separados, no tratamento da ceratoconjuntivite seca experimentalmente induzida (KCS) em coelhos.Método:Vinte e cinco coelhos Nova Zelândia foram induzidos para KCS com colírio de sulfato de atropina a 1% por sete dias antes e durante o período de tratamento (12 semanas) e foram divididos em 5 grupos, um grupo controle (C), sem indução de KCS e quatro grupos de tratamento tópico com ciclosporina em óleo de oliva (CO), ciclosporina em óleo de linhaça (CL), óleo de oliva (O) e óleo de linhaça (L). Os animais foram avaliados utilizando o teste lacrimal de Schirmer I (STT), teste de fluoresceína (FT), teste de ruptura do filme lacrimal (TBUT), teste de rosa bengala (RBT) e análise histopatológica.Resultados:Os valores de TBUT e STT diminuíram significativamente uma semana pós-indução da KCS (p<0,05) e foram semelhantes aos valores iniciais após a quarta semana de tratamento, em todos os grupos. Após a indução de KCS, houve menor dano na córnea no grupo L em relação ao grupo CL, quando avaliados FT e RBT. A histopatologia demonstrou que os grupos L e CL apresentaram menos edema e congestão da córnea. Não houve diferença significativa na densidade das células caliciformes (células/mm2) entre os grupos (p=0,147).Conclusão:Ciclosporina diluída em óleo de oliva ou linhaça foi eficiente no tratamento da CCS, porém teve uma melhor eficácia quando diluída no óleo de linhaça. O óleo de linhaça, isoladamente ou associado, apresentou melhor eficácia quando comparado ao óleo de oliva. Estes resultados podem contribuir no futuro com novas formulações oftálmicas tópicas no tratamento da CCS.

Estudo clínico e histológico das pálpebras e conjuntiva hígidas submetidas ao tratamento tópico com soluções anestésicas em coelhos / Clinical and histological evaluation of healthy eyelid and conjunctiva subject to local treatment with anesthetic solutions in rabbits

Avaliaram-se as apresentações comerciais de colírios anestésicos aplicados em 63 coelhos da raça Nova Zelândia, distribuídos em três grupos (G1, G2 e G3) de 21 animais cada e que receberam instilação de uma gota em cada olho seis vezes ao dia. Os animais do G1 foram tratados com colírio de cloridrato de proparacaína a 0,5%; os do G2, com colírio de cloridrato de tetracaína a 1% associado à fenilefrina a 0,1%; e os do G3, com solução fisiológica. Cada grupo foi subdividido em três subgrupos com sete animais cada, os quais foram tratados por três, sete e 15 dias. No final de cada tratamento, dois animais de cada subgrupo foram sacrificados para exame histológico de fragmentos retirados da conjuntiva, da terceira pálpebra e das pálpebras. Observou-se, ao exame clínico, episclerite em graus diversos em 100% dos animais do G1, no terceiro, sétimo e 15º dia, e em apenas 17,8% nos do G2, nestes mesmos dias. Ao exame microscópico, observaram-se aumento do número de células califormes, proliferação de folículos linfoides, aumento do número de eosinófilos e aumento do espaço intersticial nas pálpebras dos animais do G1. Pôde-se concluir que o colírio de tetracaína a 1% associado à fenilefrina a 0,1% promoveu maior toxicidade à conjuntiva ocular e às pálpebras de coelhos quando comparado ao colírio de proparacaína a 0,5%.

This work aimed to evaluate commercial presentations of anesthetic eye drops in sixty three New Zealand rabbits which were separated equally in three groups (G1, G2 and G3). The G1 group was treated with 0.5% proparacaine chloridrate eye drop, G2 group with 1% tetracaine chloridrate associated with 0.1% phenylephrine eye drop and G3 group with 0.9% physiologic solution eye drop. All of them received one drop in each eye six times a day. Each group was subdivided into three subgroups (seven rabbits), which are treated for 3, 7 and 15 days. At the end of each treatment, two animals in each subgroup were subject to euthanasia, for the purpose of conjunctiva, eyelids and third eyelids histological evaluation. At the clinical exam, different grades of episcleritis were found in all rabbits in G2 group and only in 17.8% of the rabbits in G1 group. Eye and eyelid histologic evaluation of G2 group revealed an upgrade of goblet cells and eosinophil number, lymphoid follicle proliferation and increase of interstitial space in the eyelids. We could conclude that 1% tetracaine associated with 0.1% phenylephrine eye drop caused more eyelid and ocular conjunctiva toxicity than 0.5% proparacaine eye drop.

[Studying the accelerated photostability of ciprofloxacin and lomefloxacin in tablets and eye drops]

In this work the photostability of two fluoroquinolones: ciprofloxacin and lomefloxacin has been detected in tables and eye drops formulations using light-stability cabinet. Ciprofloxacin and lomefloxacin were subjected to stress conditions. The degradation products were well separated from the peak of the active substance. The stability of these compounds has been studied both in containers and under direct light in the light-stability cabinet. Samples were assayed immediately and at 1,3,6 months by stability-indicating high performance liquid chromatography methods with photodiode array detector. The determination was performed on C18 [250 x4.6mm, 6 micro m]. The first mobile phase consisted of 0.025M phosphoric acid and acetonitrile [87:13] pumped at a flow rate 2ml/min for ciprofloxacin, while the second consisted of water, acetonitrile, triethylamine [80:20:0.3] pumped at a flow rate 1ml/min for lomefloxacin. The UV detector was operated at 278 nm for ciprofloxacin and 288 nm for lomefloxacin. The methods was suitably validated for linearity, accuracy, precision, robustness and selectivity. All validation parameters were within the acceptance range. Data analysis revealed that plastic and amber containers can not protect either ciprofloxacin or lomefloxacin in eye drops formulation from photodegradation after one month in the cabinet. White blister protect the two agents in tablets formulation after six months in the cabinet