Flurbiprofen and enantiomers in ophthalmic solution tested as inhibitors of prostanoid synthesis in human blood.

The purpose of this study was to assess the selectivity and potency of the nonsteroidal anti-inflammatory drug (NSAID), flurbiprofen, and its enantiomers in their inhibition of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). An assay was used with freshly drawn, heparinized human whole blood, incubated with 25 microM calcium ionophore A23187 during 60 min to produce thromboxane B2 (TXB2) by activity of COX-1 in platelets. Incubation with E. coli lipopolysaccharide (LPS) during 24 hr produced prostaglandin E2 (PGE2) by induction of COX-2 in monocytes, suppressing any possible contribution of COX-1 activity by the addition of acetylsalicylic acid. Concentration inhibition curves were determined with racemic, S(+), and R(-) flurbiprofen in final concentrations ranging from 10(-3) to 10(-10) M. The stereoselectivity of S(+) flurbiprofen vs. R(-) flurbiprofen, expressed as the reciprocal of the ratio of the concentrations giving 50% inhibition (IC50), is 340 for COX-1 and 56 for COX-2. The selectivity for COX-1 vs. COX-2, expressed as the reciprocal ratio of the IC50, was 32 for racemic, 16 for S(+), and 5.3 for R(-) flurbiprofen. Meloxicam in the same assay showed COX-2 selectivity with a ratio of 0.19.

Constitutive cyclooxygenase-1 and induced cyclooxygenase-2 in isolated human iris inhibited by S(+) flurbiprofen.

The purpose of the present study was to characterize the isoforms of cyclooxygenase (COX) in the human iris before and after stimulation with lipopolysaccharide (LPS) and to determine the selectivity of the nonsteroidal anti-inflammatory drug (NSAID), S(+) flurbiprofen, for inhibition of COX-1 and COX-2 in homogenates of this tissue. Spotblots were made of extracts of human iris in the absence and presence of LPS plus acetylsalicylic acid (aspirin). After reacting with anti-COX-1 and anti-COX-2 immunoglobulin G, the presence of both immunoreactive COX enzymes was substantiated using an indirect immunoperoxidase method. Authentic COX-1 and COX-2 were used as controls. Using an enzyme immune assay (EIA), the production of prostaglandin E2 (PGE2) was quantified in tissue homogenates of human iris under the same conditions as described above. S(+) flurbiprofen was added to tissue homogenates in order to determine the inhibitory effect on PGE2 production. Half maximal inhibitory concentrations (IC50) of S(+) flurbiprofen for the PGE2 production in the tissue homogenates were determined from concentration inhibition curves. The selectivity of S(+) flurbiprofen for inhibition of COX-1 was expressed as the ratio of IC50 for COX-2/COX-1. Spotblots of nonstimulated iris-extracts showed positive staining for COX-1 immunoreactivity (-ir) only. After incubation with LPS plus acetylsalicylic acid, positive staining was observed for both COX-1-ir and COX-2-ir. Concentrations of PGE2 released from homogenates of untreated iris varied from 1.5-4 ng/ml, and of LPS-stimulated tissue from 10-20 ng/ml of assay mixture. S(+) flurbiprofen inhibited PGE2 production of untreated tissue homogenates at an IC50 of 8 x 10(-10) M whereas, in the stimulated tissue, IC50 was found to be 3 x 10(-6) M. The selectivity of S(+) flurbiprofen for inhibition of constitutively present COX-1, relative to the inhibition of induced COX-2, was 3,600. Our results indicate that specific expression of COX isoforms in normal human iris was substantiated at the protein level by immunoreaction on spotblots. COX-1 represents the constitutively present enzyme, and COX-2 appears after stimulation with LPS. At the functional level, S(+) flurbiprofen possesses a specificity for COX-1 in inhibiting PGE2 production.

Flurbiprofen, S(+), eyedrops: formulation, enantiomeric assay, shelf-life and pharmacology.

Aphakic cystoid macula edema, occurring after cataract extraction is ascribed to trauma-induced production of intra-ocular prostaglandins. Sufficient experimental and clinical evidence supports the use of prostaglandin synthesis inhibitors to countervail this clinical condition. The active S(+)-enantiomer of flurbiprofen, a prostaglandin synthesis inhibitor, has been formulated into a stereoselective, ballast free eyedrop solution in a concentration of 0.015%. Analysis by capillary zone electrophoresis shows shelf-life stability up to four years at room temperature of this enantiomer. The inhibitory effect on the synthesis of prostaglandins as measured on a homogenate bovine iris/ciliary body, remained unaffected during a shelf-life period of three years.

Relationship between precorneal retention of viscous eye drops and tear fluid composition.

The influence of viscolysers on the precorneal residence of a fluorescent tracer was determined, using slit lamp fluorophotometry. The solution acceptability was evaluated by the volunteers by answering a standard questionnaire. The relationship between precorneal retention of viscous eye drops, discomfort and tear fluid composition after instillation of various cellulosic solutions was examined. Irritating hydroxypropylcellulose solution increases the total protein concentration of tears, without change in the ratio of lysozyme to total protein.

Prostaglandin E2 in the vitreous body of the normal rabbit eye and after ocular trauma.

Rabbit eyes were enucleated and frozen in liquid nitrogen. The vitreous was removed and analyzed for prostaglandin E2 (PGE2). The mean level (+/- SEM) of PGE2 in the anterior as well as in the posterior vitreous was 0.09 +/- 0.016 ng/ml (n = 12 rabbits). Animals pretreated with indomethacin 15 min before death, in order to prevent the formation of prostaglandin during enucleation, showed in both the anterior and posterior vitreous mean PGE2 levels of 0.04 +/- 0.008 ng/ml (n = 12) which were significantly lower. Ocular trauma such as paracentesis of the anterior chamber, indentation of the sclera or laser photocoagulation in the fundus 1 h before death of the animals did not increase the concentration of PGE2 in the vitreous humor. There is no evidence either for local release of PGE2 from tissues in the fundus of the eye or for diffusion of PGE2 from the anterior chamber into the vitreous humor.

Secretory IgA and lysozyme in tears of patients with Graves' ophthalmopathy.

Using an enzyme linked immuno-assay (ELISA) and spectrophotometry, we determined levels of secretory IgA and lysozyme in tears of 69 patients with Graves' ophthalmopathy and 28 controls. The quantitative determination of secretory IgA and lysozyme in tears provided an impression of the functioning of the lacrimal gland in the two groups. An IgA/lysozyme ratio was calculated in both patients and controls as a parameter for the activity of the secretory IgA-producing plasma cells in the lacrimal gland. An increase in the IgA/lysozyme ratio was observed in 23 patients (33%) and one control (3%). Half of the patients who had suffered from the disease for more than 5 years showed a raised IgA/lysozyme ratio. No correlation was found between the IgA/lysozyme ratio and the NOSPECS classification. Our findings suggest that the lacrimal gland is involved in the orbital condition produced by Graves' ophthalmopathy. In most cases the involvement occurs in patients with a long history of the disease.