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Biomedical subjects

A A van Sorge

Publications and source records attributed to A A van Sorge.

9 recordsLinked to original sources
PubMed2000

Oral bioavailability of phenobarbital: a comparison of a solution in Myvacet 9-08, a suspension, and a tablet.

PURPOSE: A three-way crossover study with seven healthy male volunteers was conducted to determine the relative bioavailability of phenobarbital after single dose administration of 100 mg of phenobarbital as oral solution in Myvacet 9-08, and as a suspension, compared with a 100 mg phenobarbital tablet. MATERIALS AND METHODS: At 4-week intervals each subject received the solution in Myvacet 9-08, the suspension and the tablet in randomized order. Blood samples were collected for 48 h after each dose for analysis of phenobarbital. From the individual serum concentration-versus-time curves Cmax and Tmax were determined and AUC0-48 was calculated. RESULTS: All three oral dosage forms of phenobarbital are bioequivalent. No significant differences in Tmax were observed. CONCLUSION: The oral solution in Myvacet 9-08, and the suspension of phenobarbital proved to be bioequivalent to a tablet.

Adult↗
PubMed2000

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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Potential uses of topical opioids in palliative care--report of 6 cases.

Opioids used topically may exercise several useful clinical effects. Opioids may cause immediate local analgesia and also may work indirectly through decreasing the inflammation process. In this article we describe six patients treated with topical opioids because of cutaneous pain due to tumor infiltration. skin ulcers of malignant and non-malignant origin, severe oral mucositis, pain due to knee arthrosis and severe tenesmoid pain. In all but one case, topical morphine provided rapid relief which lasted usually for 7-8 h. The side effects of topical opioids were none or minimal. Possible mechanisms of topical analgesia are discussed.

Administration, Topical↗
PubMed1999

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.

Animals↗
PubMed1984

[Dacarbazine].

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Dacarbazine↗