Drug assay in ground tissues: example of ketoprofen diffusion into tonsillar tissue

Clinical use of ketoprofen lysine salt: a reappraisal in adolescents with acute respiratory infections

Upper respiratory infections are widespread, and they are mainly of viral etiology. It has to be remarked that every infection is always associated with an inflammatory response. Inflammation implicates a cascade of bothersome symptoms, including fever, pain (headache, myalgia, and arthralgia), malaise, and respiratory complaints. As a result, anti-inflammatory medications could be beneficial as they act on different pathogenetic pathways. The ketoprofen lysine salt (KLS) has a potent anti-inflammatory activity associated with effective analgesic and antipyretic effects and has a valuable safety profile. However, adolescents present peculiar psychological characteristics that determine their difficulty to be managed. In this regard, an adolescent with a respiratory infection requires a prompt and adequate cure. KLS, thanks to its pharmacologic profile, could be favorably used in this regard. A recent primary-care experience outlined its effectiveness in this issue.

pH sensitive silica nanotubes as rationally designed vehicles for NSAIDs delivery

A novel pH-sensitive drug delivery system based on functionalized silica nanotubes was developed for the incorporation of non-steroidal anti-inflammatory drugs (NSAIDs), aimed at a tailored drug release in acidic conditions characteristic of inflamed tissues. Silica nanotubes (SNTs) were synthesized by a nanoporous alumina template assisted sol-gel method. Inner surfaces were physically and chemically modified to improve both the functionalization and subsequent incorporation of the drug. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) were used to characterize the designed nanocarriers and their functionalization. To achieve the highest degree of functionalization, three types of aminosilanes were tested and calcination conditions were optimized. APTES was shown to be the most effective aminosilane regarding the functionalization of the SNTs' inner surface and an adequate calcination temperature (220°C) was found to attain mechanical stability without compromising functionalization efficiency. Finally, the incorporation of naproxen into the nanotubes was accessed by fluorescence measurements and drug release studies were performed, revealing that the electrostatic linkage ensures effective release of the drug in the acidic pH typical of inflamed cells, while maintaining the SNT-drug conjugates stable at the typical bloodstream pH.

In vitro distribution of ketoprofen enantiomers in articular tissues of osteoarthritic patients

The distribution of ketoprofen enantiomers in joint tissues was studied as a function of their relative tissular affinities using the multi-chamber distribution dialysis system described by Bickel et al. Selected off-cuts of synovial membrane, joint capsule, cartilage and ligament were obtained from ten patients suffering from osteoarthritis of the knee (n=3) or hip (n=7). Sörensen solution (4 ml) spiked with racemic ketoprofen (2 microg ml(-1)) was dialysed against 1 ml of the four solutions of tissue homogenates (0.4 g ml(-1)). Ketoprofen enantiomers were quantified in buffer and tissue solutions by high-performance liquid chromatography. The distribution of ketoprofen enantiomers in the Bickel's multi-compartment model indicated that there was a non-stereoselective affinity of ketoprofen enantiomers for their potential target tissues. Despite the interindividual variability in articular tissues, the concentrations (+/-S.D.) of R- and S-ketoprofen were significantly higher in synovial membrane (8.69 (4.76) microg g(-1) for S, 9.14 (5.57) microg g(-1) for R), joint capsule (5.71 (2.49) microg g(-1) for S, 5.49 (2.62) microg g(-1) for R) and ligament (6.28 (3.61) microg g(-1) for S, 6.40 (3.64) microg g(-1) for R) than in articular cartilage (3.67 (1.75) microg g(-1) for S, 3.70 (1.67) microg g(-1) for R). There were no significant differences in the distribution of R- and S-ketoprofen between the solutions of joint capsule, synovium and ligament tissues. These data may be related to differences in ketoprofen affinity for the different constituents of joints. This in vitro distribution profile is similar to that reported in vivo for other non-steroidal anti-inflammatory drugs.

Tenoxicam concentrations in synovium and joint cartilage in humans

Tenoxicam is an NSAID of the oxicam group. Its distribution in articular tissues was investigated in 12 patients who required total arthroplasty of the hip. They were given tenoxicam 20 mg once daily for 8 to 30 days before surgery. Blood, synovium and cartilage samples were taken concurrently during surgery, about 14 hours after the last tenoxicam dose. The tissues were ground using a freeze grinder. Tenoxicam was assayed by HPLC. Tenoxicam concentrations averaged 6.21 +/- 3.81 micrograms/ml in plasma, 7.56 +/- 4.67 micrograms/g in synovium and 2.05 +/- 1.43 micrograms/g in cartilage. The individual synovium/cartilage ratios ranged from 1.9 to 9.7. Finally tenoxicam exhibited more affinity for its target organ (synovial tissue) than for joint cartilage.