Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1    Pharmacodynamic properties
Pharmacotherapeutic group: Topical products for joint and muscular pain; Anti-inflammatory preparations, non-steroids for topical use.

ATC code: M02AA13

Ibuprofen is a propionic acid derivative NSAID that exerts it’s efficacy through the inhibition of prostaglandin synthesis. In humans ibuprofen reduces inflammatory pain, swellings and fever.
Ibuprofen also reversibly inhibits platelet aggregation.

In the form of a medicated plaster, which locally delivers ibuprofen continuously at the site of pain over the 24 hours of application, it has topical anti-inflammatory and analgesic activity.

Pooled data from two clinical efficacy and safety studies in adults with acute soft tissue injuries showed that when applied once every 24h, the medicated plaster provided long lasting relief, with a statistically significant decrease in pain on movement compared with a placebo plaster from 2hrs post first dose and every subsequent time point over 5 days.

Analysis of tenderness at the injured site also showed a significant difference compared with placebo at 24 and 120 hours following use.
In a confirmatory efficacy and safety study ‘excellent’ or ‘good’ ratings of treatment efficacy for the medicated plaster were given by 70.3% of patients and 70.3% of healthcare professionals at 24 hours, and 92.2% of patients and 89.1% of healthcare professionals after 5 days. ‘excellent’ or ‘good’ ratings for local tolerability were given by 100% of patients and healthcare professionals after 24 hours, and 98.4% of patients and healthcare professionals following 5 consecutive days’ use. Subjective ratings were significantly better than for placebo (p<0.0001).

Data from clinical studies indicate that the rates of detachment or loss of adhesion of the medicated plaster over 24 hours are low.

Pharmacokinetic Properties

5.2    Pharmacokinetic properties

This medicated plaster provides a topical formulation of ibuprofen designed to provide a sustained transfer of ibuprofen through the skin directly to the local site of the pain and inflammation.
In a human pharmacokinetic study, 28 subjects had the medicated plaster applied once daily for 5 consecutive days over a 7 day observation period. Plasma concentrations of ibuprofen rose rapidly reaching a mean concentration of 0.49 (95% CI: 0.39-0.58) μg/ml 24hr after application of the first patch. On day 5 of treatment, the mean Cmax was 0.51 (95% CI: 0.44-0.60) μg/ml, and the mean AUC0-24 was 9.59 (95% CI: 8.33-11.0) μghr/ml. The mean Cmax and systemic bioavailability are low compared to oral ibuprofen and consistent with literature reviews for topical NSAIDs. The typical Cmax for a 200-400mg counterpart oral dose of ibuprofen is in the order of 20-50 μg/ml. The low Cmax and low AUC for the medicated plaster indicate that if used concomitantly with systemic ibuprofen, the contribution of the medicated plaster to systemic ibuprofen exposure would be negligible.
The PK profile demonstrated that of ibuprofen does not accumulate on repeated application and that there is rapid attenuation to baseline within 24 hours after discontinuation.