Objectives: Etodolac (ET D), an insoluble anti-inflammatory drug, undergoes first-pass metabolism,

which limits its oral bioavailability. The current study presents the trials for improvement of drug

solubility on one hand and formulation of different emulgel systems loaded with modified drug

on the other hand.

Significance: The Prolonged oral administration of ET D results in serious gastrointestinal problems.

Therefore, the improvement of its solubility and modifying an alternative route of administration

will increase its bioavailability and lessen its adverse effects, providing an alternative safe delivery

system for inflammatory signs treatment.

Methods: The current study focused on the formulation of different emulgel systems since

medicated emulgels were constructed by loading the emulgels with either pure ET D or modified

ET D adsorbate (ET D/Avicel, 1:2 ratio). Finally, the in vivo studies were accomplished by studying

the anti-inflammatory activity of ET D emulgels using albino rats.

Results: All the prepared emulgels showed acceptable physical properties since sodium alginate

emulgel showed superior drug release compared with other gelling agents. The drug release

profile was affected significantly by both emulsifying and gelling agents’ concentration. The

release kinetics data showed that the main mechanism of drug release was the Higuchi diffusion

model. concerning the in vivo results, the extreme edema inhibition was obtained upon using

emulgel formulae containing modified ET D with penetration enhancer (5% PG + 5% oleic acid).

The modified emulgels did not show any sign of irritation on rats’ dorsal skin.

Conclusion: The obtained results highlighted the promising application of topical ET D emulgels

as an alternative anti-inflammatory drug delivery system.