Novel phospholipid-based topical formulations of tamoxifen: evaluation for antipsoriatic activity using mouse-tail model

Abstract Objective: Tamoxifen (TAM) is widely employed in the treatment of breast malignancies and is also found to be effective in psoriasis treatment. The current studies aimed to explore the antipsoriatic potential of topical TAM encapsulated in the new generation phospholipid-based vesicular and micellar systems, i.e. flexible membrane vesicles (FMVs) and pluronic lecithinized organogels (PLOs). Methods: TAM-loaded-FMVs were prepared by thin-film hydration technique, while TAM–PLOs were prepared by simple mixing. Mouse-tail model was used to evaluate the antipsoriatic activity of the novel formulations. The mouse tails were treated once-a-day with different formulations for a period of four weeks and prepared for longitudinal histological sections by hematoxylin–eosin staining technique. The length of the orthokeratotic regions in stratum granulosum was measured on 10 sequential scales per tail section as percentage of the full length of the scale, and the drug activity was calculated further. Results: Evaluation of antipsoriatic activity on mice tail revealed significantly higher (p < 0.01) efficacy of TAM–FMV gel (i.e. 35.8%) and TAM–PLO (i.e. 24.6%) vis-à-vis the conventional TAM–hydrogel (i.e. 10.2%). Conclusions: The results of these studies demonstrated immense potential of the topically applied TAM-encapsulated vesicular and micellar systems in psoriasis, thus calling for more comprehensive investigations to establish the role of TAM in the management of psoriasis.