New eyedrops formulation based on desonide and xanthan gum: preclinical studies.

Abstract

Purpose : A new class III medical device, named XanterDES, containing a low desonide concentration 0.025% and xanthan gum 0.2% has been developed to be intended in all cases of ocular surface discomfort. Nonclinical studies were carried out to investigate XanterDES cell viability, rheological profile and in vivo efficacy in a murine model of dry eye compared to a class III medical device based on hyaluronic acid and hydrocortisone (Idroflog).

Methods : Cytocompatibility was evaluated by MTT assay in a short-time repeated-exposure (6 x 5 min) test performed on HCE cells. Rheological properties were assessed with a rheometer comparing the 2 formulations. Efficacy was investigated in a dry eye model in C57BL/6 mice exposed to a controlled environmental chamber (CEC) with low humidity, constant airflow and scopolamine s.c. injection. The 2 test items together with untreated positive control (CTRL+) and untreated negative control (CTRL-, i.e mice outside the CEC) were evaluated. Tear volume (cotton thread) and corneal damage (slit lamp) were evaluated in mice topically treated t.i.d. for 3 days. Statistics were sought by one sample t-test, One-way ANOVA or Kruskal-Wallis, as appropriate.

Results : XanterDES was found to be devoid of cytotoxic effects and it exhibited a very good pseudoplastic profile with respect to Idroflog due to the presence of xanthan gum polymer. Dry eye study showed that tear volume (Fig. 1) of CTRL+ was significantly lower (p<0.001) with respect to CTRL-, while XanterDES did not differ from CTRL- mice outside the CEC. On the contrary, Idroflog significantly reduced tear volume (p<0.0001) compared to CTRL-. Corneal damage (Fig. 2) of CTRL+ was significantly worsened (p<0.001) with respect to CTRL-. Importantly, XanterDES did not differ from CTRL- unlike Idroflog (p<0.05).

Conclusions : XanterDES is devoid of any cytotoxic effect even when administered with a higher dosage (t.i.d). XanterDES guarantees a better distribution on the ocular surface with a high comfort due to its pseudoplasticity. XanterDES exerts a protective action on corneal epithelium, demonstrating that it’s able to counteract the damage in dry eye mice maintaining both parameters (i.e tear volume and corneal damage) at physiological condition. The same results were not obtained with the other test item. Overall, XanterDES peculiar formulation, is a suitable eyedrops solution useful in case of ocular surface alteration.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.