Evaluation of muco-adhesive tacrolimus patch on caspase-3 induced apoptosis in oral lichen planus: a randomized clinical trial

Background The study compared the clinical effectiveness of topical Tacrolimus (TAC) in patches or gel with Triamcinolone acetonide (TRI) gel for erosive/atrophic oral lichen planus (OLP) and investigated the influence of these therapies on Caspase-3 expression as a marker of apoptosis. Methods Thirty patients were randomly assigned into three equal groups to receive either topical TAC 0.1% patch twice daily, topical TAC 0.1% gel, or topical TRI 0.1% gel four times daily for 8 weeks. Each patient's clinical score (CS), visual analogue scale (VAS), and total atrophic area (TAA) of the marker lesion were measured at baseline, 2, 4, and 8 weeks of treatment, as well as after 4 weeks of treatment free period. Caspase-3 expression and lymphocytic counts (LC) were assessed in pre- and post-treatment biopsied stained sections. Results TAC patch resulted in a higher reduction in CS [− 14.00 (15.54%)] and VAS [− 70.21 (15.82%)] followed by TAC gel then TRI gel within the first two weeks. The reduction in VAS and TAA were significantly higher in TAC groups compared to TRI gel, although the difference between TAC treatment was not significant and this was observed throughout the treatment and follow-up periods. Caspase-3 expression increased in connective tissue in all groups. It decreased significantly within the epithelium in both TAC groups but increased in TRI gel. (LC) were significantly lowered with the TAC patch compared to other groups. The percentage change in Caspase-3 epithelial expression was significantly correlated to the CS, TAA, and LC. Conclusion Both TAC patch and gel significantly decreased pain and lesion size than TRI gel, with a significant reduction in Caspase-3 expression within the epithelium in comparison to the increase seen with TRI gel. The study protocol was registered at www.clinicaltrials.gov (NCT05139667) on 01/12/2021. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-023-02803-8.

these two solutions were mixed together. Citric acid dissolved in distilled water and propylene glycol was added to the above solution mixture. To this the required quantity of Tacrolimus was added by dissolving the drug in a small quantity of ethanol with final concentration 0.1%w/w. The mixture was kept under magnetic stirrer for 5 minutes. Then it was casted to the petridish and kept for drying at room temperature.

Weight and patch thickness
The assessment of weight and patch thickness were completed on randomly selected patches from three patches. For mass determination, patches were weighed on an electronic digital balance

Surface PH
Was determined by dissolving the patches in dH2o for 5 minutes and measurements recorded using a PH meter, (Colley,2018).

Folding indurance
Was determined by repeatedly folding a small strip of the patch at a same place till it broke. The number of the times the patch could be folded at the same place without breaking gives the value of folding indurance which indicates the brittlness of the patch.
Folding indurance was determined in triplicate and the mean value was calculated, (Colley,2018).

Percent Elongation
The initial lengths of the patches were measured and then stretched to a lesser extent and final length was noted, (Semalty et al, 2008).

Drug Content
A patch was placed in a beaker containing 5 ml phosphate buffer (PH 6.8) and 5 ml alchol. Medium was stirred for proper dissolution on orbital shaker for 4 hours, then the content was filtered using whatman filter paper and the filtrate sample was analysed by UV spectrophotometer at 297nm, (Rathi et al, 2011).

Patch softening upon storage
Patches were stored in desiccators for 48 hours and softening was determined, (Zhang et al, 2018).

Disintigration Time
Is the time at which a patch breaks when brought in contact with water or saliva. Patches were immersed in a beaker containing 25ml phosphate buffer 6.8.
It was swirled at every 10 seconds and the time at which the patch started to break was recorded, (Ashwathy et al, 2019).

Release profile:
Were performed using USP paddle type apparatus. The studies were carried out at 37 C with stirring speed of 100 rpm in 900 ml phosphate buffer 6.8. 5 ml of samples were withdrawn at predetermined time intervals of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6 hours and replaced with the same value of buffer. The samples were collected and the concentration was determined at 297nm using UV, (Rathi et al, 2011).

Weight and patch thickness
Tacrolimus patches were recorded to have an average weight 67.4, 59.0 and 54.0 mg, weight differences were not significant.
Average thickness of the patches were 0.51, 0.46 and 0.46, the differences were not significant.

Surface PH
The value for surface PH were between 6.0 and 6.1 for the different tacrolimus patches and the difference were not significant.

Folding Indurance
Varied from 84-89 and it increase with the elevation in the concentration of HPMC K and M proportion.

Percent Elongation
was found to be 50%.

Drug Content
The results ranged from 70.93% to 67.48%.

Film softening upon storage
No softening occurred to the patches upon storage.

Disintigration Time
For the tacrolimus patches, disintigratiom time was found to be 30-45 minutes.

Release Profile.
In-vitro release of Tacrolimus patch in phosphate buffer saline pH 6.8 at 297 nm