| Abstract [eng] |
The aim of the study: to form a bilayer polymer film containing a drug and investigate its suitability for the delivery of the drug to the skin using microneedles. Tasks: to form a polymer film consisting of hydrophilic and hydrophobic layers; to embed the model drug (dexpanthenol) in a bilayer polymer film; to select microneedles according to the penetration of the drug into the skin from polymer solutions; to study the release of dexpanthenol from polymer films in vitro; to cover microneedles with polymer films containing dexpanthenol and determine its dermal penetration in vivo. Research object: bilayer polymer films and their coating on microneedles. Relevance: it‘s important to search for polymer carriers that could become a universal tool for storing drugs and successfully delivering them to the skin layers after the injury caused by microneedles. Methods: production of bilayer polymer films and determination of their drying time, thickness, mass, solubility, pH, humidity, stickiness, tensile force, distance to the rupture point; determination of skin penetration and release of dexpanthenol by ultra high performance liquid chromatography; statistical data analysis. Results: the hydrophilic layer was formed using PVA and KMC Na in a ratio 1:3, adding plasticiser PG (the ratio between polymers and PG is 1:20), and the hydrophobic layer was formed using EuE 100. The films were 209.111 ± 2.315 µm thick, weighed 121.000 ± 1.764 mg, dissolved in water in 4.222 ± 0.441 min, had a pH of 6.447 ± 0.022, their humidity after 24 hours was 6.613 ± 0.278 %, had a stickiness of the top layer 0.545 ± 0.029 N, and a stickiness of the bottom layer 0.274 ± 0.025 N. The tensile force required to deform the film was 15.287 ± 0.284 N, and the distance to the rupture point was 13,954 ± 0.120 mm. 10 % dexpanthenol was inserted into the hydrophobic layer of the film, because such films showed the highest humidity, stickiness of the top layer (it was 1,594 times bigger than the control) and the highest tensile force compared to films containing 5 % and 7 % dexpanthenol. The skin penetration from polymer solutions study showed that the best penetration of dexpanthenol was while using a microneedle with a heigh of 600 µm and a width at the base of 200 µm and a microneedle with a heigh of 800 µm and a width of 400 µm at the base. The release of dexpanthenol from the films study showed that its peak flow was during the first 30 minutes (400,821 ± 33,570 µg/cm2) and then started to slow down. After 5 hours, the flow of dexpanthenol was 987,451 ± 185,870 µg/cm2. No dermal penetration was observed during an ex vivo dermal penetration study with microneedles that were coated with films containg dexpanthenol. Conclusions: a bilayer polymer film was formed that is suitable for coating microneedles. The addition of 10 % dexpanthenol increased the humidity, stickiness of the hydrophobic layer and tensile force required to deform the film, and these changes were acceptable. The highest penetration of dexpanthenol into the skin was performed using a microneedle with a heigh of 800 µm and a width at the base of 400 µm and a microneedle with a heigh of 600 µm and a width of 200 µm at the base. Coating these microneedles with 10 % dexpanthenol and evaluating drug release showed that it occurred and its peak flow was during the first 30 minutes. No drug was detected in the skin layers after the skin damage with microneedles coated with films containg dexpanthenol. |
