iota-Carrageenan hydrogels for methotrexate delivery

•Hydrogel on the basis of i-carrageenan, MTX and βCD was developed.•Incorporation of MTX and βCD does not modify the gel rheological characteristics.•βCD considerably increased the MTX content in the gel.•β-CD affects the rate of transmembrane permeation and release mechanism of MTX. To reduce the side effects associated with systemic drug administration, topical hydrogel on the basis of iota-carrageenan, methotrexate and cyclodextrin was developed. Cyclodextrins were used to increase the methotrexate content in the gel and to control the drug release. It was shown that β-cyclodextrin is more effective solubilizer for methotrexate compared with α- and γ-cyclodextrins. Rheological properties of the prepared hydrogels were investigated. It was observed that incorporation of methotrexate and β-cyclodextrin in the gel does not modify the rheological characteristics of the material. Possible H-bonding of methotrexate and β-cyclodextrin with the polymeric matrix was revealed by means of FTIR and 1H NMR. The release and transdermal transport of methotrexate from the designed gel was studied in vitro. It was found that complexation with β-cyclodextrin affects the rate and mechanism of methotrexate release as well as the permeation of the drug across the model membrane. The prepared gel can be proposed as topical drug delivery system in the treatment of cancer and autoimmune diseases of the skin.