In vitro permeation and stability studies on developed drug-in-adhesive transdermal patch of simvastatin

Development and Characterisation of a Topical Methyl Salicylate Patch: Effect of Solvents on Adhesion and Skin Permeation

The advent of skin patch formulation design and technology has enabled the commercialisation of methyl salicylate (MS) as a topical patch. However, the most fundamental aspect of skin permeation is unknown at present. The study aims to investigate the effect of solvent choice on the skin permeation of MS in a neat solvent system and patch formulation with an emphasis on patch adhesion. MS in six selected solvents (propylene glycol (PG), Transcutol^®, isopropyl myristate, Labrasol^®, Plurol^® oleique CC 497 and Maisine^® CC) was characterised and in vitro permeation studies were also performed. An ATR-FTIR analysis on solvent-treated skin was conudcted. Patch formulation was prepared and characterised for adhesion, in vitro drug release and skin permeation studies. The highest MS permeation was found in neat PG over 24 h (~90 μg/cm²) due to its strong skin protein conformation effect. Transcutol^® and isopropyl myristate showed better skin deposition and formulation retention, respectively. Nevertheless, PG enhanced the patch adhesion despite having a lower cumulative amount of MS permeated (~80 μg/cm²) as compared with Transcutol^® and Maisine^® (~110-150 μg/cm²). These two solvents, however, demonstrated better skin deposition and formulation retention but a lower patch adhesion. The unpredictable influence of the solvent on patch adhesion highlights the importance of the trade-off between patch adhesion and skin permeation during formulation design.

Development and Evaluation of a Novel Methotrexate-Loaded Electrospun Patch to Alleviate Psoriasis Plaques

OBJECTIVE

To achieve an effective topical formulation of Methotrexate (MTX) as a first-line treatment of psoriasis, we formulated three MTX-loaded electrospun nanofibrous patches composed of polycaprolactone (PCL), Eudragit L100, and a mixture of them.

SIGNIFICANCE

Topical delivery of MTX provides an appropriate therapeutic performance while circumventing the life-threatening side effects of systemic administration.

METHODS

Three MTX-loaded electrospun nanofibrous patches were prepared and characterized in terms of size and morphology (using SEM), thermal behavior (by TGA and DSC), and crystalline structure (using XRD). Furthermore, the wettability and mechanical strength of samples were investigated through water contact angle and tensile strength tests. Also, the encapsulation efficiency of MTX was calculated. Subsequently, in vitro drug release profile of each formulation was obtained and different kinetic models were fitted to achieve the best-matched model. Accordingly, the ex vivo skin permeation of MTX was studied for the optimum formulation.

RESULTS

All samples showed appropriate morphology, thermal behavior, and encapsulation efficiency. Also, XRD results showed that MTX is dispersed within the polymeric matrices in the amorphous state (with no crystalline region). Release studies demonstrated that MTX-loaded Eudragit L100-PCL formulation outperformed in terms of mechanical behavior and in vitro drug release. This formulation also exhibited better skin permeation.

CONCLUSION

The obtained controlled-release MTX-loaded electrospun patches seem promising to provide a long-acting topical treatment of psoriatic plaques with minimized systemic side effects.

Microscopic and Spectroscopic Imaging and Thermal Analysis of Acrylates, Silicones and Active Pharmaceutical Ingredients in Adhesive Transdermal Patches

Dermal or transdermal patches are increasingly becoming a noteworthy alternative as carriers for active pharmaceutical ingredients (APIs), which makes their detailed physicochemical evaluation essential for pharmaceutical development. This paper demonstrates mid-infrared (FTIR) and Raman spectroscopy with complementary microscopic methods (SEM, optical and confocal Raman microscopy) and differential scanning calorimetry (DSC) as tools for the identification of the state of model API (testosterone TST, cytisine CYT or indomethacin IND) in selected adhesive matrices. Among the employed spectroscopic techniques, FTIR and Raman may be used not only as standard methods for API identification in the matrix, but also as a means of distinguishing commercially available polymeric materials of a similar chemical structures. A novel approach for the preparation of adhesive polymers for the FTIR analysis was introduced. In silicone matrices, all three APIs were suspended, whereas in the case of the acrylic PSA, Raman microscopy confirmed that only IND was dissolved in all three acrylic matrices, and the dissolved fraction of the CYT differed depending on the matrix type. Moreover, the recrystallization of TST was observed in one of the acrylates. Interestingly, a DSC analysis of the acrylic patches did not confirm the presence of the API even if the microscopic images showed suspended particles.

The wound healing and antibacterial potential of triple-component nanocomposite (chitosan-silver-sericin) films loaded with moxifloxacin

AIM

The current study reports the development and evaluation of chitosan-sericin-silver nanocomposite (CSSN) films without and with moxifloxacin (Mox).

METHODOLOGY

The film preparation method involved the in-situ synthesis of silver nanoparticles within the chitosan-sericin colloidal composite followed by preparation into a film by solvent casting technique. In-situ formation and the particle size analysis of the silver nanoparticles was performed via UV-Visible and zeta-size spectrometer. The prepared films were tested for swelling ratio, contents uniformity, in-vitro Mox release, and permeation analysis. The morphological (SEM), elemental (EDX), spectral (FT-IR), structural (XRD), and thermal (TGA and DSC) properties of the composites were also inspected. The antibacterial activity of the CSSN films was performed against seven pathogenic bacterial strains including five ATCC and two clinical strains. The potential wound healing activity of the composite films was evaluated on burn wound model induced in Sprague Dawley male rats.

RESULTS

The prepared films displayed good swelling profile with a sustained in-vitro Mox release and permeation profile; attaining maximum of 78.57% (CSSM3) release and 55.05% (CSSM1) permeation (CSSM1) in 24 h. The prepared films, particularly the Mox-loaded CSSN films displayed a promising antibacterial activity against all the tested strains with the activity being highest against MRSA (clinical isolates). The prepared films indicated a remarkable wound healing applications with successful fibrosis, collagen reorganization, neovascularization, and mild epidermal regeneration after 7 days of treatment with no silver ions detection in animal's blood.

CONCLUSION

The obtained findings strongly suggest the use of the prepared novel composite dressing for wound care applications.