Enhancement of Mycophenolate Mofetil Permeation for Topical Use by Eucalyptol and N-Methyl-2-pyrrolidone

Mycophenolic Acid for Topical Immunosuppression in Vascularized Composite Allotransplantation: Optimizing Formulation and Preliminary Evaluation of Bioavailability and Pharmacokinetics

Mycophenolic acid (MPA), is the active form of the ester prodrug mycophenolate mofetil (MMF). MMF is an FDA approved immunosuppressive drug that has been successfully used in systemic therapy in combination with other agents for the prevention of acute rejection (AR) following solid organ transplantation (SOT) as well as in vascularized composite allotransplantation (VCA). Systemic use of MMF is associated with gastrointestinal adverse effects. Topical delivery of the prodrug could thus provide graft-targeted immunosuppression while minimizing systemic drug exposure. Our goal was to develop a topical formulation of MPA with optimal in vitro/in vivo characteristics such as release, permeation, and tissue bioavailability to enable safety and efficacy evaluation in clinical VCA.

Permeation studies were performed with a solution of MPA (10 mg/ml). In vitro release and permeation studies were performed for different semisolid formulations (Aladerm, Lipoderm, emollient, and VersaBase) of MPA (1% w/w) using a Franz Diffusion Cell System (FDCS). In vivo pharmacokinetic characterization of MPA release from Lipoderm was performed in rats.

MPA in solution exhibited a steady state flux (3.8 ± 0.1 µg/cm²/h) and permeability (1.1 × 10⁻⁷ ± 3.2 × 10⁻⁹ cm/s). MPA in Lipoderm exhibited a steady state flux of 1.12 ± 0.24 µg/cm²/h, and permeability of 6.2 × 10⁻⁰⁹ ± 1.3 × 10⁻⁹ cm/s across the biomimetic membrane. The cumulative release of MPA from Lipoderm, showed a linear single-phase profile with a R² of 0.969. In vivo studies with MPA in Lipoderm showed markedly higher local tissue MPA levels and lower systemic MPA exposure as compared to values obtained after intravenous delivery of the same dose of drug (p < 0.05).

We successfully developed for the first time, a topical formulation of MPA in Lipoderm with optimal in vitro/in vivo permeability characteristics and no undesirable local or systemic adverse effects in vivo. Our study provides key preliminary groundwork for translational efficacy studies of topical MPA in pre-clinical large animal VCA models and for effectiveness evaluation in patients receiving VCA.

Topical mycophenolate mofetil in the treatment of vitiligo: a pilot study

BACKGROUND

Vitiligo is a multifactorial disease that is characterized by circumscribed depigmented macules and patches. Autoimmune reactions may play an important role in the pathogenesis of the disease. Mycophenolate mofetil is a drug that inhibits DNA synthesis in lymphocytes and has been used in autoimmune diseases such as immunobullous skin diseases, lupus erythematosus, and autoimmune hepatitis.

OBJECTIVES

The objective of this study was to show the efficacy of topical mycophenolate mofetil in the treatment of vitiligo.

METHODS

Thirty patients with limited vitiligo were enrolled in this study. The patients applied a topical preparation of mycophenolate mofetil 15% twice daily for three months and at the end of every month, repigmentation was assessed using the Vitiligo Area Scoring Index (VASI).

RESULTS

At the end of the third month, 36.6 % (n=11) of the patients showed about 25% repigmentation of the lesions. No side effects were observed throughout the study.

CONCLUSION

This study showed that topical mycophenolate mofetil can be somewhat effective in the treatment of vitiligo; however, it seems to be inferior to potent topical steroids in inducing repigmentation.