Water driven transformation of a nonionic microemulsion into liquid crystalline phase: Structural characterizations and drug release behavior

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

Dual-Drug-Loaded Topical Delivery of Photodynamically Active Lipid-Based Formulation for Combination Therapy of Cutaneous Melanoma

Topical administration of anti-cancer drugs along with photodynamically active molecules is a non-invasive approach, which stands to be a promising modality for treating aggressive cutaneous melanomas with the added advantage of high patient compliance. However, the efficiency of delivering drugs topically is limited by several factors, such as penetration of the drug across skin layers at the tumor site and limited light penetrability. In this study, curcumin, an active anti-cancer agent, and chlorin e6, a photoactivable molecule, were encapsulated into lipidic nanoparticles that produced reactive oxygen species (ROS) when activated at 665 nm by near-infrared (NIR) light. The optimized lipidic nanoparticle containing curcumin and chlorin e6 exhibited a particle size of less than 100 nm. The entrapment efficiency for both molecules was found to be 81%. The therapeutic efficacy of the developed formulation was tested on B16F10 and A431 cell lines via cytotoxicity evaluation, combination index, cellular uptake, nuclear staining, DNA fragmentation, ROS generation, apoptosis, and cell cycle assays under NIR irradiation (665 nm). Co-delivering curcumin and chlorin e6 exhibited higher cellular uptake, better cancer growth inhibition, and pronounced apoptotic events compared to the formulation having the free drug alone. The study results depicted that topical application of this ROS-generating dual-drug-loaded lipidic nanoparticles incorporated in SEPINEO gel achieved better permeation (80 ± 2.45%) across the skin, and exhibited the improved skin retention and a synergistic effect as well. The present work introduces photo-triggered ROS-generating dual-drug-based lipidic nanoparticles, which are simple and efficient to develop and exhibit synergistic therapeutic effects against cutaneous melanoma.