Search

The aim of this study was to develop thermosensitive gels using poloxamers for topical delivery of fluconazole (FLZ). Eight different formulations containing 1% FLZ in poloxamer and a particular co-solvent (propylene glycol (PG) or Transcutol-P) of various concentrations were prepared. The gels were characterized for transition temperatures, rheological and mechanical properties. FLZ permeability and antifungal effect of the gels were also evaluated. Except for one formulation, all gels exhibited thermosensitive property, i.e. transformed from Newtonian (liquid-like) behavior at 20 °C to non-Newtonian (gel-like) behavior at 37 °C. Transcutol-P increased the transition temperature of the formulations, while the opposite effect was observed for PG. At 37 °C, formulations with high poloxamer concentrations (17%) resulted in high viscosity, compressibility and hardness. Formulations containing 17% poloxamer and 20% Transcutol-P and 10% PG, respectively, exhibited high adhesiveness. No significant differences in the in vitro antifungal activity of FLZ were observed among the formulations suggesting that the gel vehicles did not influence the biological effect of FLZ. FLZ permeability decreased with increasing poloxamer concentration. Formulations containing 17% poloxamer and 20% Transcutol-P and 10% PG seemed to be promising in situ gelling systems for the topical delivery of FLZ. [ABSTRACT FROM AUTHOR]

Context: This study presents novel nanostructured oil-in-water (o/w) mists based on self-nanoemulsifying (SNE) mixtures capable of delivering poorly water-soluble drugs into the lungs. Objective: Formulation development of an o/w nanoemulsion (NE) capable of being nebulized for pulmonary delivery of poorly water-soluble drugs. Materials and methods: SNE mixtures were prepared and evaluated using Tween 80 and Cremophor RH 40 as surfactants; Transcutol P, Capryol 90 and PEG 400 as cosurfactants; and Labrafac Lipophile Wl 1349 (a medium-chain triglyceride) as an oil. Liquid NEs were analyzed by light scattering, zeta potential, transmission electron microscopy (TEM) and in vitro drug release studies. The aqueous NE was nebulized and assessed by light scattering and TEM. The formulation was aseptically filtered and the sterility validated. In vitro cytotoxicity of the formulations was tested in NIH 3T3 cells. The capability of the formulation to deliver a poorly water-soluble drug was determined using ibuprofen. Results: Ibuprofen was found to be stable in the NEs. The formulations were neutrally charged with a droplet size of about 20 nm. TEM images displayed 100 nm oil droplets. The aseptic filtration method produced sterile NE. The nebulized mist revealed properties ideal for pulmonary delivery. The biocompatible aerosol has a nanostructure consisting of several oil nanodroplets enclosed within each water drop. Solubility and in vitro drug release studies showed successful incorporation and release of ibuprofen. Conclusion: The developed formulation could be used as an inhalation for delivering material possessing poor water solubility into the lungs. [ABSTRACT FROM AUTHOR]

Context: Water-in-oil microemulsions (w/o ME) are ideal for parenteral drug delivery. However, no such formulations have been tested for biocompatibility in in vitro cell cultures. Furthermore, sterilization of w/o MEs is a challenging process that has not been previously developed and validated. Purpose: To formulate pharmaceutically relevant water-in-oil (w/o) microemulsion's systems suitable for use as a parenteral formulation. Methods: w/o MEs were prepared using dioctyl sodium sulfosuccinate (DOSS), ethyl oleate (EO), and water. Formulations were characterized using polarized light microscopy, electrical conductivity, rheology, and dynamic light scattering. An aseptic filtration method for sterilization was developed using membrane filtration. The biocompatibility of selected MEs were evaluated in NIH3T3 cell cultures. Dissolution studies were performed on microemulsions containing methylene blue to evaluate the drug release profile. Results: The maximum amount of water incorporated in the formulations was 14% w/w. DOSS/EO/water microemulsions exhibited Newtonian flow. Particle sizes for these MEs were less than 30 nm in size. Formulations filtered aseptically were free of bacteria when gram-stained and visualized under a microscope. All MEs showed no toxicity to NIH 3T3 cells. Discussion: The absence of birefringence and low conductivity values indicated that the formulations were w/o microemulsions. The filtration method of sterilization was validated by the absence of microbial growth on blood agar plates over a 14-day period. In vitro dye release studies demonstrate sustained release of the model drug over a 72-h time period. Conclusion: Characteristics delineated in this study demonstrate the potential for these formulations to be used as parenteral preparations. [ABSTRACT FROM AUTHOR]