Poloxamer-enhanced solubility of griseofulvin and its related antifungal activity against Trichophyton spp

Abstract Poorly water-soluble drugs, such as the antifungal drug griseofulvin (GF), exhibit limited bioavailability, despite their high membrane permeability. Several technological approaches have been proposed to enhance the water solubility and bioavailability of GF, including micellar solubilization. Poloxamers are amphiphilic block copolymers that increase drug solubility by forming micelles and supra-micellar structures via molecular self-association. In this regard, the aim of this study was to evaluate the water solubility increment of GF by poloxamer 407 (P407) and its effect on the antifungal activity against three Trichophyton mentagrophytes and two T. rubrum isolates. The GF water solubility profile with P407 revealed a non-linear behavior, well-fitted by the sigmoid model of Morgan-Mercer-Flodin. The polymer promoted an 8-fold increase in GF water solubility. Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and 2D nuclear magnetic resonance (NMR Roesy) spectroscopy suggested a GF-P407 interaction, which occurs in the GF cyclohexene ring. These results were supported by an increase in the water solubility of the GF impurities with the same molecular structure. The MIC values recorded for GF ranged from 0.0028 to 0.0172 mM, except for T. Mentagrophytes TME34. Notably, the micellar solubilization of GF did not increase its antifungal activity, which could be related to the high binding constant between GF and P407.

Application of micellar solubilization technology in pilot production of Chinese materia medica cataplasma containing volatile oil / 中草药

Objective: Through the studies on pilot production of the cataplasma of Chinese materia medica (CMM) containing volatile oil, to provide a rational and feasible preparation technology for the pilot production of CMM cataplasma, so as to promote the development of CMM cataplasma. Methods: The CMM containing volatile oil was extracted by steam distillation method (SDM), ethanol reflux extraction (ERE), and CO2 supercritical fluid extraction (SFE), respectively. The extracts were prepared to cataplasma in order to investigate the effects of extracting methods on the preparation process and quality of CMM cataplasma. The effects of micellar solubilization in the distilled liquid of STM on the quality of cataplasma such as adhesiveness, flexibleness, and stability were also investigated. Results: There was the significant difference among the groups of STM, ERE, and SFE on the quality of cataplasma. The extract by STM was beneficial to the preparation process and enhancement of the quality of cataplasma obviously, while the distilled liquid by STM would cause some limitations such as oil-water separation and volatile oil volatilization losses, which could contribute to obvious difference among batches. These disadvantages by STM would be overcome by the adoption of micellar solubilization technology and the stability would be increased (P < 0.01); segregation happened for the extract by ERE at room temperature, thereby, the water bath heating was needed in the preparation; this characteristics would cause the homogeneous appearance of cataplasma due to some black spots, lower flexibleness of matrix, and the preparation was not easy to control; the extract by SFE contained a lot of impurity of grease and performed half solid. As a result, it was very difficult to blend the extract by SFE with other materials uniformly, the adhesive force of cataplasma was also reduced. In addition, the cost of higher energy consumption and production was another disadvantage for SFE. Conclusion: The STM followed by micellar solubilization would be a feasible preparation technology for the pilot production of CMM cataplasma containing volatile oil, so it is worth popularizing and applying widely.

A comparative solubility enhancement study of rosuvastatin using solubilization techniques.

Solid dispersion of Rosuvastatin was prepared by solvent evaporation method; PEG (Polyethylene glycol) 4000, mannitol and urea were used as carriers. Hydrotropic studies were carried out using different hydrotropic agents (sodium acetate, sodium benzoate and salicylate) and Micellar solubilization was carried out using different surfactant solutions (sodium lauryl sulphate, tween 80 and cetrimide).The solubility enhancement of Rosuvastatin by different solubilization technique was observed in decreasing order as hydrotropic solubilization > solid dispersion > micellar solubilization. It was observed that the solubility increased with the increase in the concentration of hydrotropic agents and amongst the various hydrotropic agents used the solubility was Rosuvastatin was enhanced greatest to 55 folds with sodium salicylate. This increase may be attributed due to aggregation of the hydrotropic molecules and inclusion of one of these aggregates at high concentration probably by reacting to form an associated product as a result of hydrogen bonding.