Phytantriol based liquid crystal provide sustained release of anticancer drug as a novel embolic agent.

Phytantriol has received increasing amount of attention in drug delivery system, however, the ability of the phytantriol based liquid crystal as a novel embolic agent to provide a sustained release delivery system is yet to be comprehensively demonstrated. The purpose of this study was to prepare a phytantriol-based cubic phase precursor solution loaded with anticancer drug hydroxycamptothecine (HCPT) and evaluate its embolization properties, in vitro drug release and cytotoxicity. Phase behavior of the phytantriol-solvent-water system was investigated by visual inspection and polarized light microscopy, and no phase transition was observed in the presence of HCPT within the studied dose range. Water uptake by the phytantriol matrices was determined gravimetrically, suggesting that the swelling complied with the second order kinetics. In vitro evaluation of embolic efficacy indicated that the isotropic solution displayed a satisfactory embolization effect. In vitro drug release results showed a sustained-release up to 30 days and the release behavior was affected by the initial composition and drug loading. Moreover, the in vitro cytotoxicity and anticancer activity were evaluated by MTT assay. No appreciable mortality was observed for NIH 3T3 cells after 48 h exposure to blank formulations, and the anticancer activity of HCPT-loaded formulations to HepG2 and SMMC7721 cells was strongly dependent on the drug loading and treatment time. Taken together, these results indicate that phytantriol-based cubic phase embolic gelling solution is a promising potential carrier for HCPT delivery to achieve a sustained drug release by vascular embolization, and this technology may be potential for clinical applications.

Comparison of novel granulated pellet-containing tablets and traditional pellet-containing tablets by artificial neural networks.

Novel granulated pellets technique was adopted to prepare granulated pellet-containing tablets (GPCT). GPCT and traditional pellet-containing tablets (PCT) were prepared according to 29 formulations devised by the Design Expert 7.0, with doxycycline hydrochloride as model drug, blends of Eudragit FS 30D and Eudragit L 30D-55 as coating materials, for the comparison study to confirm the superiority of GPCT during compaction. Eudragit FS 30D content, coating weight gain, tablet hardness and pellet size were chosen as influential factors to investigate the properties and drug release behavior of tablets. The correlation coefficients between the experimental values and the predicted values by artificial neural networks (ANNs) for PCT and GPCT were 0.9474 and 0.9843, respectively, indicating the excellent prediction of ANNs. The similarity factors (f2) for release profiles of GPCT and the corresponding original pellets were higher than those of PCT, suggesting that the excipient layer of granulated pellets absorbed the compressing force and protected the integrity of coating films during compaction.

[Preparation and in vitro embolic efficiency evaluation of hydroxycamptothecine-loaded liquid embolic agent].

The purpose of this study is to investigate the preparation of hydroxycamptothecine (HCPT)-loaded cubic crystal liquid embolic precursor solution, and evaluate its in vitro embolic efficiency. Phytantriol was used as cubic crystal liquid embolic material, and the optimal formulation was selected according to ternary phase diagram. Polarized light microscopy, differential scanning calorimetry, and small angle X-ray scattering (SAXS) were used to characterize the cubic crystal structure. High performance liquid chromatography and X-ray diffraction analysis were used to investigate the lactone ring of HCPT. In vitro dissolution was preliminary evaluated, and the simulation embolic model was constructed to evaluate the embolic efficiency of precursor solution. Meanwhile, the gelation time and adhesion force were investigated. The results showed that HCPT-loaded precursor solution for embolization had been successfully prepared with low viscosity which was injectable. The precursor solution could transform into Pn3m structure liquid crystal phase gel rapidly when contracting with excess water. The formed HPCT gel remained its lactone form as the same in precursor solution, and expressed the good ability to block the saline flow, and HCPT could keep sustained releasing drug over 30 days. The prepared drug-loaded embolic precursor solution showed a promising potential for vascular embolization and application in clinical treatment of tumor.

[Preparation and in vitro study on diffusion of capsaicin cubosome].

This study was to investigate the permeability and absorbability of capsaicin cubosome across abdominal skin of the SD rats in vitro. Diffusion of capsaicin cubosome and cream was performed with the modified Franz diffusion cell technique. The capsaicin cubosome showed no enhancement of skin permeation within 24 hours. However, the deposition amounts of capsaicin in the rat skin in the cubosome group was markedly higher than those in the commercial cream group (P < 0.01). Cubosome showed excellent characetristic of skin-targed which could be a good carrier for the local transdermal drug delivery system.

Characterization of cubosomes as a targeted and sustained transdermal delivery system for capsaicin.

Phytantriol- and glycerol monooleate-based cubosomes were produced and characterized as a targeted and sustained transdermal delivery system for capsaicin. The cubosomes were prepared by emulsification and homogenization of phytantriol (F1), glycerol monooleate (F2), and poloxamer dispersions, characterized for morphology and particle size distribution by transmission electron microscope and photon correlation spectroscopy. Their Im3m crystallographic space group was confirmed by small-angle X-ray scattering. An in vitro release study showed that the cubosomes provided a sustained release system for capsaicin. An in vitro diffusion study conducted using Franz diffusion cells indicated that the skin retention of capsaicin from cubosomes in the stratum corneum was much higher (2.75±0.22 µg versus 4.32±0.13 µg, respectively) than that of capsaicin cream (0.72±0.13 µg). The stress testing showed that the cubosome formulations were stable under strong light and high temperature for up to 10 days. After multiapplications on mouse skin, the irritation of capsaicin cubosomes and cream was light with the least amount of side effects. Overall, the present study demonstrated that cubosomes may be a suitable skin-targeted and sustained delivery system for the transdermal administration of capsaicin.

Formulation and evaluation of novel reverse microemulsions containing salmon calcitonin in hydrofluoroalkane propellants.

To develop reverse microemulsion as a potential strategy for pulmonary delivery of salmon calcitonin (sCT) in HFA134a propellant of pressurized metered dose inhalers (pMDIs), pluronic P85 (P85) was chosen as the most appropriate surfactant to form microemulsions containing sCT. Formulation parameters, including the surfactant and ethanol content, water content, and sCT loading, were optimized to obtain two desired pMDI formulations A and B with clear and transparent appearance, Tyndall effect, good physical stability and aerosolization properties. Aerosolization properties of the optimized pMDIs were assessed by next generation impactor (NGI) and twin-stage impactor (TSI), and the dose of sCT in each stage was assayed by HPLC. The fine particle fraction (FPF) of formulations A and B were both at the range of approximately 28.0-36.0%. Cytotoxicity studies indicated the cell viability determined by MTT assay only slightly dropped when the A549 cells were exposed to the pMDI formulations. Pharmacological study performed on the male Wistar rats showed the intratracheal administration of the microemulsion pMDIs containing sCT exhibited similar but prolonged hypocalcemic activity compared with the intravenous injection of sCT solution. Therefore, such reverse microemulsions are potential for pulmonary delivery of therapeutic peptides using HFA-pMDIs.

Enhancing oral bioavailability of quercetin using novel soluplus polymeric micelles.

To improve its poor aqueous solubility and stability, the potential chemotherapeutic drug quercetin was encapsulated in soluplus polymeric micelles by a modified film dispersion method. With the encapsulation efficiency over 90%, the quercetin-loaded polymeric micelles (Qu-PMs) with drug loading of 6.7% had a narrow size distribution around mean size of 79.00 ± 2.24 nm, suggesting the complete dispersibility of quercetin in water. X-ray diffraction (XRD) patterns illustrated that quercetin was in amorphous or molecular form within PMs. Fourier transform infrared spectroscopy (FTIR) indicated that quercetin formed intermolecular hydrogen bonding with carriers. An in vitro dialysis test showed the Qu-PMs possessed significant sustained-release property, and the formulation was stable for at least 6 months under accelerated conditions. The pharmacokinetic study in beagle dogs showed that absorption of quercetin after oral administration of Qu-PMs was improved significantly, with a half-life 2.19-fold longer and a relative oral bioavailability of 286% as compared to free quercetin. Therefore, these novel soluplus polymeric micelles can be applied to encapsulate various poorly water-soluble drugs towards a development of more applicable therapeutic formulations.

Nanostructured cubosomes as advanced drug delivery system.

Some kinds of amphiphilic lipids can spontaneously self-assemble with a proper ratio of water to form liquid crystalline, also known as cubic phase. With a curved bi-continuous lipid bilayer and two congruent networks of water channels, cubic phases can enclose hydrophilic, amphiphilic and hydrophobic drugs for delivery. Nanostructured cubosomes, prepared by fragmentation of bulk cubic phase gels or lyotropic methods, retain the same inner structure of cubic phase and possess much larger specific surface area and lower viscosity. These unique properties make cubosomes excellent delivery systems applicable for oral, mucosal, transdermal and parenteral drug delivery. This article gave an overview of the accelerated development and current status of cubosomes research, with respect to their preparation, characteristics and applications in pharmaceutics.