An Optimized and Feasible Preparation Technique for the Industrial Production of Hydrogel Patches.

For hydrogel patches, the laboratory tests could not fully reveal the existing problems of full scale of industrial production, and there are few studies about the preparation technique for the industrial manufacturing process of hydrogel patches. So, the purpose of this work was to elucidate the effects of mainly technological operation and its parameters on the performance of hydrogel patches at the industrial-scale production. The results revealed the following: (1) the aqueous phase was obtained by polyvinylpyrrolidone (PVP) along with tartaric acid dissolved in purified water, then feeding this into a vacuum mixer as a whole in one batch, thus extended the crosslinking reaction time of hydrogel paste (matrix) and allowed the operation of coating/cutting-off to be carried out easily, and there was no permeation of backing layer; (2) the gel strength of the hydrogel patches increased with the increase of working temperature, however, once the temperature exceeded 35 ± 2 °C, the hydrogel paste would lose water severely and the resultant physical crosslinking structure which has lower gel/cohesive strength would easily bring gelatinization/residues during application; (3) the relative humidity (RH) of the standing-workshop was dynamically controlled (namely at 35 ± 2 °C, keeping the RH at 55 ± 5% for 4 days, then 65 ± 5% for 2 days), which would make patches with satisfactory characteristics such as better flexibility, higher adhesive force, smooth flat matrix surface, and without gelatinization/residues and warped edge during the using process; (4) the aging of the packaged hydrogel patches was very sensitive to storage temperature, higher temperature, higher gel strength and lower adhesiveness. The storage temperature of 10 ± 2 °C could effectively prevent matrix aging and adhesion losing, which would also facilitate the expiration date of patches extended obviously. In conclusion, this work provides an optimized and feasible preparation technique for the industrial production of the hydrogel patches and establishes the hydrogel patches as a novel carrier for transdermal drug delivery.

[Content comparison of pinoresinol diglucoside in original and reborn bark of Eucommia ulmoides].

OBJECTIVE: To evaluate the reborn barks quality, antihypertensive effective component of pinoresnol diglucoside (PDG) in three times reborn barks were determined. METHODS: A YWG C18 column (10 microm, 250 x 4.6 mm) was used with a mobile phase of methanol-water (30:75) and flow rate of 1.0 (ml/min). The detective wave-length was set at 277nm and the column temperature at room temperature. RESULTS: PDG in the first reborn barks are slightly higher than the original ones, and in the second reborn barks are similar with the barks before girdling (the fist reborn barks), but in the third reborn barks, PDG are much lower than the barks before girdling (the second reborn barks). CONCLUSION: In order to ensure reborn barks quality, we suggest that the girdling bark regeneration can be made two times, the time between the first and the second girdling is not less than five years. PDG in the third reborn barks should be enhanced.

Propylene glycol-embodying deformable liposomes as a novel drug delivery carrier for vaginal fibrauretine delivery applications.

The purpose of this work was to develop and characterize the fibrauretine (FN) loaded propylene glycol-embodying deformable liposomes (FDL), and evaluate the pharmacokinetic behavior and safety of FDL for vaginal drug delivery applications. FDL was characterized for structure, particle size, zeta potential, deformability and encapsulation efficiency; the ability of FDL to deliver FN across vagina tissue in vitro and the distribution behavior of FN in rat by vaginal drug delivery were investigated, the safety of FDL to the vagina of rabbits and rats as well as human vaginal epithelial cells (VK2/E6E7) were also evaluated. Results revealed that: (i) the FDL have a closed spherical shape and lamellar structure with a homogeneous size of 185±19nm, and exhibited a negative charge of -53±2.7mV, FDL also have a good flexibility with a deformability of 92±5.6 (%phospholipids/min); (ii) the dissolving capacity of inner water phase and hydrophilicity of phospholipid bilayers of deformable liposomes were increased by the presence of propylene glycol, this may be elucidated by the fluorescent probes both lipophilic Nile red and hydrophilic calcein that were filled up the entire volume of the FDL uniformly, so the FDL with a high entrapment capacity (were calculated as percentages of total drug) for FN was 78±2.14%; (iii) the permeability of FN through vaginal mucosa was obviously improved by propylene glycol-embodying deformable liposomes, no matter whether the FN loaded in liposomes or not, although FN loaded in liposomes caused the highest permeability and drug reservoir in vagina; (iv) the FN mainly aggregated in the vagina and uterus, then the blood, spleen, liver, kidney, heart and lungs for vaginal drug delivery, this indicating vaginal delivery of FDL have a better 'vaginal local targeting effect'; and (v) the results of safety evaluation illustrate that the FDL is non-irritant and well tolerated in vivo, thereby establishing its vaginal drug delivery potential. These results indicate that the propylene glycol-embodying deformable liposomes may be a promising drug delivery carrier for vaginal delivery of fibrauretine.