Needle-free injection of insulin powder: delivery efficiency and skin irritation assessment

Insulin is widely used in treating diabetes, but still needs to be administered by needle injection. This study investigated a new needle-free approach for insulin delivery. A portable powder needleless injection (PNI) device with an automatic mechanical unit was designed. Its efficiency in delivering insulin was evaluated in alloxan-induced diabetic rabbits. The skin irritation caused by the device was investigated and the results were analyzed in relation to aerodynamic parameters. Inorganic salt-carried insulin powders had hypoglycemic effects, while raw insulin powders were not effective when delivered by PNI, indicating that salt carriers play an important role in the delivery of insulin via PNI. The relative delivery efficiency of phosphate-carried insulin powder using the PNI device was 72.25%. A safety assessment test showed that three key factors (gas pressure, cylinder volume, and nozzle distance) were related to the amount of skin irritation caused by the PNI device. Optimized injection conditions caused minimal skin lesions and are safe to use in practice. The results suggest that PNI has promising prospects as a novel technology for delivering insulin and other biological drugs.

The effects of recombinant human epithelialgrowth factor and protein-free calf blood extract for recovery of corneal mechanical epithelial defects healing and neovascularization

OBJECTIVE

This study was undertaken to investigate the effects of recombinant human epidermal growth factor (rhEGF) and protein-free calf blood extract on corneal wound healing and neovascularization.

MATERIALS AND METHODS

An rabbit central corneal wound and neovascularization model was established in rabbits. One eye of each group was chosen randomly for topical administration of protein-free calf blood extract, rhEGF, or NS (physiological saline), and variability in the area of corneal epithelial wound healing and neovascularization was observed.

RESULTS

On days 1 and 2, the healing rate of corneal epithelium was various among the protein-free calf blood extract group, rhEGF group and NS group (F=6.475, p=0.012). The healing rate of corneal epithelium in the rhEGF group was better than the protein-free calf blood extract group (p=0.004) and NS group (p=0.041) on day 1. The corneal neovascularization area in the protein-free calf blood extract group was less than that of rhEGF group (p=0.04) and NS group (p=0.008) on day 18.

CONCLUSIONS

rhEGF had better promotive effect on corneal epithelial wound healing than the protein-free calf blood extract in the advanced phase (within 2 days). Both rhEGF and protein-free calf blood extract were not found to promote.

[Protection and bidirectional effect of rhubarb anthraquinone and tannins for rats' liver]

OBJECTIVE

To compare the bidirectional effect of rhubarb total anthraquinone (TA) and total tannins (TT) on rats' liver.

METHODS

One hundred rats were randomly divided into 10 groups, i.e., the blank group, the model group, the blank + high dose TA group, the blank +low dose TA group, the blank + high dose TT group, the blank + low dose TT group, the model + high dose TA group, the model + low dose TA group, the model +high dose TT group, and the model + low dose TT group, 10 in each group. The carbon tetrachloride (CCI4) was used to prepare the acute liver injury rat model. TA and TT of rhubarb (at 5.40 g crude drugs/kg and 14.69 g crude drugs/kg) were intragastrically administrated to rats in all groups except the blank group and the model group, once daily for 6 successive days.The general state of rats, biochemical indices such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), laminin (LN), hyaluronic acid (HA), transforming growth factor beta1 (TGF-beta1), as well pathological results of rat liver tissues. Finally the protection laws of TA and TT for rats' liver were analyzed using factor analysis.

RESULTS

Compared with the blank control group, all biochemical indices increased in the blank group (P < 0.05, P < 0.01). HA also increased in the blank + high dose TA group; AST, ALT, and HA also increased in the blank +high dose TT group (P < 0.05). Compared with the model group, AST, ALT, ALP, HA, and TGF-beta1 significantly decreased in the model + low dose TA group, the model + high dose TA group, the model + low dose TT group (P < 0.05, P < 0.01). Serum AST, ALT, and ALP also decreased in the model + high dose TT group (P < 0.05, P < 0.01). Pathological results showed that mild swollen liver cells in the model + high dose TA group. Fatty degeneration and fragmental necrosis around the central veins occurred in the blank + high dose TA group. The pathological injury was inproved in the model +low dose TA group. Two common factors, liver fibrosis and liver cell injury, were extracted by using factor analysis. TA showed stronger improvement of the two common factors than TT.

CONCLUSIONS

Rhubarb TA and TT showed protective and harmful effects on rats' liver. At an equivalent dosage, TA had better liver protection than TT. High dose TT played a role in liver injury to some extent.

The protective and toxic effects of rhubarb tannins and anthraquinones in treating hexavalent chromium-injured rats: the Yin/Yang actions of rhubarb

Chromium nephrotoxicity (CrNT) is thought to occur through the oxidant lesion mechanism. There is still a lack of specific remedies against CrNT. We primarily screened Chinese herbal medicines with a potential protective effect against CrNT, e.g., rhubarb (Rheum palmatum L.). However, the active constituents in rhubarb and its mechanisms remain unclear. In this study, the total rhubarb extract (TR) was successively separated into three parts: total anthraquinone extract (TA), total tannin extract (TT) and remaining component extract (RC). The effects of each extract on the potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity in rats were comparatively assessed. The results showed that only the administration of TT protected the kidney function in K(2)Cr(2)O(7)-injured rats. Besides, TT showed significant activity to scavenge hydroxyl radicals, which is considered to be the dominant lesion product generated by hexavalent chromium. TT also showed a reduced ability to transform toxic high valence chromium ions into non-toxic low valence ions. And TT was able to further precipitate chromium ions. These results suggested that rhubarb tannins treat CrNT as a free radical scavenger, reductant, and metal precipitant. The multiple protective routes of the plant tannins reveal a superior option for development into a promising natural remedy against CrNT. In addition, the opposite effects of rhubarb anthraquinones in treating CrNT were observed compared to rhubarb tannins, which suggested the duo-directional effects (Yin and Yang) of herbal medicines should be addressed.

Colorimetric grading scale can promote the standardization of experiential and sensory evaluation in quality control of traditional Chinese medicines

Experiential and sensory evaluation is an ancient method that remains important in the current quality control system of Traditional Chinese Medicines (TCMs). The process is rapid and convenient when evaluating the quality of crude materials in TCM markets. However, sensory evaluation has been met with skepticism because it is mainly based on experience and lacks a scientific basis. In this study, rhubarb was selected to demonstrate how color-based sensory evaluation could differentiate the quality of herbal medicines objectively. The colors of the rhubarb samples, expressed as RGB values, were obtained from different parts and forms of the plant, including the plant’s surface, fracture surface color, and a powdered form with or without treatment with a color-developing reagent. We first divided the rhubarb samples into three grades based on the total content of five hydroxyanthraquinone derivatives, the major pharmacological components in rhubarb. Then, a three-layer back-propagation artificial neural network (BP-ANN), calibrated with selected training samples, was used to correlate the quality of the rhubarb with its color. The color of the rhubarb powder after coloration attained the highest accuracy (92.3%) in predicting the quality grade of the test samples with the established artificial neural networks. Finally, a standardized colorimetric grading scale was created based on the spatial distribution of the rhubarb samples in a two-dimensional chromaticity diagram according to the colors of the powdered rhubarb after color enhancement. By comparing the color between the scale and the tested samples, similar to performing a pH test with indicator paper, subjects without sensory evaluation experience could quickly determine the quality grade of rhubarb. This work illustrates the technical feasibility of the color-based grading of rhubarb quality and offers references for quantifying and standardizing the sensory evaluation of TCMs, foods and other products.

[Research on standardized preparation of traditional Chinese medicine (III): difference of extracting quantity of anthraquinones from mixed decoction of rhubarb with TCMs containing different ingredients]

OBJECTIVE

To detect the influence of compatibility of rhubarb with different traditional Chinese medicines (TCM) on extracted quantities of AQs, and to provide scientific basis for the clinical code for rhubarb preparation.

METHOD

The influence of compatibility of rhubarb with different traditional Chinese medicines (saponin, alkaloids, flavonoids TCMs, animal medicines and mineral medicines) on decocting volume of anthraquinone substance was detected using ultra performance liquid chromatography.

RESULT

In comparable conditions, more AQs were extracted from mixed decoction of rhubarb and saponin medicinal materials (Astragali Radix, Notoginseng Radix et Rhizoma, Glycyrrhizae Radix et Rhizoma, Polygalae Radix, Ginseng Radix et Rhizoma) than single decocting of rhubarb. The mixed decoction of rhubarb and alkaloid medicinal materials (Coptidis Rhizoma, Sophorae Flavescentis Radix, Prepared Aconiti Lateralis Radix Praeparata, Phellodendri Chinensis Cortex, Aconiti Lateralis Radix) caused a remarkable decrease in extracted quantities of AQs. And the mixed decoction of rhubarb and mineral medicines (Natrii Sulfas, Gypsum Fibrosum, Ostreae Concha, Alumen) also resulted in less extracted quantities of AQs to varying degrees. Besides, more rhubarb AQs were extracted from mixed decoction with Curcuma than single decoction. But less rhubarb AQs were observed in mixed decoction with Lonicerae Flos, Rehmanniae, Artemisiae Herb and Forsythiae Fructus than single decoction to varying degrees. In the study, the maximum extracted quantities of AQs is 2. 3-fold higher than the minimum, the largest difference existed in the extracted quantity of physcion which was 13.5 times.

CONCLUSION

In compatibility between rhubarb and different TMCs, mixed decoction and single decoction show different influences on extracted quantity of rhubarb AQs. It is proved that more AQs may be extracted from mixed decoction between rhubarb and saponin medicinal materials, whereas less AQs may be observed in mixed decoction between rhubarb and alkaloid medicinal materials.