Spray drying technology is one of the most commonly used unit operations in the production of traditional Chinese medicine(TCM) preparations, offering advantages such as short drying time and uniform product quality. However, due to the properties of TCM extracts, such as high viscosity, strong hygroscopicity, and poor flowability, there is limited scope to solve the problems of wall adhesion and clumping in spray drying from the macroscopic perspective of pharmaceutical production. Therefore, it has become a trend to study and optimize the spray drying process from the microscopic point of view by investigating single droplet evaporation behavior. Based on the reaction engineering approach(REA), the single droplet drying system, as a novel method for studying droplets, collects parameter data on individual TCM droplets during the drying process and uses the REA to process the data and establish predictive models. This approach is crucial for understanding the mechanism of TCM spray drying. This paper summarized and analyzed the cha-racteristics of various single droplet systems, the application of REA in single droplet drying systems, and its significance in optimizing the process, predicting drying states, and shortening the development cycle in the field of TCM spray drying, and looked ahead to the prospects of this method, including the introduction of new parameters and imaging techniques, aiming to provide a reference for further research in the field of TCM spray drying.
Medicine, Chinese Traditional ; Spray Drying ; Desiccation/methods* ; Temperature ; Technology

The present study explored the effect of co-amorphous technology in improving the dissolution rate and stability of silybin based on the puerarin-silybin co-amorphous system prepared by the spray-drying method. Solid-state characterization was carried out by powder X-ray diffraction(PXRD), polarizing microscopy(PLM), Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry(DSC), etc. Saturated powder dissolution, intrinsic dissolution rate, moisture absorption, and stability were further investigated. The results showed that puerarin and silybin formed a co-amorphous system at a single glass transition temperature which was higher than that of any crude drug. The intrinsic dissolution rate and supersaturated powder dissolution of silybin in the co-amorphous system were higher than those of the crude drug and amorphous system. The co-amorphous system kept stable for as long as three months under the condition of 40 ℃, 75% relative humidity, which was longer than that of the single amorphous silybin. Therefore, the co-amorphous technology could significantly improve the dissolution and stability of silybin.
Calorimetry, Differential Scanning ; Desiccation ; Drug Compounding/methods* ; Drug Stability ; Silybin ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Technology ; X-Ray Diffraction

The volatile oil of Chuanxiong Rhizoma(CX) is known as an effective fraction. In order to seek a suitable method for processing CX and its decoction pieces, this study selected 16 volatile components as indices to investigate how different processing methods such as washing/without washing, sun-drying, baking, oven-drying and far-infrared drying at different temperatures affected the quality of CX and its decoction pieces(fresh CX was partially dried, cut into pieces, and then dried) by headspace gas chromatography-mass spectrometry(GC-MS), cluster analysis, principal component analysis and comprehensive weighted scoring. The results showed that the rapid washing before processing did not deteriorate the volatile components of CX. Considering the practical condition of production area, oven-drying was believed to be more suitable than sun-drying, baking, and far-infrared drying. The CX decoction pieces with a thickness of 0.3-0.4 cm were recommended to be oven-dried at 50 ℃. The integrated processing(partial drying, cutting into pieces, and drying) did not cause a significant loss of volatile components. For the fresh CX, the oven-drying at 60 ℃ is preferred. The temperature should not exceed 60 ℃, and drying below 60 ℃ will prolong the processing time, which will produce an unfavorable effect on volatile components. This study has provided the scientific evidence for field processing of CX, which is conducive to realizing the normalization and standardization of CX processing in the production area and stabilizing the quality of CX and its decoction pieces.
Desiccation ; Gas Chromatography-Mass Spectrometry/methods* ; Oils, Volatile ; Principal Component Analysis ; Rhizome/chemistry* ; Volatile Organic Compounds/analysis*

To improve the spray drying effect of extract of Wenjing Zhitong Prescription, this study takes the yield, hygroscopic property and the fluidity of dry powder as indexes to screen out auxiliary materials, and the proportion of the auxiliary materials was optimized based on the mixing design experiment; based on that, HPLC method was established for the determination of glycyrrhizin and 6-gingerol in spray powder, the yield of spray powder and the retention rate of the two index components were taken as indexes to further optimize the spray drying parameters. The finally selected auxiliary materials were light magnesium oxide, maltodextrin and silica, and regression equations of dry powder yield, moisture absorption rate, angle of rest with proportion of auxiliary materials were established, and the optimized proportion of auxiliary materials was dry paste-light magnesium oxide-maltodextrin-silica=0.5∶0.305∶0.145∶0.05; according to the optimized drying process parameters of Wenjing Zhitong Prescription, initial temperature was 60 ℃, air inlet temperature was 130 ℃, air flow rate was 35 m~3·h~(-1), atomizing pressure was 40 mm, and liquid inlet speed was 4.5 mL·min~(-1). Under these conditions, the dry powder yield was 90.28%, the retention rate of glycyrrhizin was 74.51%, and the retention rate of 6-gingerol was 72.10%. In this study, optimized auxiliary materials can improve the yield of spray drying and the property of spray powder, and the optimized processing conditions were good for retaining the unstable gingerol components, which can lay a foundation for the further preparation research of meridian warming and pain relieving prescriptions, and provide reference for extract of other traditional Chinese medicine extracts that are difficult to spray drying.
Chemistry, Pharmaceutical/methods* ; Desiccation/methods* ; Drugs, Chinese Herbal/chemistry* ; Hot Temperature ; Medicine, Chinese Traditional ; Powders

To explore the relationship between the variations of the physiochemical properties of traditional Chinese medicine(TCM) decoction before or after precipitation in alcohol and the wall stickiness in spray drying. In this study, widely used TCMs in clinic were selected to determine the physiochemical properties of TCM decoction before or after precipitation in alcohol separately.Afterwards, the principle component analysis(PCA),Hierarchical cluster analysis(HCA),and orthogonal partial least squares-discriminate analysis(OPLS-DA) were used to evaluate the relationship between the variations of those liquid before or after precipitation in alcohol and hot-melt stickiness in spray drying.Three types of statistical analysis methods all indicated that ethanol precipitation affected physiochemical properties of TCM decoction, and the variations of physical properties showed significant association with hot-melt stickiness in spray drying.The results of PCA-X and HCA suggested that the dynamic surface tension(DST) was impacted most by the alcohol deposition treatment,at the same time,the other 5 physiochemical properties were also affected.OPLS-DA verified that PCA-X and HCA results, and revealed that DST,equilibrium surface tension(EST) and pH were significantly affected by alcohol deposition treatment,and the order of the affecting factors from high to low was DST,EST and pH.Therefore,the downward trend of DST and pH were the important factors that directly affected the hot-melt stickiness of TCM after precipitation in alcohol,which would be probably caused by losing macromolecules alcoholic insoluble components and increasing relative proportions of organic acid and small molecule sugar.
Cluster Analysis ; Desiccation/methods* ; Drugs, Chinese Herbal/chemistry* ; Ethanol/chemistry* ; Hot Temperature ; Least-Squares Analysis ; Medicine, Chinese Traditional ; Principal Component Analysis

In this study,the protein in different Cordyceps samples,which include fresh sample( S1),22 ℃ drying sample( S2),37 ℃ drying sample( S3) and 60 ℃ drying sample( S4),were analyzed by sodium dodecylsupinate-polyacrylamide gel electrophoresis( SDS-PAGE) and two-dimensional electrophoresis( 2-DE). The total protein contents in Cordyceps samples were from 1. 655-4. 493 mg·g~(-1) and the protein contents in fresh sample was the highest. The results of SDS-PAGE showed that the mainly ranges of protein molecular weight of Cordyces samples were 10-100 kDa and the numbers of protein bands were 28 to 41,the fresh sample had the maximum number of protein bands. The 2-DE profiles were analyzed by PDQuest software. The resulted indicated that 488-876 protein spots were detected in different Cordyceps samples and the isoelectric point( pI) was distributed between 4. 5 and 6. 5,the protein molecular weight was distributed in 10-20 kDa and 25-100 kDa,the fresh sample had the maximum number of protein spots. Therefore,the drying process could decrease contents and species of protein in Cordyceps,and the different drying conditions had different effects on protein. These results provide a reference for improving the drying process of Cordyceps.
Cordyceps ; chemistry ; Desiccation ; methods ; Electrophoresis, Gel, Two-Dimensional ; Electrophoresis, Polyacrylamide Gel ; Fungal Proteins ; analysis ; Molecular Weight

Pathogenic Naegleria fowleri, Acanthamoeba castellanii, and Acanthamoeba polyphaga, are distributed worldwide. They are causative agents of primary amoebic meningoencephalitis or acanthamoebic keratitis in humans, respectively. Trophozoites encyst in unfavorable environments, such as exhausted food supply and desiccation. Until recently, the method of N. fowleri encystation used solid non-nutrient agar medium supplemented with heat-inactivated Escherichia coli; however, for the amoebic encystment of Acanthamoeba spp., a defined, slightly modified liquid media is used. In this study, in order to generate pure N. fowleri cysts, a liquid encystment medium (buffer 1) modified from Page’s amoeba saline was applied for encystation of N. fowleri. N. fowleri cysts were well induced after 24 hr with the above defined liquid encystment medium (buffer 1). This was confirmed by observation of a high expression of differential mRNA of nfa1 and actin genes in trophozoites. Thus, this liquid medium can replace the earlier non-nutrient agar medium for obtaining pure N. fowleri cysts. In addition, for cyst formation of Acanthamoeba spp., buffer 2 (adjusted to pH 9.0) was the more efficient medium. To summarize, these liquid encystment media may be useful for further studies which require axenic and pure amoebic cysts.
Acanthamoeba ; Acanthamoeba castellanii ; Actins ; Agar ; Amoeba* ; Desiccation ; Escherichia coli ; Food Supply ; Humans ; Hydrogen-Ion Concentration ; Keratitis ; Meningoencephalitis ; Methods ; Naegleria fowleri ; RNA, Messenger ; Trophozoites

Aconite is a valuable drug and also a toxic material, which can be used only after detoxification processing. Although traditional processing methods can achieve detoxification effect as desired, there are some obvious drawbacks, including a significant loss of alkaloids and poor quality consistency. It is thus necessary to develop a new detoxification approach. In the present study, we designed a novel one-step detoxification approach by quickly drying fresh-cut aconite particles. In order to evaluate the technical advantages, the contents of mesaconitine, aconitine, hypaconitine, benzoylmesaconine, benzoylaconine, benzoylhypaconine, neoline, fuziline, songorine, and talatisamine were determined using HPLC and UHPLC/Q-TOF-MS. Multivariate analysis methods, such as Clustering analysis and Principle component analysis, were applied to determine the quality differences between samples. Our results showed that traditional processes could reduce toxicity as desired, but also led to more than 85.2% alkaloids loss. However, our novel one-step method was capable of achieving virtually the same detoxification effect, with only an approximately 30% alkaloids loss. Cluster analysis and Principal component analysis analyses suggested that Shengfupian and the novel products were significantly different from various traditional products. Acute toxicity testing showed that the novel products achieved a good detoxification effect, with its maximum tolerated dose being equivalent to 20 times of adult dosage. And cardiac effect testing also showed that the activity of the novel products was stronger than that of traditional products. Moreover, particles specification greatly improved the quality consistency of the novel products, which was immensely superior to the traditional products. These results would help guide the rational optimization of aconite processing technologies, providing better drugs for clinical treatment.
Aconitum ; adverse effects ; chemistry ; toxicity ; Alkaloids ; adverse effects ; analysis ; toxicity ; Animals ; Cardiovascular Agents ; adverse effects ; chemistry ; standards ; toxicity ; Desiccation ; methods ; Drugs, Chinese Herbal ; adverse effects ; chemistry ; standards ; toxicity ; Male ; Maximum Tolerated Dose ; Plant Roots ; chemistry ; Rats, Sprague-Dawley ; Technology, Pharmaceutical ; methods

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.
Chemistry, Pharmaceutical ; instrumentation ; methods ; Desiccation ; instrumentation ; methods ; Drugs, Chinese Herbal ; chemistry ; Fruit ; chemistry ; Gardenia ; chemistry ; Research Design ; Vacuum

To establish the water dynamics model for drying process of Angelicae Sinensis Radix, the Weibull distribution model was applied to study the moisture ratio variation curves, and compared the drying rate and drying activation energy with the drying methods of temperature controllable air drying, infrared drying under different temperatures (50, 60, 70 degrees C). The Weibull distribution model could well describe the drying curves, for the moisture ratio vs. drying time profiled of the model showed high correlation (R2 = 0. 994-0. 999). The result proved that the drying process of Angelicae Sinensis Radix belonged to falling-rate drying period. For the drying process, the scale parameter (a) was related to the drying temperature, and decreased as the temperature increases. The shape parameter (β) for the same drying method, drying temperature had little impact on the shape parameter. The moisture diffusion coefficient increase along with temperature increasing from 0.425 x 10(-9) m2 x s(-1) to 2.260 x 10(-9) m2 x s(-1). The activation energy for moisture diffusion was 68.82, 29.60 kJ x mol(-1) by temperature controllable air drying and infrared drying, respectively. Therefore, the Weibull distribution model can be used to predict the moisture removal of Angelicae Sinensis Radix in the drying process, which is great significance for the drying process of prediction, control and process optimization. The results provide the technical basis for the use of modern drying technology for industrial drying of Angelicae Sinensis Radix.
Angelica sinensis ; chemistry ; Desiccation ; methods ; Models, Theoretical ; Water