Objective: To establish an HPLC method of the content and related substances of compound amino acid injection(3AA). Methods: RP-HPLC was adopted to determine compound amino acid injection(3AA), combining with the use of two-dimensional column switching-LC/MSⁿ method was applied to separate and identify the impurities. The determination was performed on Capcell PAK AQ C₁₈(250 mm×4.6 mm, 3 μm) column with 0.2 mol·L^-1 sodium dihydrogen phosphate solution (adjusted pH to 2.8 with phosphoric acid) -acetonitrile (98∶2) as mobile phase at the flow rate of 1.0 mL·min^-1. The column temperature was 40 ℃, and the detection wavelength was 210 nm. And the injection volume was 20 μL. The LC/MSⁿ method was performed on a Thermo Accucore AQ C₁₈ (100 mm×4.6 mm, 2.6 μm) column with 0.1% formic acid solution as mobile phase A, 0.1% formic acid solution-acetonitrile as mobile phase B, at a flow rate of 0.4 mL·min^-1, and at a column temperature of 40 ℃. The mass spectrometry conditions were performed using an ESI ionisation source in the positive-ion scanning mode with a scan range of m/z 100-1 000, and the secondary mass spectrum was carried out by data-dependent scanning. Results: The related substances were completely separated from the main constituents in RP-HPLC. The standard curve of valine was linear over the range of 1.263-5.050 mg·mL^-1, with the average recovery of 99.0% (n=9). The standard curve of isoleucine was linear over the range of 1.350-5.402 mg·mL^-1, with the average recovery of 99.4%(n=9). The standard curve of leucine was linear over the range of 1.647-6.588 mg·mL^-1, with the average recovery of 99.5%(n=9). The main impurities in the three batches of samples were all process impurities introduced from the raw materials, with methionine content of 4.344 μg·mL^-1, 3.751 μg·mL^-1, 4.503 μg·mL^-1, respectively, phenylalanine content of 4.636 μg·mL^-1, 4.889 μg·mL^-1, 4.753 μg·mL^-1, respectively. The maximum single impurity contents were 0.01%, 0.02% and 0.01%, respectively. Conclusion: The method is proved by the methodology validation that it can be used for the quality control of compound amino acid injection(3AA).

Ongoing procedure performance verification (OPPV) of an analytical procedure is the process of ensuring it continues to meet its intended use after completion of validation. On the basis of previous studies, this paper further discussed the indicators of ongoing procedure performance verification (including system suitability indicators and reported values, etc.) and the implementation of analysis tools (control charts), and demonstrated the specific operation steps of ongoing procedure performance verification with examples. It is hoped that this paper will provide new ideas for the accurate and standardized procedure verification in the pharmaceutical field, especially in the enterprises and regulatory departments.

Objective: To compare the quality of wild and cultivated Arnebiae Radix,using macroscopic investigation and chemometric analysis of the different components in wild and cultivated Arnebiae Radix from three different habitats. Methods: Wild and cultivated Arnebiae Radix were collected and their macroscopic features were compared. Using the ACQUITY UPLC BEH C₁₈ (2.1 mm×100 mm, 1.7 μm) column, with acetonitrile-0.05% formic acid water as the mobile phase, the contents of D-shikonin, acetylshikonin, β-acetoxyisovalerylshikonin, isobutyrylshikonin, β,β’-dimethylacrylalkannin and isovalerylshikonin in 48 batches of wild and cultivated Arnebiae Radix were determined. The detection wavelength was 275 nm and the flow rate was 0.2 mL·min^-1. PCA and OPLS-DA were performed to reveal the differential components of wild and cultivated Arnebiae Radix. Results: There were great differences in macroscopic features of wild and cultivated Arnebiae Radix, and the linear relationship between the contents of six naphthoquinone components was good. The correlation coefficients were above 0.999, the average recovery rates were 93.4%-102.9%, and the RSDs were less than 3.0%. The contents of six components in different batches of wild and cultivated Arnebiae Radix were quite different, and the contents of D-shikonin and acetylshikonin in wild products were significantly higher than those in cultivated products, indicating that there were still certain differences between wild products and cultivated products. The PCA model established could distinguish wild products and cultivars, and two differentiating components in wild products and cultivars were revealed by OPLS-DA, namely isobutyryl shikonin, β,β’-dimethylacrylalkannin. Conclusion: By comparing the core size, cork curl degree and specific odor of wild and cultivated products, the two can be identified. The established content determination method is repeatable, specific, stable and feasible. The differential components in wild and cultivated Arnebiae Radix in three different regions are identified, which provides a basis for the quality control of Arnebiae Radix and provides ideas for expanding the source of Arnebiae Radix.

Bioassays play a key role in the development and quality control of biological products, and the research on them has also made great progress in recent years. Here, the historical process of bioassays was reviewed. Then- the current contents about bioassays in pharmacopoeia and technical guidelines weresorted out. At last, the latest progress related to bioassays was summarized and analyzed including the introduction of new concepts such as analytical procedure, method life cycle and analytical target profile.This paper might provide a systematical reference for the people work in the biopharmaceutical field to fully understand the bioassays and related guidelines. Meanwhile, it can also provide a theoretical support for drug researchers to establish scientific and reliable bioassays.

Objective: To establish the RP-UPLC-PDA method for simultaneous determination of triptolide, triptonide, triptophenolide, wilforine, wilforlide A and celastrol in Tripterygii Radix. Methods: Tripterygii Radix were extracted with ethyl acetate and the extracts were dissolved and separated by methanol. The six components were determined by RP-UPLC-PDA method. The chromatographic column was Acquity^TM UPLC BEH C₁₈ column (100 mm×2.1 mm, 1.7 μm), the column temperature was 30 ℃, the injection volumn was 2 μL, the flow rate was 0.4 mL·min^-1 and the mobile phase was acetonitrile (A)-0.1% formic acid (B). Results: The linear relationship of six components was good (0.999 2≤r≤0.999 7) in the concentration ranges. The average recoveries were 99.2%-103.1% and RSDs were 1.2%-2.9%. The contents in 10 batches of Tripterygii Radix from different habitat were determined. The results showed that the contents of Tripterygii Radix in prepared pieces from different producing areas were different. The highest content of triptolide was 140.2 μg·g^-1, and the lowest content was 103.2 μg·g^-1. The highest content of triptonide was 224.7 μg·g^-1 and the lowest content was 112.2 μg·g^-1. The highest content of triptophenolide was 306.7 μg·g^-1 and the lowest content was 189.6 μg·g^-1. The highest and lowest contents of wilforine were 283.2 μg·g^-1 and 211.2 μg·g^-1. The highest content of wilfhabitat was 31.2 μg·g^-1 and the lowest content was 16.8 μg·g^-1. The highest content of celastrol was 87.6 μg·g^-1, and the lowest content was 52.1 μg·g^-1. Conclusion: The RP-UPLC-PDA method can simultaneously determine six components in Tripterygii Radix. The method is reliable and stable, which is suitable for quantitative analysis and determination of Tripterygii Radix.

Objective: To establish an innovative analytical method based on high resolution sampling two-dimensional chromatography (HiRes 2D-LC) for determination of the content of vitamin D₃ in vitamin D drops. Methods: Two-dimensional liquid chromatography was used. Thermo HYPERSIL Gold Silica (100 mm×2.1 mm, 1.9 μm) column was used in the first dimension with n-hexane-n-amyl alcohol (996∶4) as mobile phase. The flow rate was 0.2 mL·min^-1. The samples were injected and tested at the wavelength of 265 nm. The column temperature was 40 ℃. In the second dimension liquid chromatography, ShimPack Velox Hilic (50 mm×2.1 mm, 2.7 μm) was used as the column with n-hexane-n-pentanol-isopropanol (98∶1∶1) as the mobile phase. The flow rate was 0.5 mL·min^-1. The samples were injected and tested at the wavelength of 265 nm. The column temperature was 40 ℃. A six-position 14-way valve and was equipped with 2 multi-center cutting valves was equipped to make multiple consecutive cuts of the pre-vitamin D₃ peak and vitamin D₃ peak. Results: The calibration curves showed a good linearity at the range of 1.018 4-5.092 mg·mL^-1(r≥0.999 8). The precision test showed the RSDs of the peak area of pre-vitamin D₃ and vitamin D₃ were 0.95% and 0.40%, respectively. The repeatability test showed the RSD of vitamin D₃ content was 0.41%. The average recovery rate (n=9) was 101.4%. The test solution was stable at 4 ℃ and 10 ℃ for 12 h, and the RSDs were 0.58% and 0.66%, respectively. The contents of vitamin D₃ in the samples of vitamin D drops measured by this method were 100.4%, 101.6%, 100.9%, 101.6%, 102.7% and 101.6%, which was basically consistent with the results measured by the fourth method in General Chapter 0722 of ChP 2020 Vol Ⅳ. Conclusion: This method has a good specificity and high sensitivity to accurately determine the content of vitamin D₃ in vitamin D drops.

The change of analytical procedure, a part of the entire lifecycle of a method, is increasingly valued with the emergence of new technologies, the increasing demand for product quality, 3R, environmental protection, and cost reduction requirements. This paper refers to the latest progress in the study of counterpart law at home and abroad, systematically classifies changes of analytical procedures from the perspective of methodology, and discusses the differences between different types of changes and the evaluation criteria and implementation approaches of analytical procedures after procedure changes.

Liposome is a drug delivery system which has been successfully transformed for clinical application. In the past few decades, liposome as a drug delivery system has been extensively and deeply studied in the field of therapy. A variety of liposome drugs have been marketed at home and abroad, but there are few reports on the systematic quality detection and evaluation methods. In this paper, the preparation technology and systematic quality evaluation methods of liposome drugs were reviewed based on domestic and foreign literature and relevant technical guidelines, so as to provide reference for the development and evaluation of liposome drug delivery technology.

Objective: To analyze and optimize stir-baked with vinegar technology of Genkwa Flos decoction pieces by multi-index weighted scoring method based on orthogonal experiment, and to provide technical index on standardization of stir-baked with vinegar technology of Genkwa Flos decoction pieces. Methods: The orthogonal experiment was employed to analyze and evaluate the four key factors related to stir-baked with vinegar technology including the amount of vinegar, dampening time, temperature and stir-baked time by the six main indicators including the total contents of chlorogenic acid, tiliroside, luteolin, apigenin, hydroxygenkwanin and genkwanin, the content of alcohol extractive and appearance characters. Results: The amount of vinegar and stir-baked temperature had notable effects, while the dampening time and stir-baked time had no notable effects on the test results. Considering comprehensively the effects of four key factors, the optimized stir-baked with vinegar technology was as follows: add 0.3 kg of vinegar to 1 kg of Genkwa Flos, and fry at 160 ℃ for 10 min after dampening for 15 min. Conclusion: This study offers guidance and reference for standardizing the stir-baked with vinegar technology of Genkwa Flos decoction pieces.

Objective: To establish a method for related substances determination in timolol maleate by ultra-high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry(UPLC-Q/Orbitrap HRMS), by which the impurities both in active pharmaceutical ingredients(APIs) and preparations can be recognized and determined. Methods: An ACE Excel3 C₁₈-AR column(150 mm×4.6 mm, 3 μm)was used for the separation and a mixture of 0.01 mol·L^-1 ammonium acetate solution with 0.02% formic acid and methanol was employed as the mobile phase by gradient elution, at a flow rate of 0.6 mL·min^-1. The detection wavelength for UV detector was 295 nm, an HESI(heated ESI)ion source was employed in both the positive mode and negative mode. The possible fragmentation patterns prediction was conducted with the help of Mass Frontier 8.0 and Compound Discover 3.3. The related substances could be recognized and determined by means of the forced degradation of the APIs, with the calibration by the correction factors and confirmation by the mass spectrum data from UPLC-Q/Orbitrap HRMS. Results: The timolol impurity B[3-(tert-butylamino)-2-(4-morpholino-1, 2, 5-thiadiazol-3-yloxy)propan-1-ol], timolol impurity D(4-morpholino-1,2,5-thiadiazol-2-ol), timolol impurity E((S,Z)-4-(｛1-(tert-butylamino)- 3-[(4-morpholino-1, 2, 5-thiadiazol-3-yl) oxy] propan-2-yl｝oxy)-4-oxobut-2-enoic acid maleate salt) and timolol impurity C[N-(tert-butyl)-2, 3-bis (4-morphloline-1, 2, 5-thiadiazol-3-yloxy) propan-1-amine maleate] were produced from the APIs under selected conditions and separated well in the specified HPLC condition, the limit of quantitation was 0.05 μg·mL^-1 and the limit of detection was 0.015 μg·mL^-1 for HPLC-UV. The contents of individual impurities were between 0.000 4%-0.09% and the results of total impurities were between 0.02%-0.12% for the samples from 4 different manufactures. The probable chemical structures of the 6 unspecified impurities were speculated according to the fragmentation pattern of fragment ions, combined with the fragment information, chemical structure of API and the references. Conclusion: The system solution can be obtained by the degradation of the API, and be implied in the impurity analysis for the timolol maleate. The results can be used as a reference for the quality control of timolol maletae.

Objective: To compare the regulatory effects of authentic and counterfeit Arnebiae Radix on intestinal flora in mice based on metagenomic sequencing. Methods: Firstly, 24 clean grade female BLAB/C mice were randomly divided into 3 groups:blank control group, A1 (Arnebia euchroma) group and A2 (Arnebiae Radix whose origins were not included in Chinese Pharmacopoeia) group. After gavage arrived at the specified time, colon contents (feces), ileal contents (feces) and small intestinal contents (feces, except ileal parts) were extracted for intestinal flora analysis. Genomic DNA was extracted and amplified by PCR from the extracted mouse intestinal contents. The PCR products were mixed and purified. Then library was constructed and sequenced. After quality control of sequencing data and removal of chimera sequence, the final effective data was obtained. Operational taxonomic unit(OTU) clustering and species annotation were performed on the obtained valid data, and sample diversity analysis was conducted. Results: In this study, both A1 (Arnebia euchroma) group and A2 (Arnebiae Radix non-pharmacopoeia) group reduced the diversity of mice colon microbiota. At the phylum level, group A1 significantly increased the abundance of Firmicutes in the small intestine and ileum, and groups A1 and A2 significantly increased the relative abundance of Bacteroidetes in the colon. At the genus level, group A1 significantly increased the relative abundance of Lactobacillus in the small intestine of mice, and group A2 significantly increased the relative abundance of Lactobacillus in the ileum of mice. Group A1 increased the relative abundance of Lactobacillus, one of the dominant bacteria in the colon of mice, and group A2 increased the relative abundance of Bacteroides. Alistipes mainly existed in the colon, A2 group significantly reduced the relative abundance of Alistipes in the colon of mice, while Alistipes in the A1 group was cultivated. Conclusion: According to the results of the regulation effect of intestinal flora, the intestinal flora regulation effect in the two experimental groups of the authentic Arnebiae Radix and its confusion products from markets are not consistent, the results of this study can provide a theoretical basis for further exploring the mechanism of Arnebiae Radix.

Scientific design of experiment (DOE) is the main tool to ensure the accuracy of test results and the reliability of conclusions. It is discussed the validation design for bioassay with many influencing factors and great variation, and the calculation method of sample size in method validation design is elaborated in detail here. It is hoped that it could provide theoretical reference for bioassay valiadation to accurately understand the experimental design of method validation.

Objective: To establish a quantitative analysis of multi-components by single marker (QAMS) for simultaneous determination of 7 flavanoids (5-hydroxy-6, 7, 3’, 4’-tetramethoxyflavone, apigenin, hispidulin, kaempferol, jaceosidin, eupatilin and casticin) in Artemisiae Argyi Folium. Methods: The HPLC system consisted of the Agilent ZORBAX SB-C₁₈ column (150 mm×4.6 mm, 5 μm) column with gradient elution of acetonitrile and 0.2% phosphoric acid as the mobile phase at a flow rate of 1.0 mL·min^-1, a detection wavelength of 350 nm, and a column temperature of 30 ℃. Eupatilin was selected as the internal reference substance, the relative correction factors between eupatilin and the other 6 flavanoids were established, and the contents of these 7 constituents in samples were calculated to realize QAMS. At the same time, compared with the external standard method to verify the accuracy and feasibility of the QAMS method. Results: Within a certain linear range, the relative correction factors between eupatilin and 5-hydroxy-6, 7, 3’, 4’-tetramethoxyflavone, apigenin, hispidulin, kaempferol, jaceosidin as well as casticin were 0.958, 1.387, 1.000, 0.950, 0.957 and 1.297, respectively (RSDs of RCFs were less than 2.0%). The contents of 5-hydroxy-6, 7, 3’, 4’-tetramethoxyflavone, apigenin, hispidulin, kaempferol, jaceosidin, eupatilin, casticin in 20 batches of Artemisiae Argyi Folium were 0.031 4-0.623 5 mg·g^-1, 0.000 9-0.092 6 mg·g^-1, 0.020 6-0.170 7 mg·g^-1, 0.011 0-0.184 7 mg·g^-1, 0.011 7-0.864 0 mg·g^-1, 0.253 2-2.555 0 mg·g^-1 and 0.015 6-0.250 7 mg·g^-1, respectively. Conclusion: Using eupatilin as the internal reference, QAMS method for 7 flavanoids is established. The method is accurate and reliable, and can be used for quality control and quantitative analysis of Artemisiae Argyi Folium.

In recent years, the domestic gene therapy industry has developed rapidly, and innovative gene therapy products are emerging constantly. How to effectively control the quality of such products has become a highly concerned issue in the industry. This article draws inspiration from relatively mature, effective, and practical methods in the field of quality control of gene therapy products. Taking recombinant adeno-associated virus gene therapy products as an example, starting from the selection of testing items and methods, precautions, and formulation of quality standards, it elaborates on their quality control inspection items and related technical requirements. We hope this article can provide reference for practitioners to conduct quality control research on such products, and through subsequent communication and discussion, a certain consensus can be reached, thereby accelerating the development of gene therapy industry in China.

Objective: To optimize the content determination method of morphine sulfate suppositories, which had high toxicity of extraction solvent and poor specificity and generality of chromatographic conditions. Methods: The optimization of the preparation method for the test solution was to prepare the test solution by ice bath freezing and n-heptane extraction, and to compare the content determination results of the test solution prepared by the United States Pharmacopeia method (extracted with trichloromethane). The optimization of chromatographic conditions for content determination was based on the comprehensive comparison of United States Pharmacopeia, British Pharmacopeia and YBH specification. Symmetry C₁₈ column (150 mm×4.6 mm, 5 μm) was finally used. The mobile phase was 0.01 mol·L^-1 potassium dihydrogen phosphate solution containing 0.202% sodium heptane sulfonate (containing 0.1% triethylamine, adjusted to pH 2.5 with phosphoric acid) -methanol (70∶30). The flow rate was 1.0 mL·min^-1. The column temperature was 30 ℃. The detection wavelength was 284 nm. The injection volume was 20 μL. Results: The content measured by ice bath freezing method was relatively low, while the content measured by n-heptane extraction and trichloromethane extraction was basically consistent, indicating that n-heptane could be used as extraction solvent instead of halogenated alkane. The linear range of morphine sulfate was 2.12-105.94 μg·mL^-1(r=0.999 9), and the LOQ was 10.60 ng. The RSD values of system precision, repeatability, intermediate precision and stability were all less than 2%. The average recoveries were 98.6%-99.6% and RSD was 0.21%-0.66%. After forced degradation, the main peak of the tested solution could be separated from the degraded impurities, with good specificity. By changing the flow rate, column temperature, pH value, mobile phase ratio and column brand, the main peak could be well separated from each impurity peak, with good robustness. Conclusions: This study optimized the determination method for morphine sulfate suppositories. The preparation of the test solution used n-heptane instead of the highly toxic haloalkane, and meanwhile improved the chromatographic conditions, enhanced the environmental protection, specificity and applicability of the method. It can be used for the content determination of morphine sulfate suppositories.

Althought mRNA vaccines have been developed for nearly 30 years, but due to certain technical bottlenecks in production, stability, and reactivity, the development of mRNA vaccines has been relatively slow. During the epidemic of COVID-19, mRNA vaccine had been fully verified its effectiveness and safety for preventing infectious diseases. Here, this article summarized the key quality control attributes and related requirements of mRNA vaccine products for preventing infectious diseases by reviewing the quality control guidance documents of WHO and drug regulatory and standardization agencies, aiming to provide reference for the quality control of mRNA vaccine products for preventing infectious diseases in China.

Growth hormone is a protein hormone with a single peptide chain produced and released by the anterior pituitary, which is the most important hormone for growth promotion after birth. In order to exert biological effects, growth hormone first binds to a specific receptor on the cell surface, and then activates the down stream signaling pathways of the non-receptor tyrosine kinase JAK2 and Src family kinases. An in-depth understanding of the mechanism of action of growth hormone is required for its biological activity measurement. In this paper, we reviewed the recent research progress on growth hormone, including the mechanism of action of growth hormone receptor, the activation of STATs, PI3K-Akt and MEK-Erk signaling pathways by the binding of growth hormone to the receptor, and the regulatory mechanism of growth hormone action pathways. We also summarized and prospected the research on the determination methods of growth hormone activity, in order to provide a reference for the quality control of the biological activity of growth hormone drugs.

Objective: To establish an ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of daidzein, formononetin, genkwanin, quercetin, rutin, apigenin, kaempferol, luteolin and puerarin in Tongfu Jingyaotong tincture. Methods: The Waters ACQUITY UPLC HSS T3 Column (100 mm×2.1 mm,1.8 μm) was used with methanol and 0.1% formic acid (gradient elution) as the mobile phase at a flow rate of 0.3 mL·min^-1. Column temperature was 45 ℃, and injection volume was 2.0 μL. Electrospray ion source was adopted with positive and negative ion modes and multi-reaction monitoring and acquisition. Results: Apigenin, genkwanin and daidzein had good linearity in the range of 0.2-1 000 ng·mL^-1, puerarin, rutin, luteolin, kaempferol and formononetin in the range of 0.2-2 000 ng·mL^-1, and quercetin in the range of 1.0-5 000 ng·mL^-1. The resolution was good, and the RSDs of precision, repeatability, reproducibility and stability test were all below 5% (n=6). The average recoveries ranged from 82.7% to 111.8% with RSDs (n=6) of 2.0%-5.4%. The contents of daidzein, formononetin, genkwanin, quercetin, rutin, apigenin, kaempferol, luteolin and puerarin in 6 batches of Tongfu Jingyaotong tincture were 8.46-17.97 μg·mL^-1, 0.62-1.67 μg·mL^-1, 0.03-0.08 μg·mL^-1, 1.34-2.22 μg·mL^-1, 0.70-1.14 μg·mL^-1, 0.48-0.99 μg·mL^-1, 0.20-0.90 μg·mL^-1, 0.10-0.16 μg·mL^-1 and 167.95-227.75 μg·mL^-1, respectively. Conclusion: This method has strong specificity, wide linear range, accuracy and efficiency, and can detect the contents of 9 active ingredients in Tongfu Jingyaotong tincture at the same time, which offers an effective quality control method for Tongfu Jingyaotong tincture.

Objective: To establish an HPLC-MS/MS method for the simultaneous determination of six characteristic components of Scutellariae Radix including baicalein, baicalin, wogonin, wogonoside, chrysin and oroxylin A in rat plasma, and to compare their pharmacokinetic profiles after oral administration of Scutellariae Radix and Niuhuang Jiedu tablets (NHJDT) to rats. Methods: Rats were given 250 mg·kg^-1 of NHJDT suspension or the prescribed equivalent amount of Scutellariae Radix aqueous extract, and plasma samples were collected at different time intervals. Naringenin was used as internal standard. After precipitated with methanol, the plasma samples were separated on an Inertsil C₈-3 (150 mm×4.6 mm, 5 μm) column by linear gradient elution with 0.1% formic acid solution(A)-0.1% formic acid-methanol(B) as mobile phase. The flow rate was 1.0 mL·min^-1, and the column temperature was 35 ℃. The analytes were detected by tandem mass spectrometry with the electrospray ionization (ESI) source combined with multiple reaction monitoring(MRM) mode in positive ion mode. The pharmacokinetic parameters were calculated and statistically analyzed. Results: The six characteristic components of Scutellariae Radix were all in good linear relationships in the range of 5-500 ng·mL^-1. The RSDs for accuracy test were in the range of 88.43%-108.6%, and the RSDs for inter-batch and intra-batch precision tests were all below 15%. The matrix effect and plasma stability met the requirements of methodology validation in biological sample analysis. Baicalin and wogonoside were the major components detected in rat plasma after oral gavage of Scutellariae Radix aqueous extract and NHJDT suspension. The AUC_0-t of wogonoside was significantly increased in NHJDT group compared with Scutellariae Radix group. Furthermore, the C_max of wogonoside and baicalin were significantly increased while the T_max was decreased after NHJDT suspension administration. Conclusion: This method is specific and sensitive for the determination of six characteristic components of Scutellariae Radix, and suitable for pharmacokinetic study of rat plasma. NHJDT with co-existing components enhances the absorption and influences the pharmacokinetic behaviors of active ingredients of Scutellariae Radix.

Objective: To explore the definition and systematic taxonomy of bioassay method, to provide ideas for better understanding the essence of bioassay. Methods: According to the attribute characteristics of bioassay, the classification framework of bioassay was established and the meaning for the classification was explained. Results: (1) The definition of bioassay has different emphases, mainly due to the different focus in various fields, but the theme was basically the same. (2)Potency and its derivative terms had their definitive connotations and extents in bioassay, and accurate use of these terms could make the expression more professional and clearer. (3) Bioassays could be classified according to many attributes, such as whether directness or not of the biological effect detected, the type of the biological subsector used for assay, the nature and mechanism of the bioassay, and the data type of reportable value of the bioassay. Conclusion: Accurate and standardized definition and classification of bioassay are not only conducive to the standardization of expression for use, but also provide theoretical basis and technical support for further understanding, application and improvement of bioassay.

Objective: To investigate the feasibility of applying for bioequivalence exemption based on parallel artificial membrane permeability assay (PAMPA) data by evaluating the solubility and in vitro permeability of levofloxacin, comparing the prescription differences between the generic and reference formulations, assessing the impact of disparate excipients on the permeation behavior of the active pharmaceutical ingredient (API), and predicting the bioequivalence of the two formulations. Methods: The dissolution of the raw material at pH 1.0 to pH 6.8 was determined using high-performance liquid chromatography. The μFlux^TM system was employed to determine the permeability of the raw material and the mixture of raw material with sodium stearyl fumarate in various media. pH 5.0 fed-state intestinal fluid, pH 6.5 fasted-state intestinal fluid, and pH 7.4 phosphate buffer (16 mL) were precisely added to the donor chamber, while 16 mL of Accepter Sink Buffer was added to the receptor chamber. The rotor speed was set at 200 r·min^-1, and the collection time was 180 min. Determine the permeability of the raw material and the mixture of raw material with sodium stearyl fumarate in various media, as well as the permeability of the raw material in the reference and generic formulations powders. The impact of newly added excipients and other changed excipients on API was evaluated through a two-tailed t-test. The Macro Flux^TM system was used to measure the dissolution-permeation curves of the reference and generic formulations, intestinal simulation fluids at pH 5.0 and pH 6.5 (1 000 mL) were added to the dissolution cup as dissolution media, with a stirring speed of 75 r·min^-1 using a paddle method, 12 mL of Accepter Sink Buffer was added to the receptor chamber, and the stirring speed of the micro-stirring rod was set at 450 r·min^-1, one tablet of each reference or generic formulation was placed in the dissolution cup, and the dissolution-permeation curves of the formulations were measured. The similarity of dissolution curves was compared, and the permeability rate (J_Flux) and cumulative drug permeation amount (AMT) were calculated to predict the bioequivalence of the two formulations, ensuring that the 90% confidence interval for the geometric mean ratio of J_Flux and AMT of the two formulations fell within the range of 80% to 125%. Results: Levofloxacin solubility ranged from 16.4 mg·mL^-1 to 62.7 mg·mL^-1 across different mediums, its permeability in pH 5.0 fed-state simulated intestinal fluid, pH 6.5 fasted-state simulated intestinal fluid, and pH 7.4 phosphate-buffered saline was 2.92×10^-6 cm·s^-1, 1.01×10^-5 cm·s^-1, and 1.07×10^-5 cm·s^-1, respectively. The addition of sodium stearyl fumarate showed no significant difference in permeability compared to the original API (P＜0.05), and there were no significant differences between the powder API of the reference and generic formulations (P＜0.05). The dissolution curves of both formulations were similar, with the 90% confidence interval for JFlux and AMT within the predefined range. Conclusion: Levofloxacin tablets, classified as BCS Class Ⅰ, demonstrated that the altered excipients in the formulation did not impact on the API's permeability, confirming bioequivalence between the reference and generic formulations. The bioequivalence exemption study based on PAMPA can be utilized for permeability studies of raw materials, excipient screening and optimization, and prediction of formulation bioequivalence, effectively reducing drug development costs and time. This study provides reference data for pharmaceutical companies applying for bioequivalence exemptions.