Diffusion Coefficients of l-Lysine Hydrochloride and l-Arginine Hydrochloride in Their Aqueous Solutions at 25℃

The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined. Based on all these data a semi-empirical model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions at 25℃ was proposed. The fitting result of this model is comparatively satisfactory. Compared to a former model, Gordon Model, this model can avoid a number of difficulties and arduous work.

Degradation kinetic study of lysine in lysine hydrochloride solutions for injection by determining its main degradation product

A limited number of researches have been reported to apply the Arrhenius equation to study the relationship between drugs and its degradation products so far.In the present work,the thermal degradation kinetics of lysine hydrochloride solutions for injection,the special solvent for ademetionine 1,4-butanedisulfonate(SAM)for injection,was investigated at selected temperatures and pH values.The main degradation product of lysine was separated,purified,and confirmed as lysine lactam.A reversed-phase high performance liquid chromatographic(RP-HPLC)method without derivation was developed for the simultaneous determination of lysine and lysine lactam.The results confirmed that both the lysine degradation and lysine lactam generation followed zero-order reaction kinetics.The degradation and generation rate constants increased with increasing temperatures and decreasing pH values.The temperature-dependent degradation and generation reaction could be sufficiently modeled on the Arrhenius equation with the activation energy of 80.14 and 83.22 kJ/mol,respectively.Meanwhile,a linear relationship existed between the amount of lysine degradation and lysine lactam generation since the approximate activation energy.Considering there could be other side effects,we established an upper limit of lysine lactam(500 mg/ml),as the acceptable criteria for stability to estimate the shelf life together with lysine,which made the prediction more accurate and credible.Extrapolation data demonstrated that the lysine hydrochloride solutions for injection could be stable for two years stored at room temperature.

Dissolution of highly molecular weight cellulose isolated from wheat straw in deep eutectic solvent of Choline/L-Lysine hydrochloride

Green solvents for cellulose dissolution is a key topic for green chemistry,especially natural cellulose with high molecular weight,and there are scarce solvents reported.Deep eutectic solvent(DES)is a typical kind of green solvent that has been attracted much attention recently.Here,high molecular weight natural cellulose(DP>3000)was first isolated from wheat straw and then be directly dissolved in the choline/L-lysine(Ch/Lys)DES.The solution owns excellent stability,and the solubility reaches^5%.Rheological studies revealed that the natural cellulose can be well dispersed in the DES solution and showed gelation at high concentrations.The dissolved cellulose can be regenerated when the dilute acid aqueous solution was added into the solution.It provides an energy conversation and an environmentally friendly route to prepare a cellulose solution,which makes it possible to convert cellulose to valuable chemicals and materials in its homogeneous solution.

Hypidone hydrochloride(YL-0919)ameliorates functional deficits after traumatic brain injury in mice by activating the sigma-1 receptor for antioxidation

Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.

Design and optimization of a greener sinomenine hydrochloride preparation process considering variations among different batches of the medicinal herb

The current methods used to industrially produce sinomenine hydrochloride involve several issues,including high solvent toxicity,long process flow,and low atomic utilization efficiency,and the greenness scores of the processes are below 65 points.To solve these problems,a new process using anisole as the extractant was proposed.Anisole exhibits high selectivity for sinomenine and can be connected to the subsequent water-washing steps.After alkalization of the medicinal material,heating extraction,water washing,and acidification crystallization were carried out.The process was modeled and optimized.The design space was constructed.The recommended operating ranges for the critical process parameters were 3.0–4.0 h for alkalization time,60.0–80.0℃ for extraction temperature,2.0–3.0(volume ratio)for washing solution amount,and 2.0–2.4 mol·L^(-1) for hydrochloric acid concentration.The new process shows good robustness because different batches of medicinal materials did not greatly impact crystal purity or sinomenine transfer rate.The sinomenine transfer rate was about 20%higher than that of industrial processes.The greenness score increased to 90 points since the novel process proposed in this research solves the problems of long process flow,high solvent toxicity,and poor atomic economy,better aligning with the concept of green chemistry.

Identification of the lysine and histidine transporter family in Camellia sinensis and the characterizations in nitrogen utilization

In plants,the lysine and histidine transporter(LHT)family represent a class of proteins that mediate the uptake,translocation,and utilization of amino acids.The tea plant(Camellia sinensis)is a perennial evergreen with a relatively high level of amino acids.However,systematic identification and molecular characterization of the LHT gene family has rarely been reported in tea plants.In this study,22 CsLHTs were identified from the‘Shuchazao’genome and classified into two groups.The modeled three-dimensional structure and the conserved domains presented a high similarity among the LHTs proteins.Moreover,it was predicted that a few genes were conserved through the analysis of the physiochemical characters,structures and cis-elements in promoters.The expression patterns in tea plants revealed that CsLHT7 was mainly expressed in the roots,and CsLHT4 and CsLHT11 exhibited relatively high expression in both the roots and leaves.Moreover,the expression of all three genes could be induced by organic nitrogen.Additionally,heterogeneous expression of CsLHT4,CsLHT7 and CsLHT11 in Arabidopsis thaliana decreased the aerial parts biomass compared with that in WT plants while significantly increased the rosette biomass only for CsLHT11transgenic plants versus WT plants.Overall,our results provide fundamental information about CsLHTs and potential genes in N utilization for further analysis in tea plants.

Carbon-doped CuFe_(2)O_(4) with C-O-M channels for enhanced Fenton-like degradation of tetracycline hydrochloride: From construction to mechanism

Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.

Benzydamine hydrochloride ameliorates ethanol-induced inflammation in RAW 264.7 macrophages by stabilizing redox homeostasis

Objective:To evaluate the protective effect of benzydamine hydrochloride against ethanol-induced oxidative stress and inflammation in RAW 264.7 macrophages.Methods:RAW 264.7 macrophages were treated with ethanol(100 mM)and benzydamine hydrochloride(7.5μM).The imflammatory status was confirmed by measuring pro-(TNF-αand IL-6)and anti-inflammatory(IL-10)cytokines through ELISA and RT-PCR assays.Reactive oxygen species generation and mitochondrial membrane potential were investigated to study the protective role of benzydamine hydrochloride against ethanol-induced oxidative stress.Apoptosis detection was also investigated using flow cytometry and acridine orange/ethidium bromide staining.Results:Benzydamine hydrochloride significantly decreased the secretion of TNF-αand IL-6,as well as the generation of reactive oxygen species inside the cells,thereby stabilizing the mitochondrial membrane potential and reducing DNA fragmentation.The ethanol-induced cellular necrosis was also reversed by the administration of benzydamine hydrochloride.Conclusions:Benzydamine hydrochloride ameliorates ethanol-induced cell apoptosis and inflammation in RAW macrophages.

Wetting alternating with partial drying during grain filling increases lysine biosynthesis in inferior rice grain

Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.

Method Verification and Validation of Hydralazine Hydrochloride: Spectrophotometric Analysis in Pure and Pharmaceutical Formulations

The new method proposed is based on the formation of hydralazine-Bromophenol blue ion pair simply and without further extraction or heating. The ion pair was prepared in the presence of pH 3 citrate buffer forming a yellow-colored chromogen. A new maximum UV-visible band formed at 416 nm. The color was stable for more than 10 hours and obeyed Beer’s Law over the concentration range of 10 - 50 µg/mL. The calculated molar absorptivity and Sandell’s sensitivity were 1.01 × 104 L∙mol−1∙cm−1 and 0.0514 µg/mL, respectively. The elements of method validation stipulated by The International Conference on Harmonization [Q2 (R1)] were applied for hydralazine hydrochloride assay in pure and pharmaceutical tablet formulation. The average recoveries of the pure solution and the pharmaceutical formulation were 98.94% and 99.50%, respectively. The results were statistically compared by F-test, which indicates that the method can be precise and repeatable for both pure and pharmaceutical solutions. The method was found to be accurate, reproducible, and cost-effective, and validated for the assay of hydralazine in terms of the routine quality control.

Feeding Practices and Use of Lysine and Methionine in Pigrationing on Intensified Pig Breeding in the West Center and Hauts Bassins Regions of Burkina Faso

The aim of the study was to assess feeding practices and the use of lysine and methionine in pig rationing on intensified and semi-intensive pig breeding in the Koudougou and Bobo-Dioulasso areas. To this end, a cross-sectional survey was carried out on 87 breeding in these towns. A Discriminant Factorial Analysis (DFA) confirming a k-means classification of the data collected was used to retain 71 breeding divided into three breeding classes: Class A (32.4% of breeding), Class B (14.08%) and Class C (53.52%). The results show that the majority of pig breeders were men between the ages of 36 and 59. Average herd sizes were 35 ± 28;79 ± 42 and 89 ± 21 pigs for Classes A, B and C respectively. The main breeds of pig found on the breeding were crossbred, Large white, local, Landrace and Duroc. Class A (26.1%), B (30%) and C (15.8%) breeders were familiar with both lysine and methionine. Class A breeders distributed feed staggered (65.2%) and in rations (34.8%). Lysine (13%) and methionine (8.7%) were purchased at 5250 FCFA/kg. Those in class B distributed feed staggered (50%) and in the form of rations (50%), in which they incorporated lysine (30%) and methionine (30%) purchased at a cost of 2500 FCFA/kg and 3000 FCFA/kg respectively. Rationing and staggered feeding were practiced by 23.7% and 76.3% of Class C breeders respectively. Only lysine purchased at 3400 FCFA/kg was incorporated into rations by 10.5% of breeders. The high cost of lysine and methionine was incriminated by Class A (100%), B (33.3%) and C (50%) breeders. In conclusion, intensive pig breeding, the practice of rationing and the incorporation of the amino acids lysine and methionine are of ascending importance from classes C, A to B. The high cost of feedstuffs, particularly lysine and methionine, compromises their use in rations, which could have a negative impact on expected breeding performance. The screening and use of feeds rich in and/or enriched with these amino acids, through the development or adaptation of technologies, could improve the efficiency of rations and the productivity of intensive pig breeding in Burkina Faso.

Effect of exogenous free N^(ε)-(carboxymethyl)lysine on diabetes-associated cognitive dysfunction:neuroinflammation,and metabolic disorders

Diabetes-associated cognitive dysfunction has already been attracted considerable attention.Advanced glycation end products(AGEs)from daily diets are thought to be a vital contributor to the development of this diseases.However,the effect of one of the best-characterized exogenous AGEs N^(ε)-(carboxymethyl)lysine(CML)on cognitive function is not fully reported.In the present study,diabetical Goto-Kakizaki(GK)rats were treated with free CML for 8-weeks.It was found that oral consumption of exogenous CML significantly aggravated diabetes-associated cognitive dysfunction in behavioral test.In details,exogenous CML increased levels of oxidative stress,promoted the activation of glial cells in the brain,up-regulated the release of inflammatory cytokines interleukin-6,inhibited the protein expression of the brain-derived neurotrophic factor and thus led to neuroinflammation.Furthermore,exogenous CML promoted the amyloidogenesis in the brain of GK rats,and inhibited the expression of GLUT4.Additionally,several tricarboxylic acid cycle and glutamate-glutamine/γ-aminobutyric acid cycle intermediates including pyruvate,succinic acid,glutamine,glutamate were significantly changed in brain of GK rats treated with exogenous free CML.In conclusion,exogenous free CML is a potentially noxious compounds led to aggravated diabetes-associated cognitive dysfunction which could be possibly explained by its effects on neuroinflammation,energy and neurotransmitter amino acid homeostasis.

Effects of Supplemental Glutamine and Lysine on Growth Performance of Broiler Chickens

The optimum levels of Lysine and Glutamine needed for growth performance and maintenance of the chicken broilers were evaluated in a randomized 3 × 4 factorial arrangement of dietary treatments. The battery cages measured 99 × 66 × 25 cm that can be sufficient for 5 birds. Day old Chicken broilers totaling 180 were assigned to dietary treatments comprising of 3 concentrations of Lysine (0.85, 1.14, and 1.42) each in combination with 4 concentrations of Glutamine (0, 1, 2, and 3). Each dietary treatment was replicated 3 times and each replication had 5 birds. The birds were given feed and water ad libitum with a 23-hour light regimen for a period of 4 weeks. Then, the experimental birds were evaluated for body weight gain, feed consumption, and feed conversion in order to determine their optimum requirement for dietary Lysine and Glutamine. Based on the findings of this study, the highest performance was observed in birds fed the diet supplemented with 1.42 lysine and 1% glutamine, but the highest improvement in feed conversion was observed in diet contain 1.14 and 1.42 with 1% and 3% glutamine, respectively. Birds fed 1.42 lysine and 1% glutamine had the highest total body weight gain and feed consumption. The lysine requirements in the diet for Chicken are between 1.14 and 1.42 with glutamine level of 1%.

Exploring the efficacy of(R)-PFI-2 hydrochloride in mitigating noise-induced hearing loss by targeting NLRP3 inflammasome and NF-κB pathway to reduce inner ear inflammation

Noise-induced hearing loss(NIHL)is primarily driven by inflammatory processes within the cochlea,where noise exposure triggers the activation of the NOD-like receptor protein 3(NLRP3)inflammasome,leading to an inflammatory cascade.The interaction between increased NLRP3 expression and NF-κB activity can further amplify cochlear inflammation.Our findings reveal that(R)-PFI-2 hydrochloride,a selective inhibitor of the SETD7 enzyme,effectively inhibits the activation of the cochlear NF-κB pathway,suppresses the release of proinflammatory factors,and prevents inflammasome assembly.This intervention disrupts the perpetuating cycle of inflammation,thereby alleviating damage to cochlear hair cells attributed to acoustic trauma.Consequently,(R)-PFI-2 hydrochloride emerges as a promising pharmacological candidate for NIHL,targeting and moderating the excessive immune and inflammatory responses implicated in the pathology of hearing loss.

Transfer of Lysine-rich Protein Gene into Rice and Production of Fertile Transgenic Plants

Lysine-rich protein gene (lys) was cloned from Psophocarpus tetragonolobus (L.) DC. A plant expression plasmid was constructed and lys gene was under the control of maize ubiquitin promoter which is the highest efficient monocotyledon promoter. The plasmid was introduced into rice embryogenic calli by microprojectile bombardment. The regenerated fertile plants were obtained by effective selection for hygromycin B resistance. Genomic PCR and Southern blotting analyses showed that the lys gene has been integrated into rice genome. Simultaneously, the results of GUS histochemical assay demonstrated that gus report gene is also expressed in leaves, stems and roots of the transgenic rice plants. Data analysis showed that lysine content in most of the 11 transgenic plants is differently improved, and in one of them increased by 16.04%.

Clinical effect of acupuncture at ghost points combined with fluoxetine hydrochloride on mild-to-moderate depression

BACKGROUND Depression is a common,chronic,and recurrent mood disorder that has become a worldwide health hazard.Fluoxetine hydrochloride,a common treatment method,can inhibit 5-hydroxytryptamine(5-HT)recycling in the presynaptic membrane;however,the efficacy of a single drug is inadequate.At present,mildto-moderate depression can be treated with acupuncture of ghost caves,but the clinical curative effect of combined therapy with fluoxetine hydrochloride has not been sufficiently reported.AIM To evaluate the clinical effect of acupuncture at ghost points combined with fluoxetine hydrochloride in the treatment of mild-to-moderate depression.METHODS This retrospective study included 160 patients with mild-to-moderate depression who were admitted to Shanghai Hospital of Integrated Traditional Chinese and Western Medicine,Affiliated to Shanghai University of Traditional Chinese Medicine,between January 2022 and June 2023.Patients were separated into a single-agent group(fluoxetine hydrochloride treatment,n=80)and a coalition group(fluoxetine hydrochloride treatment combined with acupuncture at ghost points,n=80).Pre-treatment symptoms were recorded,and the clinical curative effect and adverse reactions[Asberg Antidepressant Side Effects Scale(SERS)]were assessed.Depression before and after treatment[Hamilton Depression Scale(HAMD)-24],neurotransmitter levels[5-HT,norepinephrine(NE),dopamine(DA)],oxidative stress indicators[superoxide dismutase(SOD),malondialdehyde(MDA)],and sleep quality[Pittsburgh Sleep Quality Index(PSQI)]were compared.RESULTS The total efficacy rate was 97.50%in the coalition group and 86.25%in the single-agent group(P<0.05).After 2,4,6,and 8 wk of treatment,the HAMD,self-rating depression scale,and SERS scores of the coalition and single-agent groups decreased compared with pre-treatment,and the decrease was more significant in the coalition group(P<0.05).After 8 wk of treatment,the levels of NE,DA,5-HT,and SOD in the coalition and single-agent groups increased,while the levels of MDA decreased;the increases and decrease in the coalition group were more significant(P<0.05).The PSQI scores of the coalition and single-agent groups decreased,and the decrease was more significant in the coalition group(P<0.05).CONCLUSION Acupuncture at ghost points combined with paroxetine tablets can safely improve depressive symptoms and sleep disorders,regulate neurotransmitter levels,and reduce stress responses in patients with mild-to-moderate depression.

Analysis of the Efficacy of Atomoxetine Hydrochloride Combined with Psycho-Behavioral Modification Therapy in the Treatment of ADHD in Children

Objective: To evaluate the therapeutic efficacy of atomoxetine hydrochloride (ATX) combined with psychological-behavioral modification therapy for attention-deficit/hyperactivity disorder (ADHD) in children. Methods: A total of 60 cases of ADHD children admitted to our hospital between November 2021 and November 2022 were selected and randomly grouped into Group I and Group II. There were 30 cases in Group I who were treated with ATX combined with psychological-behavioral modification therapy. There were 30 cases in Group II who were treated with ATX monotherapy, and the therapeutic effects were compared. Results: Before treatment, there was no difference in the behavioral problem scores and cognitive function indexes of the two groups (P>0.05). After treatment, the behavioral problem scores of Group I were lower than those of Group II, and the cognitive function indicators of Group I were lower than those of Group II (P < 0.05). The adverse reaction rate of Group I was lower than that of Group II, and the total effective rate was higher than that of Group II (P < 0.05). Conclusion: ATX combined with psychological-behavioral modification therapy improved the behavioral problems of ADHD children, enhanced their cognitive function, and reduced the adverse reactions to drug treatment.

Clinical Study on the Treatment of Senile Alzheimer’s Dementia with Sodium Oligomannate Combined with Memantine Hydrochloride

Objective:To analyze the clinical effects of sodium oligomannate combined with memantine hydrochloride in the treatment of senile Alzheimer’s dementia.Methods:Sixty-eight cases of Alzheimer’s dementia treated at the Second People’s Hospital of Fujian University of Traditional Chinese Medicine from March 2020 to March 2022 were selected as the study subjects.The patients were divided into two groups based on different treatment methods:the control group(treated with memantine hydrochloride,34 cases)and the treatment group(treated with sodium oligomannate+memantine hydrochloride,34 cases).Cognitive function,activities of daily living,neurotransmitters,serum intestinal flora metabolic markers,inflammatory factors,neurotrophic factors,and adverse reactions were compared between the two groups.Results:The treatment group showed better cognitive function,quality of life scores,and levels of relevant metabolic markers in the body compared to the control group,with statistically significant differences(P<0.05).The incidence of adverse reactions between the two groups(treatment group:2%;control group:4%)was not statistically significant(χ^(2)=0.731,P=0.393).Conclusion:Sodium oligomannate combined with memantine hydrochloride has better efficacy than the control group for treating senile Alzheimer’s dementia.It significantly improves and restores cognitive function and daily living abilities,benefits neurotransmitter secretion and internal regulation,upregulates the expression of neurotrophic factors,and has fewer adverse reactions,making it a treatment worthy of further clinical promotion and application.

Development of Prolonged Release Microspheres of Metformin Hydrochloride Using Ion Exchange Resins

Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.

Influence of pH Environment on Nasal Absorption of Meptazinol Hydrochloride

Aim To investigate the relationship between pH environment of meptazinolhydrochloride (MEP) and its nasal absorption. Methods In situ nasal peifusion was performed to studythe effect of pH environment on the nasal absorption. Its effect on the transport from nose tobrain was further researched by in vivo experiment. Results In in situ perfusion experiment, thenasal absorption of MEP in basic environment was significantly higher than that in acid condition,but the difference was not observed in in vivo experiment. Conclusion The pH environment ofmeptazinol hydrocloride in formulation cannot be regarded as an important factor influencing nasalabsorption and transport from nose to brain.