OBJECTIVE To establish an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of dexmedetomidine(DEX)in plasma of beagle dogs and evaluate the pharmacokinetics and sedation after nasal,buccal and sublingual mucosal admin-istration.METHODS A UPLC-MS/MS method was established and validated for dertermination of DEX in plasma of beagle dogs.DEX was administered to the nasal cavity,buccal and sublingual mucous membranes of beagle dogs,respectively.Blood samples were collected at different time points.The plasma concentration of DEX was measured by the established UPLC-MS/MS method.Pharmacokinetic parameters were fitted by Phoenix software and the sedative effect at different mucous membrane sites was evaluated in conjunction with behavioral and Ramsay scores.RESULTS The linearity of DEX was fine within the range of 0.05-100 μg·L-1(r>0.999),which was validated methodologically to meet the requirements of quantitative detection.The plasma concentration of the drug peaked the fastest with nasal administration.Tmax was 0.25 h,Cmax(4.43±1.19)μg·L-1,and the AUC0-6h was(8.92±2.07)μg·h·L-1,compared with 0.92 and 1 h,(2.87±0.69),(2.70±0.41)μg·L-1,and(7.99±1.77),(7.01±2.09)μg·h·L-1 with buccal and sublingual administration.Nasal administration had the fastest onset at 7 min,with a Ramsay score of 4,and sedation lasted for 36 min,compared with 33 and 35 min,and 38 and 37 min for buccal and sublingual administration.CONCLUSION The proposed method is sensitive,reliable and applicable to quantitative analysis of DEX in plasma of beagle dogs.Administration of DEX to the nasal cavity mucosa has a faster onset and a better sedative effect than to the buccal and sublingual mucosa.

Poloxamer， as a non-ionic surfactant， exhibits a unique triblock [polyethylene oxide-poly （propylene oxide）-polyethylene oxide] structure， which endows it with broad application potential in various fields， including solid dispersion technology， nanotechnology， gel technology， biologics， gene engineering and 3D printing. As a carrier， it enhances the solubility and bioavailability of poorly soluble drugs. In the field of nanotechnology， it serves as a stabilizer etc.， enriching preparation methods. In gel technology， its self-assembly behavior and thermosensitive properties facilitate controlled drug release. In biologics， it improves targeting efficiency and reduces side effects. In gene engineering， it enhances delivery efficiency and expression levels. In 3D printing， it provides novel strategies for precise drug release control and the production of high-quality biological products. As a versatile material， poloxamer holds promising prospects in the pharmaceutical field.

Uncontrolled hemorrhage is the leading cause of potentially survivable combat casualty death,dominated by non-compressible hemorrhage in the torso and junctional areas.Rapid hemostasis using war trauma dressings is the mainstay of treatment for such casualties.The article reviews the research progress of novel hemostatic dressings for war trauma,including novel improved dressings,multifunctional dressings,electrospinning wound dressings,and smart dressings in order to provide references for the research on war trauma dressings.

Compared with conventional transdermal drug delivery systems, dissolving microneedles significantly enhance drug bioavailability by penetrating the stratum corneum barrier and achieving intradermal drug delivery. In order to improve the transdermal bioavailability of dexmedetomidine hydrochloride, in this study, a novel microneedle delivery system was developed for dexmedetomidine hydrochloride based on 3D printing combined with micro-molding. By systematically optimizing the microneedle geometrical parameters, array arrangement, and preparation process parameters, we determined the optimal ratio of drug-carrying matrix as 15% PVP (polyvinyl pyrrolidone) K90. The microneedles exhibited significant drug loading gradients, with mean content of (209.99±27.56) μg/patch, (405.31±30.31) μg/patch, and (621.61±34.43) μg/patch. They showed a regular pyramidal structure under SEM and handheld electron microscopy, and their mechanical strength allowed effective penetration into the stratum corneum. The surface contact angles were all < 90°, indicating excellent hydrophilicity. The microneedles dissolved completely within 10 min after skin insertion, achieving a cumulative release rate of 90% (Higuchi model, r=0.996) during 2 hours of in vitro transdermal permeation. The cytotoxicity test and hemolysis test verified good biocompatibility. Pharmacodynamic evaluation showed that the microneedle group demonstrated pain-relieving effect within 15 min, with the pain threshold at the time point of 60 min being 3 times that in the transdermal cream group. The microneedle system developed in this study not only offers an efficient drug delivery option for patients but also establishes an innovative platform for rapid percutaneous delivery of hydrophilic drugs, demonstrating significant potential in perioperative pain management.
Dexmedetomidine/pharmacokinetics* ; Printing, Three-Dimensional ; Needles ; Drug Delivery Systems/methods* ; Administration, Cutaneous ; Animals ; Microinjections/instrumentation* ; Skin Absorption ; Skin/metabolism*

OBJECTIVE To establish an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of dexmedetomidine(DEX)in plasma of beagle dogs and evaluate the pharmacokinetics and sedation after nasal,buccal and sublingual mucosal admin-istration.METHODS A UPLC-MS/MS method was established and validated for dertermination of DEX in plasma of beagle dogs.DEX was administered to the nasal cavity,buccal and sublingual mucous membranes of beagle dogs,respectively.Blood samples were collected at different time points.The plasma concentration of DEX was measured by the established UPLC-MS/MS method.Pharmacokinetic parameters were fitted by Phoenix software and the sedative effect at different mucous membrane sites was evaluated in conjunction with behavioral and Ramsay scores.RESULTS The linearity of DEX was fine within the range of 0.05-100 μg·L-1(r>0.999),which was validated methodologically to meet the requirements of quantitative detection.The plasma concentration of the drug peaked the fastest with nasal administration.Tmax was 0.25 h,Cmax(4.43±1.19)μg·L-1,and the AUC0-6h was(8.92±2.07)μg·h·L-1,compared with 0.92 and 1 h,(2.87±0.69),(2.70±0.41)μg·L-1,and(7.99±1.77),(7.01±2.09)μg·h·L-1 with buccal and sublingual administration.Nasal administration had the fastest onset at 7 min,with a Ramsay score of 4,and sedation lasted for 36 min,compared with 33 and 35 min,and 38 and 37 min for buccal and sublingual administration.CONCLUSION The proposed method is sensitive,reliable and applicable to quantitative analysis of DEX in plasma of beagle dogs.Administration of DEX to the nasal cavity mucosa has a faster onset and a better sedative effect than to the buccal and sublingual mucosa.

Hot melt extrusion(HME)technology employs thermodynamic and kinetic principles to mix pharmaceutical polymers with crystalline drugs at high temperatures and extrude them,embedding drug molecules within the polymer matrix to form solid dispersions.Due to its solvent-free nature,capability for one-step processing,and support for continuous operation,HME has garnered significant attention in the pharmaceutical industry in recent years.This article introduced the basic principles and development history of HME technology and its marketed drugs.It reviewed the research progress of HME technology in improving drug solubility,masking taste,controlled release,targeted release,oral dispersible films,implant formulations,semi-solid formulations,and 3D printed formulations.Additionally,the article summarized the advantages and limitations of HME technology and provided an outlook on its future development.

Hot melt extrusion(HME)technology employs thermodynamic and kinetic principles to mix pharmaceutical polymers with crystalline drugs at high temperatures and extrude them,embedding drug molecules within the polymer matrix to form solid dispersions.Due to its solvent-free nature,capability for one-step processing,and support for continuous operation,HME has garnered significant attention in the pharmaceutical industry in recent years.This article introduced the basic principles and development history of HME technology and its marketed drugs.It reviewed the research progress of HME technology in improving drug solubility,masking taste,controlled release,targeted release,oral dispersible films,implant formulations,semi-solid formulations,and 3D printed formulations.Additionally,the article summarized the advantages and limitations of HME technology and provided an outlook on its future development.

Biological toxins are toxic molecules produced by specific microorganisms,plants or animals.Due to their wide range of sources and high toxicity,the availability of protein and non-protein toxins is becoming increasingly important,some of which are used for military purposes and developed as biotoxin warfare agents.In this paper,the classification and mechanism of action of biological toxins are discussed.In addition,the strategies for prevention and control of biological toxins as well as their therapeutic applications are reviewed.

OBJECTIVE To study the pharmacokinetics of Esketamine hydrochloride nasal spray in rats and ciliary toxicity to maxillary mucosa of bullfrog. METHODS The plasma concentration of esketamine hydrochloride in rats was determined by LC-MS/ MS after intravenous injection of esketamine hydrochloride solution and nasal administration of esketamine hydrochloride； the pharmacokinetic parameters were calculated by using Phoenix WinNonlin 8.1.0 software. Using the maxillary mucosa of isolated bullfrog as a model， the morphological changes of maxillary mucosa were investigated， and the duration and recovery of ciliary oscillation were recorded after nasal administration of esketamine hydrochloride. RESULTS The peak of blood concentration occurred 2 min after nasal administration of esketamine hydrochloride； cmax was （814.58±418.80） ng/mL， AUC0－∞ was （203.75± 92.76） ng·h/mL， and the absolute bioavailability was 60.68%. After nasal administration of esketamine hydrochloride， it was observed that the cilia of bullfrog were arranged neatly， the edges were clear， the cilia tissue structure was complete and the cilia moved actively. The cilia movement time was （178.17±13.30） min for the first time， and after the cilia moved again， the ciliary movement time measured again was （24.50±9.19）min with a relative movement percentage of 53.56%. CONCLUSIONS Esketamine hydrochloride nasal spray has a rapid onset of action， high bioavailability， and low ciliary toxicity.

OBJECTIVE To evaluate the palatability and chewability of chewable tablets， and provide reference for the quality evaluation of various types of chewable tablets. METHODS Using self-made Glucosamine hydrochloride chewable tablets as the model drug， the quality test was conducted. The in vitro simulation system for chewable tablets was established by using a texture analyzer and rheometer， and an oral simulation experiment was conducted on chewable tablets. The texture analyzer was used to measure the force required for chewing and simulate the static disintegration process of chewable tablets； the rheometer was adopted to measure the viscoelasticity， thixotropy， and deformability of chewable tablets during the chewing process. RESULTS The disintegration time limit， principal component content， and dissolution of self-made Glucosamine hydrochloride chewable tablets all met the limit requirements. The in vitro simulation results of the texture analyzer showed that self-made chewable tablets were easy to chew in both axial and radial directions， and the force required for chewing was within the range of the chewing force of the teeth； chewable tablets could disintegrate at an appropriate time without being chewed and only taken in the oral cavity. The in vitro simulation results of the rheometer showed that the chewable tablets in the oral cavity exhibited a behavior of elasticity as the main factor and viscosity as the secondary factor through the continuous stirring of the tongue， and the viscosity of the chewable tablets gradually decreased with tongue stirring or tooth chewing； when chewing with teeth， the internal force of the chewing tablets decreased， causing plastic deformation and crushing. After being crushed， the shape couldn’t be restored， making it easy to chew and swallow. CONCLUSIONS The combination of texture analyzer and rheometer can be used to simulate the oral chewing process and evaluate the palatability and chewability of self-made Glucosamine hydrochloride chewable tablets. This model can provide reference for the evaluation of various chewable tablets.