31 results about "Diffusion cell" patented technology

The invention provides pet tear stain eye drops containing haematococcus pluvialis extract, the pH value of the eye drops is 6.8-7.2, the osmotic pressure is 280-320 mOsm / kg, the viscosity is 3-8 mPa.s (25 DEG C), and the eye drops comprise the following components in percentage by mass: 0.05-0.5% of haematococcus pluvialis astaxanthin extract (based on the astaxanthin content being greater than or equal to 5%), 0.05-0.5% of a pH regulator (based on the astaxanthin content being greater than or equal to 5%), and the balance of water. 1%-3% of an anti-inflammatory plant compound; 0.5%-1.2% of an isoosmotic adjusting agent; 0.2%-0.8% of a nano carrier stabilizer; 0.01%-0.1% of a pH buffer agent; compared with the prior art, the invention has the following beneficial effects: the corneal permeability of the astaxanthin is increased to 82% (measured by a Franz diffusion cell) through PLGA coating, and is increased by 5.5 times compared with the corneal permeability of the astaxanthin in a free state (15%); natural tocopherol is reserved through supercritical CO2 extraction (the content of the natural tocopherol is larger than or equal to 0.5% through HPLC detection), and the retention rate of the astaxanthin stored at 40 DEG C for 90 days is larger than or equal to 90% through Calendula quercitrin inhibits the expression of IL-6 (enzyme-linked immunosorbent assay (ELISA) detection is reduced by 76%), and chamomile bisabolol blocks a COX-2 pathway.

The invention discloses an in-vitro release method of a semisolid preparation for a water-containing matrix, and relates to the technical field of in-vitro release, and the in-vitro release method comprises the following steps: S1, assembling an IVRT device which comprises a diffusion instrument, a receiving medium is added into the diffusion instrument, and the receiving medium comprises a salt buffer solution and an organic solvent; s2, controlling experiment conditions; s3, sampling is carried out, and the sampling mode comprises the step that after sampling is carried out each time, a receiving medium with the same volume as the taken sample needs to be added; and S4, analyzing the sample. According to the method, the organic solvent is added into the receiving medium to improve the solubility of the medicine in the in-vitro release test, meanwhile, the sampling mode is improved, the sampling mode in the embodiment comprises the steps that after sampling is conducted every time, the receiving medium with the same volume as the taken-out sample needs to be added, a diffusion pool does not need to be inclined in the sampling process, and the uniformity is improved.

The invention discloses a dynamic diffusion cell for oral mucosa drug delivery and a method for simulating oral mucosa drug delivery. The dynamic diffusion cell comprises a sample cell, a receiving cell and a simulation membrane, and the bottom of the sample cell is communicated with the receiving cell through the simulation membrane; one horizontal side of the sample cell is connected with a sample cell inflow pipeline, and the other side is connected with a sample cell outflow pipeline; a receiving pool inflow pipeline is arranged on the upper portion of the side wall of the receiving pool, a receiving pool outflow pipeline is arranged at the bottom of the side wall, and the receiving pool inflow pipeline and the receiving pool outflow pipeline are communicated through a liquid storage bottle and form a circulation flow path with the receiving pool. By increasing the flow mechanism of the sample pool and the receiving pool, the amount of medicine lost due to salivary secretion of oral mucosa delivered medicine is effectively evaluated, the medicine concentration difference between the sample pool and the receiving pool is increased, the real proportion of medicine cross-mucosa absorption and swallowing loss is predicted, and the correlation between an in-vitro penetration test and the in-vivo actual penetration condition is improved.

The utility model relates to the technical field of transdermal testers, and discloses a diffusion cell for a drug transdermal tester, which comprises a base, the rear side of the top of the base is fixedly connected with an outer shell, the left side of the top of the outer shell is fixedly connected with a top shell, the top of the left side of the base is provided with a reaction cell, the top of the reaction cell is fixedly connected with a test plate, and the test plate is fixedly connected with the outer shell. The front side of the interior of the top shell is fixedly connected with a hydraulic press, the bottom of the hydraulic press is fixedly connected with a push rod, the interior of the push rod is fixedly connected with a converter, the bottom of the converter communicates with a plurality of puncture pipes, and the bottoms of the puncture pipes are fixedly connected with an inner three-hole puncture outfit; the outer wall of the inner three-hole puncture outfit is connected with a rebound device in a sliding mode. According to the device, the puncture depth is accurately controlled through the hydraulic press, the suction amount is stably controlled through the self-priming pump, the accuracy of the puncture amount is improved, experimental errors are reduced, and reliable data support is provided for a drug transdermal test.

To provide a shellfish culture device in which oxygen is easily distributed to each shellfish evenly even if a lot of shellfishes are cultured.SOLUTION: A shellfish culture device comprises: a diffusion cell 10 for being arranged near a bottom part in a culture water tank 100 installed on land; a culture cell 20 connected to an upper side of the diffusion cell 10, and for culturing shellfishes S thereinside; a seawater supply pipe 30 for supplying seawater taken from the outside of the culture water tank 100, into the diffusion cell 10; and oxygen amount increasing means 40 for increasing an amount of dissolved oxygen in the seawater in the seawater supply pipe 30. While a side surface part 10a and a bottom surface part 10b of the diffusion cell 10 and a side surface part 20a of the culture cell 20 are made water-impermeable, a connection portion between the diffusion cell 10 and the culture cell 20 is made water-permeable. High-oxygen seawater increased in the amount of dissolved oxygen by the oxygen amount increasing means 40 can be supplied to the shellfishes S in the culture cell 20 after being diffused in the diffusion cell 10.SELECTED DRAWING: Figure 2

This invention provides a diffusion dish for determining soil alkaline nitrogen, relating to the field of laboratory apparatus. It includes: a dish body, a lid, and a stopper assembly; the lid is detachably placed on top of the dish body; the stopper assembly is installed on top of the lid; the dish body includes: a main body, a central chamber, and an inner cavity; the inner cavity is formed by the internal space of the main body; the central chamber is located at the center of the main body; the lid includes: a lid body and an injection hole; the injection hole is located off-center on the lid body and corresponds to the position of the inner cavity; it also includes: a connecting component; the dish body and the lid body are tightly fastened together by the connecting component; the connecting component includes: a positioning groove, an outward-flaring edge, an upper edge, a bent arm, and a lid latch. By designing a multi-seal structure, a seal can be achieved while locking the lid, preventing the entry of ambient air and impurities, and reducing the risk of ammonia diffusion.

The invention belongs to the technical field of pharmaceutical analysis methods, and particularly relates to an in-vitro transdermal test method for fluralab and moxidectin in a fluralab moxidectin drop. According to the method, a Franz diffusion cell device is adopted, SD rat skin is taken as simulated skin, a normal saline solution of polyoxyethylene 20 oil ether is taken as a receiving medium, and a high performance liquid chromatography-ultraviolet visible detector is adopted to detect the contents of the flurala and the moxidectin in the receiving medium, so that the accumulated transdermal amount of the flurala and the moxidectin is calculated. The in-vitro transdermal test method disclosed by the invention is simple, rapid, easy to operate and high in universality.

The invention relates to the field of analytical chemistry, in particular to a method for determining the content of LL37 in an LL37-coated ZPF-2 compound and a gel thereof by adopting a high performance liquid chromatography, carrying out an in-vitro release test on the LL37-coated ZPF-2 compound gel by adopting a vertical diffusion cell method, and then determining the release amount of the LL37 at each time point by adopting the high performance liquid chromatography, so as to obtain the in-vitro release rate. According to the content detection method disclosed by the invention, the content of LL37 in the LL37-coated ZPF-2 compound and the gel thereof is measured by adopting a high performance liquid chromatography through exploration of specific detection conditions and repeated test screening, and the method is simple to operate, high in specificity and high in sensitivity, has good precision and durability, and can be used for detecting the content of LL37 in the LL37-coated ZPF-2 compound and the gel thereof. Meanwhile, by changing different adding sequences of water and a citric acid-sodium citrate buffer solution, the problem of inaccurate detection result caused by different dissolution rates of LL37 and LL37 ZPF-2 compounds in the same solvent system is solved.

The invention relates to a fusidic acid cream in-vitro release analysis method, which relates to the technical field of medicine, and comprises the following steps: taking a fusidic acid cream sample to be detected, smearing the fusidic acid cream sample on a filter membrane, placing the filter membrane on a transdermal instrument, enabling a sample-free layer of the filter membrane to face downwards and face a receiving pool, carrying out closed-loop sample loading, adding a receiving medium into the receiving pool, and operating according to a method set by the transdermal instrument, and taking the receiving liquid in the receiving pool at different times for detection. According to the in-vitro release method, a vertical diffusion cell is selected, a cellulose acetate membrane is selected as a filter membrane, and a phosphate buffer solution containing an organic solvent is selected as a receiving medium, so that the release rate and degree of fusidic acid from a matrix can be accurately evaluated, the quality of fusidic acid cream can be controlled, the performance of a preparation can be evaluated, and the safety of a product can be improved. The method can quickly evaluate the drug performance, and is low in cost, short in period, green and environment-friendly.

The present application relates to a kind of transdermal migration devices, including the receiving pool for containing human body fluid, adsorption phase, link cover, diffusion membrane, sealing element, diffusion cell for placing sample and top cover;Adsorption phase is placed in receiving pool;Link cover is recessed, hollow in the middle, and the upper and lower ends are respectively detachably connected to diffusion cell and receiving pool;Diffusion membrane is laid in the recess of link cover and is fixed by diffusion cell, and the upper and lower surfaces of diffusion membrane are respectively closely attached to sample in diffusion cell and human body fluid in receiving pool;Link cover is provided with air hole, for connecting receiving pool and ambient air, and sealing element is detachably blocked in air hole;Top cover covers the top of diffusion cell.The device is set through diffusion membrane, so that sample is only contacted with human body fluid through membrane surface, and realizes that chemical substance in sample is unidirectional migration to human body fluid;The position of diffusion membrane is fixed by the design of link cover, and it is convenient to place and replace adsorption phase.The device is simple to operate, and can resist environmental background anti-interference.

The invention discloses a self-powered process and device for reducing nitrate to produce ammonia and crystallizing magnesium ammonium phosphate. The device mainly comprises an internal reaction module (a diffusion chamber, a positive electrode chamber and a negative electrode chamber) and an external crystallization module (a raw material pool, a diffusion pool and a crystallization pool). The device is of a primary battery structure, NO3 <-> is subjected to catalytic reduction in the positive electrode chamber to generate NH4 < + >, the NH4 < + > is converted into NH3 gas under the alkaline condition, the NH3 gas enters the diffusion chamber through the composite positive electrode membrane assembly, and the NH4 < + > is re-protonated in the acid environment. A negative electrode Mg sheet in the negative electrode chamber is spontaneously oxidized in the acidic electrolyte to release Mg < 2 + > and supply electrons to drive nitric acid reduction reaction, so that a closed circuit is formed; nH < 4 + > and Mg < 2 + > are conveyed to a negative electrode tank, enter a crystallization tank through a cation exchange membrane and are combined with PO4 < 3-> in the crystallization tank to generate MgNH4PO4 precipitates, so that nitrogen, phosphorus and magnesium resources are synergistically recycled. The process device can realize the unification of energy self-supply, reaction separation and product high value under the condition of no external power supply, and has wide application potential.

The invention relates to a model construction method and application for testing toxicity of environmental pollutants to primary arterial smooth muscle cells-endothelial cells. The method comprises the following steps: uniformly mixing primary arterial smooth muscle cells and a BD-Matrigel matrigel solution by adopting a convection type double-channel microchip, filling a cell culture channel with the mixture, filling a single-cell suspension of the primary arterial endothelial cells, constructing a primary arterial smooth muscle cell-endothelial cell in-vitro layered co-culture model, and after the model is intervened by environmental pollutants, establishing a primary arterial smooth muscle cell-endothelial cell in-vitro layered co-culture model. Collecting liquid in the diffusion pool and detecting the secretion level of the liquid; and observing the state and dynamic change of the gap junction channel formed by the smooth muscle cell-endothelial cell and the expression condition of the gap junction protein by using a laser confocal microscope. The construction of the model provides a new target for occurrence and development of arterial vascular remodeling and functional lesions caused by environmental exposure of harmful substances and drug prevention and treatment.

The application discloses a kind of calcitriol soft capsule content in vitro evaluation method and its application, belong to the technical field of pharmaceutical analysis.The method uses diffusion cell device, under certain conditions, the dissolution and penetration behavior of calcitriol soft capsule content is simulated and determined.Specifically, acidic or buffered salt medium solution containing specific proportion alcohol is added to diffusion cell, so that liquid surface is flush with filter membrane;The sample to be measured content is placed above filter membrane;At specified temperature, rotation speed, sample is taken from the lower part of diffusion cell at different time points, and the concentration of calcitriol is determined.The method of the application can accurately and conveniently evaluate the in vitro release behavior of calcitriol soft capsule content prepared by different prescriptions or processes, has high correlation degree with in vivo effectiveness, and has good repeatability, to provide reliable in vitro evaluation tool for product quality control and prescription screening.

This invention relates to a staggered covalent organic framework thin film, its preparation method, and its application, belonging to the field of thin film technology. The invention first dissolves an amine monomer in acetic acid solution to obtain an aqueous solution; then dissolves an aldehyde monomer in mesitylene to obtain an organic solution; finally, the aqueous and organic solutions are added to the aqueous and organic phase chambers of a diffusion cell, respectively, for interfacial polymerization. After the reaction, the membrane material is removed, washed, and dried to obtain the staggered covalent organic framework thin film. This film forms a staggered stacked structure and constructs sub-nanometer transport channels with pore sizes of approximately 0.5 nm to 0.7 nm. Through a synergistic mechanism of Donnan repulsion and hydrogen bonding interactions, it maintains structural stability under extreme environments of high acidity, strong corrosion, and high radiation, achieving highly efficient selective permeation of protons and efficient retention of metal ions in high-level radioactive waste liquids.

The invention relates to an in-vitro transdermal test method of a ketoprofen gel patch, which specifically comprises the following steps: (1) removing an anti-sticking film on the ketoprofen gel patch, sticking the ketoprofen gel patch on the surface of pigskin, and carrying out a transdermal test in a Franz diffusion cell; (2) adding the pigskin subjected to the transdermal test into a potassium hydroxide solution, soaking at the temperature of 45-85 DEG C, homogenizing under the condition of 5000-7000 rpm after soaking, adding methanol into the obtained suspension for diluting, centrifuging, taking the supernate for filtering, and taking the subsequent filtrate as a test solution for the intradermal retention transdermal test; and (3) determining the intradermal retention volume of the test solution or calculating the material balance by adopting a high performance liquid chromatography method. By adopting the method to treat the pigskin, the pigskin is easy to smash in the homogenate treatment process, the main component ketoprofen is easy to extract, and the retention volume in the skin can be accurately measured.

The invention relates to the technical field of diffusion, dissolution and absorption related parameter measurement, and discloses an interference type liquid phase diffusion parameter measurement system and measurement method.The interference type liquid core column lens is formed by combining two opposite meniscus column lenses, a partition plate is arranged between the two meniscus column lenses, and a reference cell and a diffusion cell are obtained; the interference type liquid core column lens is used for imaging an incident light beam onto the imaging system, the imaging system is used for acquiring an interference image, and the interference image comprises a plurality of interference fringes and a reference intersection point when a dispersion image and a reference image interfere with each other; the control device is used for analyzing each frame of interference image, determining the refractive index of the target interference fringes in combination with the number of the interference fringes, the reference points and the like, determining the concentration according to the fitted functional relationship between the refractive index and the concentration, and further measuring the liquid phase diffusion parameters; the measurement precision is improved, and the measurement application scene is expanded.

Disclosed herein a carbon-dioxide selective gas membrane supporting a metal-doped laser-induced graphene conductive layer. The membrane may be used for electrocatalytic reduction of carbon dioxide using gas diffusion cells.

The invention discloses a COFs (Covalent Organic Frameworks) forward osmosis membrane constructed by electrostatic spinning-based double-acid concerted catalysis and water treatment application of the COFs forward osmosis membrane. The preparation method of the COFs forward osmosis membrane comprises the following steps: firstly, dissolving polyacrylonitrile in DMF (Dimethyl Formamide), and carrying out electrostatic spinning, hot pressing and hydrolysis treatment to prepare an HPAN substrate with a three-dimensional network structure; then dissolving trialdehyde phloroglucinol in an organic phase containing a fatty acid synergistic regulator and a Bronsted acid catalyst, dissolving 2, 5-diaminobenzene sulfonic acid in a water phase, fixing the substrate in a diffusion pool according to a specific orientation, and growing an ultrathin and compact COFs separation layer with controllable thickness through double-acid synergistic catalysis oil-water interface polymerization reaction. The COFs forward osmosis membrane prepared by the invention has good structural integrity, high water flux and pollutant interception performance, and can maintain stable operation. The COFs forward osmosis membrane is used for efficient treatment and resource utilization of antibiotic micropollutant wastewater.

The present application provides a high skin permeation effect truffle vesicle-nicotinamide composition, which uses natural nanovesicles extracted from truffles as carriers, and encapsulates hydrophobic drug nicotinamide by ultrasonic method to form truffle vesicle-nicotinamide composition. The preparation method comprises the steps of extraction and purification of truffle vesicles, ultrasonic drug loading with nicotinamide, and ultrafiltration purification. The composition is characterized by transmission electron microscopy, and the particle size is uniform, about 30-200 nm, and the encapsulation efficiency can reach more than 75%. In vitro Franz diffusion cell experiment shows that the composition can significantly enhance the skin permeability of nicotinamide, and can promote the accumulation of drugs in the epidermis and dermis. The composition has the natural biological activity of truffle and the pharmacological efficacy of nicotinamide, and can be used for preparing transdermal preparations with the effects of whitening, anti-aging, repair, etc., and has a wide application prospect in the field of cosmetics and skin local administration.

The application belongs to the technical field of membrane separation, and particularly relates to a composite membrane and a preparation method and device thereof, which comprises the following steps: S1, a macroporous neutral charge base membrane is selected, a supporting substrate is used to support the base membrane, and the base membrane is assembled into a polytetrafluoroethylene diffusion cell to divide the diffusion cell into two independent chambers; S2, a ligand solution is prepared and injected, and a metal organic framework precursor solution is prepared according to a 1:1 molar ratio; metal organic framework materials with sub-nanometer channels are synthesized in-situ in membrane holes through diffusion effects of two specific ligands in the membrane holes, and the membrane holes of the base membrane are filled with the materials to prepare a high-performance composite membrane, the synthesis process of the membrane material avoids inevitable surface charges and defects of the metal organic framework materials in a traditional membrane preparation method, the mechanical strength of the composite membrane is improved by introducing a polymer base, and the sub-nanometer channels of the neutral charge metal organic framework materials are used for lithium-magnesium separation.

The utility model relates to the technical field of diffusion pools, and discloses a detachable diffusion pool for a drug transdermal tester, which comprises a fixed seat, a lower receiving pool is arranged in the middle of the inner wall of the fixed seat, a threaded groove is arranged at the top end of the lower receiving pool, a threaded groove II is arranged at the top of the inner wall of the lower receiving pool, and a threaded groove II is arranged in the threaded groove II. A circular plate is fixedly connected to the outer wall of the threaded groove, an upper receiving tank is arranged at the top of the outer wall of the lower receiving tank, a threaded block is fixedly connected to the bottom end of the upper receiving tank, the outer wall of the threaded block is in threaded connection with the inner wall of the second threaded groove, and a fixing sleeve is slidably connected to the bottom of the outer wall of the upper receiving tank; first fixing columns are slidably connected to the left side and the right side of the inner wall of the fixing sleeve. According to the utility model, during butt joint, the threaded block at the bottom end of the upper receiving tank is matched with the threaded groove II of the lower receiving tank to finish preliminary connection, and the fixed sleeve is sleeved on the outer wall of the upper receiving tank, and the fixed column I on the inner wall of the fixed sleeve can rotate in the circular plate.

The invention provides an adjustable diffusion cell for dynamic gas distribution through a diffusion method, and relates to the technical field of standard gas preparation, the adjustable diffusion cell comprises a liquid storage tank and at least two diffusion pipes communicated with a gas phase space of the liquid storage tank, the liquid storage tank is provided with a sample adding port, and the outlet end of the top of each diffusion pipe is provided with a sealing cover. The diffusion pipes on the liquid storage tank are configured to be different in length or inner diameter, and stepped diffusivity adjustment is achieved by opening different diffusion pipe combinations.

The utility model relates to the technical field of diffusion cell test equipment, and discloses a diffusion cell for a transdermal absorption test, which comprises a sample adding bin, a sample receiving bin and a sample receiving bin, one end of the receiving tank is connected with the sample adding bin, the receiving tank is provided with a cavity which is coaxial and communicated with the through hole, and the cavity is suitable for storing normal saline; the plurality of sampling pipes are arranged on the peripheral side of the receiving tank and are communicated with the cavity. According to the utility model, the plurality of sampling pipes communicated with the inner cavity of the receiving tank are arranged on the peripheral side of the receiving tank, so that the inner cavity of the receiving tank can be always communicated with the external atmosphere, and the cavity is prevented from forming a closed space in a liquid taking or liquid supplementing process, so that the convenience of liquid taking or liquid supplementing operation can be improved, and the working efficiency is improved. The liquid taking amount and the liquid supplementing amount can be more accurately controlled, and the accuracy and the reliability of test data are improved.

The invention discloses a dynamic calibration method of a gas telemetering system, which comprises the following steps: opening a gas inlet valve, and closing the gas inlet valve when an adjusted pressure threshold value is reached; opening a gas outlet valve to enable the target mixed gas to enter a diffusion cell for diffusion; an incident light beam enters the diffusion cell; the gas telemetering system receives the light intensity signals, and different gas detection modules determine measurement data of different gases based on the light intensity signals; under the condition that the intensity of the light intensity signal is greater than the expected intensity, performing alignment operation on the measured data based on the detection frequencies of different gas detection modules to generate a synchronous data set; and determining the detection concentrations of different gases in the target mixed gas according to the data in the synchronous data set and the combustion equation, and performing linear fitting according to the detection concentrations of different gases and the reference concentrations of different gases in the target mixed gas introduced into the dynamic calibration device so as to calibrate the gas telemetry system. According to the invention, the calibration deviation in the calibration process can be avoided, the accurate calibration of the telemetering system is realized, and the applicability of the dynamic calibration device is improved.

The invention provides an in-vitro release test method for desonide ointment. The in-vitro release test method comprises the following steps: (1) releasing a desonide component in the desonide ointment by using an in-vitro transdermal instrument; (2) determining through high performance liquid chromatography; and (3) calculating the release amount of the desonide ointment by using a standard curve method. The step (1) is specifically as follows: a test device is based on a Franz diffusion cell method; a proper inert and commercialized artificial film is installed in the Franz diffusion cell system; setting in-vitro release test parameters; and testing an in-vitro release test of the model medicine.

The application discloses a dynamic calibration method of a gas remote sensing system, comprising the following steps: opening an inlet valve, and closing the inlet valve when reaching an adjusted pressure threshold; opening an outlet valve, and making target mixed gas enter a diffusion cell for diffusion; making an incident light beam enter the diffusion cell; receiving a light intensity signal by the gas remote sensing system, and determining measurement data of different gases based on the light intensity signal by different gas detection modules; in the case that the light intensity signal is greater than an expected intensity, performing an alignment operation on the measurement data based on a detection frequency of the different gas detection modules to generate a synchronous data set; determining detection concentrations of the different gases in the target mixed gas according to data in the synchronous data set and a combustion equation, and performing linear fitting according to the detection concentrations of the different gases and reference concentrations of the different gases in the target mixed gas input into the dynamic calibration device to calibrate the gas remote sensing system. The application can avoid calibration deviation in the calibration process, realize accurate calibration of the remote sensing system, and improve the applicability of the dynamic calibration device.

The present application relates to experimental equipment technical field, disclose a kind of real-time monitoring drug interfacial diffusion device and its detection method, by the two same frequency same direction stirring device of independent design, in diffusion cell it constructs an ideal mass transfer model, phase concentration is uniform, interfacial stability is stable, make the concentration change of drug in phase only reflect the interfacial diffusion process of drug.And by real-time monitoring the absorbance change in phase obtains the concentration change information of drug, to obtain the interfacial diffusion rate of drug per unit area in real time accurately.The present application includes a kind of real-time monitoring drug interfacial diffusion method and device, can accurately reflect the dynamic process of molecular diffusion at liquid-liquid interface, thereby has extensive application value.

The invention discloses an in-vitro release test method of diazepam rectum gel, which comprises the following steps: preparing a test solution: smearing the diazepam rectum gel on an artificial membrane, placing the artificial membrane on an automatic transdermal diffusion instrument, carrying out a release experiment, and collecting a solution in a diffusion cell as the test solution according to a sampling time point; a proper amount of a diazepam reference substance is weighed, a methanol solution is added to prepare a reference substance stock solution with the concentration being 1 mg / mL, and the reference substance stock solution is diluted to prepare a reference substance solution with the concentration being 0.1 mg / mL; and testing the test solution and the reference solution by adopting a high performance liquid chromatography. The in-vitro release method provided by the invention has good discrimination, linearity, precision and durability. By comparing the release amounts of the diazepam self-developed preparation and the reference preparation, the consistent release rate of each batch of the self-developed preparation and the reference preparation is ensured, so that the quality of the self-developed preparation is ensured.

The present invention relates to improved methods for characterising diffusion of compounds through the skin using open flow micro-perfusion (OFM) in conjunction with Diffusion Cell apparatus, particularly static Franz Diffusion cell (FDC). The methods are in vitro methods using ex vivo skin explants.

Automated Diffusion Cell System for Drug Release Study.