TWI807858B - Device and method of importing drug into tissue based on electrochemical iontophoresis - Google Patents

Abstract

The present invention discloses a device and a method of importing drug into tissue based on electrochemical iontophoresis with generating direct current, a waveform of which has gradually changing potential pulses in a shape of step mixed with square wave, for applying electrochemical iontophoresis method. One of two electrodes electrically connects to a patch containing drugs and a power supply providing the direct current, and the other one of the electrodes electrically connects to a sample of biological tissue and the power supply to import the drugs into the sample of the tissue.

Description

Drug iontophoresis device and method thereof

The present invention relates to iontophoresis devices and methods, and more particularly to drug iontophoresis devices and methods for facilitating the penetration of drugs into biological tissue samples based on electrochemical iontophoresis.

Oral cancer is one of the top ten causes of cancer death. The current treatment methods are mainly surgery, radiation therapy and chemotherapy. For example, oral squamous cell carcinoma (OSCC) is a malignant tumor, accounting for more than 90% of all oral cancers. Surgical resection of the affected part is the most commonly used treatment. However, if the resection is too extensive, it is likely to cause damage to the appearance and function of the patient, so it is often used in conjunction with chemotherapy drugs. However, most chemotherapy drugs are used in high doses to kill cancer cells, which can easily cause serious side effects, including nephrotoxicity, severe nausea and vomiting, bone marrow suppression, ototoxicity and neurotoxicity. The most significant and common toxicity in clinical practice is nephrotoxicity. Therefore, how to reduce the dose of chemotherapy drugs and reduce the degree of side effects under the premise of maintaining drug efficacy is still an urgent research goal.

An object of the present invention is to provide a drug iontophoresis device and method, which provides a direct current for the implementation of electrochemical iontophoresis, promotes the penetration of drugs into biological tissue samples, and preferably uses Nanocarriers to overcome drug solubility or stability issues and reduce drug dosage to minimize drug-induced side effects.

According to one aspect of the present invention, the present invention discloses a drug iontophoresis device, comprising: a power supply and two electrodes. The power supply provides a direct current for performing electrochemical iontophoresis. The waveform of the direct current is a stepped pulse wave and is accompanied by a square wave pulse potential that gradually increases or decreases in oscillation. One electrode is electrically connected to a patch and the power supply, and the patch contains medicine, and the other electrode is electrically connected to a biological tissue sample and the power supply, so as to promote the medicine in the patch to penetrate into the biological tissue sample.

According to another aspect of the present invention, the present invention discloses a drug iontophoresis method, comprising: providing a direct current for performing electrochemical iontophoresis, and electrically connecting one of the two electrodes to a patch containing a drug and the power source, and the other electrode is electrically connected to a biological tissue sample and the power source, so as to promote the drug in the patch to penetrate into the biological tissue sample, wherein the waveform of the direct current is a step-like pulse wave accompanied by a square wave pulse potential that gradually oscillates to increase or decrease.

100: Drug iontophoresis device

110: power supply

120: electrode

130: platinum foil

140: Patch

150: Biological tissue samples

S1, S2, S3, S4: steps

FIG. 1 shows a drug iontophoresis device according to an example of the present invention, which is suitable for applying the drug iontophoresis method as shown in FIG. 2 .

FIG. 2 shows a drug iontophoresis method according to an embodiment of the present invention.

FIG. 3 shows a schematic diagram of a waveform of a direct current according to an embodiment of the present invention.

FIG. 4 shows the coating ratios of drug nanoparticles at different nanocarrier:coating molecular mass ratios according to an embodiment of the present invention.

FIG. 5 shows the experimental results of the drug concentration of the biological tissue samples in each experimental group and control group.

FIG. 6 shows a table of parameter settings for each experimental group in FIG. 5 .

In order to further illustrate the various embodiments and their advantages, the present invention provides the following descriptions in conjunction with the drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the manual to explain the operating principles of the embodiments. With reference to these contents, those skilled in the art should understand other possible implementations and advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to denote similar components. As disclosed herein, "embodiment", "example" and "the present embodiment" do not specifically refer to a single embodiment, but may refer to examples implemented in different combinations according to the present invention, without departing from the spirit and scope of the present invention. The terms used herein are only used to illustrate specific embodiments of the principle of the present invention, and should not limit the present invention. Therefore, if "in" can include "within" and "above", "a" and "the" can include singular or plural; "borrow" can refer to "from", and "if" can refer to "when" or "once". In addition, "and/or" may include any possible combination of related elements.

The present specification discloses several examples of drug iontophoresis devices and methods thereof. Please refer to FIG. 1 to FIG. 3, wherein FIG. 1 shows a drug iontophoresis device according to an example of the present invention, which is suitable for applying the drug iontophoresis method shown in FIG. Please note that the drug iontophoresis device in this embodiment is only an example of many systems applying the drug iontophoresis method, and the drug iontophoresis method of the present invention is not limited thereto. The drug iontophoresis device 100 includes a power source 110 and two electrodes 120 electrically connected to the positive and negative electrodes of the power source 110 . When step S3 of the drug iontophoresis method is implemented, the electrochemical ion can be provided by the power supply 110 of the drug iontophoresis device 100 The direct current of the induction method, the waveform of this direct current is a step-like pulse wave and accompanied by a square wave pulse potential that gradually increases or decreases in oscillation, as shown in Figure 3. Depending on the electrical property of the drug to be driven is positive or negative, the direct current can be positive or negative, and accompanied by a corresponding square-wave pulse potential that gradually increases or decreases in oscillation. The electrochemical iontophoresis method can be a differential pulse method, such as differential pulse voltammetry (DPV), which uses the difference between current points for data calculation. The first point is generally taken before the pulse, and the second point is taken at the current about 40ms after the pulse. After subtraction, it is the displayed single-point current value. When step S4 of the drug iontophoresis method is implemented, the electrochemical iontophoresis method can be implemented by the drug iontophoresis device 100. An electrode 120 is electrically connected to a patch 140 and a power supply 110. In this example, the electrode 120 connected to the positive pole of the power supply 110 is electrically connected to the patch 140 through the platinum foil 130. The patch contains medicine, which is cisplatin in this example; a biological tissue sample 150 is electrically connected to the power supply 110 with another electrode 120. In this example, the electrode 120 connected to the negative pole of the power supply 110 is electrically connected to the biological tissue sample 150 through the platinum foil 130 . In this example, the biological tissue sample 150 is pig skin. The patch 140 is suitable for close contact with the biological tissue sample 150. Therefore, through the aforementioned electrical connection, the direct current of the power source 110 can be applied between the patch 140 and the biological tissue sample 150, so as to promote the medicine in the patch 140 to penetrate into the biological tissue sample 150. Before steps S3 and S4, the drug iontophoresis method may optionally additionally include steps S1 and S2, details of which will be introduced in subsequent paragraphs.

In this embodiment, as shown in FIG. 3 , the DC current can be a differential pulse waveform, and multiple parameters can be set, such as: cycle number, initial voltage value Ei, upper limit voltage value Ev, number of applied pulses (steps), voltage drop range _PH of each pulse, duration P _W of maintaining the voltage value of each pulse, required voltage value _SH for applying a pulse, time required for applying a pulse _ST and other parameters. Preferably, the number of cycles can be between 1~300, the initial voltage value Ei can be between -3~3V, the upper limit voltage value Ev can be between -0.5~-5V or 0.5~5V, the number of applied pulses can be between 2-2000, the voltage drop range _PH of each pulse can be between 2~1000mV, and the duration _PW of each pulse can be between 50~100000mS. _SH can be between 2~1500mV, and the time _ST required to apply a pulse wave can be between 100~25000mS. More preferably, after multiple experiments, it can be obtained that when the initial voltage value Ei is between -0.5~-2V, the upper limit voltage value Ev can be between -0.5~-5V, the number of cycles is between 5~75, and the power supply continues to provide DC current to the electrode 120 for 0.5 to 4 hours; 4 hours; in this way, a more excellent introduction effect can be obtained, for example, the drug between 5-7 μg/mL can penetrate into the biological tissue sample 150 .

As shown in FIG. 5 , the drug iontophoresis device 100 is used to implement the electrochemical iontophoresis method according to the drug iontophoresis method. The experimental results of the drug concentration of the biological tissue samples in each experimental group (labeled variable voltage (differential pulse voltammetry, DPV) group) and each control group (labeled passive osmosis group/chronoamperometry group/variable current group). The parameters of the nine experimental groups are set according to the table shown in FIG. 6 . The control group-chronopotentiometry (CP) group was divided into three groups, which were treated with 0.75mA for two hours, 1.5mA for two hours, and 3mA for two hours. For the CP group, only the best group is shown in Figure 5: the experimental results of the control group-chronoamperometry group acted on at 1.5mA for two hours. In the control group—passive infiltration group, no electric current was applied, only magnets were placed on both sides of the patch 140 and the biological tissue sample 150, and stirred at 500 rpm for two hours.

In order to understand whether reducing _PH is helpful for electrotransport, a DPV 10 cycle, PH _/ 2,2h (variable voltage group) group was designed, and _PH was halved, but the results showed no significant difference. In order to understand the influence of voltage changes, Ei was set to 0V, and the DPV 10 cycles, _PH /2,2h (variable voltage group) group was compared with the DPV 10 cycles, 2h (variable voltage group). After testing the drug content in the biological tissue sample 150 of the experimental results, it was found that the percentage of drug content did increase. In order to understand the effect of increasing the voltage application time on the conduction efficiency, the ratio of voltage application and rest during the DPV period of the other groups was designed, that is, the on/off ratio was 1:1, and the different DPV 10 cycles, on/off=3:1, 2h (variable voltage group) group had an on/off ratio of 3:1, and no significant difference was found. In order to understand whether providing Ei is helpful for electroconduction, three groups of DPV 18 cycles, Ei=0V, 2h (variable voltage group), DPV 34 cycles, Ei=1.0V, 2h (variable voltage group) and DPV 63 cycles, Ei=1.5V, 2h (variable voltage group) were designed. It was found that the drug content in biological tissue sample 150 increased significantly with the increase of Ei value. Therefore, it is preferable to adjust the setting of Ei to obtain a better drug electrotransport effect.

As shown in FIG. 5 , after the last group of experimental groups implemented a drug iontophoresis method with a cycle number of 63 times and an initial voltage value Ei of 1.5V, the power supply continuously provided DC current to the electrode 120 for two hours, and then the best introduction effect of this embodiment could be obtained: the drug between 6.74±0.18 μg/mL was infiltrated into the biological tissue sample 150 .

Here is an optional additional step S1 included in the drug iontophoresis method: in the following examples, the nanocarrier is chitosan, the drug is cisplatin, and the coating molecule is sodium tripolyphosphate, but the present invention is not limited thereto. Prepare chitosan/cisplatin nanoparticles, use cisplatin as drug, and coat it in chitosan nanocarriers. Chitosan/cisplatin nanoparticles can have a size of 1-1000nm, and its structure can better retain the drug inside and release the drug slowly. It is suitable for drug delivery applications, can overcome the solubility or stability of the drug, and minimize the side effects caused by the drug. Chitosan is prepared by deacetylation of chitin. The reason for choosing chitosan as the nanocarrier here is that chitin is the second most abundant natural biopolymer, which is convenient to obtain, and chitosan has good biocompatibility, degradability, low cytotoxicity, and is positively charged. Since the electrochemical iontophoresis method needs to enhance the delivery of drugs on biological tissues through electrorepulsion and electroosmosis, and biological tissues are negatively charged, chitin Glycans have cationic permeability to facilitate drug introduction into biological tissues, so as to reduce the dose of drugs. When the biological tissue is cancerous tissue, such as oral cancer biological tissue, good drug introduction can be expected to reduce the lesion area and improve the specificity of the drug to the cancerous tissue.

In step S1, sodium tripolyphosphate (TPP) is used as a cross-linking agent, and the TPP solution is added dropwise into the chitosan solution to form chitosan nanocarriers. The reason for using TPP here is to take advantage of its dissociation into anions during the ionic gelation process, so that the electrostatic interaction between chitosan chains and TPP molecules can be established to spontaneously form nanocarriers, and the process does not require the use of organic solvents. Please refer to Figure 4, which shows the coating ratio of drug nanoparticles in different chitosan nanocarriers: TPP mass ratios according to an embodiment of the present invention. It can be seen that the coating ratio tends to increase as the mass ratio increases. The coverage ratio is optimal at a mass ratio of 15:1, and begins to decrease when the mass ratio is 20:1. However, considering the drug release effect, the group with a mass ratio of 15:1 released a drug concentration of 0.009 mg/mL within 24 hours, accounting for about 26.16% of the drug amount coated on the drug nanoparticles, and reached the final release of 100% drug amount on the 35th day, and the final release concentration reached 0.033 mg/mL, which was the best among the four groups. Therefore, preferably, the mass ratio of chitosan nanocarriers: TPP can be adjusted to obtain better drug coating rate and drug release effect. The mass ratios of chitosan nanocarriers: TPP in the experimental group provided here are all 15:1.

The steps for preparing chitosan/cisplatin nanoparticles in detail are: 1. Prepare 1% acetic acid to dissolve chitosan; 2. Prepare 1.5mg/mL chitosan solution with 1% acetic acid, and addmum filter material to filter out impurities; 3. Prepare a cisplatin solution with a concentration of 1.25 mg/mL with deionized water; 4. Prepare a 0.5 mg/mL TPP solution with deionized water, and filter out impurities with a filter material; 5. Take 4 mL of the prepared cisplatin solution and add it to 40 mL of chitosan solution, stir with a magnet at 600 rpm for one minute; 6. Add 200muL Tween80, stir with a magnet at 600rpm for five minutes; 7. Shake with an ultrasonic probe at an amplitude of 6 (about 33W) for five minutes to mix cisplatin and chitosan evenly; 8. Use 1N NaOH to adjust the pH of the mixed solution to 4.6~4.8; Drug nanoparticles; 10. Centrifuge the mixture at 12000 rpm for 60 minutes at 20° C. to obtain drug nanoparticles.

Here is an optional additional step S2 of the drug iontophoresis method: mixing chitosan/cisplatin nanoparticles with thermosensitive hydrogel to form a patch 140 . Thermosensitive hydrogel is suitable as an injectable drug delivery system because it can undergo phase transition at body temperature (about 37 °C), and can release drugs continuously in the target area to maximize the drug effect. Since chemically cross-linked N-isopropylacrylamide (NIPAAm) can excrete liquid at close to human body temperature, has good biocompatibility, and is not cytotoxic, the thermosensitive hydrogel used here is NIPAAm, which has a lower critical solution temperature or transition temperature of about 32 °C. Add 1.358g Poly(N-isopropylacrylamide) to 20mL deionized water, stir until completely dissolved, then add 0.0264g ammonium persulfate (APS), stir until completely dissolved to prepare a thermosensitive hydrogel capable of phase transition at 32°C.

From the above, it can be known that the drug iontophoresis device and method of the present invention provide a direct current for performing electrochemical iontophoresis, thereby promoting the penetration of drugs into biological tissue samples, and preferably using nanocarriers to overcome the solubility or stability of drugs, and reduce the dosage of drugs to minimize the side effects caused by drugs.

The above description is based on multiple different embodiments of the present invention, wherein each feature can be implemented singly or in different combinations. Therefore, the disclosure of the embodiments of the present invention is a specific example to illustrate the principles of the present invention, and should not be limited to the disclosed embodiments of the present invention. Furthermore, the foregoing descriptions and accompanying drawings are merely illustrative of the present invention and are not intended to limit it. Changes or combinations of other elements are possible without departing from the spirit and scope of the present invention.

100: Drug iontophoresis device

110: power supply

120: electrode

130: platinum foil

140: Patch

150: Biological tissue samples

Claims (12)

A drug iontophoresis device, comprising: a power supply, which provides a direct current for electrochemical iontophoresis, the waveform of the direct current is a stepped pulse wave accompanied by a square wave pulse potential that gradually oscillates up or down; and two electrodes, one of which is electrically connected to a patch and the power supply, the patch contains medicine, and the other electrode is electrically connected to a biological tissue sample and the power supply, so as to promote the drug on the patch to penetrate into the biological tissue sample. The drug iontophoresis device as claimed in item 1, wherein the direct current is set by a parameter of an initial voltage value Ei, and the initial voltage value Ei is between -3~3V. The drug iontophoresis device as described in claim 2, wherein the parameter setting of the direct current further includes the number of cycles and the upper limit voltage value Ev, when the initial voltage value Ei is between 0.5~2V, the number of cycles is between 1~300, the upper limit voltage value Ev is between 0.5~5V, and the power supply continues to provide the direct current to the electrodes for 0.5~4 hours; when the initial voltage value Ei is between -0.5~-2V, the number of cycles is between 1~300, The upper limit voltage value Ev is between -0.5~-5V, and the power supply continuously provides the direct current to the electrodes for 0.5~4 hours. The drug iontophoresis device as _described in claim item 2, wherein the parameters for setting the direct current _also include the number of applied pulses, the voltage drop range PH of each pulse wave, the duration P _W of each pulse wave maintenance voltage value, the required voltage value _SH for applying a pulse wave, and the _required time S _T for applying a pulse _{wave. Between 0~100000mS, the required voltage SH for applying one pulse is between 2~1500mV, and the time S T required} for applying one pulse is between 100~25000mS. The drug iontophoresis device as described in Claim 1, wherein the nano-carrier is chitosan, the coating molecule is sodium tripolyphosphate, the drug is cisplatin, and the drug is coated in the nano-carrier to form drug nanoparticles, which are mixed with thermosensitive hydrogel to form the patch. As for the drug iontophoresis device described in claim 3, one of the two electrodes is electrically connected to a patch containing a drug and the power supply, and the other electrode is electrically connected to a biological tissue sample and the power supply, so as to promote the drug in the patch to penetrate into the biological tissue sample, and the amount of the drug penetrated into the biological tissue sample can be between 5-7 μg/mL. A drug iontophoresis method, comprising: providing a direct current for electrochemical iontophoresis, and electrically connecting one of the two electrodes to a patch containing a drug and the power supply, and the other electrode is electrically connected to a biological tissue sample and the power supply, so as to promote the drug in the patch to penetrate into the biological tissue sample, wherein the waveform of the direct current is a step-like pulse wave and is accompanied by a square wave pulse potential that gradually increases or decreases in oscillation. The drug iontophoresis method as described in Claim 7, further comprising: setting the direct current with a parameter of an initial voltage value Ei, and the initial voltage value Ei is between -3V and 3V. The drug iontophoresis method as described in claim 8, further comprising: setting the direct current with the parameters of the number of cycles and the upper limit voltage value Ev, so that when the initial voltage value Ei is between 0.5~2V, the number of cycles is between 1~300, the upper limit voltage value Ev is between 0.5~5V, and the power supply continues to provide the direct current to the electrodes for 0.5~4 hours; and such that when the initial voltage value Ei is between -0.5~-2V, the number of cycles is between 1~ 300, the upper limit voltage value Ev is between -0.5~-5V, and the power supply continuously provides the direct current to the electrodes for 0.5~4 hours. The drug iontophoresis method as _described in claim 8, which further includes: setting the DC current with parameters such as the number of applied pulses, the voltage drop _PH of each pulse, the duration P _{W of} each pulse maintaining the voltage, the required voltage _SH for applying one _pulse , and the time _ST required for applying a pulse. Between 50~100000mS, the voltage SH required for applying one pulse is between 2~1500mV, and the time S _T required for applying one pulse is between 100~25000mS. The drug iontophoresis method as described in Claim 7, further comprising: using chitosan as a nanocarrier, using sodium tripolyphosphate as a coating molecule, and cisplatin as an example of the drug, coating it in the nanocarrier to form drug nanoparticles, and mixing it with a thermosensitive hydrogel to form the patch. The drug iontophoresis method as described in Claim 9, wherein one of the two electrodes is electrically connected to a patch containing a drug and the power source, and the other electrode is electrically connected to a biological tissue sample and the power source, so as to promote the drug in the patch to penetrate into the biological tissue sample, and the amount of the drug penetrated into the biological tissue sample can be between 5-7 μg/mL.