Medical syringes. Diagram of the structure of a disposable syringe - a method for general examination of a patient with fever

A syringe (its name comes from the German spritzen - to splash) is the name of a tool used in technology, cooking and medicine for introducing and removing various liquids or gases using piston pressure.

Medical syringes - instruments used for injections, diagnostic punctures or suction of pathological contents from cavities human body. The principle of its operation is that when the piston is raised and the needle is placed in any vessel containing liquid, a vacuum is created between the surface and the instrument. Since the liquid in the vessel is affected by Atmosphere pressure, she rises into his cavity.

Basically, a syringe is nothing more than a hollow graduated cylinder with an open end (into which a piston and rod are inserted) and a cone at the other end (to which a needle is attached). Modern disposable syringes are made almost entirely of plastic, while some reusable ones are made of metal.

Types of syringes and needles are distinguished depending on their size, purpose, design and number of possible uses.

Let's start by classifying tools by their design.

There are two-component and three-component syringes. What is their difference? We have already described the design of two-component ones above - they consist only of a cylinder and a piston. In three-component ones, a third is added to these two parts - a plunger.

Let us explain what it is and what it is needed for. A couple of decades ago, doctors noticed that the pain of an injection depends not only on how sharp the needle is in the syringe, but also on the smooth movement of the piston in it. The thing is that the nurse, when giving an injection, makes a noticeable effort to “push” the piston inside the cylinder. Because of this, the entire syringe moves, and so does the needle located in the human tissue. Actually, this is the cause of pain.

Now let's move directly to the plunger. This is the usual one that is attached to the piston for its smoother movement along the syringe cylinder. Thus, the person giving the injection puts less force on the syringe and painful sensations almost disappear.

Currently, both types are used in medicine.

Let's also consider the classification of syringes by number of uses. As you know, on this basis they are divided into disposable and reusable.

Disposable syringes (SHOP - single use syringes)

They became widespread in the early 80s. They are almost entirely made of plastic, with the exception of the needle - it is made of stainless steel. For a single administration of drugs, a syringe tube (or syrette) is sometimes also used.

Most often, medical disposable syringes are types of injection syringes. Let's take a closer look at them.

Regular disposable syringe

Regular disposable syringes (types whose sizes we'll look at later) are commonly used to administer a variety of injections. Its operating principle and structure have already been described above.

There are types of disposable syringes with the following volumes: 2 ml, 3 ml, 5 ml, 10 ml, 20 ml and 50 ml. There are also some non-standard types, for example, a small insulin syringe or a Janet syringe with a volume of 150 ml.

Insulin syringes

These are types of syringes used to inject insulin into the patient's body. The volume of such a syringe is 1 ml. It has a thin and fairly short needle, which makes the administration of the medicine painless. Due to the fact that this medicine is almost always self-administered by patients, this fact is very important.

All types of insulin syringes are marked not only in milliliters, but also in units (units by which insulin is dosed). In all drugs existing today, 1 ml contains 100 units - no more, no less.

These syringes also have a special piston shape that ensures maximum precision when administering the medicine. A standard insulin syringe is marked in increments of 1 unit, a children's syringe is marked in 0.5 or 0.25 unit increments.

Previously, 40-unit syringes were also used, but this moment they have practically gone out of use.

To administer insulin, a syringe pen is also often used, since it is easier to do with it. We will consider these types of syringes in more detail later.

Even though the insulin syringe is considered disposable, it can be used several times until the needle wears out.

Syringe Janet

Of all types of medical syringes, this is the largest. Its capacity is 150 ml. The Janet syringe is most often used for washing the cavities of the human body or sucking out liquids, but it can also be used for other purposes. For example, it is sometimes used when administering enemas. Can be used for intra-abdominal, intravenous or intratracheal infusions for which a conventional syringe would be too small.

If you watched “Prisoner of the Caucasus,” then you must remember the scene in which Byvaloy is given sleeping pills using that same Zhanet syringe. You have to understand that this is just a movie, and real life Janet's syringe is not used for such purposes.

Self-locking syringes

Types of disposable syringes that were designed specifically for regular large-scale population immunization programs or for any other injections in large volumes.

Their peculiarity is that reuse of such a syringe is impossible and is mechanically excluded. They are designed in such a way that after the first use the piston is blocked and the syringe can only be thrown away. This is their main advantage over all other disposable types, which can actually be used more than once.

Syringe tube

Medical syringes intended for one-time administration of any drug. Such varieties are usually found in every paramedic's first aid kit. They are completely sterile and already contain the required dose of medication in a sealed container.

The types of syringes, photos of which you will find under the description, do not end with disposable syringes.

Now let's look at reusable models and their varieties.

Reusable syringes

It seemed that in modern world There's simply no room for something as unreliable as reusable syringes. But no, some types are often used and are completely safe.

Regular reusable syringes

Reusable glass syringes first appeared back in 1857 and they looked almost the same as modern ones. The idea of creating a glass syringe belongs to the glass blower Fournier. At the end of the 19th century, a French company bought his idea and immediately introduced glass syringes into practice. It was from that moment that solid reusable syringes became the property of mankind. Even then they were produced in various sizes, from 2 to 100 ml. The syringe of that time had a graduated glass cylinder ending in a cone. There was a piston inside the cylinder. This structure was sterilized by boiling. The glass was thermally resistant and could withstand temperatures up to 200 degrees.

This model was replaced in 1906 by a syringe of the “Record” type, which had a metal needle, a glass cylinder embedded in metal rings on both sides, and a metal piston with rubber rings for sealing.

Sterilized syringes were usually stored in thick paper Brown. It was called “craft package”. Reusable needles were included with the syringe. At the time of using these instruments, the injection procedure was indeed very painful, since reusable needles became dull very quickly due to repeated boiling. Before the process itself, the syringes were cleaned with a special wire - a “mandrel”. Pharmacies of that time sold special containers designed for storing instruments.

It’s probably not worth talking about the possibility of transfer various infections using syringes like these.

Fortunately, such designs are no longer used today. Our generation of reusable syringes includes the following types:

Syringe pen

This type of syringe has already been mentioned in the article. With its help, people with diabetes introduce insulin into the body.

This syringe got its name because of its apparent resemblance to a fountain pen. It consists of several parts: the body itself, the cartridge (or with a dose of insulin), a removable needle that fits onto the tip of the cartridge, a piston trigger mechanism, a case and a cap.

Just like an insulin syringe, a pen syringe has a very thin needle to make the procedure less painful. With this device, the procedures become almost invisible, which means a lot for people who inject several times a day.

The difference between this device and an insulin syringe is that the operation is less labor intensive and more convenient.

The dosing mechanism of the pen syringe accurately allows you to administer the desired dose of medication. It is advisable to recharge the cartridge once every few days. It only takes a few seconds to change the insulin cartridge.

Some pen syringe models have a removable needle, in which case it must be changed at least once a week. In models where the needle cannot be replaced, it must be sterilized.

The syringe pen is widely used all over the world.

Carpule syringes

Despite the fact that in modern medicine Disposable carpule syringes are increasingly being used; we still classify them in the “reusable” section.

The carpule syringe is an injection syringe and is mainly used in dentistry. Yes, yes, it is with the help of this metal device with an ampoule and a tiny needle that we are given anesthesia during dental treatment.

Sometimes it is also used to introduce other medicines.

In 2010, the AERS-MED company patented the first disposable ones. Every year they are only gaining popularity, gradually displacing their predecessors.

Syringe gun

A miracle device for those who are absolutely afraid of injections. It is also called the Kalashnikov syringe, but not because of its similarity with the same machine gun, but because of the name of the person who invented it. The entire mechanism was invented for quick and painless administration of the medicine and is designed for independent use. Everything is very simple: install a 5 ml syringe (pre-filled with medicine) into the device, bring it to the skin and press the trigger.

It is very important that the volume of the syringe used is exactly 5 ml, then it will hold tightly and will not fall out during the process.

The inventor indicates that his mechanism makes the procedure painless and absolutely safe, that is, the needle will hit the target exactly and will not damage anything.

Syringe dart

Types of syringes that are most often used in veterinary medicine. With their help, sick animals are injected with anesthetics or any medications.

Also, this type of syringe is used when hunting wild animals, or when a large animal needs to be euthanized for a while.

There are special veterinary guns; instead of cartridges, they shoot darts containing sleeping pills.

Syringes: types, length of needles for syringes

As you already understand, this article is not only about syringes. The types of syringes and needles for them are closely interrelated. There are two types of medical needles - injection and surgical. We are only interested in the first ones, intended for the introduction or removal of any liquid into/from the body(s). They are hollow inside, and their most important property is absolute sterility.

Hollow needles are classified by point type and caliber. There are 5 main types of points: AS, 2, 3, 4, 5. We will not consider each separately, let us only clarify that in medicine, type 4 needles are most often used, with a point beveled by 10-12 degrees. There are 23 types of needles by caliber, from 33 gauge to 10 gauge. Any can be used in medicine.

Below is a small compatibility table. Syringes (types by volume) are indicated in the left column, and the corresponding needles for them are in the right.

Syringe volume used	Matching needle
Insulin, 1 ml	10 x 0.45 or 0.40 mm






Syringe Janet, 150 ml

We looked at medical syringes and the needles that are used with them. Without a doubt, an entire article could also be devoted to other types of tools, but in this one we will not focus on them.

Parenteral route of administration medicinal substances.

Injection route of administration medicinal substances - bypassing digestive tract, through injections (from lat. inectio.- injection)

Parenteral administration medications:

Provides rapid entry into the blood when oral administration is not possible;
Preferably in the case of decomposition of substances in the gastrointestinal tract intestinal tract or difficult absorption.

Variety of routes of administration:

· In fabric – leather, subcutaneous tissue, muscle, bone;

· Into vessels - veins, arteries, lymphatic vessels;

· In the cavity – abdominal, pleural, cardiac, articular;

· In the subarachnoid space - under the meninges.

Application benefits:

Fast action - use in emergency care;

Dosage accuracy;

Independence from the patient's condition.

Disadvantages of this method:

Possibility of complications;

Risk of infection.

Medicines are injected into the tissue with a needle using a syringe. Performing injections requires mandatory professional competence.

Syringe - consists of main parts: a cylinder with a scale, a needle cone, a piston with a rod and a handle

Exist different kinds syringes:

· syringe "Record" "with a metal piston,

· luer syringe " - all glass,

· combination syringe - glass, but with a metal needle cone. Syringes and syringe plungers of the same brand are interchangeable.

· disposable syringes made of plastic in sterile, sealed, factory-made packaging. The disposable syringe has become an integral element of a nurse’s work in our country. Many years of experience in using disposable syringes gives reason to consider them not only the simplest injection device for administering a drug or collecting biological fluids, but also a tool for ensuring the safety of the patient and nurse

· Syringe tubes - sterile single-use syringes, already filled with medications.

· Syringe Janet with a capacity of 100 and 200 ml is used for rinsing cavities.

A - reusable and disposable syringes, B - syringe tube.

The syringe must be intact, without cracks, with a well-fitting piston, then it will maintain a seal. Checking the syringe for leaks is carried out as follows: close the cylinder cone with the second or third finger of the left hand (in which the syringe is held), and with the right hand move the piston down and then release it. If the piston quickly returns to its original position, the syringe is sealed

The capacity of the injection syringe is 1, 2, 5, 10 and 20 ml.

The capacity of the syringe must be selected depending on the amount of solution that needs to be injected. The needle is used depending on the injection site, the amount and nature of the solution:

For intradermal- syringe with a capacity of 1 ml - tuberculin, needle 15 mm long and

with a diameter of 0.4 mm.

For subcutaneous- a syringe 1-2 ml, less often 5 ml and a needle 20 mm long and 0.4-0.6 mm in diameter.

For intramuscular- syringe 1-10 ml, needle 60-80 mm long, 0.8 mm in diameter.

For intravenous- syringe 10-20 ml, needle 40 mm long, 0.8 mm in diameter.

In order to correctly draw a dose of medicine into a syringe, you need to know the “price” of dividing the syringe. The “price” of a division is the amount of solution between the two nearest divisions of the cylinder. In order to determine the “price” of the division, you should find the number on the cylinder closest to the needle cone indicating the number of milliliters, then determine the number of divisions on the cylinder between this number and the needle cone and divide the found figure by the number of divisions. For example: on the barrel of a syringe with a capacity of 20 ml, the number closest to the needle cone is 10. The number of divisions between the cone and the number 10 is 5. Dividing 10 by 5, we get 2 ml. The “price” of dividing this syringe is 2 ml.

Syringes available special purpose, which, with a small capacity, have a narrowed and elongated cylinder, due to which divisions corresponding to 0.01 and 0.02 ml can be applied at a large distance from each other. This allows for more precise dosage when administering potent drugs - insulin, vaccines, serums.

You need to hold the syringe like this: the cylinder is clamped between fingers I and III–IV, the second finger holds the needle coupling, and the fifth finger holds the handle or piston rod (or vice versa).

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The syringe has a long history from the invention of Hippocrates to three-component disposable designs. Today, the types of syringes and needles are quite varied and the choice depends on what exactly they are used for.

History of the syringe

The first types of syringes were created in antiquity. Thus, Hippocrates used bladder pigs, and the first reusable syringes, which became somewhat widespread at the end of the Middle Ages, were made of rubber. The first injection devices, similar to modern ones, were invented by the scientist Blaise Pascal, but then the novelty went unnoticed. Around the same time, the German scientist Elsholtz conducted his experiments on injections. The first injection devices similar to modern ones appeared in the 19th century, and disposable versions of the device appeared in the mid-20th century. The inventor, Murdoch, was a veterinarian and patented his creation in New Zealand. Through short term he came up with the idea of using a new product for subcutaneous and intravenous injections not only in cows, but also in people. The first disposable syringes were not very perfect, because they consisted of only two components: a piston and a cylinder. Several decades ago, the idea arose to create a three-component syringe. All current types of disposable syringes can be divided into several categories: cylinder volume, position of the cone-tip, needle fastening and design.

Volume

The volume of a syringe can be small, standard or large.

Small-volume syringes include types such as insulin, tuberculin, for neonatology and for skin tests for allergies, as well as for vaccination.
Standard volume syringes are needed for subcutaneous injections, intramuscular injections and intravenous injections. Standard devices include all devices with a volume from 2 mm to 22.
A large volume is needed for procedures such as lavage of the cavity, suction of fluids and administration nutrient media. Large ones include devices with a volume of 30 ml, 60 and 100.

Cone tip

Concentric tip position. In this case, the cone is located right in the middle of the cylinder. This arrangement is typical for syringes that are used for injections under the skin and into muscles.

An eccentric or offset position is needed for a syringe with a volume of 20 ml. , which is used to draw blood from a vein. Their tip is located in the side of the cylinder.

Needle attachment

There are three types of fastening of needles to cylinders: non-removable (integrated), luer-type fastening of needles and luer-lock fastening.

Integrated into the cylinder or non-removable fastening of needles is found in syringes with the smallest volume: 0.3 or 0.5 ml.
Luer type needle fastening. The most popular type of fastening of needles is in which they are put on a cylinder, or more precisely, its protruding part. This is a standard needle mount for devices with different volumes - from 2 ml. up to 100. Sometimes it happens with millimeter syringes.
"Luer-lock." This is a fastening in which the needle is screwed into the cylinder. Typically, luer lock occurs in machine-driven syringes and droppers. Sometimes they are used for simple injections, but this is not very convenient, because changing such a needle and then disassembling the syringe is not so easy. But if you need a particularly strong connection between needles and syringes, then Luer-lock is quite suitable.

And there are many varieties of injection needles. They are divided by size, there are infusion, puncture-biopsy and transinfusion. They are also divided into normal ones, with a bead, a stop and a side hole. You can also divide them into curved and straight, and also according to the shape of the sharpening: it can be spear-shaped or dagger-shaped.

Design

There are two-component and three-component injection devices.

The two-component one consists of only a piston and cylinder and is considered obsolete, and it can also make the injection painful. It can be mobile in the hands medical worker, and this affects the mobility of the needle, and therefore the pain of the injection.

Three-component ones are considered modern, the design of which also includes a seal on the rubber piston. It makes the device operate smoothly and softly, and also ensures that no particles of the materials from which the piston and cylinder are made will get under the patient’s skin.

And most importantly, three-component syringes make injections completely painless, because “picking with a needle” in the muscles and subcutaneous tissue is eliminated.

Expiration dates of syringes

The shelf life of disposable syringes does not vary much depending on the volume or whether the syringe is a three-part or two-part syringe. But still, the shelf life depends on the type of sterilization. She also has different types, but depending on the type of this procedure, the shelf life of the device can vary from three years to five. During this period, the syringe should not lose all its properties and remain non-toxic and sterile. When the shelf life has expired, the device can be used for injections, but only if the syringes have been stored far from sun rays: in this case, a disposable syringe still does not pose a danger. If the shelf life exceeds ten years, all the materials in it age and all its properties deteriorate. In addition, such a long shelf life with poor quality packaging can cause bacteria to penetrate into the syringe.

Disinfection of disposable syringes - processing rules Syringe pen for insulin with a removable needle - how to choose? Medical syringes: dimensions and other characteristics Syringe pen Novopen 4 - injector for insulin administration
Needles for insulin syringe pens, device features and applications

Therapy diabetes mellitus involves carrying out a number of activities aimed at maintaining glycemia within normal limits.

To achieve this goal, some patients have to not only follow a diet, but also take special drugs or inject subcutaneously necessary for the body amount of insulin. Thanks to special syringes, hormone injections can be performed quickly and painlessly.

What is an insulin syringe?

Insulin therapy requires the mandatory use of special medical devices and supplies.

Most often, insulin syringes are used to administer medication. They are similar in appearance to regular medical devices, since they contain a body, a special piston, and a needle.

What products are there:

glass;
plastic.

The disadvantage of a glass product is the need to regularly count the number of units of the drug, so it is now used less often. The plastic version ensures that injections are performed in the required proportion. The drug is completely consumed, leaving no residue inside the body. Any of the listed syringes can be used several times, provided they are constantly treated with an antiseptic and used by one patient.

Plastic products are available in several versions. You can buy them at almost every pharmacy.

Needle volume and length

Insulin syringes can have different volumes, which determine the amount of insulin they hold, and the length of the needle. Each model has a scale and special divisions that help you determine how many milliliters of medicine you can put into the body.

According to established standards, 1 ml of medicine is equal to 40 units/ml. This medical device marked u40. Some countries use insulins containing 100 units in each ml of solution. To perform injections with such hormones, you will need to purchase special syringes engraved u100. Before using the instruments, it is necessary to additionally determine the concentration of the administered drug.

The presence of pain at the time of injection of the drug depends on the selected insulin needle. The medicine is delivered by subcutaneous injection into the fatty tissue. Its accidental entry into the muscles contributes to the development of hypoglycemia, so you need to choose the right needle. Its thickness is selected taking into account the area on the body where the medicine will be injected.

Types of needles depending on length:

short (4-5 mm);
medium (6-8 mm);
long (over 8 mm).

The optimal length is considered to be 5-6 mm. Using needles with such parameters prevents the drug from entering the muscles, eliminating the risk of complications.

Types of syringes

The patient may not have medical skills, but he can easily inject the drug. To do this, it is enough to choose the most convenient version of the insulin product. The use of syringes that are suitable for the patient in all respects allows the injection to be given completely painlessly, and also provides the necessary control over the dosage of the hormone.

There are several types of instruments:

with a removable needle or integrated;
syringe pens.

With replaceable needles

Such devices differ from other similar devices in the ability to remove the nozzles together with the needle at the time of drawing the medicine. The piston in the product moves smoothly and gently along the body, reducing the risk of errors.

This feature is an important advantage, since even a slight error in dosage can lead to negative consequences. Products that allow for changing needles minimize the risk of complications during insulin therapy.

The most common disposable instruments have a volume of 1 ml and are designed to collect 40-80 units of the drug.

Syringes with an integrated or replaceable needle are practically no different from each other. The only difference between them is that the needle is soldered into the product, which does not have the ability to change the piercing nozzle.

Advantages of syringes with built-in components:

safer, since they do not lose drops of the drug and ensure that the patient receives the selected dosage in full;
have no dead zone.

The remaining characteristics, including divisions and scale on the case, are identical to those of other medical products.

Syringe pen

A medical instrument that includes an automatic piston is called a syringe pen. The product can be either plastic or glass. The first option is the most common among patients.

Composition of the syringe pen:

frame;
a cartridge filled with medicine;
dispenser;
needle cap and protection;
rubber compressor;
indicator (digital);
button for administering medication;
pen cap.

The advantages of such devices:

painless puncture;
ease of operation;
no need to change the concentration of the drug, since special cartridges are used;
a cartridge with medicine lasts for a long period;
have a detailed scale for selecting dosage;
It is possible to adjust the puncture depth.

Flaws:

the injector cannot be repaired if a malfunction occurs;
it is difficult to choose a suitable cartridge with medicine;
high price.

Divisions

The graduation on the product corresponds to the concentration of the drug. The markings on the body indicate a certain number of units of medicine. For example, in injections intended for u40 concentration, 0.5 milliliters corresponds to 20 units.

Using improperly labeled products may result in an incorrectly administered dose of the drug. For the right choice the volume of the hormone is provided with a special distinctive sign. u40 products have a red cap, while u100 instruments have an orange cap.

Insulin pens also have their own graduations. Injectors are used with hormones whose concentration is 100 units. The accuracy of dosages depends on the length of the step between divisions: the smaller it is, the more accurately the amount of insulin will be determined.

How to use?

Before performing the procedure, you should prepare all the instruments and a bottle of medicine.

If it is necessary to simultaneously administer hormones with long-acting and short-acting effects, you need to:

Introduce air into the container with the drug (extended).
Perform a similar procedure using short-acting insulin.
Draw up medicine with a syringe short acting, and then only extended.

Rules for administering the drug:

Wipe the medicine bottle with an alcohol wipe. If you need to enter a large number of, then the insulin must first be shaken until a homogeneous suspension is obtained.
Place the needle in the bottle, then pull the piston to the desired division.
There should be a little more solution in the syringe than needed.
If bubbles appear, the solution should be shaken and the air should be squeezed out with a piston.
Wipe the injection area with an antiseptic.
Make a fold in the skin, then inject.
After each injection, the needles must be changed if they are replaceable.
If the length of the piercer exceeds 8 mm, then the injection must be performed at an angle to avoid getting into the muscle.

The photo shows how to properly administer the medicine:

How to calculate insulin?

To administer the drug correctly, you must be able to calculate its dosage. The amount of insulin a patient needs depends on the glycemic level. The dosage cannot be the same all the time, as it depends on XE ( grain units). It is important for the patient to learn to calculate the need for insulin, since it is impossible to understand differently how many ml of medication will be needed to compensate for the carbohydrates eaten.

Each division on the injector is a graduation of the drug corresponding to a specific volume of solution. If the patient received 40 units, then using a solution of 100 units, he will need to administer 2.5 units/ml on u100 products (100:40 = 2.5).

Calculation rule table:

Video material on calculating the required doses of insulin:

How to use the pen?

The use of a syringe pen is as follows:

Install a new disposable needle on the product.
Determine the dose of the drug.
Scroll the scale until the desired number appears on the scale.
Perform the injection by pressing the button located on top of the handle (after the puncture).

Video instructions for using a syringe pen:

Cost and selection rules

People who regularly carry out insulin therapy know how much the materials necessary for this cost.

Approximate cost per piece:

from 130 rubles for product u100;
from 150 rubles for product u40;
about 2000 rubles for a syringe pen.

The indicated prices apply only to imported devices. The cost of domestic (one-time use) is approximately 4-12 rubles.

There are standards that should be considered when selecting insulin therapy products.

These include:

The length of the needle depends on the age of the patient. It is recommended to use needles with a length of 5 mm for small children, and up to 12 for adults.
Obese people should use products that puncture to a depth of 8 mm or more.
Cheap products have lower quality and reliability.
Not all syringe pens can easily find replacement cartridges, so when purchasing them, you should find out in advance information about the availability of consumables necessary for injections.

It is important to understand that the effectiveness of insulin therapy depends on the injection tool chosen by the patient.

Today, sterile products are widely represented on the domestic pharmaceutical market. medical purposes. Manufacturers are constantly improving and expanding their range. A special place among them is occupied by disposable injection syringes. This is primarily determined by their use as medical specialists to help patients with severe pathological processes, and people far from medicine to help themselves or their loved ones and acquaintances.

According to their structure, syringes are divided into two large groups:

· two-component (cylinder and piston);
· three-component (cylinder, piston and plunger, i.e. piston tip (seal).

Depending on the volume they are:

· small volume (0.3, 0.5 and 1 ml). Used for precise insertion medicine in endocrinology (insulin syringes), phthisiology (tuberculin syringes), neonatology, as well as for vaccination and conducting allergy intradermal tests;
· standard volume (2, 3, 5, 10 and 20 ml). Used in all branches of medicine to perform subcutaneous, intramuscular, intravenous and other types of injections;
· large volume (30, 50, 60 and 100 ml). Used for suctioning pus, fluid, etc., introducing nutrient media, and washing cavities.

Based on the type of connection of the needle to the cylinder cone, they are distinguished:

· Luer-type connector, which prevents the syringe from being disconnected from the needle;
· Luer-Lock type connector, in which the needle is screwed into the syringe;
· a syringe with a non-removable needle integrated into the cylinder body.

It should be noted that today the domestic pharmaceutical market offers a wide range of disposable injection syringes, both domestic and foreign.

The universal design of a conventional OP syringe is shown in Fig. 1. The syringe consists of a cylinder and a piston rod (collapsible or non-collapsible). The cylinder has a cone tip of the “Luer” type (Record syringes can be produced upon request, they are practically not produced), a finger rest (a) and a graduated scale (b). The rod-piston assembly consists of a rod (c) with a stop (d), a piston (e) with a seal (f) and a reference line (g).

Depending on the structure of the piston rod, the designs of OP syringes are divided (Fig. 2) into 2-component (a) and 3-component (b). In 2-component syringes, the rod and piston are a single unit; in 3-component syringes, the rod and piston are separate. The main functional difference between the named designs is the characteristics of lightness and smooth movement of the piston.

OP syringes can be coaxial (a) and eccentric (b), which is determined by the position of the cone tip (Fig. 3).

The capacity of syringes is determined by their purpose and ranges (GOST) from 1 to 50 ml (reduction and increase are allowed); ISO --< 2 -- ? 50 мл (диапазон объемов не устанавливается). Практически диапазон объемов ИШ ОП колеблется от 0,3 до 60 мл. Шприцы объемом 0,3; 0,5 и 1,0 мл используют для точного введения лекарственных препаратов (туберкулина, инсулина, стандартных экстрактов аллергенов) в малых объемах -- от 0,01 мл (рис. 4).

The materials from which OP syringes are made depend on their design, purpose and sterilization method. Materials must be compatible with injectable drugs. Determining compatibility with specific drug is the task of pharmaceutical manufacturers. For this purpose, the materials most commonly used for the production of OP syringes are tested for compatibility. Product compatibility with injection solutions and solvents included in the list of pharmacopoeial drugs recommended for testing are determined by health authorities. In case of revealed incompatibility of the syringe materials with any injectable substance, the consumer packaging must contain an appropriate warning, for example: “do not use with paraldehyde.” Methods for determining compatibility are constantly being improved and remain a relevant area of quality control for injection tools, which is what the ISO technical committee draws attention to “ Medical supplies for injection."

For the manufacture of cylinders, mainly certain types of polypropylene, polystyrene and styrene-acrylonitrile copolymer that meet pharmacopoeial requirements are recommended. Pistons are made from high-quality natural (natural rubber) and artificial (silicone rubber) rubber. High-density polyethylene is used for rods and seals of non-separable piston rods.

For better sliding, the rubber piston is coated with polydimethylsiloxane lubricant. The force that ensures the movement of the syringe piston? 2 ml, in this case below the 10 N set by ISO. The venous pressure created when a tourniquet is applied can practically move the rod of a high-quality syringe with a rubber piston. The piston of a high-quality syringe with a 3-component design slides without jerking. These qualities are of great importance when it is necessary to perform slow jet infusions, precise dosing of drugs in anesthesiology, intensive care. The stated advantages of 3-component syringes are determined by the manufacturer.

It should be noted that currently, high-quality 2-component syringes, thanks to amide additives and sterilization with ethylene oxide, are not much inferior to 3-component syringes in terms of smoothness of piston movement.

The achieved smoothness and relative ease of movement of the piston gives 2-component syringes some advantage due to the absence of natural rubber (usually black) containing latex, which, according to some data, can cause allergic reactions. The last statement in relation to standard IS is not indisputable. Nevertheless, most reputable manufacturers have in their assortment syringes with latex-free (milky white) and sometimes silicone-free pistons.

sterile medicinal injection syringe