In 1851, a Russian doctor from a military hospital in Vladikavkaz carried out the first subcutaneous injection of a dosage form. For injection, a liquid form of the solution was used. Since there were no syringes in the form in which we are used to seeing them today, he used a fragment of a barometric tube with a piston. On the free end was fixed a tip of silver, shaped like a needle. A year later, a syringe developed by a doctor from the Czech Republic - Pravac began to be used for injection.
Definition, benefits of choice
Under the definition of dosage forms for injection, it is customary to understand powder and aqueous sterile, oily solutions, emulsions and suspensions, tablets that must first be dissolved. They are introduced into the body with a syringe, violating the integrity of the skin. If the volume of the solution is very large (more than 100 ml), the drug is administered by infusion, infusion method.
Main benefits of using liquid dosage forms forinjection:
- Instant action (the effect occurs as soon as the solution penetrates the body).
- Dosage forms for injection do not affect the gastrointestinal tract, liver, do not violate the pharmacological action of other drugs (hormones, antibiotics, insulin).
- You can administer the drug to an unconscious person.
- The medicine is mostly tasteless and smellless.
Disadvantages of application
Many people remember the discomfort when they had to give injections. Any damage to the skin causes pain. This is the main reason for refusing treatment with injections. You should not exclude the risk of infection entering the circulatory system, the formation of hematomas, bumps. It is important to resort to this method of administration of the dosage form in a specialized medical institution. This is a well-founded requirement, since one of the undesirable consequences is the entry of air bubbles or solid particles into the body, the risk of contracting HIV and hepatitis.
With the introduction of some medicinal solutions for injection, there may be a burning sensation, sharp pain, and in rare cases, febrile phenomena. Since the drug is rapidly distributed throughout the circulatory system, if the procedure is carried out in a hurry, with a violation of the drug dilution technique, dizziness, a decrease in blood pressure, and even fainting may occur. In an unequipped room, in the absence of qualified personnel, the firstmedical assistance.
Liquid solutions
Drugs can be produced in ampoules or vials, manufactured at specialized factories. To determine the pharmacology of the dosage form for injection, information is applied regarding the name, volume, concentration, date of manufacture and expiration date.
With the help of a medical diluent (eg distilled water, fatty oils, alcohols), a solution can be prepared for later use. Powder dosage forms for injection are diluted with sodium chloride, glucose, novocaine. As a result, the liquid should not contain impurities, the sediment is usually transparent.
Solvents for the preparation of injection material
The use of a liquid is necessary to dissolve the powder form of the drug. The solution is called “Water for injections”, its price is relatively low, you can buy it at any pharmacy chain. During use, they collect water from the ampoule and pour it into the vial with the drug, dilute it so that there are no small lumps left.
When writing a prescription for injectable dosage forms, the doctor usually indicates which diluent will need to be purchased additionally. Non-aqueous oils include oils such as castor, olive, cottonseed, coconut, or peach. It must be deodorized, refined. Due to the fact that the oil is viscous in structure, injections with them are painful, there is a risk of formationgranulomas. Ethyl ether can be used to slightly lower the viscosity.
If the doctor prescribed vitamins of group B in ampoules for injection, then ethyl oleate can be used as a solvent. It has a better ability to dilute the drug, it is more easily absorbed than oily ones. Suitable for hormonal dosage forms. When prescribing vitamins A and D, antibiotics, barbiturates, sulfonamides, alkaloid bases, propylene glycol is used.
Ethanol is chosen as an antiseptic and solvent for injectable preparations of cardiac glycosides (strophanthin K, convallatoxin). In the latter case, glycerin will also do a good job of this role. With it, injections of fetanol, mezaton, dibazol and others are made.
Uses
Depending on which part of the body the injection is made, it is customary to distinguish between the following methods of application:
- Intramuscular.
- Subcutaneous and intradermal.
- Intravascular, intracavitary and intraosseous.
- Under the lining of the brain.
Most of the above is done only by qualified medical personnel in a he althcare facility. Intramuscular, as a rule, many can do at home. Skill, sterility and confidence in one's own actions are important here.
Intramuscular
Prescribing immunomodulatory drugs by a doctor is usually limited to B vitamins. You can buy it in ampoules for injection at anypharmacy. The clear liquid has a yellowish-greenish tint, with a characteristic smell of thiamine. The drug is injected intramuscularly into the femoral, deltoid or gluteal muscle, at an angle of 90 degrees. Some vitamin groups can also be administered intravenously.
For one application, from 1 to 20 ml of solution is injected, in some cases, if there are indications, 50-70 ml. The form of the drug can be any, suspensions for injection, oily, aqueous solutions, emulsions. It should be understood that the absorption process can be slow, so it is recommended to stay at rest for some time after the procedures.
Oil solutions, suspensions, emulsions provide a gradual intake of the drug into the body, creating a kind of "depot". These include hormonal contraceptives, anabolic steroids. This form prolongs the duration of the drug, in some cases for several months. After the procedure, it is necessary to ensure that a post-injection abscess does not form.
In addition to the above drugs, vaccines against influenza, hepatitis A, rabies, morphine, penicillin, prednisolone, codeine and others can be administered intramuscularly. All of them are prescribed by the attending physician and cannot be recommended for self-treatment.
Intradermal and subcutaneous
All injectable dosage forms must be packed in sterile containers. Intradermal injections are introduced into the upper layer of the epidermis, the volume of liquid is 0.2-0.5 ml, for example, Tuberculin. Heknown to many when the Mantoux test is done. In this case, the needle is used with a beveled tip, as a result of the injection of the drug, a bubble forms under the skin, a small seal.
During subcutaneous injections, the needle reaches the subcutaneous fat. The volume of a single drug administered is 1-2 ml. If drip injections are used, then up to 500 ml of the solution can be administered at a time. Subcutaneous, in which an emulsion in a dosage form is used for injection, quickly enters the bloodstream and spreads throughout the body. As a rule, the procedure is carried out in the area of the inner surface of the arm, lower abdomen, thighs.
The most important types of medicines: insulins and heparins. If it is necessary to prolong their action, then oil solutions, emulsions or suspensions are used as a diluent. For which it may be necessary to install a special device that contains a microcapsule of the drug in a dosing grid.
The composition of the solvent for the preparation of dosage forms for injection depends on the rate of its absorption. The slowest it occurs in oil, and water, on the contrary, penetrate the body faster. The main requirement when carrying out this kind of procedure is the possession of a sufficient number of skills. Since there is a high probability of damage to soft tissues, the formation of hematomas. As a rule, when applying a warm and moist compress, the infiltrates quickly resolve.
Intravascular, intracavitary and intraosseous procedures
To intravascularinclude intra-arterial (it can be the brachial, carotid or femoral artery) and intravenous (introduced into the subclavian or ulnar). Phosphate or erythromycin ascorbate is used as a solvent. The solution must be aseptically made, completely sterile. The effect of the introduction of the dosage form is achieved in a matter of seconds.
If we talk about intravascular injections, then a special system for infusion of liquid dosage forms is used for this. Consequences of an incorrect procedure:
- hematoma, which is formed as a result of damage to the vein;
- air embolism (blockage of a blood vessel with air bubbles);
- nerve damage;
- through vein puncture.
It is extremely important to trust the administration of intramuscular injections to qualified medical personnel.
A distinctive feature of intravascular procedures is the use of only water-based solutions. They should not lead to the formation of blood clots, hemolysis of red blood cells, and also not have a detrimental effect on the walls of blood vessels. It is worth buying sterile water for injection, the price is low, moreover, it is sold in a pharmacy near the house.
If the area of application of the drug is in a certain artery, then intra-arterial administration will allow local action on it. Carrying out intracavitary and intraosseous procedures should be carried out in a specialized medical institution, by a qualified specialist.
Under the shell of the brain
This viewused for intracranial and spinal injections. The first method is used with the introduction of a solution of streptomycin in case of meningitis. The dosage form of the solution can only be an aqueous, neutral reaction, the volume of the drug administered at a time is one to two milliliters. The effect of the application is achieved immediately. The procedure can only be performed by a doctor or an experienced nurse in a medical facility.
The second method is often found with the introduction of anesthetics or antibiotics. The solution can only be water-based, have a neutral pH of 5 to 8. The location for the procedure is inside the epidural and subarachnoid space between the 3rd and 4th lumbar vertebrae. The danger of unskilled injection is the risk of damage to the terminal filum of the spinal cord, as a result, paralysis of the legs may occur. Conducted in a medical facility.
Basic application rules
It is important to comply with the requirements for dosage forms for injections, control the date and expiration date of use, temperature during storage. For the procedure, it is necessary to prepare equipment: a syringe with a needle, alcohol wipes, a dilution solution, an ampoule with the drug. It is important to observe the storage conditions for dosage forms and injections in order to prevent the use of a spoiled drug.
Safety is to carry out the procedure with clean hands, preferably treated with alcohol. Before preparing for the injection, it is necessary to choose the right syringe. He is differentvolume, two- and three-component, imported or Russian-made.
The needle is attached to the syringe, the liquid is shaken off the tip of the ampoule, for example, by lightly tapping with a finger. If the ampoule is glass, then along the incision line it must be filed with a special device (as a rule, it comes with the preparation). To protect your fingers, you can wrap it with a gauze napkin and break it at the saw cut. Next, you need to collect the solution from the ampoule and squeeze out excess air with a piston from the syringe.
If the injection is done intravenously, then you will need to pull the arm above the elbow with a tourniquet, and immediately after the end of the procedure, it is weakened. The injection site is treated with an antiseptic. Before injecting the medicine, check whether the needle has entered the vein or not. To do this, pull the piston towards itself until blood appears inside the syringe. If its color is dark, then you can enter the drug. It happens that the location of the veins in the elbow bend does not allow the procedure, and then it may be necessary to administer the drug on the back of the wrist. To avoid the formation of a hematoma, the arm bent at the elbow must be held for 5 minutes.
Intramuscular injections do not require special preparation on the part of the patient. The one who performs the procedure must know in which area to inject. By visually dividing the buttock area into four parts, you can determine the optimal area for manipulation. The best place is considered to be the upper outer square. Thus, it is possible to avoid getting the drug into the sciatic nerve. If you inject yourselfon your own, you can choose the area of the anterior surface of the thigh, however, this is not very convenient.
During an intramuscular injection, the main condition is the gradual introduction and smooth descent of the piston. The optimal length of the needle is no more than 5 cm. This will reduce pain during the procedure and do without post-injection seals. If the drug is injected too quickly, the patient may feel severe pain, the formation of stagnation of the drug is possible and further bumps at the injection site cannot be avoided.
After finishing the manipulations, the work surface must be cleaned. Used vials, syringe, cotton swabs - discard.
