Effect of Administration Methods on Drug Absorption

EFFECT OF METHODS OF ADMINISTRATION ON DRUG ABSORBATION Practical Objectives Students can get to know,practice and compare methods of drug administrationon absorption speed, using pharmacological data as a benchmark. Students are able to explain the effect of the method of administering drugs to experimental animals on the speed of the drug's effects. Basic theory Medicines are chemical substances (natural or synthetic) other than foods that contain theminfluences or can cause effects on living organisms, both psychological and physiological effectsand biochemical. There are various purposes of treatment, including establishing a diagnosis,prevention (preventive), healing (curative), symptomatic, recovery (rehabilitative)and improving health (promotive) and including contraception.Pharmacology can be defined as the science that studies drug interactionswith living organisms. Drugs are molecules that, if introduced into the body, willinfluences body functions by interacting at the molecular level. The size of the molecules varies, therefore they can penetrate target cellsSo drug molecules must be able to diffuse and pass through the body's cell membranes. Generally drugsis a weak acid or weak base. This has an important role in handlingdrugs by the body that can change the degree of ionization of the compound.The action of a drug is the result of many processes that are based on a seriesThe reaction is divided into three phases: 1. Pharmaceuticals This pharmaceutical phase includes the fabrication process, dosage setting, dosage form formulation,the destruction of the medicinal dosage form and the dissolution of the medicinal substance as determined by the propertiesmedicinal galenic. This phase plays a role in the availability of drugs for absorption into the body(pharmaceutical availability). 2. Pharmacodynamics Science that studies how drugs work, the effects of drugs on various internal functionsorgans, the effect of drugs on chemical reactions and drug structure. In brief,Pharmacodynamics can be interpreted as the effect of a drug on living cells. This phase plays a rolein determining how much effect the drug has in the body. 3. Pharmacokinetics Pharmacokinetics is the study of absorption, distribution, metabolism,and drug excretion or can be interpreted as the body's effect on the drug. In this phaseDrugs undergo ongoing processes of absorption, distribution, metabolism and excretiondirectly or indirectly following the passage of a drug across a cell membrane.This phase plays a role in determining the availability of the drug in plasma (bioavailability)so it can have an effect. This phase includes parts of the invasion and elimination process.Invasionare the processes that take place when a medicinal substance is taken internallyorganism. Meanwhile, elimination are processes that cause a declinedrug concentration in the organism.In the pharmacokinetic phase, the drug undergoes the ADME process (Absorption,Distribution, Metabolism, Excretion): a. Absorption Absorption is the process of moving a drug from the site of administration to the circulationblood which then reaches the target of drug action. Clinically it is the most importantis bioavailability which states the amount of drug in percent that reachessystemic circulation in intact or active form. This happens because on certain drugs,not everything absorbed from the site of administration will reach the systemic circulation.Some will be metabolized by enzymes in the intestinal wall when administered orally or metabolized in the liver in first pass metabolism. Such a drug haslow bioavailability. Absorption is influenced by several factors, namely: i. Physicochemical properties of drugs ii. Drug dosage form iii. Drug dosage iv. Route and method of administration v. Contact time with absorption surface vi. The pH value of the fluid at the absorption site vii. Membrane integrity viii. Blood flow at the site of absorption The amount of drug absorbed is influenced by: 1) Absorption surface area The greater the absorption surface area, the greater the amount of drug absorbedmore and the faster the absorption process takes place, the same happenson the contrary. 2) The number of barrier membranes that are passed The more membrane barriers that are passed, the less drug is availableabsorbed, and vice versa. 3) The amount of drug that is degraded The more drug is degraded, the less drug is absorbed(reduced bioavailability) and vice versa. 4) Number of ties with the depot Drugs that are absorbed by the body are drugs that are in a statefree and not bound to inactive molecules (proteins). Bytherefore, the greater the number of ties to the depot, the less drugwhich is absorbed (reduced bioavailability) and vice versa. b. Distribution Is the transfer of drugs between tissues and plasma. After the drug is absorbed into thebloodstream, the drug will pass through cell membranes to reach the site of action.Most drugs are distributed through body fluids. Drug distributionIt is divided into two phases based on its distribution in the body.First phase: occurs immediately after absorption, namely into the organ good perfusion, for example the heart, liver, kidneys and brain.Second phase: occurs more widely, covering tissue that is not as well perfusedthe above tissues, which include muscle, viscera, skin, and fatty tissue.Factors that influence the distribution of drugs in the body are: i. Perfusion of blood through tissues ii. Gradient levels, pH and bonds of substances with macromolecules iii. Partition into fat iv. Active transport v. Blood barrier vi. Drug binding to plasma proteins c. Metabolism Biotransformation or metabolism is the process of changing the chemical structure of a drugin the body catalyzed by enzymes. In this process there is a change in the form of the drug from non-polar to more polar so that the drug is more easily excreted through the kidneys because it becomes soluble in water and difficult to dissolve in fat. Process This metabolism occurs in the liver, apart from that it also occurs in the kidneys, plasma and membranes intestinal mucus. d. Excretion Drugs are excreted from the body through various excretory organs in the form of metabolites resulting from biotransformation or in their original form. Kidneys are organs the most important expression. Excretion in the kidneys is the resultant of three processes namely, filtration in the glomerulus, active secretion in the proximal tubule and passive reabsorption in the proximal and distal tubules. Apart from occurring in the kidneys, drug excretion also occurs through saliva, tears, sweat, milk and hair