Drug Absorption - Aspirin

Note: Due to incompetent teacher, I have no idea if this is good or bad. Assume it's bad.

Drug absorption

Although there is no precise definition of what a drug is, as there are many, saying that a drug is a substance which alters the biological functioning of the body shouldn't be wrong. Drug absorption is the movement of a drug into the blood stream, which is necessary if the drug is to have any effect on the body. In order to reach the blood stream, the drug has to be taken into the body. The way of getting the drug into the body is decided by the drugs solubility and the desired effect.

For instance, some drugs, such as injections of synthetic hormones used as birth control, should let the drug slowly into the blood-stream, so that the effect will last a long time, usually one or three months. The original solubility of the drug is likely to allow all of the hormones to get into the blood stream quicker, but this would neither be healthy nor useful. Therefore, the manufacturers of the drug use either a miniature implant or a depot injection. Depot injections are placed in the outer layer of the skin, as they are fat soluble, and allow the drug to enter the blood stream through the fat in the body slowly. If all of the hormones in the injection entered the bloodstream closer to instantaneously, the effect of the drug would be completely different. Instead of being a method of contraception, the high amount of hormones could be used as a method of abortion during early pregnancy, although using depot injections for this purpose is far from recommended.

Epinephrine, or adrenaline in layman words, is also a hormone found naturally in the body. Adrenaline is used to treat anaphylaxis, among other things. Anaphylaxis is an allergic reaction in the body which can be caused by many different allergens, and can result in death in severe cases, if not treated properly. The reaction can be caused by, but isn't limited to, food, insect stings and some drugs. Due to the many possible causes and symptoms which might occur, anaphylaxis is hard to diagnose. Once it's been recognised as anaphylaxis, "Adrenaline injected by an auto-injector into the anterolateral aspect of the thigh is the gold standard of care [...]" In other words, as adrenaline is water soluble, injecting it into a muscle in the thigh with an auto-injector (a prepared single dose which is easy to use, usually 0,3mg for adults) is the best treatment for anaphylaxis.

The solubility of Aspirin

Acetylsalicylic acid, commonly known as Aspirin (a trademarked product), is a drug used to relieve minor aches and pains. As it has a blood-thinning effect, it can also be used in low doses to prevent heart attacks and blood clots in people who are at risk of suffering these things. Coincidentally, one of the possible side effects of Aspirin is anaphylaxis.

My main interest about the solubility of Aspirin (I will refer to pure acetylsalicylic acid as Aspirin, although the product contains other inactive ingredients which alter its abilities) is whether it is water soluble or not. I assume that if it's not water soluble, it has to be oil soluble, or else I can't see how our body can absorb it. I would also like to know how the solubility changes at different temperatures of the solvent. A simple conclusion I could draw from observing it is that it is solid at room temperature. Another simple thing that's easy to find out is that Aspirin is heavier than water: just drop a piece of it in and it'll sink. By a little cheating I know that Aspirin has a density of 1.4g/cmÑ- and that it is solid up to at least a temperature of 138oC.

Step one is to find out whether Aspirin is fat or water soluble. I'd fill two beakers (small/medium sized) with any oil (fat which is in liquid form at room temperature) found in the kitchen, as long as it is clear (as in easy to see through), and then fill two beakers with water. I'd either use 20ml or 50ml of fluid in all beakers, depending on the size of the beaker. Most important is that the bottom of the beaker should be covered properly, and that the amount of fluid should allow easy stirring.

Step two is to add the Aspirin. I'd use a set amount, most likely 2g. If it matters, 2g of Aspirin is half of a high daily dosage, which means it shouldn't be unreasonably expensive. In one of the beakers filled with water, I'd add the Aspirin as one whole unit. In the other one, I would crush it to powder first. The same with the beakers filled with oil: crushed Aspirin in one of them, and whole in the other one. I would add Aspirin to the beakers one by one, so that they can all get the same treatment at the same stage: adding the Aspirin first, waiting for one minute to see if it will dissolve by itself, then stir for one minute afterwards, or until