The Life Cycle of Pharmaceuticals - Essay Example

?THE LIFE CYCLE OF PHARMACEUTICALS I am a bulk shipment of a drug precursor arriving at a manufacturing plant. In my current raw form, I am not a medicine, but I do have pharmacological properties. In the coming hours and days, I will be converted from bulk raw materials into a pharmaceutical product that might save someone's life. At the end of this process, I could become either a tablet or a suspension formulation of a consumer drug product, and I will be released into the market for consumption. There will be binding agents, fillers, and lubricants added to me to make tablets, and a liquid media and other agents mixed with me to create a suspension formulation. Of course, there are many other formulations that I could become as a drug: powder, gel capsules, even nasal spray. But the most common types are the tablet and suspension forms. All of the equipment I come into contact with between now and when I am ingested by a patient must be clean and sterile. I must be sealed away from outside contact, so that I do not become contaminated with debris, bacteria, or other microscopic particles. Every canister, tank, mixer, pipe, hose, and bottle has to be sterilized completely. Many of the items I will come in contact with have been steam-sterilized, because using clean steam prevents me from being contaminated by the cleaning products themselves. I am pumped from a delivery vehicle into a tank to be stored at the manufacturing site. The tank I am in is only one of many in the tank farm at this pharmaceutical plant. In order to assure safety, the tanks are sterilized before I am pumped into them through an airtight transfer pump. After a period of storage, I am then pumped from the storage tanks into a make-up and boot tank, and then from there into a reactor tank to start the manufacturing process. The plant keeps very careful track of the arrival times of all the ingredients for their products, including me, in order to ensure that nothing is stored too long. They also have to keep track of the temperature and humidity of the storage areas, because some ingredients cannot be exposed to temperatures that are too high or too low, and some cannot be exposed to humid air in case they react with the oxygen. Some chemicals must even be kept away from contact with the oxygen in the air, because they will oxidize and change form. At the start of the manufacturing process, I am weighed with great precision, as are the excipients that will make up the tablets or suspension with me. The weights of the various ingredients will depend on batch size and dosage amount, and all of the weights are recorded for quality assurance. Each of the ingredients are all weighed individually in separate sterile canisters because having the right amounts of each ingredient is vital to the properties of the final product. The reactor mixes us together in the right proportions, according to the size of the batch and the dosage amount of the final product. Depending on my properties and the properties of the other ingredients in my mixture, the next steps will vary. If I and the other active and inactive ingredients are dry powder that can be mixed together smoothly, we can be sent on to the next step of tablet pressing without further processing. If the right mixtures cannot be obtained through simple stirring in the reactor, there are two other possibilities to create the necessary homogeneity of the mixture for the creation of tablets. These possibilities are wet granulation or dry granulation. If I can be mixed with water, the manufacturer will use an aqueous solution, as that will be safer; if, like many pharmacological chemicals, I cannot come in contact with water without reacting to it and degrading, I will be mixed with a solvent solution. If I go through wet granulation, a liquid binder-adhesive will be added to me in the reactor, where we will be thoroughly mixed together. Using the correct amounts of the liquid binder-adhesive is vital, because if too much of the liquid is added to me, my granules will come out to be too large and too hard for tablet formation, and if too little liquid is added, I will come out too soft and loose. If I am put through dry granulation, I and the other ingredients will be gently compressed with a low pressure system. For example, a rolling press might be used to press us all together so we stay mixed. Since this is the easier and less expensive option, I expect this is what the manufacturer will use unless it is impossible to mix me that way. Once all the ingredients are mixed in, lubricant is added to me through a blending process in order to keep me from sticking to the inside of the equipment during the next steps of the process. A liquid lubricant might be vegetable oil; a dry lubricant could be magnesium stearate, talc, or stearic acid. After mixing and the granulation process, I am now formed in small slugs and transported to the next step, which is to purify the slugs before making them into tablets. If I am to be made into a suspension, in the reactor I will be mixed with a liquid media and other inactive ingredients chosen depending on the method of application and desired properties of the final product. Usually, I will be mixed into an aqueous solution, but sometimes I may be mixed into an oil-based or organic solution. If the active ingredient is produced by chemical reaction, during this step I will be mixed with the other reactants in dilute solution until the desired product precipitates. Suspensions meant to be given by mouth will have flavoring agents and sweeteners added, while thickening agents may be added to creams to produce a texture that will be more comfortable for the patient. Suspending agents are added to me to keep various ingredients in the mixture from settling out during the rest of the manufacturing process. This also increases the stability of the final product, since the particles will now be less likely to settle out during shipment and storage. There may be thickening agents added to create just the right level of viscosity, so that I can be injected, eaten, or spread as necessary but remain stable for long-term shelf storage. After the reactor mixing process, I am sent for separation, which removes all the undesired extra components from me and leaves just the active ingredient, which is me, and the other vital inactive ingredients. The other purpose of separation is to remove air and lumps from my mixture. This has to be done in such a way that I am not lost in the process and the desired product mixture can be moved to the next step of manufacturing. The separation process must also allow the manufacturing to keep track of the exact weight and volume of the product, since they have to be able to calculate the amount of the mixture needed to reach the desired dosage. The separation process might involve a separator, a centrifuge, or a filter. For example, a separator could be used to remove particles of larger size than the ones desired for the final product; one way this could be done is by forcing the mixture through a fine mesh and removing anything that will not pass through. Another method of removing differently-sized particles would be through use of the centrifuge, which would spin the product at high speeds until each layer in the product would be separated, sorted by density. I may go through the separation and filtering process multiple times to ensure that all impurities are removed. Testing is done at several points during the separation process to make sure that everything is working as it should. The manufacturers continue to check for the right proportions of active and inactive ingredients; they also continue to monitor very closely the possibility of microbial contamination. In the next step of tablet manufacturing, once I reach an acceptable level of purity, I am re-compressed into individual tablets which are tested for quality and cleanliness. Depending on the size of the drug batch, I will be compressed by either a single-punch or a rotary tablet machine. If I go through a single-punch machine, the mixture I am in will be poured into a mold by a feeder that will scrape off and remove any extra material. A punch forms the tablets one at a time. The newly formed tablet is then forced out of the mold by another punch pushing up from the bottom. In contrast, a rotary machine will take in a plate of molds at the same time and fill them all with the unformed process. A punch will travel around the disk holding the molds, punching out the shape of the tablets; once each tablet is formed, it is pushed out of the plate and travels to the packaging area. To ensure that the final product I am turned into is of high quality and meets standards, many tests are done before I am shipped out. The finished tablets are tested for hardness, friability or crumbliness, resistance to disintegration, individual tablet weight, and thickness. Suspensions are tested for re-dispersibility, or the tendency of sediment in a suspension to return to solution, the size and size range of the particles in the solution, uniformity of distribution of those particles, and sedimentation volume, or the amount of precipitation that has occurred since manufacture. And once more, they will test to make sure that no contaminants have gotten in at stage of manufacture, be they bacteriological or not. It is very important to them that only I and the ingredients they select end up in the final product. Once I complete the final step of the manufacturing process that forms the ingredients of the medication into tablets, I may be packaged in plastic blister packs or into bottles of clear or opaque plastic. Both types of containers are sterilized before use and sealed so that no contaminants enter the drug during shipment. The bottles are designed with child-proof lids and an additional seal to prevent tampering during shipping. The packaging is clearly labeled with product information, ingredients, expiration date, and the name of the manufacturer. This way, the manufacturer can keep track of how many packages of drugs they ship out, and the recipient knows where I came from and how long I can be kept before I lose my effectiveness. I am transported from the manufacturing plant to a pharmacy, hospital, or store, where a customer purchases me and takes me home. Due to the careful and thorough cleanliness of the manufacturing process, the customer can be sure that I contain only the ingredients listed on the bottle and that, other factors being equal, I am safe to take. The labeling on my packaging tells the patient the correct dosage. They know they can trust that the manufacturer's statement of the amount of medication per pill is correct, because of the careful records that have been kept. When I reach my final destination, everyone knows that I have been very carefully measured, cleaned, and maintained. BIBLIOGRAPHY Aulton, M.E. (ed.) 2007, Aulton's pharmaceutics: The design and manufacture of medicine, Elsevier, Edinburgh. Flow Services Division 2001, Mechanical seal guidelines for pharmaceutical applications, Flowserve, viewed 13 Jan 2011 Read More

 

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