Aspirin is considered one of the safest and probably the inexpensive pain relievers on the market. These tablets are manufactured in various shapes. The size, weight, hardness and thickness vary depending on the dosage amount. The upper and lower surfaces of the tablets can be flat, concave or convex, or round.
The first step in manufacturing aspirin tablets is weighing the ingredients in separate canisters such as corn starch and lubricant to determine if the ingredients meet the specifications for the amount of dosage and batch size
Then the corn starch is distributed into the cold purified water, heated and stirred until it forms a translucent paste. The active ingredient which is the corn starch as well as part of the lubricant are to be poured in one sterile canister then it will be wheeled into a mixing machine that will blend all of the ingredients and at the same time release air from the mixture. The mixture is separated mechanically into units called slugs.
The small batches of slugs are then forced with mesh screen by stainless steel spatula. The large sizes are filtered through the Fitzpatrick mill and the rest of the lubricant is incorporated into the mixture, gently blended in sifter and rotary granulator. The lubricant will prevent the mixture from sticking into the tablet machine when the compression process takes place.
Then the mixture will be compressed into tablets, by single punch machine, or rotary tablet machine, depending on the scale of production. Single punch machines are power driven and the mixture is fed into one tablet mold with a feed shoe. On rotary tablet machines, the mixture will run through feed line into several dye cavities located on huge steel plate.
After compressing the tablets, they will be subjected into test of hardness and friability, along with tablet disintegration test. The tablets are transported into the bottling assembly line that is automated where the tablets are distributed into color coated or clear polyethylene plastic or glass bottles. The bottles will be topped with cotton packing and sheer aluminum is sealed on top before it is sealed with plastic and rubber lid.