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Pharmaceutical formulation is the process of combining different chemical ingredients, including the active medicine, to create a finished therapeutic product in pharmaceutics. The term formulation is frequently used in conjunction with the term dosage form.

Stages and timeline

Formulation studies entail creating a medicine formulation that is both stable and acceptable to the patient. This usually entails putting the medicine into a tablet or capsule for orally delivered drugs. It's vital to note that, aside from the drug, a tablet contains a range of other potentially inactive components, and studies must be conducted to guarantee that the encapsulated drug is compatible with these other substances in a way that causes no harm, whether direct or indirect.

Preformulation is the process of determining which extra substances (excipients should be included in the manufacture of a medicine based on its physical, chemical, and mechanical qualities. Understanding the solution behaviour of a given protein under a number of stress circumstances such as freeze/thaw, temperature, and shear stress, among others, is critical in dealing with protein preformulation in order to discover pathways of degradation and hence mitigation.

Particle size, polymorphism, pH, and solubility are all parameters that can influence bioavailability and thus the activity of a medication in formulation studies. The drug must be blended with inactive substances in a way that assures that the amount of drug present in each dosage unit, such as each tablet, is consistent. The dosage should be uniform in look, taste, tablet hardness, and capsule disintegration should all be acceptable.

By the time clinical trials begin, formulation studies are unlikely to be completed. This means that simple formulations are first produced for phase I clinical studies. Hand-filled capsules containing a little amount of the medicine and a diluent are the most common. These formulations will be employed (tested) in a few of days, thus there is no need to prove their long-term stability. The ratio of the active drug to the total contents of the dose, known as "drug loading," must be taken into account. Low drug loads can lead to uniformity issues. If the substance has a low bulk density, a high drug load may cause flow issues or necessitate large capsules.

By the time phase III clinical trials are completed, the drug's formulation should be close to the one that will be utilised on the market. By this point, stability knowledge is vital, and conditions must have been established to ensure that the drug is stable in the preparation. If the medicine is unstable, clinical trial data will be invalidated because it will be difficult to establish what the provided dose was. Stability tests are performed to examine whether temperature, humidity, oxidation, or photolysis have any influence on the preparation, and the preparation is analysed to see if any degradation products have produced.

Container closure

Long amounts of time are spent storing prepared medications in container sealing mechanisms. Blisters, bottles, vials, ampules, syringes, and cartridges are examples. Glass, plastic, and metal are among the materials that can be used to create the containers. The medication can be kept as a solid, liquid, or gas.

It's critical to look for any unfavourable interactions between the preparation and the container. If a plastic container is used, for example, tests are conducted to see if any of the ingredients are adsorbed on the plastic and if any plasticizers, lubricants, colours, or stabilisers leach out of the plastic into the preparation. Even the adhesives for the container label must be checked to verify that they do not leach into the preparation through the plastic container.