An overview of oral solid dosage manufacturing

Oral solid dosage (OSD) forms can exist in various types like tablets, capsules, gels, pills etc and vary according to the production techniques and facility designs involved. Oral solid dosage method is the most common dosage form as it is the most convenient method. They are administered orally which is later dissolved in the digestive system and absorbed into the bloodstream. They are easy to administer, can be self medicated and are easily distinguished from one another. The manufacturing methods for oral solid dosage forms are well developed and efficiently processed.

Oral solid dosage forms consist of an active pharmaceutical ingredient (API) mixed with dry powder ingredients called excipients. They are of different forms such as tablets, capsules and pills. Tablets, which is the most commonly used oral solid dosage form, are made through compression technique. Capsules on the other hand are made through a coating process where active components and excipients form a coating around a seed material. Oral solid dosage forms have been found to give good oral bioavailability and release rate in the body system. The kind of technology incorporated during the manufacturing process can greatly influence the release rate of the drug substance.

In order to develop a drug whether tablet or capsule with a consistent dose becomes a difficult task to ascertain certain parameters in terms of distribution of ingredients, dissolution factors and bioavailability. This makes sure that the drug developed is safe and efficacious to use in every way.

An overview of the pharmaceutical dosage forms reflects the pattern of selection of excipients in the preformulation and formulation research. It forms an essential part of the formulation to understand the physical, mechanical as well as chemical properties. It influences the other critical parameters that govern disintegration, dissolution, and shelf life.  During the drug manufacturing process the relative stability and compatibility studies are validated for the API to understand the drug interactions. 

The nature and property of the active pharmaceutical ingredient and the active excipients can greatly influence the development and commercialization of oral solid dosage formulations like tablets, capsules and powders. They can relatively impact the stability and effectiveness of the drug product along with the dissolution behaviour of the drug that in turn can affect the bioavailability and efficacy.

The overall performance of a formulation can be assessed through the process of optimization in which the chemical properties of the excipients and the coatings can decide the effectiveness of bioavailability, release profile and internal stability.

The most common and convenient route of administration is oral method as compared to any other route of administration as it follows patient compliance and bioavailability. And therefore, the oral solid dosage form development includes pre-formulation, drug product development, and manufacturing. Pre-formulation studies optimize the formulation process through the physicochemical and excipient studies. Hence optimization of the formulation development can effectively bring down the cost thus making the process robust and reliable. The formulation of the solid dosage forms of (APIs) and excipients are blended, grinded, granulated, dried, tableted or encapsulated. The excipients used generally are bulking agents, binders, fillers, and disintegrating agents to bring maximum product stability.

Formulation processes involve robust engineering techniques having a lot of challenges and complexities through the preformulation and formulation process. Hence, they completely rely upon the fundamental properties of excipients and coatings that affect the stability, bioavailability, efficacy and dissolution.  Oral solid dose manufacturing, development and administration induce cost effective methods to avoid drug failure and increase in efficiency.