Pharmaceutical excipients for solid oral dosage forms with specific functionalities for effective drug delivery
Pharmaceutical excipients refer to a wide range of substances that are included in the dosage form together with the active pharmaceutical ingredient (API) to fulfil certain functions. Conventionally, excipients were considered inert substances that were basically vehicles not expected to play an active role in the delivery of the drug and treatment of the condition. This notion has led to the under-appreciation of the importance of excipients, but it is now realised that excipients are indispensable in the development of quality pharmaceutical products. Pharmaceutical excipients are now considered essential for the manufacture of dosage forms, but also to facilitate optimal API delivery. Modified release dosage forms contain excipients that control the rate of API release. Due to unfavourable biopharmaceutical properties of certain API’s, excipients are included to improve drug solubility and dissolution rate, membrane permeation and targeted delivery at a specific site of the gastrointestinal tract.
Since the inception of the manufacturing of medicinal products, substances called pharmaceutical excipients were added to the active pharmaceutical ingredient (API) to convert a raw material into an elegant product that complies with certain quality requirements (1). These excipients have initially fulfilled relatively simple functions in dosage forms such as provision of a vehicle to reach the required volume and to administer the API in the correct dose. It has, however, become very quickly evident that pharmaceutical excipients were indispensable in the design of dosage forms that could meet the required quality standards and therapeutic efficacy (2). Furthermore, with the advancement of pharmaceutical technology, specialised dosage forms with improved treatment outcomes have been developed. These technologically advanced dosage forms require excipients with specific characteristics that can fulfil certain roles such as sustain drug release at a specific rate, enhance the ...