Authors Jannes van der Merwe, Jan Steenekamp, Dewald Steyn and Josias Hamman
solubility; bioavailability; excipients; dissolution, active pharmaceutical ingredients (APIs), poor solubility and low dissolution rates, luminal fluids of the gastrointestinal tract, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, selected excipients (e.g., alkalinizing agents, surfactants and sugars), formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions, drug solubility and bioavailability enhancement, active pharmaceutical ingredients; APIs) are usually not administered to patients on their own as single compounds, formulated into carefully designed dosage forms, accurate dosing, quality, efficacy, safety, stability as well as high patient acceptance and compliance, dosage forms were made by simply adding pharmacologically inert substances (also referred to as excipients), selection and production of excipients that fulfil specific functions, beyond just making up volume, such as assisting in production of the dosage form and optimizing drug delivery from novel dosage forms, functions of excipients in dosage forms are related to all the different aspects of the final product including its manufacturability, the stability of the API, dose uniformity, effective delivery of the API to the systemic circulation after administration as well as acceptable organoleptic properties , Pharmaceutical excipients are usually included in dosage forms in larger quantities than the API and can make up to about 90% of the total mass/volume of medicinal products, The International Pharmaceutical Excipient Council (IPEC), different classes of pharmaceutical excipients, regulatory requirements for pharmaceutical excipients, new chemical excipients, existing excipients that are modified with respect to purity and/or physical properties such as particle size, co-processed excipients (i.e., two or more existing excipients which are formulated into a new excipient with physical properties, excipients that are chemically modified, development of novel drug delivery systems, sophisticated excipients are needed to impart certain properties, fulfil multiple roles in a dosage form or drug delivery system, high functionality excipients, single excipient that provides additional functions to innovative drug delivery systems to improve the overall performance of the product with significant economic benefits, provide better flow, act as a disintegrant and simultaneously allow a higher drug loading in the dosage form due to its high compressibility, functional excipients are needed to assist in overcoming their poor physico-chemical properties, Specialty excipients are used to produce dosage forms that can reduce the number of doses by modifying the rate of drug release or improve drug delivery by targeting drug release in a specific region in the gastrointestinal tract where drug absorption is the highest. Functional excipients are also used to re-formulate existing drugs in order to produce more effective products that are more cost-effective, Aqueous solubility and membrane permeability, Biopharmaceutics Classification System (BCS), influence the bioavailability of a drug, many promising new drugs exhibit poor solubility, and some also exhibit poor membrane permeability, a drug that exhibits an aqueous solubility lower than 0.1 mg per mL is likely to experience limited bioavailability, and its rate of absorption will be governed by the dissolution rate, improve the solubility of these drugs include formation of pro-drugs, formation of salts, co-precipitation, solvent evaporation and size reduction (or micronation), Formulation strategies, melt extrusion/granulation, formation of solid dispersions and formation of inclusion complexes. Furthermore, excipients such as surfactants, polymers, super-disintegrants and multifunctional fillers have been included in dosage forms to increase the apparent solubility of drugs, solubility/dissolution and/or membrane permeation/absorption and thereby also the bioavailability of poorly soluble APIs., aloe vera as functional vehicle excipient for dietary supplements.
