The Solubility–Permeability Interplay and Its Implications in Formulation Design and Development for Poorly Soluble Drugs
Journal Title: The AAPS Journal - Year 2012, Vol 14, Issue 2
Abstract
While each of the two key parameters of oral drug absorption, the solubility and the permeability, has been comprehensively studied separately, the relationship and interplay between the two have been largely ignored. For instance, when formulating a low-solubility drug using various solubilization techniques: what are we doing to the apparent permeability when we increase the solubility? Permeability is equal to the drug’s diffusion coefficient through the membrane times the membrane/aqueous partition coefficient divided by the membrane thickness. The direct correlation between the intestinal permeability and the membrane/aqueous partitioning, which in turn is dependent on the drug’s apparent solubility in the GI milieu, suggests that the solubility and the permeability are closely associated, exhibiting a certain interplay between them, and the current view of treating the one irrespectively of the other may not be sufficient. In this paper, we describe the research that has been done thus far, and present new data, to shed light on this solubility–permeability interplay. It has been shown that decreased apparent permeability accompanies the solubility increase when using different solubilization methods. Overall, the weight of the evidence indicates that the solubility–permeability interplay cannot be ignored when using solubility-enabling formulations; looking solely at the solubility enhancement that the formulation enables may be misleading with regards to predicting the resulting absorption, and hence, the solubility–permeability interplay must be taken into account to strike the optimal solubility–permeability balance, in order to maximize the overall absorption.
Authors and Affiliations
Arik Dahan, Jonathan M. Miller
Impact of Epigenetic Dietary Compounds on Transgenerational Prevention of Human Diseases
The etiology of most human diseases involves complicated interactions of multiple environmental factors with individual genetic background which is initially generated early in human life, for example, during the process...
Immunogenicity of Subcutaneously Administered Therapeutic Proteins—a Mechanistic Perspective
The administration of therapeutic proteins via the subcutaneous route (sc) is desired for compliance and convenience, but could be challenging due to perceived immunogenic potential or unwanted immune responses. There ar...
The Use of Biorelevant Dissolution Media to Forecast the In Vivo Performance of a Drug
Simulation of gastrointestinal conditions is essential to adequately predict the in vivo behavior of drug formulations. To reduce the size and number of human studies required to identify a drug product with appropriate...
Antibody Drug Conjugates: Nonclinical Safety Considerations
Antibody drug conjugates (ADCs) are biopharmaceutical molecules consisting of a cytotoxic small molecule covalently linked to a targeted protein carrier via a stable cleavable or noncleavable linker. The process of conju...
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation
Chitosan-coated alginate microspheres prepared by emulsification/internal gelation were chosen as carriers for a model protein, hemoglobin (Hb), owing to nontoxicity of the polymers and mild conditions of the method. The...