The limited water solubility of pharmacoactive molecules hinders their ability to be used as pharmacological agents, yet the indispensability of a certain solubility parameter precludes any compromises. To overcome this challenge, various methods are employed in order to increase their bioavailability. Pharmaceutical molecules with lower solubility present an elevated risk of failure for drug development and innovation. Their solubility affects important processes such as pharmacokinetics, pharmacodynamics, distribution, protein binding, and absorption. As a result these parameters are greatly impacted by the dissolution rate of a particular molecule. Out of all pharmaceutical dosage forms, more than half are oral. For the drug molecule to reach its target site and be effective therapeutically, solubility and bioavailability must be taken into consideration. Unfortunately, during screening programs conducted by the pharmaceutical industry it became evident that nearly 40% of new chemical entities (NCEs) face various roadblocks when transitioning from formulation to development due to their poor solubility and bioavailability. The pharmaceutical industry is constantly confronted with the difficulty of improving drug bioavailability and solubility in formulations. This article covers a range of technological advancements to boost the solubility of insoluble drugs, such as complexation, emulsions and micelles production, microemulsion generation with cosolvents, polymeric micelle preparation methods, particle size decrease techniques, pharmaceutical salts application, prodrugs usage, solid-state alteration practices, soft gel technology implementation crystal engineering approaches and nanomorphology. Through this review, we will discuss a variety of more complex methods for improving solubility and bioavailability such as crystal engineering, micronization, solid dispersions, nano sizing, and use of cyclodextrins, solid lipid nanoparticles (SLNPs), colloidal drug delivery systems and drug conjugates. We'll also provide references to studies that have been conducted in connection with these topics.
Keywords: Solubility, permeability, bioavailability, nano particles drug delivery systems, microemulsions, low water solubility