Lidocaine is often added to cocaine as a diluent. [74][75] Cocaine and lidocaine both numb the gums when applied. This gives the user the impression of high-quality cocaine when in actuality the user is receiving a diluted product. Lidocaine is very lipid soluble and, thus, has a more rapid onset and a longer duration of action than most amino ester-type local anesthetics, such as procaine and tetracaine. Discover what dissolves lidocaine by exploring the critical difference between its free base (lipid-soluble) and hydrochloride salt (water-soluble) forms, and how this affects its use in medicine. Research Interest: The ethoxy group in the structure can enhance solubility and bioavailability, making this compound a subject of research interest in drug development and formulation chemistry. The product is soluble in alcohol, ether, benzene, chloroform and oils, according to the chemicals encyclopedia published by the Royal Society of Chemistry , 14th ed. online (2006). The aim of this work is to obtain solubility data of lidocaine, and correlate equation parameters of lidocaine and thermodynamic parameters in the dissolution process. Nevertheless, it has been observed that lidocaine hydrochloride is completely absorbed following parenteral administration, its rate of absorption depending also on lipid solubility and the presence or absence of a vasoconstrictor agent. This study aimed to improve the solubility and permeability of lidocaine (Lid) by preparing solid dispersions of Lid and ascorbic acid 2-glucoside (AG) and evaluating their physicochemical properties, solubility, and permeability. This guide provides troubleshooting assistance for researchers, scientists, and drug development professionals encountering solubility issues with lidocaine hydrochloride in physiological buffers. Solubility: very soluble in water, freely soluble in ethanol. (96 per cent). Melting point (2.2.14): 74 °C to 79 °C, determined without previous drying. Infrared absorption spectrophotometry (2.2.24). Comparison: lidocaine hydrochloride CRS.