Betaine- and L-Carnitine-Based Ionic Liquids as Solubilising and Stabilising Agents for the Formulation of Antimicrobial Eye Drops Containing Diacerein.

The therapeutic efficacy of topically administered drugs, however powerful, is largely affected by their bioavailability and, thus, ultimately, on their aqueous solubility and stability. The aim of this study was to evaluate the use of ionic liquids (ILs) as functional excipients to solubilise, stabilise, and prolong the ocular residence time of diacerein (DIA) in eye drop formulations. DIA is a poorly soluble and unstable anthraquinone prodrug, rapidly hydrolysed to rhein (Rhe), for the treatment of osteoarthritis. DIA has recently been evaluated as an antimicrobial agent for bacterial keratitis. Two ILs based on natural zwitterionic compounds were investigated: L-carnitine C6 alkyl ester bromide (Carn6), and betaine C6 alkyl ester bromide (Bet6). The stabilising, solubilising, and mucoadhesive properties of ILs were investigated, as well as their cytotoxicity to the murine fibroblast BALB/3T3 clone A31 cell line. Two IL-DIA-based eye drop formulations were prepared, and their efficacy against both Staphylococcus aureus and Pseudomonas aeruginosa was determined. Finally, the eye drops were administered in vivo on New Zealand albino rabbits, testing their tolerability as well as their elimination and degradation kinetics. Both Bet6 and Carn6 have good potential as functional excipients, showing solubilising, stabilising, mucoadhesive, and antimicrobial properties; their in vitro cytotoxicity and in vivo ocular tolerability pave the way for their future use in ophthalmic applications.

Cocamidopropyl Betaine Surfactant 0.075% Solution in Physiological Serum for Hygiene Process of COVID-19 Intubated Patients.

When using ventilators in the management of the coronavirus disease 2019 patient, dense and abundant mucous secretions are formed, obstructing the endotracheal tube and making its aspiration difficult. This situation is worsened if in order to minimize the risk of infection of the medical personnel, the humidifier is disconnected. This circumstance forces the tube to be removed, cleaned, or changed, increasing the workload of the intensive care unit staff. Other therapies tested until now, like mesna, acetylcysteine, or hypertonic saline solution, are valid alternatives, although they have not shown great efficacy for this specific procedure in the past. The sanitary emergency forced the collaboration between a pharmacist and an otorhinolaryngologist to develop the cocamidopropyl betaine surfactant formula, after several tests with different concentrations of the surfactant. The objective of this compounding formula was to resolve a mechanical problem and avoid reintubation due to obstruction of the ventilator tube. The cocamidopropyl betaine surfactant solution 0.075% in saline 0.9% (physiological serum) solution demonstrated to be a well-tolerated formula, using inexpensive materials, was simple to prepare, and was easy to use in clinical practice.