Co-amorphization of atorvastatin by lisinopril as a co-former for solubility improvement

Co-Amorphization of Acemetacin with Basic Amino Acids as Co-Formers for Solubility Improvement and Gastric Ulcer Mitigation

Acemetacin (ACM) is a new non-steroidal anti-inflammatory drug with anti-inflammatory, analgesic, and antipyretic effects. However, the poor water solubility and gastrointestinal side effects limit its use. Recently, the co-amorphous (CAM) strategy has attracted great interest to improve solubility for poorly water-soluble drugs, and basic amino acids have the potential to protect the gastrointestinal tract. In order to develop a highly efficient and low-toxic ACM formulation, we prepared ACM CAM systems, with basic amino acids (lysine, arginine, and histidine) as co-formers, using a cryo-milling method. The solid-state behaviors of the ACM CAM systems were characterized by polarizing light microscopy, differential scanning calorimetry, and powder X-ray diffraction. Fourier transform infrared spectroscopy and molecular docking were carried out to understand the formation mechanism. Moreover, the gastro-protective effects of ACM CAM systems were evaluated in a rat gastric ulcer model. The results demonstrated that the CAM systems improved the dissolution rates of ACM compared with the neat amorphous counterpart. Furthermore, ACM CAM systems are significantly effective in mitigating the ACM-induced gastric ulcer in rats, and the ulcer inhibition rates were almost 90%. More importantly, this study provided a useful method for mitigating drug-induced gastrointestinal damage and broadened the applications of drug-amino acid CAM systems.

Drug-drug co-amorphous systems: An emerging formulation strategy for poorly water-soluble drugs

Overcoming the poor water solubility of small-molecule drugs is a major challenge in the development of clinical pharmaceuticals. Amorphization of crystalline drugs is a highly effective strategy to improve their aqueous solubility. However, amorphous drugs are thermodynamically unstable and likely to crystallize during manufacturing and storage. Recently, drug-drug co-amorphous systems have emerged as a novel strategy to not only enable enhanced dissolution and physical stability of the individual drugs within the system but also to provide a strategy for combination therapy of the same or different clinical indications. This review serves to highlight advances in the methods used to manufacture and characterize drug-drug co-amorphous systems, summarize drug-drug co-amorphous applications reported in recent decades, and provide an outlook on future possibilities and perspectives.

Solid dispersions of atorvastatin with Kolliphor RH40: Enhanced supersaturation and improvement in a hyperlipidemic rat model

Atorvastatin is a potent lipid-lowering drug with poor solubility and high presystemic clearance that limits its therapeutic efficacy. The aim of this study was to develop solid dispersions and micellar systems to obtain fast-dissolving atorvastatin systems that enhances their anti-hyperlipidemic effect. Solubility and wettability studies allow the development of solid dispersions with low proportions of croscarmellose sodium as hydrophilic carrier. Solid state characterization studies indicated that the addition of Kolliphor® RH40 surfactant to solid dispersions increases intermolecular hydrogen bonding between drug and polymer chains. Dissolution studies in biorelevant Fasted State Simulate Intestinal Fluid (FaSSIF pH 6.5) medium showed for atorvastatin solid dispersion a supersaturation peak of atorvastatin followed by an aggregation/precipitation process. Only the presence of a surfactant such as Kolliphor® RH40 in atorvastatin micellar system, promotes the presence of micelles that achieve delayed recrystallization. Efficacy studies were carried out using a hyperlipidemic model of rats fed with a high- fat diet. The atorvastatin micellar system at doses of 10 mg/kg, revealed a significant improvement in serum levels of total cholesterol, low-density lipoproteins, and triglycerides compared to atorvastatin raw material. This micellar system also exhibited more beneficial effects on liver steatosis, inflammation and ballooning injury.

Liquid-liquid phase separation drug aggregate: Merit for oral delivery of amorphous solid dispersions

As a promising strategy, amorphous solid dispersion has been extensively employed in improving the oral bioavailability of insoluble drugs. Despite the numerous advantages, the problems associated with supersaturation stability limit its further application. Recently, the formation and stability of the liquid-liquid phase separation drug aggregate (LLPS-DA) have been found to be vital for supersaturation maintenance. An in-depth review of LLPS-DA was required to further explore the supersaturation maintenance mechanism in vivo. Hence, this study aimed to present a short review to introduce the LLPS-DA, highlight the in vivo advantages for oral administration, and discuss the prospects to help understand the in vivo behavior of LLPS-DA.