Introduction to Pharmaceutical Co-amorphous Systems Using a Green Co-milling Technique

Antibiotic Coordination Frameworks against Antibiotic Resistance: How to Involve Students through Experimental Practices in the Search for Solutions to Public Health Problems

For decades, multiple varieties of antibiotics have been successfully used for therapeutic purposes. Nevertheless, antibiotic resistance is currently one of the major threats to global health. This work presents an innovative laboratory practice carried out in an inorganic medicinal chemistry course within the Degrees of Pharmacy and Biochemistry for undergraduate students. This experiment includes three classes of 2 h each. The first class consisted of the mechanochemical synthesis of an antibiotic coordination framework (ACF) using a known antibiotic (nalidixic acid) and zinc as the ligand. The prepared Zn-nalidixic acid ACF (Zn-ACF) was obtained in up to 82% yield with high purity. On the second day, the synthesized Zn-ACF was characterized by Fourier-transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). Finally, during the last class, the antimicrobial activity was tested against Escherichia coli by the well diffusion method. The students verified the higher antimicrobial activity of Zn-ACF compared to nalidixic acid, proving that small changes in the chemical structure can result in great biological differences. In the end, the students presented their results in a poster format, encouraging the development of their soft skills and scientific results communication and dissemination. In the future, it is expected that such a laboratory experiment at the interface between medicinal chemistry, microbiology, analytical techniques, public health, and pharmacology will lead to the development and implementation of some service-learning practices and will serve as a model to look at for other courses and institutions.

Spectroscopic Monitoring and Modeling Drug Dissolution for Undergraduate Chemistry Curriculum

The pharmaceutical and medicine manufacturing industry has become the largest industrial sector for the employment of chemists, indicating a need for experiments with a pharmaceutical sciences context in the undergraduate chemistry curriculum. In the pharmaceutical industry, testing drug dissolution is a key analytical task for solid oral dosage forms that is performed in different phases of drug development to test the release behavior of new formulations, ensure consistency between manufacturing lots, and help predict the in vivo absorption of the drug substance after administration. However, there are a limited number of laboratory experiments in dissolution testing developed for the undergraduate chemistry curriculum. To help students obtain hands-on experience in dissolution testing, a protocol has been developed for an undergraduate chemistry laboratory course for students to build a dissolution apparatus, monitor dissolution processes, model the dissolution to extract kinetic parameters, and evaluate the consistency between dissolution curves with FDA regulated methods. Students successfully collected dissolution curves and completed the modeling analysis with nonlinear least-squares fitting. The designed dissolution protocol has been evaluated to have consistency and reproducibility to be implemented in the undergraduate chemistry laboratory curriculum.

Rapid screening of ternary amorphous formulations by a spray drying robot

Spray drying is commonly used for producing amorphous solid dispersions to improve drug solubility. The development of such formulations typically relies on comprehensive excipient and composition screening, which requires the preparation of many spray-dried powder samples. This is both labour-intensive and time-consuming when carried out manually. In the present work, the formulation screening task was automated by coupling a laboratory spray dryer operated in a semi-continuous mode with custom-made add-ons, allowing for rapid, computer-controlled production of formulation samples with systematically varying composition. The practical use of the spray drying robot in formulation development was demonstrated on a case study of poorly water-soluble model drugs simvastatin and ezetimibe. Six different polymers and several drug:polymer ratios were screened for the enhancement of dissolution properties. From a pool of 28 spray-dried samples, ternary compositions containing Eudragit L100-55 were identified as the most suitable ones for further processing and characterisation. The ability to populate the formulation design space rapidly and automatically made it possible to construct maps of physico-chemical properties such as glass transition temperature or dissolution rate. The spray drying robot thus enables the acceleration of early formulation development and a deeper understanding of composition-property relationships for multi-component spray dried powders.

Molecular complexes of drug combinations: A review of cocrystals, salts, coamorphous systems and amorphous solid dispersions

As the advancements in the medical technology and healthcare develop through the years, combinational therapy has evolved to be an important treatment modality in many disease settings, including cancer, cardiovascular disease and infectious diseases. In an effort to alleviate "pill burden" and improve patient compliance, fixed dose combinations (FDCs) have been developed to be used as effective therapeutics. Among all FDCs, the category of drug-drug molecular complexes has been proven an efficient methodology in designing and treating diseases, with many drugs being approved. Among all drug-drug molecular complexes, drug-drug cocrystals, salts, coamorphous systems and solid dispersions have been successfully developed and many have been approved by the FDA. In this review, we dwell deeply into the molecular mechanisms behind the different types of drug-drug molecular complexes, including the key functional groups involved in the intermolecular interactions, the applications of each category of molecular complexes, as well as the advantages and challenges thereof. This comprehensive review provides useful insights into the practical design and manufacture of drug-drug molecular complexes and points out the future direction for the development of new advantageous combinational therapies that benefit more patients.