Dual-drug co-crystal synthesis for synergistic in vitro effect of three key first-line antiretroviral drugs

Pharmaceutical approaches for enhancing solubility and oral bioavailability of poorly soluble drugs

High solubility in water and physiological fluids is an indispensable requirement for the pharmacological efficacy of an active pharmaceutical ingredient. Indeed, it is well established that pharmaceutical substances exhibiting limited solubility in water are inclined towards diminished and inconsistent absorption following oral administration, consequently resulting in variability in therapeutic outcomes. The current advancements in combinatorial chemistry and pharmaceutical design have facilitated the creation of drug candidates characterized by increased lipophilicity, elevated molecular size, and reduced aqueous solubility. Undoubtedly, the issue of poorly water-soluble medications has been progressively escalating over recent years. Indeed, 40% of the top 200 oral medications marketed in the United States, 33% of drugs listed in the US pharmacopoeia, 75% of compounds under development and 90% of new chemical entities are insufficiently water-soluble compounds. In order to address this obstacle, formulation scientists employ a variety of approaches, encompassing both physical and chemical methods such as prodrug synthesis, salt formation, solid dispersions formation, hydrotropic substances utilization, solubilizing agents incorporation, cosolvent addition, polymorphism exploration, cocrystal creation, cyclodextrins complexation, lipid formulations, particle size reduction and nanoformulation techniques. Despite the utilization of these diverse approaches, the primary reason for the failure in new drug development persists as the poor aqueous solubility of pharmaceutical compounds. This paper, therefore, delves into the foundational principles that underpin the implementation of various formulation strategies, along with a discussion on the respective advantages and drawbacks associated with each approach. Additionally, a discourse is provided regarding methodological frameworks for making informed decisions on selecting an appropriate formulation strategy to effectively tackle the key challenges posed during the development of a poorly water-soluble drug candidate.

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.

Pharmaceutical Co-crystal of Antiviral Agent Efavirenz with Nicotinamide for the Enhancement of Solubility, Physicochemical Stability, and Oral Bioavailability

The present research work attempted to improve the oral bioavailability of the antiviral drug Efavirenz (EFV) using a pharmaceutical cocrystallization technique. EFV comes under BCS-II and has extremely low water solubility, and results in low oral bioavailability. EFV and nicotinamide (NICO) were selected in a (1:1) stoichiometric ratio and efavirenz nicotinamide cocrystal (ENCOC) was prepared through the liquid-assisted grinding method (LAG). The confirmation of the formation of a new solid phase was done through spectroscopic techniques like Fourier transmission infrared (FTIR), Raman, and ¹³C solid-state nuclear magnetic resonance (¹³C ssNMR). Thermal techniques like differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and hot stage microscopy (HSM) illustrated the thermal behavior and melting patterns of ENCOC, EFV, and NICO. The X-ray powder diffraction (XRPD) confirms the formation of a new crystalline phase in ENCOC. The Morphology was determined through scanning electron microscopy (FESEM). The results of saturated solubility studies and in vitro drug release studies exhibited 8.9-fold enhancement in solubility and 2.56-fold enhancement in percentage cumulative drug release. The percentage drug content of ENCOC was found higher than 97% and cocrystal exhibits excellent accelerated stability. The oral bioavailability of EFV (C_max, 799.08 ng/mL) exhibits significant enhancement after cocrystallization (C_max, 5597.09 ng/mL) than EFV and Efcure®-200 tablet (2896.21 ng/mL). The current work investigates the scalable and cost-effective method for enhancement of physicochemical stability, solubility, and oral bioavailability of an antiviral agent EFV.

Taming the dynamics in a pharmaceutical by cocrystallization: investigating the impact of the coformer by solid-state NMR

The anti-HIV pharmaceutical efavirenz is highly dynamic in its crystalline state, and we show that these dynamics can be tamed through the introduction of a coformer.