1st Edition

Supramolecular Synthons in Crystal Engineering of Pharmaceutical Properties

By Ashwini Kumar Nangia Copyright 2025
    200 Pages 106 Color & 67 B/W Illustrations
    by CRC Press

    This comprehensive resource skillfully consolidates Crystal Engineering, the design of organic solids, and Supramolecular Synthons (i.e. structural hydrogen bond units) to achieve desired Pharmaceutical Properties, including solubility, dissolution, bioavailability, permeability, particle size, tableting, hydration, and mechanical strength. Covering 30 years of crystal engineering developments and pharmaceutical applications, this book will be a single and complete resource for supramolecular and structural chemists, the crystal engineering community, pharmaceutical scientists, and industrial researchers.

    Selling Points

    • Covers the fundamentals of crystal engineering and supramolecular synthons.
    • Details the challenges of low solubility and low permeability facing oral drug formulations.
    • Explains how heterosynthons provide a rational approach to address and implement solutions.
    • Provides case studies from academic and industrial labs to walk the reader through the actual steps.
    • Explores developments in the scale up and manufacture of crystal forms in pharmaceutical industry.

    Chapter 1 Introduction to Supramolecular Chemistry and Crystal Engineering

    1.1 Introduction

    1.2 Organic synthesis

    1.3 Supramolecular chemistry

    1.4 Crystal engineering

    1.5 Hydrogen bonding

    1.6 Space groups

    1.7 Summary conclusions

    1.8 References

    1.9 Questions and thoughts

    1.10 Additional reading

    Chapter 2 Crystal Engineering, Supramolecular Synthons, and Cocrystal Design

    2.1 Introduction

    2.2 Supramolecular synthons

    2.3 Crystal engineering of pharmaceutical cocrystals

    2.3.1 Cocrystals

    2.3.2 Pharmaceutical cocrystals

    2.4 Cocrystal design approaches

    2.4.1 Hydrogen bond synthons

    2.4.2 ΔpKa rule

    2.4.3 Computational methods

    2.4.4 Molecular electrostatic potential surface energy

    2.4.5 Hansen solubility parameter

    2.5 Summary conclusions

    2.6 References

    2.7 Questions and thoughts

    Chapter 3 Pharmaceutical Solid-State Forms

    3.1 Introduction

    3.2 Pharmaceutical multi-component crystals

    3.2.1 Drug salts and pharmaceutical cocrystals

    3.2.2 Pharmaceutical cocrystals via crystal engineering

    3.2.3 Coamorphous solids

    3.2.4 Solid solutions and eutectics

    3.2.5 Ionic liquids

    3.2.6 Ionic cocrystals

    3.2.7 Nanocrystalline drugs

    3.2.8 Supramolecular gels of drugs

    3.2.9 Salt−cocrystal continuum or hybrid quasi-state of proton

    3.2.10 Cocrystal polymorphs

    3.2.11 Ternary and higher organic cocrystals

    3.3 Summary conclusions

    3.4 References

    3.5 Questions and thoughts

    Chapter 4 Design and Methodology of Pharmaceutical Cocrystals

    4.1 Introduction

    4.2 Complementarity between API and coformer

    4.3 Preparation methods of cocrystals

    4.3.1 Spray drying

    4.3.2 Freeze drying

    4.3.3 Hot melt extrusion 

    4.3.4 Rotary evaporator method

    4.3.5 Vapor-assisted tumbling

    4.4 Drug−drug cocrystals 

    4.5 Drug−nutraceutical cocrystals

    4.6 Ternary and higher order cocrystals

    4.7 Cocrystals of different stoichiometry

    4.8 Zwitterionic cocrystals

    4.9 Halogen-bonded pharmaceutical cocrystals

    4.10 Characterization methods of cocrystals

    4.11 Summary conclusions

    4.12 References

    4.13 Questions and thoughts

    Chapter 5 Applications of Pharmaceutical Cocrystals

    5.1 Introduction

    5.2 Bioavailability improvement

    5.3 Hydration stability

    5.4 Chemical degradation stability

    5.5 Tableting 

    5.6 Mechanical properties

    5.7 Phase diagram and solubility measurements

    5.8 Permeability and plasma concentration

    5.9 Spring and Parachute model

    5.10 Summary conclusions

    5.11 References

    5.12 Questions and thoughts

    Chapter 6 Continuous Manufacturing of Cocrystals and Salts

    6.1 Introduction

    6.2 Batch and flow chemistry

    6.3 Flow chemistry and pharmaceutical cocrystals manufacturing

    6.4 Case studies of pharmaceutical cocrystals and salts 

    6.5 Continuous process technologies

    6.6 Flow guide for the synthetic chemist

    6.7 Summary conclusions

    6.8 References

    6.9 Questions and thoughts

     

    Chapter 7 Commercial Outlook of Pharmaceutical Cocrystals

    7.1 Introduction

    7.2 Present status

    7.3 Patenting and regulatory aspects

    7.4 Entresto® drug-drug cocrystal salt

    7.5 Seglentis® US-FDA approval

    7.6 Summary conclusions

    7.7 References

    7.8 Questions and thoughts

    Chapter 8 Controlling Polymorphism

    8.1 Introduction

    8.2 Definition and importance

    8.3 Polymorphism and cocrystallization

    8.4 Tailored additives to control crystal size and morphology

    8.5 Summary conclusions

    8.6 References

    8.7 Questions and thoughts

    Chapter 9 Supramolecular Heterosynthon in High Bioavailability Drugs

    9.1 Introduction

    9.2 Common heterosynthons in drugs

    9.3 Heterosynthon model for high bioavailability drugs

    9.4 Models for permeability enhancement

    9.5 Cocrystal drugs beyond the Rule of 5

    9.6 Improving cell penetration by atom replacement

    9.7 Summary conclusions

    9.9 Questions and thoughts

     

     

     

     

    Chapter 10 Other Applications of Cocrystals

    10.1 Introduction

    10.2 Property engineering

    10.3 Mechanochemistry

    10.4 Energetic cocrystals

    10.5 Summary conclusions

    10.6 References

    10.7 Questions and thoughts

    Chapter 11 AI ML ChatGPT in Chemistry

    11.1 Introduction

    11.2 Retrosynthetic reaction prediction

    11.3 Medicinal molecules

    11.4 MOFs and inorganic materials

    11.5 Cocrystals

    11.6 Summary conclusions

    11.7 References

    11.8 Questions and thoughts

    Chapter 12 3D Electron Diffraction

    12.1 Introduction

    12.2 Advantages of ED

    12.3 Resurgence of ED

    12.4 New pharmaceutical challenges solved by ED

    12.5 Summary conclusions

    12.6 References

    12.7 Questions and thoughts

    Chapter 13 Challenges, Conclusions, and Future Directions

    13.1 Introduction

    13.2 Carboxamide−pyridine-N-oxide heterosynthon

    13.3 Browsing the literature

    13.4 Challenges in pharmaceutical cocrystal technology

    13.5 Conclusions

    13.6 References

    13.7 Suggested reading

    Index

    Biography

    Ashwini Nangia (born 1960) is Senior Professor of Chemistry at University of Hyderabad, India. He completed his MSc from I.I.T. Kanpur (1983) and PhD from Yale University (1988). He joined University of Hyderabad in 1989, was promoted to Professor in 2002, and Senior Professor in 2019. His research interests in crystal engineering include polymorphs, cocrystals, salts, eutectics and amorphous forms of drugs and pharmaceuticals.