Pharmaceutical science is built upon a deep understanding of the physical and chemical principles that govern drug formulation, delivery, and performance. Physical Pharmaceutics – I introduces these core principles, laying a strong foundation for students to grasp the scientific basis of dosage form development and drug behavior. This book, published by AGPH, is tailored for undergraduate pharmacy students and is aligned with the curriculum prescribed by the Pharmacy Council of India (PCI). It covers essential topics such as states of matter, solubility, pH and buffers, complexation, and rheology, which are critical in the preformulation and formulation stages of drug development.