Preface

Pharmaceutical formulations have evolved from simple and traditional systems to more modern and complex novel dosage forms. Formulation development is a tedious process and requires an enormous amount of effort from many different people. Developing a stable novel dosage form and further targeting it to the desired site inside the body has always been a challenge. The purpose of this book is to bring together scholarly articles that highlight recent developments and trends in pharmaceutical formulation science. Each article has been written by authors specializing in the subject area and hailing from top institutions around the world. The entire book has been written in a systematic and lucid style explaining all basic concepts and fundamentals in a very simple way.

Developing a novel dosage form necessitates the formulators to possess sound knowledge of preformulation studies. Prior to developing a stable formulation, knowledge and estimation of various physicochemical properties of the drug is a necessity. Estimation of drug solubility, partition coefficient, melting point etc. helps in selecting a proper route and dosage form for the drug. For this reason, a chapter is solely dedicated to preformulation studies and this will not only help the investigators but also students of pharmaceutics developing novel dosage forms. A chapter on drug analysis describes the different techniques and instruments used for identification and analysis of drugs in biological samples and formulations. Techniques such as UV spectrophotometry, derivative and difference spectrophotometry, chromatographic methods such as HPLC, HPTLC etc. are described in detail. Estimation of bioavailability of a drug is crucial in pharmaceutical sciences as it's the amount of drug that is available in systemic circulation to show its therapeutic efficacy. The chapter on bioavailability and bioequivalence highlights the strategies employed in designing experiments for conducting bioavailability and bioequivalence studies along with the methods used for estimation of drug concentration. A very interesting chapter on microcrystalline cellulose is described highlighting the importance of this widely used pharmaceutical excipient. Chapters related to recent advances in drug delivery systems are included to emphasize the latest trends in drug delivery systems. It includes a chapter dedicated to microbubbles for the management of AIDS. A chapter on pH-responsive microgels for controlled drug delivery is included highlighting the importance of stimuli-responsive drug delivery systems. Most of the current delivery systems are based on the passive approach, which means the drug struggles to reach the target site. Targeting various receptors inside the body not only enhances the pharmacological activity but also minimizes the toxicity and side effects associated with the drug. The brain has always been a challenge because of the presence of the blood brain barrier. The introduction of nanotechnology in pharmaceutical formulations has helped to successfully deliver and target the medication to treat various neurological disorders. A chapter describes the importance and approaches utilized in development of nanopharmaceuticals to target and treat brain disorders. A very interesting chapter on 3D printing of pharmaceuticals is described, which highlights the evolution and application of 3D printing technology in the healthcare sector.

**II**

**Chapter 8 139**

3D Printing in Pharmaceutical Sector: An Overview

*by Asad Ali, Usama Ahmad and Juber Akhtar*

This book aims to serve the need of all individuals involved at any level in the pharmaceutical dosage form development. I sincerely hope that the book will be liked by inquisitive students and learned colleagues.

> **Dr. Usama Ahmad** Assistant Professor, Faculty of Pharmacy, Integral University, Lucknow, India

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Section 1

Preformulation Study

Section 1
