ABSTRACT Purpose: Cocrystallisation is a promising technique for altering important physicochemical properties of drugs such as solubility and dissolution. The present study thus aims to utilize this technique to improve the drug solubility and study its efect on taste masking. Method: Azithromycin co-crystals were formulated by solvent evaporation technique utilizing a synthetic sweetener neotame as the coformer. The study of microscopic characters characterized the formulated co-crystals, Fourier transforms infrared spectroscopy (FTIR), Diferential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM), and Xray difraction studies (XRD). Other evaluation parameters included taste evaluation, drug content determination, solubility, angle of repose, Carr’s index, Hausner’s ratio, and dissolution studies. Results: The study revealed that the prepared co-crystals showed a marked improvement in taste and physicochemical properties. Co-crystals prepared in the ratio of 1:1 of drug and neotame displayed a nearly two-fold increase in solubility, improvement in fow properties, and a tremendous improvement in the taste as compared to the pure drug. Conclusion: Thus, co-crystallization can be efectively used for solubility improvement and taste masking of poorly soluble bitter drugs such as azithromycin. Keywords: Azithromycin, Bitter taste, Co-crystals, Neotame, Taste masking. International Journal of Drug Delivery Technology (2021); DOI: 10.25258/ijddt.11.3.46 How to cite this article: Upadhye KP, Dhakate CS, Dixit GR, Bakhle SS. Development and Evaluation of Taste Masked Azithromycin by Crystal Engineering. International Journal of Drug Delivery Technology. 2021;11(0):920-925. Source of support: Nil. Confict of interest: None Development and Evaluation of Taste Masked Azithromycin by Crystal Engineering Kanchan P. Upadhye * , Chetana S. Dhakate, Gouri R. Dixit, Suparna S. Bakhle Department of Pharmaceutics, Priyadarshini J. L. College of Pharmacy, Nagpur, Maharashtra, India Received: 25th May, 2021; Revised: 5th June, 2021; Accepted: 20th August, 2021; Available Online: 25th September, 2021 INTRODUCTION Drug administration by the oral route is the most popular due to the ease of self-administration, manufacturing, and good stability on storage compared to the other dosage forms. However, a major drawback of the oral dosage form is the difculty in swallowing and bitter taste, leading to a severe pediatric and geriatric patient in compliance. Taste arises from the stimulation of taste buds present on the surface of the tongue. 1,2 Taste masking is necessary for an active ingredient with an unpleasant taste for increased patient compliance. Taste masking has been done by various techniques like adding favoring and sweetening agent, 3 ion-exchange resin complex, 4 micro-encapsulation, 5 prodrug approach, 6 inclusion complexation, 7 granulation, multiple emulsion technique, gel formation. However, very little work has been done using co-crystallization as a method of taste masking. This method not only improves the bitter taste but also improves the physicochemical properties of the drug. 8 Co-crystals are coordination types of molecular complexes involving noncovalent interaction between the drug and coformer and their complementary functional groups. 9 Thus, it involves drug RESEARCH ARTICLE and coformer that self-assemble by noncovalent interactions such as electrostatic interactions and hydrogen bonding in a well-defned stoichiometry. Such a development of co-crystal of an API leads to improved properties such as stability, solubility, drug release rate and taste. 10-12 Azithromycin, with an IUPAC name 9-deoxo-9a-aza-9a- methyl-9a-homoerythromycin, belongs to the azalide subclass of macrolides. It consists of a 15-membered ring, and methyl- substituted nitrogen at the 9a position on the aglycone ring, which is responsible for preventing its metabolism. Such a type of structure makes azithromycin diferent from other types of macrolides azithromycin is a broad-spectrum macrolide antibiotic having a long half-life and a high degree of tissue penetration. 13 Azithromycin is structurally related to erythromycin 14 and is commonly used for the treatment of infections of the respiratory and genitourinary tract as well as for enteric infections and may be used for sexually transmitted infections. It is a BCS Class II drug with an extremely bitter taste and a poor water solubility. Therefore the present work was aimed at using the co crystallisation technique of crystal engineering for the purpose of masking the bitter taste of the drug. *Author for Correspondence: upadhyekanchan@gmail. com