Indian Journal of Pharmaceutical Education and Research | Vol 56 | Issue 3 | Jul-Sep, 2022 689 Original Artcle www.ijper.org Utility of Different Lipids and Effect of Soya Lecithin on Sustained Delivery of Zidovudine via Biodegradable Solid Lipid Microparticles: Formulation and in-vitro Characterization Nandhakumar Sathyamoorthy 1, *, Vankayala Devendiran Sundar 2 , Vijayalakshmi Rajendran 3 , Navyashri Sirikonda 2 , Harikrishnan Narayanaswamy 1 1 Department of Pharmaceutics, Faculty of Pharmacy, Dr. M.G.R. Educational and Research Institute, Velappanchavadi, Tamil Nadu, INDIA. 2 Department of Pharmaceutical Technology, GIET School of Pharmacy, Rajahmundry, Andhra Pradesh, INDIA. 3 Department of Pharmaceutical Analysis, GIET School of Pharmacy, Rajahmundry, Andhra Pradesh, INDIA. ABSTRACT Background: Zidovudine (Azidothymidine, AZT) is widely used in the treatment of Acquired Immuno Deficiency Syndrome (AIDS) and related conditions, either alone or in combination with other antiviral agents to combat HIV. AZT is a Biopharmaceutical Classification System (BCS) class III drug and has various disadvantages. Thus, AZT is a potential candidate for delivery via lipid-based drug delivery system. Materials and Methods: In the present work, solid lipid microparticles (SLMs) of Zidovudine were developed for sustaining the drug release, to overcome or to reduce the hepatic metabolism and to ensure optimal bioavailability. A total of sixteen formulations of Zidovudine loaded solid lipid microparticles in two groups viz., one with tripalmitin and another with trimyristin were prepared by emulsion-solvent evaporation method. Results: The average particle size and entrapment efficiency of the prepared SLM varied between 5.48 µm-10.64 µm and 46.92 % and 58.39% respectively. The release of zidovudine from the SLM varied between 70.47% and 100% at the end of 24 hrs. 80% of the drug release which is required for obtaining the optimal therapeutic concentration was achieved by SLM 8. Conclusion: Formulation SLM 8 was considered best with maximum sustainability in the drug release along with maintaining therapeutic optimum. The formulation was found stable under stressed conditions. Keywords: Zidovudine, Azidothymidine, AIDS, Solid lipid microparticles, Tripalmitin, Trimyristin. DOI: 10.5530/ijper.56.3.117 Correspondence: Dr. Nandhakumar Sathyamoorthy Professor, Department of Pharmaceutics, Faculty of Pharmacy Dr. MGR Educa- tional and Research Institute, Velappanchavadi, Chennai-600077, Tamil Nadu, INDIA. E-mail: nandha.pharm@ gmail.com Submission Date: 05-01-2022; Revision Date: 26-03-2022; Accepted Date: 21-04-2022. INTRODUCTION Solid lipid particles were frst presented in the early 1990s as an alternative to emulsions, liposomes, and polymeric microparticles as a drug delivery mechanism. 1 Solid Lipid Microparticles (SLMs) are solid lipid particles that are roughly spherical and range in size from 1 to 1000 um. 2 Solid lipid microparticles have a better physicochemical stability than other lipid-based drug carriers, such as liposomes, and are easier to sterilize and scale-up. 3 The formulation of solid lipid microparticles (SLMs) for effective oral administration of biological medicines begins with the selection of appropriate lipid excipients with the right hydrophobicity and lipolysis propensity. 4 Zidovudine is a synthetic nucleoside analogue that is increasingly being employed as the cornerstone of antiretroviral therapy for HIV infection. Zidovudine is a nucleoside analogue that inhibits HIV reverse transcriptase. It is the (-)- enantiomer of 2′, 3′-dideoxy-3′-thiacytidine. 5,6 Zidovudine (Azidothymidine, AZT) is widely used in the treatment of AIDS and similar illnesses, either alone or in combination