Original Article DESIGN, FORMULATION AND EVALUATION OF LIPOSOME CONTAINING ISONIAZID AKSHAY SINGHA ROY, SUDIPTA DAS * , ARNAB SAMANTA PG Research Laboratories, Department of Pharmaceutics, Netaji Subhas Chandra Bose Institute of Pharmacy, Chakdaha 741222, Nadia, West Bengal, India Email: sudipta_pharmacy@rediffmail.com Received: 07 Dec 2017, Revised and Accepted: 23 Jan 2018 ABSTRACT Objective: The objective of the present study was to formulate and evaluate liposomes loaded with isoniazid. Methods: Liposome of isoniazid was made by thin layer film hydration method. L-α-phosphatidylcholine and cholesterol were used to make multiamellar vesicles. Six batches of liposomes were prepared based on the different weight ratio of L-α-phosphatidylcholine and cholesterol. Differential scanning calorimetry (DSC) study conducted to study in any incompatibility. Results: The prepared liposomes were evaluated by particle size analysis, entrapment efficiency, release study and stability study. Particle sizes were determined from the scanning electron microscopy (SEM) photographs. When particle frequencies were plotted against particle diameter in the histogram, it showed that F1 batch had a skewed distribution towards smaller liposomes while F6 shows a proper bell-shaped curve with a mean at 225 μm. The percentage entrapment efficiency was found to be 8.99 ± 0.15 to 4.19 ± 0.12 % respectively. From the release profile, it was seen that F1 batch was fastest and F6 was slowest to release the drug. The satisfactory batch F1 was packed in Eppendorf tube and stored at 4 °C temperature for one month. At the end of one month, the samples were analyzed for their physical properties, drug entrapment and in vitro release profile. The percentage release was found to be 96.5 ± 3.2 after 4 h. Conclusion: The F1 batch showed most promising results compared to other. No significant change was found during one month’s stability study of final batch (F1). Keyword: Liposome, Isoniazid, L-α-phosphatidylcholine, Cholesterol, Stability © 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open-access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijap.2018v10i2.24174 INTRODUCTION Liposome has become an essential therapeutic tool most notably in drug delivery and targeting. Structurally, liposomes are concentric bilayered vesicles in which an aqueous volume is enclosed by a membranous lipid bilayer mainly composed of natural or synthetic phospholipids [1]. Liposomes are formed when thin lipid films or lipid cakes are hydrated and stacks of lipid crystalline bilayers become fluid and swell. The hydrated lipid sheets get detached during agitation and self-close to form large, multiamellar vesicles (MLVs), which prevent interaction of water with the hydrocarbon core of the bilayer at the edges. Once these MLVs are formed, a change in vesicle shape and morphology may require energy input in the form of sonic energy and/or mechanical energy. The former produce small unilamellar vesicles (SUVs) while the latter usually produces large unilamellar vesicles. Liposomal drug delivery system is very useful for delivery of anticancer, antifungal, antibacterial, antiparasites, ocular and antiviral drugs [2-4]. Phospholipids such as phosphatidylcholine (PC) and cholesterol were selected for the formation of liposomes into which the drug was incorporated. Phospholipids are amphipathic molecules as they have a hydrophobic tail and a hydrophilic or polar head. Cholesterol acts as a ‘fluidity buffer’ since below the phase transition it tends to make membrane less ordered while above transition it tends to make membrane more ordered thus suppressing the tilts and shifts in membrane structure specifically at the phase transition. Though cholesterol itself does not form bilayers, but it can be incorporated into phospholipid membrane in high concentration in the different molar ratio of cholesterol to PC [5]. Tuberculosis is an infectious bacterial disease, which most commonly affects the lungs. Isoniazid, also known as isonicotinic acid hydrazide (INH), is the first-line medication for tuberculosis and it is most widely used for treatment and prevention of tuberculosis [6]. The purpose of the present study was to design, formulate and evaluate the liposomes containing Isoniazid by in vitro methods. The liposomal formulations are designed for intramuscular administration for a sustained release action and at the same time automatic absorption of the delivery system, since all the components are biodegradable. MATERIALS AND METHODS Materials Isoniazid, L-α-phosphatidylcholine (soya lecithin), cholesterol were purchased from yarrow Chem., Mumbai. Chloroform was purchased from Merck India. All the chemicals and reagents were used were of analytical grade. Preparation of liposome by thin layer film hydration method A solution of L-α-phosphatidylcholine and cholesterol in a specified weight ratio (F1=1:1, F2=2:1, F3=3:1, F4=4:1, F5=5:1 and F6=6:1) was dissolved in 5 ml chloroform. The chloroform solution was placed inside a 250 ml round bottom flask and rotated in the same direction. The flask was kept in a thermostatic water bath, and rotated while maintaining a temperature of 30 ° to 35 ° C. Rotation was continued till all the chloroform evaporates from the solution and a thin lipid film was deposited on the inner wall of the flask. An aqueous solution of isoniazid (5 ml containing 100 mg drug) was added to the flask and was rotated with the same speed as before for 30 min or until all the lipid was removed from the wall of the flask. The suspension was allowed to stand for a period of 15 min on water bath at 30 °C temperature for complete hydration. Then, the suspension was taken into a bath type sonicator and sonicated for 30 min. Separation of non-entrapped drug was carried out by centrifugation at 3700 rpm for 40 min. The liposomal suspension was cooled by placing the test tubes in ice-cold water prior to centrifugation. Then liposome pellet was collected and re- suspended in distilled water [7, 13, 15]. Study of physical interaction between drug and excipients Differential Scanning Calorimetry (DSC) thermograms were taken by scanning the samples of (i) pure isoniazid, (ii) excipients containing (lecithin, cholesterol) and (iii) the formulation (F1 and F6) using International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 10, Issue 2, 2018