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1 ISSN: X CODEN: IJPTFI Available Online through Research Article NIOSOMES FOR ENHANCED TRANSDERMAL DELIVERY OF DOMPERIDONE Ch. Saritha, D. Sathish, S. Himabindu, Shayeda University College of Pharmaceutical Sciences, Kakatiya University, Warangal. Received on Accepted on Abstract Niosomes have been reported as a possible approach to improve the low skin penetration and bioavailability characteristics shown by Domperidone. Niosomes were formed from span 20, 40, 60 and 80 using thin film-hydration method. The prepared systems were characterized for entrapment efficiency, particle size, zeta potential, stability, in vitro drug release and ex vivo permeation studies. Skin permeation studies were performed using static vertical diffusion Franz cells and hairless mouse skin treated with either niosomes, niosomal gels. The results showed that the type of surfactant altered the entrapment efficiency of niosomes. Higher entrapment efficiency was obtained with the niosomes prepared from Span 60. Niosomal formulations have shown a fairly high retention of domperidone inside the vesicles at refrigerated temperature up to a period of 2 months. The optimized niosomal formulation was incorporated into Aloe gel and gel prepared with Hydroxy Propyl Methyl Cellulose (HPMC). Niosomes formulated with Span 60 showed highest permeation and transdermal flux among other formulations. Aloe gel was found to be good vehicle for niosomes compared to HPMC gel. The results suggested that niosomes could better promote the transdermal delivery of Domperidone, especially due to their simple scaling up and their ability to control drug release. Key words: Neosomes, Hydroxy Propyl Methyl Cellulose, Domperidone. 1. Introduction Niosomes are formed by the self-assembly of non-ionic amphiphiles in aqueous media thus providing closed bilayer structures. Niosomes are analogous to liposomes and, like them, can be multilamellar or unilamellar vesicles that are able to encapsulate both hydrophilic and lypophilic drugs. Niosome properties make them a versatile carrier that is suitable for different systemic and topical applications, e.g. the administration of anti inflammatory drugs (1), non invasive vaccines and anticancer and anti-infective agents (2) IJPT July-2015 Vol. 7 Issue No Page 8120

2 Different types of surfactants are proposed as starting material to prepare niosomes, i.e. the Span series, tween series and the Brij series, and their physico-chemical properties can modulate the stability and the features of vesicular systems because they are able to influence the fluidity of bilayers (3,4). Usually, cholesterol is added to the formulations with the aim of reducing the temperature of the vesicular gel to liquid crystal phase transition and to decrease the overall HLB value of the surfactant mixture used for the preparation (5), thus allowing the formation of niosomes. Several mechanisms have been used to explain the ability of niosomes to modulate drug transfer through the skin, e.g. adsorption and fusion of niosomes on the surface of the skin, leading to a high thermodynamic activity gradient of the drug at the interface, which is the driving force for the permeation of a lipophilic drug, and the reduction of the barrier properties of stratum corneum resulting from the property of vesicles as a penetration enhancer (6). domperidone was selected as a model lipophilic drug in this study, it is a synthetic benzimidazole derivative, D 2 receptor antagonist and used as an antiemetic and prokinetic agent. It has got certain characteristics that a drug should possess to get absorbed through transdermal route viz., high log P, low dose and low molecular weight. Moreover domperidone undergoes extensive first-pass metabolism, so its bioavailability may be improved when delivered through transdermal route. Its bioavailability when given by oral route is only 15 % and its dose is low i.e., 10 mg. hence, it can be conveniently loaded into niosomes. 2: Materials and methods 2.1. Materials Span 20, span 40, span 60 and Cholesterol were obtained from Hi Media Laboratories Pvt. Ltd., Mumbai. Span 80 supplied by S.D. Fine-Chem Ltd., Mumbai. Domperidone was obtained from Aurobindo pharma Ltd., Hyderabad. All other chemicals and solvents were of analytical grade. 2.2 Preparation of niosomes Niosomes are prepared by thin film hydration method. In this method accurately weighed quantities of nonionic surfactant, cholesterol were dissolved in a 1:1 mixture of dichloromethane and methanol. Drug was also dissolved in same mixture and transferred into round bottom flask. Then it was evaporated under reduced pressure until a dry film was formed. The temperature was maintained above the transition temperature of surfactants and it was rotated at 100 rpm in a rotary flash evaporator. IJPT July-2015 Vol. 7 Issue No Page 8121

3 Table-1: Composition of various niosomal formulations. Formulation code Domperidone Span 20 Span 40 Span 60 Span 80 Cholesterol * ** * * ** * F F F F F F F F F F F F *all values represented in mg; **all values represented in µl Then the film was hydrated with the aqueous phase, i.e ph 7.4 phosphate buffers, which was preheated to the same temperature. Then hydration was continued for 15 minutes in the rotating flask. The size of niosomes containing Domperidone prepared by film hydration method was obtained in micron range. They were sonicated for 3 min by using a probe sonicator at amplitude of 50% of its maximum output, at the same temperature as that of hydration temperature. 2.3 Size and zeta potential The prepared niosomal formulations were diluted in 1:50 ratio with double distilled water and size was measured at 90 angles by Malvern zeta sizer (Nano ZS90). The average particle size and polydispersity index were obtained directly from the instrument. The same sample which was used for size analysis was taken and dip cell (containing electrodes) was inserted into the sample holder. And then zeta potential in mv and the standard deviation were obtained directly from the instrument. IJPT July-2015 Vol. 7 Issue No Page 8122

4 2.4 Entrapment efficiency Shayeda* et al. International Journal Of Pharmacy & Technology The unentrapped drug was separated from niosomes using centrifugation method. Niosomal dispersion was centrifuged at rpm for 90 min at a controlled temperature of 4 C (Remi cooling centrifuge). Supernatant containing unentrapped drug was withdrawn and measured UV spectrophotometrically at 284 nm against phosphate buffer saline (ph 7.4). All the determinations were made in triplicate. The amount of drug entrapped in niosomes was determined as follows EE (%) = [(C d -C)/C d ]*100 Where C d is the concentration of total drugand C is the concentration of unentrapped drug. 2.5 Microscopy A drop of vesicle dispersion was applied on a carbon film-covered copper grid. Excess dispersion was blotted from the grid with filter paper to form a thin-film specimen. The sample was then stained with 2 % uranyl acetate, air dried and examined under transmission electron microscope (Hitachi, H-7500) at various magnifications. 2.6 In vitro drug release studies Cellulose membrane (DM 70, Himedia, molecular weight cut off ) was hydrated by soaking in double distilled water overnight at room temperature. The experimental unit consists of a donor and receptor compartment. Donor compartment consists of a boiling tube which was cut open at one end and tied with dialysis membrane at the other end into which niosomal dispersion was taken for release study. Receptor compartment consists of a 250 ml beaker which was filled with 50mL of mixed buffer containing Tween 80, PEG 400, ph 7.4 phosphate buffer in 0.2:0.8:9 ratio as release medium. The receptor compartment was maintained at 37 C and stirred by a magnetic bar at 500 rpm. At predetermined time intervals 1 ml aliquots were withdrawn from the sampling port and were replaced with an equal volume of fresh buffer to maintain constant volume. The samples were analyzed spectrophotometrically at 284 nm in reference with the constructed calibration curve. 2.7 Ex vivo permeation studies Ex vivo permeation studies were conducted using rat skin. The abdominal hair of albino rats (wistar strain) was removed using depilatories. The abdominal skin was surgically removed from the animal and adhering subcutaneous fat was carefully cleaned. The membrane was soaked in the buffer prior to the experiment. The permeation of drug from all the formulations was determined by using Franz diffusion cell. The excised rat skin was mounted on the receptor compartment with the stratum corneum side facing upwards into the donor compartment. IJPT July-2015 Vol. 7 Issue No Page 8123

5 The diffusion assembly was prepared byplacing formulation over rat skin mounted between donor and receptor compartment. The receptor fluid consisted of 25mL of mixed buffer containing Tween 80, PEG 400, ph 7.4 phosphate buffer in 0.2:0.8:9 ratio. The entire setup was placed over magnetic stirrer and temperature was maintained at about 37± c. The samples were collected at 0.5,1,2,4,8,12 and 24 hr and stored under refrigerator conditions till the analysis was carried out. All the experiments were conducted in triplicate. 2.8 Drug polymer interaction study In order to determine a possible interaction between Domperidone and the polymeric materials, infrared (IR) spectroscopy studies were carried out on pure substances and their physical mixtures. The IR spectra were recorded using an IR-Spectrophotometer (PerkinElmer FT-IR, PerkinElmer,BX-I SYSTEM) utilizing the KBr pellet method. The infrared spectra of Domperidone, physical mixture of drug (Domperidone) and excipients were recorded between 400 to 4000 cm -1 on FT-IR to detect the drug-excipients interactions. The resultant spectra were compared for any possible changes in the peaks of the spectra. 2.9 Stability study For this study, the optimized niosomal dispersion of span 20, span 40, span 60 and span 80 were kept at 2 8 C for a period of 6 weeks. The stability of the niosomes in terms of change in % EE and vesicle size were investigated Preparation of niosomal gels Optimized batch of niosomal dispersion based on least particle size, highest entrapment efficiency and maximum drug release was used for the preparation of niosomal gel. HPMC and aloe vera gels were selected as the gel base. Initially required amount of HPMC was added to water and kept overnight for complete hydration of polymer chains. Niosomal dispersion was incorporated into the hydrated HPMC gel base and aloe vera gel base to give 5, 1% W/W gels respectively. 3. Results and discussion 3.1 Encapsulation efficiency and vesicle size As shown in Table 2, encapsulation efficiency of niosomes formed from S20, S40, S60 and S80. Highly lipophilic drugs like estradiol are intercalated almost completely within the lipid bilayer of liposomes and niosomes (7). Entrapment efficiencies of Niosomal dispersions prepared with different surfactants were in the order span 60>span 80>span 40>span 20. This may be due to increase in chain length from span 20 to span 80. The introduction of IJPT July-2015 Vol. 7 Issue No Page 8124

6 double bonds into the paraffin Chains resulted in lowest entrapment of span 80 formulation compared to span 60. The range obtained was %. Table 2: entrapment efficiency, size and zeta potential of niosomes. Formulation code Entrapment efficiency (%) Size (nm) PDI Zeta Potential F1 62.3± ±6.8 F2 68.7± ±8.7 F3 69.9± ±7.4 F4 79.7± ±12.0 F5 81.5± ±8.9 F6 82.8± ±11.4 F7 83.2± ±4.6 F8 89.6± ±5.9 F9 91.9± ±9.3 F ± ±3.9 F ± ±7.3 F ± ±9.2 The mean vesicle size of niosomes formed from estradiol proniosome formulations is given in Table 2. The differences of vesicle size among all niosomes with different grades of Spans were not great. All vesicles were in the size ranging from to 0.409µm which favored efficient transdermal delivery 3.2 Microscopy: A, B, C and D are optical microscope images of span 20, 40, 60 and 80 niosomes respectively before sonication when observed in 40X magnification. Transmission electron microscopy of the vesicles was performed to elucidate the morphology of the domperidone niosomes. As shown in fig. 1. The niosomes obtained were spherical large unilamellar vesicles. A B C IJPT July-2015 Vol. 7 Issue No Page 8125

7 D E Fig 1: (A) Span 20 niosomes; (B) span 40 niosomes; (C) span 60 niosomes; (D) span 80 niosomes; (E) Transmission electron micrograph of niosomal vesicle 3.3 In vitro drug release: Results of domperidone in vitro release from different formulae are illustrated in fig. 2. The kinetic analysis of all release profiles followed diffusion controlled mechanism with an initial relative fast release phase followed by a slower release one. The initial phase was due to the desorption of domperidone from the surface of niosomes while the drug release in the slower phase was regulated by diffusion through the swollen niosomal bilayers (8). Cumulative % drug released Time(h) F1 F2 F3 Cumulative % drug released Time(h) F4 F5 F6 A B Cumulative % drug released Time (h) F7 F8 F9 Cumulative % drug released Time (h) F10 F11 F12 C D IJPT July-2015 Vol. 7 Issue No Page 8126

8 Fig 2: (A) Comparision of in vitro drug release of different formulations of span 20; (B) Comparision of in vitro drug release of different formulations of span 40; (C) Comparision of in vitro drug release of different formulations of span 60; (D) Comparision of in vitro drug release of different formulations of spn 80. [[ This profile could be advantageous if we considered the importance of epidermis saturation with initial fast drug released to achieve high concentration gradient required for successful drug delivery to the blood (9). Among all the formulations F8 exhibited maximum amount of drug release i.e % in 24 hour. Based on the results of entrapment efficiency, vesicle size, in vitro drug release F2, F5, F8, F11 formulations were optimized and used for ex vivo permeation studies through rat abdominal skin. 3.4 Ex vivo permeation study Comparative ex vivo permeation studies were conducted for optimized batch of niosomal suspension of span 20, span 40, span 60 and span 80, HPMC and Aloe niosomal gels prepared using optimized batch and for plain HPMC and Aloe gels. The results are given in the Table. Domperidone loaded niosomes showed an improvement of the drug percutaneous permeation through rat abdominal membranes with respect to solution of the drug (33.3 µg/hr/cm 2 ). This phenomenon is probably due to the enhanced percutaneous carrier capacity of niosomes (10,11) coming from the flexibility and deformability of the structure of these colloidal systems, which enables them to pass through skin (12,13), similarly to other deformable and flexible vesicular carriers, e.g. ethosomes (14,15).The permeation of drug from niosomal gel is more compared to plain gel as encapsulation of domperidone in niosomes produced an enhancement of permeation compared to plain gel. The permeation of drug from niosomal gel is more compared to the niosomal dispersion as the gel structure can promote the penetration of drug across the stratum corneum owing to the occlusion effects from the gel formulation which can enhance skin hydration and consequently increase the absorption and penetration of drug across the rat skin. Transdermal flux obtained was in the order span 60 niosomal gel>span 80 niosomal gel>span 40 niosomal gel>span 20 niosomal gel>span 60 niosomes>span 80 niosomes>span 40 niosomes>span 20 niosomes>plain drug gels>drug solution. Several mechanisms can be used to explain the ability of niosomes to modulate drug transfer across skin (16,17), including (i) adsorption and fusion of niosomes onto the surface of skin leading to a high thermodynamic activity gradient of drug at the interface, which is the driving force for permeation of lipophilic drugs, (ii) the effect of vesicles as the penetration enhancers to reduce the barrier properties of stratum corneum, and (iii) the lipid bilayers of niosomes as rate-limiting membrane barrier for drugs. IJPT July-2015 Vol. 7 Issue No Page 8127

9 Domperidone loaded in span 60 niosomes incorporated in gel exhibited maximum amount of drug permeation in 24 hours and highest flux of 67.4 µg/hr/cm 2. Table-3: ex vivo permeation through rat skin. Formulation Cumulative Amount of Flux drug permeated in 24 h (µg/hr/cm 2 ) Drug solution ± Span 20 niosomes ± Span 40 niosomes ± Span 60 niosomes ± Span 80 niosomes ± Span 20 aloe gel ± Span 40 aloe gel ± Span 60 aloe gel ± Span 80 aloe gel ± Plain aloe gel ± Span 20 HPMC gel ± Span 20 HPMC gel ± Span 20 HPMC gel ± Span 20 HPMC gel ± HPMC gel ± Drug polymer interaction studies FTIR spectra of domperidone exhibited principal peaks at 3003 cm -1 corresponding to N-H stretching, 1722cm - 1 corresponding to C=O stretching, and cm -1 corresponding to N=C stretching peak, 730 cm -1 for out of plane CH bending of disubstituted aromatic ring. There were some other characteristic peaks which were observed at 1158cm -1, 1062cm -1. The physical mixture of drug and span 40, drug and span 60 showed approximate superimposition of the drug. The results suggest that there was no interaction between drug and polymer which were used in the present study. IJPT July-2015 Vol. 7 Issue No Page 8128

10 Fig 3: FT-IR spectra of domperidone (A); drug+span 60 (B); 3.6 Stability studies Domperidone loaded niosomes were stored at refrigerated temperature for 60 days, and average size, % entrapment efficiency were determined. Stability studies were conducted for optimized formulation (F2, F5, F8, F11) which showed better size, PDI, zeta potential, entrapment efficiency and release characteristics. The number of samples estimated was in triplicate. Stability data showed that the niosomal dispersions were stable over period of time. Table 4: stability data. Storage period 68 F2 Size (nm) %EE F5 Size (nm) %EE F8 Size (nm) %EE F11 Size (nm) 1 st day %EE 60 th day Conclusion Niosomal dispersions of domperidone were prepared by film hydration method using Span 20, Span 40, Span 60 and Span 80 as surfactants in different ratios. The formulated niosomes were evaluated for entrapment effienciency, size, zeta potential, poly dispersity index, morphology, in vitro drug release studies and ex vivo permeation through rat abdominal skin. Domperidone loaded in span 60 niosomes incorporated in gel exhibited maximum amount of drug permeation and high transdermal flux. Aloe gel was found to be a good vehicle for niosomes compared to HPMC gel as it showed higher flux compared to HPMC gels. The results suggested that niosomes could better promote the IJPT July-2015 Vol. 7 Issue No Page 8129

11 transdermal delivery of Domperidone, especially due to their simple scaling up and their ability to control drug release. References 1. Shahiwala A, Misra A. 2002, J Pharm Sci, 5, Balasubramaniam A, Kumar VA, Pillai KS. 2002, Drug Dev Ind Pharm, 28, Jain CP, Vyas SP. 1995, J Microencapsul, 12, Paolino D, Lucania G, Mardente D, Alhaique F, Fresta M. 2005, J Control Rel, 106, Uchegbu IF, Vyas PS. 1998, Int J Pharm, 172, Schreier H, Bouwstra J. 1994, J Contr Release, 30, Gulati M, Grover M, Singh S, Singh M. 1998, Int J Pharm,165, Pardakhty A, Varshosaz J, Rouholamini A. 2007, Int J Pharm, 328 (2), Csoka G, Marton S, Zelko R, Otomo N, Antal I. 2007, Eur J Pharm Biopharm, 65 (2), Paolino D, Muzzalupo R, Ricciardi A, Celia C, Picci N, Fresta M. 2007, Biomed Microdevices, 9, Menger FM, Keiper JS. Gemini surfactants. Angew. Chem. Int. Ed. Engl. 200, Maghraby EI, Williams GM, Barry AC. 2004, Int J Pharm, 276, Touitou E, Dayan N, Bergelson L, Godin B, Eliaz M. 2000, J Control Rel, 65, Vora B, Khopade AJ, Jain NK. 1998, J Contr Release, 54, Aranya M, Penpan K, Warangkana L, Wernerc, Friedrich Götz, Worapaka M, Jiradej Manosroi. 2010, Int J Pharm, 392, Chul Soon Yong. 2009, Int J Pharm, 377, Gupta RR, Jain SK, Varshney M. 2005, Biointerfaces, 41, Corresponding author Dr. Shayeda Asst. Prof. Department of Pharmaceutics, University College of Pharmaceutical Sciences, Kakatiya University, Warangal shayeda_ucpsc@yahoo.com, IJPT July-2015 Vol. 7 Issue No Page 8130