EFFECT OF SURFACTANTS AND CHOLESTEROL ON PHYSICAL PROPERTIES OF BCS CLASS II DRUG LOADED NIOSOMES

Transcription

1 International journal of Applied Pharmaceutical and Biological Research, 217; 2(6): 8-14 Research Article ISSN : EFFECT OF SURFACTANTS AND CHOLESTEROL ON PHYSICAL PROPERTIES OF BCS CLASS II DRUG LOADED NIOSOMES SHALIN C* 1, SWATHI P NAIR 1, SHIJILA P 1 1Department of Pharmaceutics, Rajiv Gandhi Institute of Pharmacy Trikaripur, Kasargod, Kerala, ABSTRACT Niosomal promising drug delivery system and have successfully used in various treatment in the medical field. It shows sustained drug release and the localized or targeted drug delivery. Both hydrophilic and lipophilic drugs are incorporated into niosomes to improve its efficacy. So many factors will affect the physical characteristics of niosomal vesicle. The physicochemical characters of encapsulated drug, type and properties of non-ionic surfactant and the cholesterol content may affect the properties of niosomes. Loratadine is an antihistaminic drug used for the treatment of allergic diseases. It belongs to BCS class II. Effect of surfactant and cholesterol on the loratadine loaded niosomes be investigated by preparing niosomes using Lipid Film Hydration method. Niosomes were assessed for particle size was determination, morphological studies, entrapment efficiency and in-vitro drug release. The mean particle size was found to be in between µm. The niosomes prepared by using span 6 shows highest entrapment efficiency 94.9% and in-vitro drug release Keywords: - Niosome; Cholesterol; Non-ionic surfactant; BCS II; INTRODUCTION Niosomes are radically non-ionic surfactant based vesicle in which an aqueous solution of solute is entirely enclosed by a membrane resulted from the self-assembly of hydrated surfactant molecules as bilayer. 12 Niosomes are one of the best drug delivery system among these carriers. Structurally, niosomes are similar to liposomes and also are equiactive in drug delivery potential but high chemical stability and economy make niosomes superior to liposomes. 1 The formation of vesicle size was regulated by different types of physicochemical factors such as HLB value of surfactants, Nature of drug, Concentration of cholesterol and non-ionic surfactant etc. 2 Niosomes are amphiphilic in nature. 13 The hydrophilic drug will entrap within the aqueous cavity and lipophilic drug will entrap between the non-ionic surfactant bi-layer. The vesicle formations are regulated by several factors like HLB value of non-ionic surfactants, nature of drug, concentration of cholesterol and non-ionic surfactant surfactants, method of preparation, etc. 14 The variation in vesicle formation will alter the drug release, entrapment efficiency, stability, etc of the niosomes which can be studied by preparing niosomes using different non-ionic surfactants and cholesterol with varying ratios. 4 Loratadine belongs to the BCS class II and this drug shows high lipophilic characters. It will entrap between the non-ionic surfactant bi-layer 5. The effect of surfactants and cholesterol on the drug loaded niosomes can be studied using this drug. 8

2 MATERIALS AND METHODS Loratadine was a kind gift sample from Caplin.laboratories.Ltd, Tamilnadu. Cholesterol, span 2, span 6, span 8, methanol, chloroform were obtained from Burdoyne Burbidges Mumbai. Preparation and Evaluation of Loratadine Niosomes Preparation of standard curve of loratadine 14 5 mg of loratadine was accurately weighed and dissolved in a small portion of methanol and made the volume up to 1 ml with double distilled water to give a concentration of 5µg/mL. Different volumes (1,2,3,4,5,6,7,8,9 and 1 ml) of the prepared solution were transferred to volumetric flasks. Each flask was made up to 25 ml with double distilled water to get concentrations 2, 4, 6, 8, 1, 12, 14, 16, 18, and 2 µg/ml. The different concentrations were analyzed spectrophotometrically a wavelength ranging from 2 nm to 4 nm to determine the wavelength of maximum absorbance. The calibration curve of loratadine was plotted by using the absorbance of different concentration of drug at 248 nm versus concentration. Preparation of niosomes 4 Niosomes were prepared using lipid film hydration technique with various concentrations of span and cholesterol. Surfactant ( span 2, 6, 8 ), cholesterol and drug were accurately weighed and dissolved in 15 ml ofchloroform : methanol mixture (2:1 v/v ratio). [33] The formula was shown in Table 1 Above mixture was sonicated for 1 min. Then it was vortexed in a round bottom flask at a temperature of C to remove the solvent for about 3 min. The formed thin lipid layer was hydrated with 1 ml of 7.4 Phosphate buffer at 6 C for 1hr. 7 the resultant dispersion was cooled in an ice bath then left for 4hrs at room temperature for complete hydration and stored at 4 C overnight before use. 6 Table 1: Composition of developed niosomes Formulation code Surfactant Used Weight taken ( in mg ) Drug Surfactant Cholesterol F Span 2 F F F F Span 6 F F F Span Surfactant: Cholesterol ratio 1 : 1 2 : 1 1 : 2 2 : 2 1 : 1 2 : 1 1 : 2 2 : 2 1 : 1 2 : 1 1 : 2 2 : 2 Evaluation of niosomes Vesicle size of niosomes 4 Vesicle size of each formulation was determined by an optical microscope. Each formulation was spread uniformly on a glass slide and observed under the 1X magnification optical lens. Vesicle shape of niosomes 4,8 The shape and morphological characters were obtained by SEM photographs of the niosomes. The formulations were placed into circular aluminium stubs using double adhesive carbon tape and coated 9

3 with gold in HITACHI ION SPUTTER E-11 vacuum evaporator, it was observed in HITACHI SU66 FE SEM (field emission scanning electron microscope) having acceleration voltage of 1.kv and magnification of 6.k-1.k Entrapment efficiency(ee%) 9,1 Entrapment efficiency of niosomes was determined by centrifugation method where the niosomal dispersion was centrifuged at 12 rpm for 9 min. The supernatant layer was separated and diluted using 7.4 phosphate buffer. Then determined the unentrapped drug spectrophotometrically. The percentage of entrapment efficiency was calculated using following equation. 7 % In-vitro drug release 6,15 The in-vitro drug release profile of niosomal dispersion was investigated using semipermeable cellophane membrane. The membrane which was previously soaked in 7.4 phosphate buffer and glycerin was stretched over the open end of diffusion tube, made watertight by a rubber band. Added niosomal dispersion equivalent to 2 mg into the diffusion tube having diameter 2.5cm which acted as donor compartment. 8 The glass tube was immersed in a vertical position inside a 1mL beaker containing 7.4 phosphate buffer (5 ml). The temperature was maintained at 37±.5 C and stirred at 1 rpm speed using magnetic stirrer. Samples were withdrawn from the receptor compartment at specified time intervals 1,2,3,4,5,6,7,8,9,1,11 and 12 hours. 11 Each time immediately after the removal of sample, the medium was replaced with fresh 7.4 phosphate buffer. The samples were analyzed for drug release spectrophotometrically at 248 nm. RESULTS AND DISCUSSION Preparation of standard curve of loratadine The slope of the standard plot of loratadine was found to be.47 with r 2.999, which is shown in figure 1. Absorbance (nm) STANDARD CURVE OF LORATADINE Concentration (µg/ml) y =.475x -.24 R² =.9998 Fig 1: Standard plot of loratadine Evaluation of niosomes Vesicle size of niosomes The mean particle size of the formulations was shown in the table 2 and figure 2. The vesicle size was determined for 5 niosomes in each formulation. It was found that as cholesterol content increased vesicle size also increases. As surfactant content increased vesicle size was found to be decreasing. The vesicle size of niosomes prepared by span 6 showed the lowest size than other. The order of particle size distribution of types of surfactant was span 2 > span 8 > span 6 1

4 Available Online : SHALIN C et al Int. J. Appl. Pharm. Bio. Res., 217; 2(6):8-14 Table 2 : Evaluation values of noisome %Entrapment Efficiency SL NO Formulation Code Mean Particle Size(µm) ( n=3) F F3 4 SD % Cumulative Drug Release ( n=3) SD F F F F F F Particle Size F2 F3 F4 F5 F6 F7 F8 Formulation code F9 1 2 Fig 2: Mean particle size of niosomes Vesicle shape of niosomes It was found that all 12 formulations has excellent morphology and spherical in structure. Which indicates that the formation of niosomes. Photographs are shown in the figure Entrapment efficiency(ee%) Fig 3 : SEM Photograph of loratadine niosomes 11

5 The entrapment efficiency of 12 formulations was shown in the table 2. It was found to be in the range of 8-96 %. Higher entrapment efficiency of the vesicles of span 6 is predictable because of its higher alkyl chain length. The entrapment efficiency was found to be higher with the formulation no. The niosomal formulations having high surfactant concentration (F2, F6 and ) have the higher entrapment efficiency which might be due to the high fluidity of the vesicles. F6 (94.9%), which shows higher entrapment of loratadine. It reveals that the HLB value of surfactant plays an important role in entrapment efficiency. As HLB value of surfactants increasing, the encapsulation efficiency also found to be increasing. But the variation in gel-liquid transition temperature may affect the entrapment efficiency of span 2. The order of entrapment efficiency was span 6 > span 2 > span 8. It was also observed that very high cholesterol content (F3, 1) had a lowering effect on drug entrapment in the vesicles (85.9 %, 81.6%). This could be due to the fact that cholesterol beyond a certain level started disrupting the regular bi-layered structure leading to loss of drug entrapment. In-vitro drug release The release study was conducted for all the 12 formulations, which is shown in the table 2 and figure. The formulations were found to have provided approximately 9% release within a period of 12 hours. The formulations which had high cholesterol ratio (F3, F7, 1) were found to reduced drug release. The slower release of drug from multilamellar vesicles may be attributed to the fact that multilamellar vesicles consist of several concentric spheres of bilayer separated by aqueous compartment. The three formulations F2, F6, and F9 were found to give a cumulative release of 9.37 %, % and % respectively over a period of 12 hrs, which indicating that the surfactant content increasing the drug release of BCS class II drug. From the 12 formulations, formulation F6 showed highest drug release, which was prepared by using span 6. Optimum HLB value also playing an important role in the drug release %CDR F5 F6 F7 F8 5 1 Time(hours) 15 Fig 4: In-vitro release profile of niosomes formulated using span %CDR 4 2 F2 F3 F4 5 1 Time(hours) 15 12

6 Fig 5: In-vitro release profile of niosomes formulated using span %CDR F Time(hours) Fig 6: In-vitro release profile of niosomes formulated using span 8 CONCLUSION To conclude, the findings of the present investigation was an evidence that, the non-ionic surfactants and cholesterol was affecting the BCS class II drug loaded niosomes in different ways. Niosomes formulated using span 6 have shown the best drug release profile, smallest vesicle size, and entrapment efficiency. The optimum HLB value of the surfactant span 6 made this formulation better than others. The surfactant content increasing entrapment efficiency and in-vitro drug release. In the same time, cholesterol content was decreasing entrapment efficiency and drug release of loratadine loaded niosomes. Finally, it can be concluded that the surfactants and cholesterol plays an important role upon the lipophilic drug loaded niosomes. ACKNOWLEDGEMENT The author expresses sincere thanks to the Kerala University of Health Sciences, management, and principal of Rajiv Gandhi Institute of Pharmacy for providing a platform for the research work. We also thank Caplin.laboratories.Ltd Tamilnadu for providing gift samples for this work REFERENCES 1) Shakya.V and Bansal.B.K. Niosomes: A Novel Trend In Drug Delivery. International Journal of Research and Development in Pharmacy and Life Sciences, 214; 3(4): ) Vyas S.P and Khar R.K. Niosomes, Targeted and Controlled Drug Delivery. 1 st edition, CBS Publishers & Distributors Pvt. Ltd. 212, pp ) Lohumi Ashutosh, Rawat Suman, Sarkar Sidhyartha, Sipai Altaf bhai, Yadav M, and Vandana. A Novel Drug Delivery System: Niosomes Review. Journal of Drug Delivery & Therapeutic,. 212; 2(5): ) Vyshnavi. V, Indira. S and Prathima Srinivas. Formulation and Evaluation of Nasal Niosomal in situ Gels of Loratadine. International Journal of Pharmaceutical Sciences and Drug Research, 215; 7(1): ) Pooja and Gupta Ashok Kumar. Formulation and evaluation of aceclofenac ophthalmic gel. African Journal of Pharmacy and Pharmacology, 213; 7(34): ) Shivhare UD and Wasnik SV. Formulation development and evaluation of niosomal gel for transdermal delivery of an antihypertensive drug. International Journal of Biopharmaceutics, 213; 4(3): ) Ahmad Usama, Gihan Fetih and Tahani El-Faham. Performance of Meloxicam Niosomal Gel Formulations for Transdermal Drug Delivery. British Journal of Pharmaceutical Resear, 216; 12(2): ) Puja H. Jaiswal, Nayan A. Gujarathi, Bhushan R. Rane and Sunil P Pawar. Formulation of Niosomal Gel of Diclofenac Sodium and its In - Vitro Characterization. International journal of pharmacy and pharmaceutical research, 216; 6(4):

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