Available online at www.scholarsresearchlibrary.com Scholars Research Library Der Pharmacia Lettre,, 7 (12):365-371 (http://scholarsresearchlibrary.com/archive.html) ISSN 975-71 USA CODEN: DPLEB4 The study the effect of polymer and surfactant concentration on characteristics of nanoparticle formulations Priyanka Saharan, D. C. Bhatt, S. P. Saharan and Kavita Bahmani Department of Pharmaceutical Sciences, faculty of Pharmacy, Guru Jambheshwar University of Science and Technology, Hisar ABSTRACT The Aim of the present work was to study the effect of polymer and surfactant concentration on characteristics of nanoparticle formulations. Nanoparticles were prepared by solvent evaporation method. The prepared nanoparticles were characterized by particle size, entrapment efficiency, drug loading. Compatibility study of drug and polymer was carried out by Fourier transform infrared spectroscopy (FTIR). The results of this study showed that the particle size, entrapment efficiency and drug loading were 295.5nm, 79.61% and 36.78% respectively. The drug release from optimized batch was found to be 74.98 % in hrs. In this study Glipizide loaded PLA nanoparticles were prepared successfully and showed promising sustained drug release profile. Keywords: Glipizide, PLA, Nanoparticles, Entrapment efficiency, Diabetes mellitus INTRODUCTION Diabetes mellitus is characterized by insulin dependency, altered metabolism of lipids, carbohydrates, and proteins, and an increased risk of complications from vascular diseases [1]. Glipizide belongs to the second-generation sulfonylureas that can be used in the treatment of non-insulin-dependent diabetes mellitus (NIDDM) [2]. Glipizide stimulates secretion of insulin from the β cells of pancreatic islets tissue and increases the number of insulin receptors and may increase the concentration of insulin in the pancreatic vein. Glipizide is a weak acid (pka = 5.9) and low solubility in water and highly permeable drugs according to the Biopharmaceutical Classification System (BCS class II) [3].As the drug is having low solubility; it dissolves very poorly so it delays the absorption which indicates that the rate of dissolution is the controlling step for absorption. Glipizide is having good permeability, poor aqueous solubility and poor drug dissolution, which leads to improper absorption and decreased oral bioavailability. So these limitations have to be addressed in order to achieve intended therapeutic effect, which can be done by preferring nanoparticles approach over others. The main goal in designing of polymeric nanoparticles for drug delivery system is to deliver the drug in controlled and targeted release to the specific site of action at the therapeutically optimal rate [4]. This approach can also offer advantages such as limiting fluctuation within a therapeutic range, reducing side effects, decreasing dosing frequency, and improving patient compliance [5]. 365
The present investigation aims to formulate and characterize PLA controlled release nanoparticles containing Glipizide by solvent evaporation method for improved bioavailability which could overcome the drawbacks of Glipizide delivery through conventional dosage forms [6]. MATERIALS AND METHODS Materials Glipizide was purchased from the international test centre, (Panchkula, India) and Poly-D, L-lactide (PLA) from MP Biomedical, LLC. All other chemicals and reagent were used are of analytical grade. Experimental design The optimization technique was utilized to obtain systematic formulation design in order to minimize the number of trials, and analyse the response surface to investigate the effect of independent variables on the response [7]. In this study, 3 2 full factorial design was adopted for optimization of the formulation of nanoparticles. The amount of PLA polymer (X 1, mg) and the concentration of PVA (X 2, %w/v) were taken at three level (-1,, +1) as formulation factors (Table 1). The particle size (nm), entrapment efficiency (EE) and drug loading (DL) were taken as dependent variables. Response surface methodology (RSM) was used for the analysis using Design Expert Software (Version 8..7.1). The software suggested 13 trial runs for the factorial design batches (F1-F13) are shown in table No.2 Table No.1 Independent variables Levels Low ( 1) Medium () High (1) X 1 1 X 2...45 Preparation of nanoparticles Polymeric nanoparticles were prepared by solvent evaporation method. Accurately weighed quantity of drug (mg) was dissolved in dichloro methan (DCM) and acetone (5ml each) and polymer in DCM ( ml) separately and added into the aqueous phase ( ml distilled water) containing surfactant using magnetic stirrer. The solution was sonicated using a probe sonicator for 6 min. The emulsion was kept on magnetic stirrer for 4-5 hrs at room temperature for the evaporation of organic solvent. After that the nanoparticles were collected by centrifugation for minutes at, rpm (Remi, Mumbai).During centrifugation PVA was removed along with decant. Trace amount of PVA present in nanoparticles was removed by washing with distilled water. After washing final nanoparticles were lyophilized for 48 hrs. Characteristics of Glipizide loaded PLA nanoparticles Particle size determination The particle size of the PLA Glipizide nanoparticles was measured by particle size analyzer (Malvern Zetasizer)[8]. Entrapment efficiency (%EE) and drug loading (%DL) The suspension of nanoparticles was centrifuged at rpm for min. The supernatant was analyzed for free Glipizide at 276 nm spectrophotometrically. The entrapment efficiency was calculated using formula given below Entrapment efficiency (%) = (total amount of the drug amount of the free drug) Total drug Drug loading The drug loading refers to the percentage amount of drug entrapped in nanoparticles. [9]. The drug loading was calculated using formula given below Drug Loading (%) = (Amount of drug Unentrapped drug) Weight of nanoparticles recovered FT- IR Studies: FTIR studies were performed to analyze the compatibility studies between the drug and excipients. Peaks of individual pure drug and the peak of drug polymer combination were compared to find out the interactions. IR 366
spectra of pure drug and the drug polymer mixture were obtained in KBR pellets method by using IR affinity- FTIR spectrophotometer (Perkin Elmer BX II) []. Drug release studies The in-vitro drug release studies were performed on nanoparticles formulations using dissolution Test Apparatus, Type-II (paddle type) (stirring speed rpm in 9ml, phosphate buffer ph 6.8 temperature 37±.5 C. Sample aliquots of 5 ml were withdrawn at specific intervals and replaced with equal volume of fresh buffer solution to maintain the sink conditions. The samples were analyzed spectrophotometrically at 276 nm against the blank [11]. RESULTS AND DISCUSSION Particle size The results of particle sizes of Glipizide loaded nanoparticles of different batches are shown in table 2. The particle size of prepared formulations F1 to F13 was found to be in the range of 295.5 7.4 nm. From the above results, it would be inferred that the particle size increases with increase in amount of polymer. The size of polymeric nanoparticles was highly dependent on polymer concentration that would be explained in term of tendency of polymer to coalesce at high polymer concentration. The increased amount of polymer provided an additional space for drug molecules to get entrapped, thus decreasing the total surface area. On increasing the concentration of surfactant (PVA), the particle size was found to decrease. This might be due to the tight surface formed by PVA macromolecular chains at high concentration. Percentage entrapment efficiency and Percentage drug loading The entrapment efficiency and drug loading of different batches are shown in table 2. The entrapment efficiency and drug loading ranged from.67-79.16% and 14.1-36.78% which indicated that increase in amount of PLA polymer also decreased the % E.E and % drug loading but increase with increase in PVA concentration. This may be due to the more compact polymer coat, which limits its entrapment and more time taken for the precipitation of polymer which was in higher amount. The percentage entrapment efficiency increased with increase in PVA concentration, this may be due to more free drug available on the surface of nanoparticles in place of entrapment on the nanoparticles. Run TABLE (2): Experimental design of PLA nanoparticles and results for the various measured responses Amount of polymer PLA(mg) X 1 Amount of surfactant PVA(%w/v) X 2 Particle size(nm) Y 1 Entrapment efficiency (%) Y 2 %Drug loading Y 3 1. 58.5 62.48 19.13 2 1. 7.4.67 14.1 3.3 5.4 63.45 21.93 4 1.3 6.1 52.37.9 5.3 463.2 64.2.89 6 1.45 566.3 55.23 17.37 7.3 473.8 63.98 21.4 8.3 4.5 63.49 9. 4.5 64.13.14.45 295.5 79.16 36.78 11.3 398.6 71.34 32.34 12.3 498.7 65 21.16 13.45 376.4 67.92. Response surface analysis Response surface (3 Dimensional) plot showed the combined effect of PLA polymer and PVA surfactant on particle size of nanoparticles (fig.1).response surface plot (3 Dimensional) (fig.2 and fig. 3) shows combined effect of PLA polymer and PVA surfactant on entrapment efficiency and drug loading.. 367
Design-Expert Software Factor Coding: Actual Particle Size (PS) (nm) Design points above predicted value Design points below predicted value 7.4 295.5 X1 = A: Amount of polymer (PLA) X2 = B: surfactant(pva) Particle Size (PS) (nm) 277.41 8 7 6.45 1.375 1.3 B: surfactant(pva) (%w/v).2. 75 A: Amount of polymer (PLA) (mg) Fig.1: Response surface plot showing the combined effect of PLA and PVA on particle size of nanoparticles Fig.2: Response surface plot showing the combined effect of PLA and PVA on % entrapment efficiency of nanoparticles Design-Expert Software Factor Coding: Actual Drug Loading (%) Design points above predicted value Design points below predicted value 36.78 14.1 X1 = A: Amount of polymer (PLA) X2 = B: surfactant(pva) 36.8847 Drug Loading (%).45 1.375 1.3 B: surfactant(pva) (%w/v).2. 75 A: Amount of polymer (PLA) (mg) Fig.3: Response surface plot showing the combined effect of PLA and PVA on % Drug loading of nanoparticles Fourier Transforms Infrared Spectroscopy (FTIR) The FTIR spectrum of Glipizide, PLA polymer and physical mixture of Glipizide with PLA is shown in fig.4, 5 and 6. 368
67.6 65 727.64 6 786.49 55 45 31.71 2365.47 2345.54 1926.21 1618.37 97.96 14.4 12.17 6.6 1248.41 1274.91 748.49 463.42 3.76 443.96 61.21 972.1 817.82 652.82 413. %T 8.37 5 2855.62 2943.24 31.81 33.13 1193.61 87.52 883.99 1292.11 18.99 93.65 137. 1333.61 686.28 1444.57 34.6 83.72 1484.99 116.27 1689.32 1651.62.34 5.91 577.72 631.36 6.44 66. -5.. 36 3 28 18 16 1 8 6. cm-1 57.4 Fig 4: FTIR spectrum of Glipizide 55 919.8 956.57 45 541.85 3652.4 66.91 11.37 3248.21 3327.8 2364.98 2345.69 94.6 %T 169.68 691.85 2998.76 2947. 871.94 756.22 1387.74 1458.92 1364.7 5 43.8 1762.84 1134.33 1186.31 89.11.. 36 3 28 18 16 1 8 6. cm-1 Fig 5: FTIR spectrum of PLA 45. 817.65 3. 463.55 2244.74 96.5 2365.13 2667.92 727.72 443.97 %T 97.95 412.81 756. 5 8.16.73 1758.59 1248.6 2855.59 26. 1333.43 18.5 93.16 686. 6.46 3328. 2997.64 1684.45 1446.37 87.55 66.7 31.39 2943.84 83.74.46 883.75 577.45-5 1655.61 5.75-7.. 36 3 28 18 16 1 8 6. cm-1 Fig 6: FTIR spectrum of physical mixture of Glipizide with PLA 369
Drug release studies The drug release pattern of Glipizide loaded nanoparticle is shown in Fig 7. The percentage cumulative drug release from the nanoparticles was found to be in the range of 73.72% to 78.12% in hrs at ph 6.8. From the study it was observed that drug release decreased with increase in polymer concentration due to the high viscosity of PLA which on contact with the dissolution medium, surface of nanoparticles becomes wet and forms viscous gel layers. As the concentration of PLA increases viscosity of the gel layers increases while the diffusion coefficient of drug decreases. % Cumulative release 9 8 7 6 Dissolution profile of nanoparticles in phosphate buffer (ph 6.8) Time (Min.) 6 7 Fig.7: Drug Release Profile of F1 F6 F1 F2 F3 F4 F5 F6. % Cumulative release 9 8 7 6 Dissolution profile of nanoparticles in phosphate buffer (ph 6.8) Time (Min.) 6 7 Fig.8: Drug Release Profile of F7 F13 CONCLUSION F7 F8 F9 F F11 F12 F13. Glipizide loaded PLA nanoparticles were prepared by solvent evaporation method with average particle size of 295.5 nm, entrapment efficiency of 79.16% and drug loading 36.78%. FT-IR study showed there was no interaction 37
of drug with polymer. A slow drug release from the Glipizide loaded PLA nanoparticles was observed which suggested that Glipizide is a suitable candidate for the further development of nanoformulations. Acknowledgment The author is highly thankful to Chairman, Department of Pharmaceutical Sciences, for providing necessary facilities. REFERENCES [1] Roy Somadas, Manjanna K.M., J Adv Scient Res, 11, 2, 4, 46-54. [2] D. Mahalaxmi, A. Senthil, V. Prasad, B. Sudhakar, S. Mohideen, International Journal of Biopharmaceutics,, 1, 2, -7. [3] Kambham Venkateswarlu, A. Shanthi, Journal of Pharmacy and Biological Sciences, 12,, 17-23. [4] L. Mu, M.B. Chan-Park, C.Y. Yue, S.S. Feng, Innovation in Manufacturing Systems and Technology (IMST), 4, 1, 1-7. [5] Behera Amulyaratna and Sahoo Sunit Kumar, Tropical Journal of Pharmaceutical Research June, 12, 11, 3, 345-3. [6] Shelesh Jain, Swarnlata Saraf, Diabetes & Metabolic Syndrome: Clinical Research & Reviews, 9, 3,113 117. [7] A. Umar faruksha, T. Vetrichelvan, Int.J.PharmTech Res., 13, 5, 2. [8] Lynda Lamoudi, Jean Claude Chaumeil, and Kamel Daoud. International Journal of Chemical Engineering and Applications, 13, 4, 6. [9] Aenugu Saritha Reddy, Abbaraju Krishna Sailaja. World Journal of Pharmacy and Pharmaceutical Sciences, 14, 3, 6, 1783. [] Sutar PS, Joshi VG. UJP, 13, 2, 5, 1-141. [11] Naik JB, Mokale VJ, Shevalkar GB, Patil KV, Patil JS, Yadava S, Verma U, International Journal of Drug Delivery, 13, 5, -8. 371