Characterization study and optimization of swelling behavior for p(HEMA-co-Eudragit L-100) hydrogels by using Taguchi Method

Abstract

The aim of this study is to produce the smart hydrogel to use insulin release for human body. p(HEMA-co-Eudragit L-100) hydrogels containing different ratios of 2-Hydroxyethyl methacrylate (HEMA) and Eudragait L-100 were synthesized by using ammonium persulfate (APS) as an initiator and ethylene glycol dimethacrylate (EGDMA) as a cross linker. The structures of hydrogels produced were characterized by using Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning electron microscope (SEM) analysis. In this way, optimum synthesis conditions were determined for p(HEMA-co-Eudragit L-100) hydrogels by using Taguchi method as an optimization method. The gelling percentages of all hydrogels were calculated. After all, the swelling behaviors (%) of hydrogels were investigated in range of various times (1–44 hrs), temperatures (20–50°C) and pH (2–12) and the optimum process conditions in the production of hydrogels were determined. Consequently, the optimum time, temperature and pH were 24 hours, 37°C and 7, respectively. Thus, this hydrogel could be evaluated in insulin release for diabetes treatment and drug industry.

Keywords

Hydrogel optimization spectroscopy structure

1. Introduction

Hydrogels are known as three-dimensional crosslinked polymeric structures. They are insoluble in water that are able to swell in an aqueous medium. Nowadays, the studies obtained that many hydrogels show continuous or discontinuous phase transition with a small variation of surrounding conditions such as temperature, pH, light, electric fields and chemical and ionic strength [1]. The hydrophilicity of the polymers impart water-attracting properties to the system. Their characteristic water-insoluble behavior makes a contribution to the presence of chemical or physical cross-links [2].

Hydrogels have been used mainly in the pharmaceutical field as carriers for delivery of different drugs, peptides etc. [3]. pH-responsive delivery systems are known in a number of different dosage forms, such as sustained-release tablets, micelles, microparticles and microspheres. Microsphere form is one of the prospect dosage forms because of its large specific surface area and high drug loading efficiency [4].

The researchers with an extensive research has been performed poly(hydroxyethyl methacrylate) as a synthetic hydrogel in the biomedical use of hydrogels due to its biocompatible and well-controlled rather than sustained-release delivery systems containing bioactive agents [5].

Zhang et al. (2012) [6] studied the preparation and characterization of nanoparticles based on thiolated Eudragit L-100 and unmodified polymer and evaluation their potential for the transportation of insulin in rats. The delivery system was a novel tool to improve the absorption of protein and peptide drugs.

Huynh et al. (2009) [7] investigated the profile of insulin release from mixtures of various pH/temperature-sensitive hydrogels and insulin in rats. The results showed that the diabetic rats could be treated for more than 1 week with a single injection of the complex mixture containing insulin in a copolymer solution and the pH/temperature-sensitive insulin–hydrogel complex system had therapeutic potential.

Advances in polymer science and modifications of the backbone structures of biopolymers as copolymers, grafted copolymers, interpenetrating polymeric network hydrogels, polymeric micro-/nano-devices have contributed to the development of devices for oral insulin delivery. These systems resisted the variable pH medium before delivering insulin through various pathways in the intestine [8].

Hao et al. (2013) [9] studied a novel emulsion diffusion method to prepare enteric Eudragit L/100-55 nanoparticles by ultrasonic dispersion and diffusion solidification. In addition, the Eudragit L/100-55 nanoparticles showed a strong pH-sensitive release in vitro. The enteric Eudragit L/100-55 nanoparticle could be synthesized successfully via this method.

In previous study, Eudragit RL-PO was used as a polymer for preparation of acyclovir loaded nanoparticles due to its high permeability property and application for sustained release drug delivery systems by using nanoprecipitation method. Eudragit RL-PO is a copolymer of ethyl acrylate, methyl methacrylate and a low content of methacrylic acid ester with quaternary ammonium groups. The preliminary results showed that acyclovir loaded Eudragit RL-PO nanoparticles have an effect in sustaining drug release for a prolonged period [10].

Sadeghi (2010) [11] investigated acrylic acid and 2-hydroxyethyl methacrylate monomers were directly grafted onto chitosan using ammonium persulfate as an initiator and methylenebisacrylamide as a crosslinking agent under an inert atmosphere medium. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Moreover, the swelling of superabsorbing hydrogels was examined in solutions with pH values in range of 1–13.

Swelling behavior of poly((2-dimethyl amino)ethyl methacrylate-co-BMA) was investigated by Emileh et al. [12]. The results indicated that the pH/temperature sensitive phase transition behavior of the gels could be changed in various temperature/pH of the swelling enviroment at constant hydrogel composition.

Haque and Sheela (2013) [13] surveyed the preparation polymer blends of eudragit/chitosan of varying compositions and observe the miscibility at different temperatures by viscosity, ultrasonic velocity, density etc. techniques. The polymers used in the study have been selected based on pharmaceutical and medical applications to create an adjustable system towards sustained release oral drug delivery system.

In this study, p(HEMA-co-Eudragit L-100) hydrogels containing HEMA and Eudragait L-100 were synthesized by using APS as an initiator and EGDMA as a cross linker. The optimum synthesis conditions were determined for hydrogels. Taguchi method was used as an optimization method for 16 experiments as 4 levels and 4 parameters. The analysis results (FT-IR, SEM) showed that the hydrogels were synthesized successfully.

2. Experimental

2.1. Materials

APS used as an initiator was supplied from Sigma-Aldrich. Also, EGDMA, HEMA, Eudragit L-100 were supplied from Sigma-Aldrich (95%), Fluka (97%) and Evonik, respectively.

2.2. Methods

2.2.1. Preparation of p(HEMA-co-Eudragit L-100) hydrogels

Eudragit L-100 (0.3–0.6 g) polymer was dissolved in ethanol, then HEMA (0.5–2 mL), EGDMA (0.005–0.02 mL) and APS (0.03–0.06 g) initiator was added at 70°C in the reactor (Fig. 1) [14]. The reaction of hydrogels were shown in Fig. 2. After 24 hours waiting in the hydrogel tube, the hydrogels were cut with determined sizes (Fig. 3).

Fig. 1.

Experimental set up.

Fig. 2.

An illustrated scheme of reaction for p(HEMA-co-Eudragit L-100) hydrogel.

Fig. 3.

Hydrogels.

Gels were dried in an oven at 40°C for 24 hours to constant until weighing was recorded. Gelling samples was allowed to gel in distilled water (10 mL). Gelling values (%) were calculated at constant weight for samples (1): $\begin{matrix} (1) & Gelling (%) = [m / m_{0}] \times 100 \end{matrix}$ where $m_{0}$ : the constant weighing result (g); m: after gelling weighing result (g).

Gelling samples was allowed to swell in phosphate acid buffer (boric acid, acetic acid, phosphate acid) to pH:7.42. Then, the swelling ratios were calculated (2): $\begin{matrix} (2) & Swelling (%) = [(w - w_{0}) \times 100] / w_{0} \end{matrix}$ where $w_{0}$ : constant mass before put into the buffer (g); w: constant mass after put into the buffer (g). Swelling was investigated in range of 1–44 hours, temperatures (20–50°C) and pH (2–12), respectively.

2.3. Taguchi Method

Taguchi is a statistical method to optimize the process parameters and improve the quality of components in production. Graphs in method give optimum parameter values for experiments. Originally, Taguchi Method was developed for improving the quality of goods manufactured, later the application of method was expanded in many fields in Engineering, such as Biotechnology [15]. Taguchi Method includes identification of suitable control factors to obtain the optimum results of the processes. Results of the experiments are used to analyze the results and predict the quality of components in production. In addition, the method has a high effect on the manufacturing cost and it provides minimum cost for biomedical industry. Taguchi developed a special design of orthogonal arrays to study the entire parameter space with a small number of experiments only [16].

For the Taguchi design and analysis of results Minitab Release 13.20 Statistical Software was used after determined parameters. In classical methods one parameter was varied while keeping all others constant. The Taguchi approach provides an opportunity to select a suitable orthogonal array depending on the number of control factors and their levels. The benefit of using a fractional factorial approach is the radical reduction in the number of experiments [17].

In this study, Taguchi’s L-16 orthogonal array table was used to carry out experiments by choosing four parameters at four levels (Table 1, Table 2).

Table 1
Taguchi Method

HEMA Eudragit L-100 EGDMA APS

1 1 1 1 1

2 1 2 2 2

3 1 3 3 3

4 1 4 4 4

5 2 1 2 3

6 2 2 1 4

7 2 3 4 1

8 2 4 3 2

9 3 1 3 4

10 3 2 4 3

11 3 3 1 2

12 3 4 2 1

13 4 1 4 2

14 4 2 3 1

15 4 3 2 4

16 4 4 1 3

	HEMA	Eudragit L-100	EGDMA	APS
1	1	1	1	1
2	1	2	2	2
3	1	3	3	3
4	1	4	4	4
5	2	1	2	3
6	2	2	1	4
7	2	3	4	1
8	2	4	3	2
9	3	1	3	4
10	3	2	4	3
11	3	3	1	2
12	3	4	2	1
13	4	1	4	2
14	4	2	3	1
15	4	3	2	4
16	4	4	1	3

Table 2

The compositions of experiments

	HEMA (mL)	Eudragit L-100 (g)	EGDMA (mL)	APS (g)
1	0.5	0.3	0.005	0.03
2	0.5	0.4	0.010	0.04
3	0.5	0.5	0.015	0.05
4	0.5	0.6	0.020	0.06
5	1	0.3	0.010	0.05
6	1	0.4	0.005	0.06
7	1	0.5	0.020	0.03
8	1	0.6	0.015	0.04
9	1.5	0.3	0.015	0.06
10	1.5	0.4	0.020	0.05
11	1.5	0.5	0.005	0.04
12	1.5	0.6	0.010	0.03
13	2	0.3	0.020	0.04
14	2	0.4	0.015	0.03
15	2	0.5	0.010	0.06
16	2	0.6	0.005	0.05

2.4. Characterization

To analyze the hydrogels, Bruker Opus-Alpha P (FT-IR) technique with Universal ATR sampling accessory was used to identify the chemical bonds of samples. Before the FT-IR analysis, the crystal area had been cleaned and the background collected; the solid material was placed over the small crystal area on universal diamond ATR top plate. The FT-IR spectrum was achieved after force was applied to the sample, pushing it onto the diamond surface. The IR measurement range was selected as 4000–650 cm⁻¹, scan number was 4 and resolution set as 4 cm⁻¹. Jeol-JSM 5410LV Scanning Electron Microanalyzer was used to take the micrograph of the sample. Sample was put on aluminum stubs by using conductive glue and was then coated with a thin layer of carbon.

3. Results and discussion

3.1. Characterization of p(HEMA-co-Eudragit L-100) hydrogels

The characteristic peak of Eudragit L-100 was at 3744 cm⁻¹ observed due to the presence of O–H; 2994 and 2951 cm⁻¹ showed the CH-vibration. The peak observed in 1447 cm⁻¹ was –CH₃ bending, and 1706 cm⁻¹ showed C=O (ester) presence. The peak of HEMA was at 1723 cm⁻¹ showed a carbonyl group C=O ester; the peak observed at 1392 cm⁻¹ was =CH₂ band; 1438 cm⁻¹ was asymmetrical methyl tendency. C–O stretching vibration of the ester carbonyl groups was seen 1092 and 1161 cm⁻¹. Peaks observed at 1138 cm⁻¹ and 1707 cm⁻¹ showed the presence of C=O group and the synthesis of the p(HEMA-co-Eudragit) hydrogel (Fig. 4).

Fig. 4.

FT-IR spectra: (a) Eudragit L-100, (b) HEMA, (c) p(HEMA-co-Eudragit).

SEM image of p(HEMA-co-Eudragit) showed that desired pores were obtained for insulin release (Fig. 5).

Fig. 5.

SEM image of p(HEMA-co-Eudragit).

3.2. Swelling behavior of hydrogels

The p(HEMA-co-Eudragit) hydrogels were weighed on a top loading electronic balance with an accuracy of ±0.0001 g. All the swollen hydrogels were put in 10 mL of swelling medium. At intervals, the swollen gels were dried on filter paper, and weighed. The swelling studies were carried out until equilibrium in swelling was reached [18]. Each parameter of the experiments was carried out in three replicates (Table 3). First of all, the gellings (%) were calculated. The optimum gelling ratio (%) was determined for experiment 13 as average 86%. Then, the percentages of the swelling of hydrogel were investigated with changing of time, temperature and pH.

Table 3
Gelling values (%)

No Gelling (%)

1 76

75

74

2 75

78

78

3 75

71

75

4 77

78

78

5 72

73

72

6 69

69

68

7 73

73

73

8 72

73

73

No Gelling (%)

9 68

68

69

10 72

71

71

11 71

71

71

12 76

75

73

13 87

85

87

14 75

74

74

15 78

80

78

16 80

79

79

No	Gelling (%)
1	76
75
74
2	75
78
78
3	75
71
75
4	77
78
78
5	72
73
72
6	69
69
68
7	73
73
73
8	72
73
73

No	Gelling (%)
9	68
68
69
10	72
71
71
11	71
71
71
12	76
75
73
13	87
85
87
14	75
74
74
15	78
80
78
16	80
79
79

Fig. 6.

Swelling curves of p(HEMA-co-Eudragit) hydrogels produced by changing time.

3.3. The effect of time on swelling

The samples prepared for each experiment in the buffer solution (pH:7.4) were weighed over 44 hours. The optimum time was 24 hours for swelling of the hydrogel (Fig. 6). This optimum time was used as equilibrium swelling time for following experiments. Maximum and minimum swelling percentages in 24 h were observed for experiment 6 and 14, respectively. HEMA (mL) as monomer and EGDMA (mL) as crosslinked in experiment 14 were used more than 6. Contrary to expectations, swelling of experiment 6 was higher due to amount of EGDMA.

3.4. The effect of temperature on swelling

The effect of temperature on the swelling behavior of hydrogel was given in Fig. 7. When the temperature of the medium was around 37°C, the swelling ratio of the hydrogel samples reached equilibrium. Therefore, the optimum temperature was obtained as 37°C. This temperature is proper with body temperature. Maximum and minimum swelling percentages in 24 h-37°C were observed for experiment 6 and 7, respectively. Most of studies showed that Eudragit was themo-sensitive polymer to use in drug delivery systems [19]. In this study, although Eudragit as thermo and pH-sensitive polymer in experiment 7 was used more than 6, swelling of 7 was lower due to EGDMA.

Fig. 7.

Swelling curves of p(HEMA-co-Eudragit) hydrogels produced by changing temperature.

3.5. The effect of pH on swelling

Most of hydrogel systems are pH responsive and variations in pH occur at several body sites, such as the gastrointestinal tract, vagina and blood vessels, and these can provide a suitable base for pH-responsive drug release. Local pH changes in response to specific substrates can be generated and used for modulating drug release [20]. As characterization of the response of the hydrogels, samples were allowed to swell to equilibrium in different aqueous buffers as previous study [21]. As a result, pH 7.4 was obtained as an optimum pH value. It was seen that this value was consistent with blood pH. The pH values were selected to allow comparison of swelling behavior of hydrogels in all experiments (Fig. 8). Maximum and minimum swelling percentages in 24 h–37°C–pH:7 were observed for experiment 2 and 9, respectively. Because of HEMA (mL)/Eudragit L-100 (g)/EGDMA (mL) ratio (Experiment 2: 0.5/0.4/0.010), maximum swelling was obtained for this sample.

Fig. 8.

Swelling curves of p(HEMA-co-Eudragit) hydrogels produced by changing pH.

3.6. Taguchi results

The experimental results are transformed into a signal-to-noise (S/N) ratio. η (S/N ratio) indicates a measure of quality characteristics deviating from or nearing to the desired values. There are three categories of quality characteristics in the analysis of the S/N ratio, for example, the smaller the better, the higher the better, and the nominal the best.

The factor levels corresponding to the highest S/N ratio are chosen to optimize the condition. In the study, linear graphs show that the “higher the better” category was proper to obtain the optimum values of the factors.

The formula used for calculating of S/N ratio was given below [22] as Fig. 9:

Smaller the better: It is used where the smaller value is desired as Eq. (3). $\begin{matrix} (3) & S / N ratio (η) = - 10 {log}_{10} \frac{1}{n} \sum_{i = 1}^{n} y_{i}^{2} \end{matrix}$ where $y_{i}$ = observed response value and n = number of replications.

Nominal the best: It is used where the nominal or target value and variation about that value is minimum as Eq. (4). $\begin{matrix} (4) & S / N ratio (η) = - 10 {log}_{10} \frac{μ^{2}}{σ^{2}} \end{matrix}$ where μ = mean and σ = variance.

Higher the better: It is used where the larger value is desired as Eq. (5). $\begin{matrix} (5) & S / N ratio (η) = - 10 {log}_{10} \frac{1}{n} \sum_{i = 1}^{n} \frac{1}{y_{i}^{2}} \end{matrix}$ where $y_{i}$ = observed response value and n = number of replications.

Taguchi showed a standard procedure for optimizing the process parameters [17].

Fig. 9.

Taguchi Results of (A) HEMA, (B) Eudragit L-100, (C) EGDMA, (D) APS.

Formula (3), Formula (5) indicate “smaller is better” and “higher is better” values, respectively. The $y_{i}$ values show observed response value as swelling (%). Therefore, formula (5) was used to calculate the highest swelling values with Taguchi Method.

4. Conclusion

In conclusion, a total of 16 experiments were performed owing to Taguchi method as an optimization method. Characterization results (FT-IR, SEM) showed that p(HEMA-co-Eudragit) hydrogels were synthesized successfully. The swelling behavior of p(HEMA-co-Eudragit) hydrogels prepared has been investigated in buffer solutions of pH 7.4. The optimum time, temperature and pH were obtained as 24 hours, 37°C and 7, respectively. Swelling values were evaluated for temperature, time and pH, seperately. Maximum and minimum swellings (%) were found for that parameters. Although hydrogel swellings (%) in different parameters (time, temperature, pH) showed various minimum and maximum values, linear graphs in Taguchi Method indicated that Experiment 8 was optimum for swelling (%) by using “higher is better” category. Because, Taguchi Method analyzed the effects of four parameters (HEMA/Eudragit L-100/EGDMA/APS), simultaneously. As a result of this method analysis, it can be said that the optimum mixture was experiment 8 for 2–4–3–2 at pH:7, Temperature: 37°C, Time: 24 hours in Taguchi method by using S/N ratio. It has also been approved that the swelling values (%) and the results of Taguchi Method were consistent. Taguchi Method will provide high quality and low cost in drug industry as well as uses in various industrial applications. And also, HEMA is a monomer used as temperature-sensitive and Eudragit L-100 is a polimer used as pH-sensitive. This features show that the hydrogels produced in this study can be used in controlled release studies etc. insulin release. In addition, optimum conditions in experiments are proper for body temperature (37°C) and blood acidity (pH:7). It was seen that this hydrogel could be evaluated in insulin release for diabetes treatment in future studies.

Conflict of interest

The authors have no conflict of interest to report.

References

Chen

Liu

and Ma

, Synthesis, swelling and drug release behavior of poly(N,N-diethylacrylamide-co-N-hydroxymethyl acrylamide) hydrogel, Mater. Sci. Eng 29(7) (2009), 2116. doi:10.1016/j.msec.2009.04.008.

www.drugdiscoverytoday.com. Accessed 24 December 2014.

Byrne

M.E.

Park

and Peppas

N.A.

, Synthesis, swelling and drug release behavior of poly(N,N-diethylacrylamide-co-N-hydroxymethyl acrylamide) hydrogel, Adv. Drug Deliver. Rev. 54(1) (2002), 149. doi:10.1016/S0169-409X(01)00246-0.

Zou

Zhao

Wang

and Li

, Preparation and drug release behavior of pH-responsive bovine serum albumin-loaded chitosan microspheres, J. Ind. Eng. Chem. (2014), in press. doi:10.1016/j.jiec.2014.06.012.

de Leede

L.G.J.

de Boer

A.G.

Ptirtzgen

Feijen

and Breimer

D.D.

, Rate-controlled rectal drug delivery in man with a hydrogel preparation, Journal of Controlled Release 4 (1986), 17. doi:10.1016/0168-3659(86)90029-5.

Zhang

Meng

Zhang

and Tang

, Thiolated eudragit nanoparticles for oral insulin delivery: Preparation, characterization and in vivo evaluation, International Journal of Pharmaceutics 436 (2012), 341. doi:10.1016/j.ijpharm.2012.06.054.

Huynh

D.P.

G.J.

Chae

S.Y.

Lee

K.C.

and Lee

D.S.

, Controlled release of insulin from pH/temperature-sensitive injectable pentablock copolymer hydrogel, J. Control. Release 137 (2009), 20. doi:10.1016/j.jconrel.2009.02.021.

Chaturvedi

Ganguly

Nadagouda

M.N.

and Aminabhavi

T.M.

, Polymeric hydrogels for oral insulin delivery, J. Control. Release 165 (2013), 129. doi:10.1016/j.jconrel.2012.11.005.

Hao

Wang

Zhu

Wang

and Guo

, Preparation of Eudragit L 100-55 enteric nanoparticles by a novel emulsion diffusion method, Colloid. Surface B 108 (2013), 127. doi:10.1016/j.colsurfb.2013.02.036.

10.

Gandhi

Jana

and Sen

K.K.

, In-vitro release of acyclovir loaded Eudragit RLPO^® nanoparticles for sustained drug delivery, Int. J. Biol. Macromol. 67 (2014), 478. doi:10.1016/j.ijbiomac.2014.04.019.

11.

Sadeghi

, Synthesis and swelling behaviors of graft copolymer based on chitosan-g-poly(AA-co-HEMA), Int. J. Chem. Eng. App. 1(4) (2010), 354.

12.

Emileh

Vasheghani-Farahani

and Imani

, Swelling behavior, mechanical properties and network parameters of pH- and temperature sensitive hydrogels of poly((2-dimethyl amino) ethyl methacrylate-co-butyl methacrylate), Eur. Polym. J. 43 (2007), 1986. doi:10.1016/j.eurpolymj.2007.02.002.

13.

Haque

S.E.

and Sheela

, Miscibility of eudragit/chitosan polymer blend in water determined by physical property measurements, Int. J. Pharm. 441(1–2) (2013), 648. doi:10.1016/j.ijpharm.2012.10.031.

14.

Ozgunduz

H.İ.

Kandilci

H.G.

Acaralı

and Sarac

, Production and optimization method of smart hydrogels based on biocompatible polymer for controlled insülin release, Sigma J. Eng & Nat. Sci. 34(1) (2016), 115–122.

15.

R.S.

Kumar

C.G.

Prakasham

R.S.

and Hobbs

P.J.

, The Taguchi Methodology as a statistical tool for biotechnological applications: A critical appraisal, Biotechnol. J. 3(4) (2012), 510. doi:10.1002/biot.200700201.

16.

Vankantia

V.K.

and Ganta

, Optimization of process parameters in drilling of GFRP composite using Taguchi method, J. Mater. Res. Technol. 3(1) (2014), 35. doi:10.1016/j.jmrt.2013.10.007.

17.

Kaushik

and Thakur

I.S.

, Isolation and characterization of distillery spent wash color reducing bacteria and process optimization by Taguchi approach, Int. Biodeter. Biodegr. 63 (2009), 420. doi:10.1016/j.ibiod.2008.11.007.

18.

Thakur

Wanchoo

R.K.

and Singh

, Structural parameters and swelling behavior of pH sensitive poly(acrylamide-co-acrylic acid) hydrogels, Chem. Biochem. Eng. Q. 25(2) (2011), 181.

19.

Fujımori

Yonemochi

Fukuoka

and Terada

, Application of Eudragit RS to thermo-sensitive drug delivery systems. I. Thermo-sensitive drug release from acetaminophen matrix tablets consisting of Eudragit RS/PEG 400 blend polymers, Chem. Pharm. Bull. 50(3) (2002), 408. doi:10.1248/cpb.50.408.

20.

Gupta

Vermani

and Garg

, Hydrogels: From controlled release to pH-responsive drug delivery, Drug Discov. Today 7(10) (2002), 569. doi:10.1016/S1359-6446(02)02255-9.

21.

Bajpai

A.K.

and Giri

, Water sorption behavior of highly swelling (carboxy methylcellulose-g-polyacrylamide) hydrogels and release of potassium nitrate as agrochemical, Carbohyd. Polym. 53(3) (2003), 271. doi:10.1016/S0144-8617(03)00071-7.

22.

Phadke

S.M.

, Quality Engineering Using Robust Design, Prentice Hall, Englewood Cliffs, New Jersey, USA, 1989, p. 209.

Characterization study and optimization of swelling behavior for p(HEMA-co-Eudragit L-100) hydrogels by using Taguchi Method

Abstract

Keywords

1. Introduction

2. Experimental

2.1. Materials

2.2. Methods

2.2.1. Preparation of p(HEMA-co-Eudragit L-100) hydrogels

Table 1 Taguchi Method HEMA Eudragit L-100 EGDMA APS 1 1 1 1 1 2 1 2 2 2 3 1 3 3 3 4 1 4 4 4 5 2 1 2 3 6 2 2 1 4 7 2 3 4 1 8 2 4 3 2 9 3 1 3 4 10 3 2 4 3 11 3 3 1 2 12 3 4 2 1 13 4 1 4 2 14 4 2 3 1 15 4 3 2 4 16 4 4 1 3

3. Results and discussion

3.1. Characterization of p(HEMA-co-Eudragit L-100) hydrogels

Table 3 Gelling values (%) No Gelling (%) 1 76 75 74 2 75 78 78 3 75 71 75 4 77 78 78 5 72 73 72 6 69 69 68 7 73 73 73 8 72 73 73 No Gelling (%) 9 68 68 69 10 72 71 71 11 71 71 71 12 76 75 73 13 87 85 87 14 75 74 74 15 78 80 78 16 80 79 79

3.4. The effect of temperature on swelling

Conflict of interest

References

Table 1
Taguchi Method

HEMA Eudragit L-100 EGDMA APS

1 1 1 1 1

2 1 2 2 2

3 1 3 3 3

4 1 4 4 4

5 2 1 2 3

6 2 2 1 4

7 2 3 4 1

8 2 4 3 2

9 3 1 3 4

10 3 2 4 3

11 3 3 1 2

12 3 4 2 1

13 4 1 4 2

14 4 2 3 1

15 4 3 2 4

16 4 4 1 3

Table 3
Gelling values (%)

No Gelling (%)

1 76

75

74

2 75

78

78

3 75

71

75

4 77

78

78

5 72

73

72

6 69

69

68

7 73

73

73

8 72

73

73

No Gelling (%)

9 68

68

69

10 72

71

71

11 71

71

71

12 76

75

73

13 87

85

87

14 75

74

74

15 78

80

78

16 80

79

79