Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 INTERNATIONAL RESEARCH JOURNAL OF PHARMACY
ISSN 2230 – 8407 Research Article
Available online www.irjponline.com
FORMULATION AND EVALUATION OF MICROSPONGE DRUG DELIVERY SYSTEM USING INDOMETHACIN Mahajan Aniruddha G*1, Jagtap Leena S2, Chaudhari Atul L, Swami Sima P, Mali Prabha R2 1
Cognizant Technology Solutions India Pvt. Ltd., Powai, Mumbai, India 2 Padmashree Dr. D Y Patil Institute of Pharmacy, Akurdi, Pune, India Article Received on: 14/08/11 Revised on: 22/09/11 Approved for publication: 18/10/11
*Email:
[email protected] ABSTRACT In the present study controlled release formulation of Indomethacin microsponges were prepared by using Eudragit RS 100, pH independent release retardant polymer and PVA, stabilizer or emulsifier. Microsponges were prepared by Quasi emulsion solvent diffusion method by changing drug polymer ratio (3:1, 4:1, 5:1) and process was optimized. Microsponges were evaluated by micromeritic properties, drug content, encapsulation efficiency, and particle size. Characterization of Indomethacin microsponges were done by FT-IR spectroscopy, Differential scanning calorimetry, X-ray diffractometry and Scanning electron microscopy for pure drug, polymer, physical mixture and formulation. In-vitro dissolution study indicated that the release of Indomethacin varied according to the concentration of matrix forming polymer. Therefore, Indomethacin microsponges prepared in thus study are promising as being more useful than conventional formulation in therapy. Keywords: Microsponge, Quasi-emulsion solvent diffusion method, DSC, XRD, FTIR and SEM
INTRODUCTION Microsponges are porous microspheres having myriad of interconnected voids of particle size ranging from 5-150 µm. Microsponge Drug Delivery System is a unique technology which provides controlled release of active ingredients1,2. It offers numerous advantages over other technologies like reduced side effects, improved stability, increased elegance and enhanced formulation flexibility3,4. Microsponges are porous, polymeric microspheres that are used mostly for topical and recently for oral administration. They can be incorporated into conventional dosage forms such as creams, lotions, gels, ointment, tablet and powder and share a broad package of benefits & thus provides formulation flexibility5,6,7. Non-steroidal anti-inflammatory drugs (NSAIDs) are used as an analgesic and anti-inflammatory agents in various disorders e.g. rheumatoid arthritis, spondylitis, acute gout etc. These are nonselective inhibitor of COX І and COX ІІ enzymes that participate in prostaglandin synthesis from arachidonic acid8,9,10. In case of disease state like arthritis, conventional oral dosage forms are ineffective in delivering the drugs to lower GI tract due to absorption or degradation of drug in upper GI tract and from the therapeutic point of view it is beneficial to increase the residence time of drug to get maximum absorption11,12. Among the NSAID’s, Indomethacin is the drug having short biological half life (2 to 3 hours), degradation in the upper part of GIT and posses side effect like GI irritation. Also the usual dosage regimen is 25 to 100 mg, three times a day13,14,15. From the literature study, it was evident that modified release dosage form of indomethacin was required to be formulated to minimize the side effects like GI irritation and protect the drug from first pass effect i.e. presystemic degradation of drug in liver16,17,18. Hence, in the present work an attempt was made to develop controlled release microsponges using synthetic polymer to
minimize frequent dosing, prolong the pharmacological effect and thus improve patient compliance19,20. MATERIALS & METHODS Indomethacin was obtained as a gift sample from Themis laboratories Mumbai. Eudragit RS 100 was purchased from Degussa laboratories. PVA was obtained from Colorcon Goa. Method of Preparation of Microsponges The microsponges were prepared by Quasi-emulsion solvent diffusion method. The method consists of two steps. In first step inner phase was prepared and in second step outer phase was prepared. Inner phase was prepared by dissolving the Eudragit RS 100 in ethanol. Then the drug Indomethacin was added to solution and dissolved under ultrasonication at 35 0C for 15 minutes. Outer phase was prepared by dissolving PVA in distilled water and the process was carried out at room temperature. Then Inner phase was then poured into outer phase at room temperature. After emulsification, the mixture was continuously stirred at 500 rpm for two hours. After the formation of microsponges the mixture is filtered to separate the microsponges. The product was washed and dried in oven at 400C Initially preliminary batches were prepared by using drug polymer ratio (3:1, 4:1, 5:1) and process was optimized as shown in Table No.1. In order to study the effect of PVA the microsponges are prepared by changing the concentration Table no. 2 gives the detail of the formulated batches. Once the formulation was prepared characterization of microsponges were done by determining drug loading and encapsulation efficiency as shown in Table No. 3 and Table No. 4, FTIR, DSC, XRD, SEM and In-vitro study. RESULTS Evaluation of drug content The Indomethacin content in the microsponges was estimated by procedure given in (USP 30 NF 25, 2007) and calculation was done by using formula
Actual drug content Encapsulation efficiency (%) = ----------------------------------------× 100 Theoretical drug content
and
Weight of drug Drug Loading (%) = ---------------------------------------- × 100 Weight of microsponges
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011
Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 In-Vitro Release study Accurately weighted quantity of microsponges equivalent to 40 mg of Indomethacin were taken in muslin cloth and was kept in basket. During dissolution study, 10 ml aliquot was withdrawn at different time intervals of 1, 2, 3---12 hrs and same was replaced with equal volume of fresh medium. The withdrawn sample was filtered through Whatman filter paper No.42 and absorbances were measured at 318nm (USP 30 NF25, 2007). The experiment was performed in triplicate. FT –IR Study To know the interaction between drug and polymer FT-IR spectrum obtained using KBr pellets technique and was compared with the spectrum available in official book. X-Ray Diffractometry Study The X-Ray powder diffraction patterns was obtained by x-ray diffractometer with Cu O ) radiation and a crystal monochrometer, K voltage : 45 mv and current 20 amp. The diffraction patterns run at 5-100 C / min in terms of 2 crystal and physical state characterization of Indomethacin. Differential Scanning Calorimetry For the structural, crystal and physical state characterization of Indomethacin, the DSC study was performed for pure drug, polymer and formulations. All accurately weighed samples were placed in a sealed aluminium pans before heating under nitrogen flow (20 ml/min) at a scanning rate of 10 0C per min from 25 to 300 0C. An empty aluminium pan was used as a reference. Scanning Electron Microscopy This study was performed using Scanning Electron Microscopy (SEM).The microsponges were coated with platinum by ion sputtering using autofine coater.The microsponges were kept on the sample holder and the scanning electron micrographs were taken. DISSCUSION The primary benefit of controlled release preparation compared to conventional dosage forms is that more uniform maintenance of blood plasma level of active agent which is helpful to avoid undesirable peaks and troughs achieved with multiple immediate release preparations. Therefore, in this study controlled release formulation of Indomethacin was prepared. The drug polymer ratio showed significant effect on the encapsulation efficiency of microsponges. The decreased concentration of polymer showed the decreased drug encapsulation efficiency of microsponges. In-vitro dissolution study indicated that the release of indomethacin varied according to the concentration of matrix forming polymer. The release of indomethacin increased with decreasing concentration of Eudragit RS 100. The release of drug from formulations containing varying concentration of Eudragit RS 100 was inversely proportional i.e. 0.666< 0.500< 0.400 (gm). Higher release rate was found from microsponges prepared from the lower concentration of Eudragit RS 100 in 12 hours study. The effect of PVA on drug release from microsponge formulations showed a slight decrease in release with increased concentration. Characterization of Indomethacin microsponges were done by FT-IR spectroscopy, DSC, X-ray diffractometry and scanning electron microscopy for pure drug, polymer, physical mixture and formulation. The results of FT-IR study revealed that there was no chemical interaction between drug and polymer or formation of any decomposition product in the final formulation. From the thermograms of DSC study obtained, it was observed that there was no interaction between pure drug and polymer as well as
crystalline nature of drug remains thermally stable up to the final formulation which was also supported by XRD study while SEM study revealed that the microsponges observed was discrete and spherical. With this kind of formulation, the undesirable side effects and presystemic metabolism of the drug can be eliminated and a sustained effect can be obtained. Therefore, Indomethacin microsponges prepared in thus study are promising as being more useful than conventional formulation in therapy. Finally it can be concluded that the objective of this study is achieved. FUTURE PROSPECTUS In future microsponges can be used to prepare suitable dosage form and its in-vivo absorption studies in animals/ humans can be carried out to know the bioavailability from sustained release formulation. REFERENCES [1] Jain NK. Advances in controlled and novel drug delivery. New Delhi: CBS Publishers and Distributors; 2003: 89-91. [2] Kydonius AF, Controlled release technologies: Methods, Theory and Applications, Boca Raton: CRC; 1980 Press,: 21-49. [3] Nacht S, Katz M. The microsponge ; a programmable delivery system. In Osborne , DW, Aman AH , Topical drug delivery formulations. New York: Marcel Dekker; 1990 : 299-325. [4] Embil K, Nacht S. The microsponge delivery system (MDS): a topical delivery system with reduced irritancy incorporating multiple triggering mechanisms for release of actives. J. Microencapsul 1994; 13:575-588. [5] Kim W, Hwang S, Park J, Park H. Preparation and characterization of drug loaded polymethacrylate microspheres by an emulsion solvent evaporation method. J. Microencapsul200; 6: 811-822. [6] Kawashima Y, Niwa T, Hand T, Takeuchi H, Iwamoto T. Control of prolonged drug release and compression properties of ibuprofen microspheres with acrylic polymer by changing their intra-particle porosity. Chem. Pharm Bull 1992; 40: 196201. [7] Dashora K, Saraf S. Effect of processing variables on micro particulate system of nimesulide. Chinese J. Pharm 2006;58: 67-74. [8] Jelvehgari M, Shadbad M, Azarmi S, Martin J. The microsponge delivery system of benzoyl peroxide: preparation characterization and release studies. Int J Pharm 2006; 308: 124-132. [9] Tiyaboonchi W, Ritthidej C. Development of indomethacin sustained release microcapsules using chitosan carboxymethyl cellulose complex coacervation. J Sci Tech 2003; 25: 245-354. [10] James W. Pharmaceutical preformulation: the physicochemical properties of drug substances. In: Aulton ME. (Ed.), Pharmaceutics The Science of Dosage Form Design. Edinburgh: Churchill Livingstone 2002: 133-135. [11] Schroder K, Schmid K, Lobenberg R.Influence of bulk and tapped density on the determination of thermal nature of powders and blends. AAPS Pharm Sci Tech 2007; 8:3: 78. [12] Conors K. A Textbook of Pharmaceutical Analysis. New York: Wiley Interscience Publication; 1982 : 173-178. [13] Comoglu T, Gonul N, Baykara T. Preparation and in vitro evaluation of modified release ketoprofen microsponges. IL Farmaco2002;58: 101-106. [14] Perumal D. Microencapsulation of ibuprofen and Eudragit RS 100 by the emulsion solvent diffusion technique. Int. J Pharm 2001;218: 1-11. [15] Perumal D, Danger C, Alock R, Hurbans N, Moonpanar K. Effect of formulation variables on in vitro drug release and micromeritic properties of modified release ibuprofen microspheres. J Microencapsul 1999;16: 475-487. [16] Orlu M, Cevher E, Araman A. Design and evaluation of colon specific drug delivery system containing flurbiprofen microsponges. Int J Pharm 2006; 318: 103117. [17] Nokhodchi A, Jelvehgari M, Siahi M, Mozafari M. Factors affecting the morphology of benzoyl peroxide microsponges. Micron 2007;38: 834-840. [18] Nokhodchi A.The effect of type and concentration of vehicles on the dissolution rate of a poorly soluble drug indomethacin. J Pharm Sci. 2005; 8: 18-25 [19] Pan X, Julian T, Augsburger L. Quantitative measurement of indomethacin crystallinity using differential scanning calorimetry and X-ray powder diffractometry. AAPS Pharm Sci Tech 2006; 7: 11. [20] Akhavein N, Khan F, Uddin, N, Lai Y. In vito release of indomethacin from crosslinked albumin microspheres. Int J Pharm 2004; 209: 167-174.
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011
Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 Table No. 1 Optimum values for microsponge formulation Specifications
Optimum Values
Drug: Polymer ratio
3:1, 4:1 and 5:1
Amount of drug (g)
2
PVA (mg)
30-70
Inner phase solvent
Ethyl alcohol
Amount of inner phase solvent (ml)
10 ml
Amount of water in outer phase (ml)
200 ml
Temperature of inner phase (0C)
37
Stirrer type
Three blade
Stirring rate (rpm)
500
Stirring time (min)
60
Table No. 2 Batches prepared on basis of preliminary batches of microsponges Batch Code
Drug (g)
Eudragit RS 100 (g)
PVA (mg)
Ethanol (ml)
Distilled water (ml)
F1
2
0.666
30
10
200
F2
2
0.666
40
10
200
F3
2
0.666
50
10
200
F4
2
0.666
60
10
200
F5
2
0.666
70
10
200
F6
2
0.500
30
10
200
F7
2
0.500
40
10
200
F8
2
0.500
50
10
200
F9
2
0.500
60
10
200
F10
2
0.500
70
10
200
F11
2
0.400
30
10
200
F12
2
0.400
40
10
200
F13
2
0.400
50
10
200
F14
2
0.400
60
10
200
F15
2
0.400
70
10
200
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011
Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 Table No. 3 Actual drug content, encapsulation efficiency and yield of microsponges Batch No.
Actual Drug Loading (%)
Theoretical Loading (%)
Encapsulation Efficiency (%)
Yield (%)
F1
74.58±0.01
81.63
90.53±0.01
81.90±2.68
F2
74.82±0.02
81.96
91.28±0.02
82.74±2.71
F3
73.87±0.02
82.30
90.43±0.01
82.04±3.38
F4
74.64±0.01
82.64
89.10±0.01
81.38±2.96
F5
74.17±0.02
82.98
89.38±0.02
82.14±3.31
F6
73.43±0.01
78.43
93.54±0.02
79.40±2.49
F7
73.22±0.02
78.74
91.82±0.02
80.07±3.12
F8
73.63±0.02
79.05
93.15±0.03
79.78±1.97
F9
72.14±0.01
79.36
90.90±0.01
78.34±2.73
F10
72.84±0.03
79.68
91.41±0.02
78.64±1.89
F11
69.94±0.01
73.63
94.98±0.03
79.08±2.83
F12
68.90±0.02
73.90
93.20±0.02
81.03±2.14
F13
69.75±0.02
74.18
94.02±0.01
80.86±2.67
F14
69.08±0.01
74.46
92.77±0.02
79.74±2.34
F15
68.12±0.01
74.73
91.15±0.02
78.69±1.83
Table No. 4 Cumulative percent drug release of batches F1 to F15 Time ( USP 30 Test 3 Requirement ) Batch No.
1 Hour (15-40)
2 hour (35-55)
4 Hour (55-75)
6 Hour (65-85)
8 Hour
12 Hour
F1
25.103
37.829
52.431
65.308
74.600
88.698
F2
24.991
37.491
52.197
65.070
74.134
88.227
F3
24.879
37.602
51.860
64.841
73.896
87.746
F4
24.879
37.602
51.521
63.701
72.730
86.306
F5
24.991
37.491
51.294
63.355
72.376
85.941
F6
27.234
39.983
56.891
70.415
80.041
93.673
F7
27.234
39.647
56.545
70.172
78.220
93.385
F8
27.010
39.644
56.314
69.820
77.750
92.879
F9
26.561
39.291
55.629
68.564
77.135
92.381
F10
26.337
38.852
55.284
68.323
76.779
91.653
F11
27.907
40.776
57.930
71.143
81.577
95.533
F12
27.907
40.663
57.703
70.910
81.338
95.170
F13
27.408
40.210
57.355
70.215
80.515
94.878
F14
27.682
40.325
57.246
70.444
80.752
94.565
F15
27.570
40.099
57.016
69.871
80.280
94.074
Microsponge Batches F1,F2,F3,F4,F5
100
Cumulative % Release
90 80 70 60 50 40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
Time (hrs) F1
F2
F3
F4
F5
Fig. No.1. Dissolution profile of batches F1, F2, F3, F4 and F5
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011
Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 Microsponge Batches F6,F7,F8,F9,F10 100 Cumulative % Release
90 80 70 60 50 40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
Tim e (hrs)
F6
F7
F8
F9
F10
Fig. No. 2. Dissolution profile of batches F6, F7, F8, F9 and F10 Microsponge Batches F11,F12,F13,F14,F15 Cumulative % Drug Release
100 90 80 70 60 50 40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
11
12
13
Tim e (hrs)
F11
F12
F13
F14
F15
Fig. No. 3. Dissolution profile of batches F11, F12, F13, F14 and 15
Fig. No.4. FT-IR spectra of microsponge formulation (F11)
Fig.No.5. XRD Spectrum of microsponge formulation
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011
Mahajan Aniruddha G et al. IRJP 2011, 2 (10), 64-69 DSC mW 0.00
-10.00
Onset
157.53C
Endset
177.65C
Transition
-1.70mW -0.34mW/mg
Mid Point
152.13C
Peak
160.99C
Onset
157.53C
Endset
164.60C
Heat
-589.18mJ -117.84J/g
-20.00
-30.00
200.00
100.00 Temp [C]
Fig.No.6. DSC thermogram of microsponge formulation
Fig.No.7 SEM photograph of Indomethacin microsponges Source of support: Nil, Conflict of interest: None Declared
INTERNATIONAL RESEARCH JOURNAL OF PHARMACY, 2(10), 2011