Medicated Pressure Sensitive Adhesive Patches from STR-5L Block Rubber: Effect of Preparation Process

Abstract:

STR-5L is a high quality block rubber in Thailand that is interesting to apply in medical and pharmaceutical products because it has very low impurity but high uniformity. In this study, medicated pressure sensitive adhesive (PSA) patches were developed by melt blending technique using hydroxyethyl cellulose (HEC) as tackifier and paraffinic oil as softener. Two rolls mill was used to blend all ingredients and the thin PSA patches were rolled out. Various preparation parameters were studied such as initial viscosity of rubber (60 or 80 Mooney viscosity; MV), mastication time (5-20 minutes), step of mixing, mixing time (35-80 minutes) and gap between rollers (0.1-0.4 mm). The suitable processing conditions were optimized. It was found that the rubber having initial viscosity of 80 MV provided better physical properties, for example, higher force T-peel, lap shear strength and shear holding time. Longer mastication time increased the shear holding time of patches. At 70 minutes of mixing time, the patches showed the highest shear holding time and did not leave any residue on the testing equipment surface. Moreover, the shear holding time decreased when the gap between rollers was expanded. Mixing method with the sequential addition of STR-5L, HEC and then paraffinic oil, provided good PSA patches. However, preparation process did not affect the plasticity retention index of PSA patches due to there were not significant change of values when those all parameters were varied. Next, lidocaine or its hydrochloride salt in powder form could be blended into this PSA to be the homogeneous patches. This lidocaine PSA patches for local anesthetics application on the skin would be evaluated in further study.

• Periodical: Key Engineering Materials (Volume 751)
• Pages: 236-241
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.751.236
• Online since: August 2017
• Authors: Ekwipoo Kalkornsurapranee, Rungtiwa Waiprib, Wiwat Pichayakorn*
• Keywords: Hydroxyethyl Cellulose, Patch, Pressure Sensitive Adhesives, Rubber

References

[1] S. Sun, M. Li, A. Liu, A review on mechanical properties of pressure sensitive adhesives, Int. J. Adhes. Adhes. 41 (2013) 98-106.

[2] I. Benedek, Pressure-sensitive adhesives and applications, second ed., Marcel Dekker, New York, (2004).

[3] C. Creton, Pressure-sensitive adhesives: An introductory course, Mat. Sci. Adhes. 28 (2003) 434-439.

DOI: 10.1557/mrs2003.124

[4] F. Mrue, J.C. Netto, R. Ceneviva, J.J. Lachat, J.A. Thomazini, H. Tambelini. Evaluation of the biocompatibility of a new biomembrane. Mat. Res. 7 (2004) 277-283.

DOI: 10.1590/s1516-14392004000200010

[5] H.S. Tan, W.R. Pfister, Pressure-sensitive adhesives for transdermal drug delivery systems. Pharm. Sci. Technolo. Today. 2 (1999) 60-69.

DOI: 10.1016/s1461-5347(99)00119-4

[6] T.H. Lowery, K.S. Richardson. Solvent, mechanical and theory in organic chemistry, Harper Collins, New York, (1998).

[7] C. Nakason, A. Kaesaman, P. Supasanthitikul, the grafting of maleic anhydride onto natural rubber. Polym. Test. 23 (2004) 35-41.

DOI: 10.1016/s0142-9418(03)00059-x

[8] H. Ismail, S.M. Shaari, N. Othman. The effect of chitosan loading on the curing characteristics, mechanical and morphological properties of chitosan-filled natural rubber, epoxides natural rubber and styrene-nutadienen rubber conpounds. Polym. Test. 30 (2011).

DOI: 10.1016/j.polymertesting.2011.07.003

[9] Y. Song, Q. Zheng, C. Liu, Green biocomposites from wheat gluten and hydroxyethel cellulose: Processing and properties. Ind. Crops. Prod. 28 (2008) 56-62.

DOI: 10.1016/j.indcrop.2008.01.004

[10] W.F. Lee, R.J. Wu, Superabsorbent polymeric material, I. Swelling behaviors of crosslinked poly(sodium acrylate-co-hydroxyethyl methacrylate) in aqueous salt solution. J. Appl. Polym. Sci. 62 (1996) 1099-1114.

DOI: 10.1002/(sici)1097-4628(19961114)62:7<1099::aid-app16>3.0.co;2-1

[11] ASTM, Standard test method for strength properties of adhesives in cleavage peel by tension loading (Engineering plastics-to-Engineering plastics) D3807-98 (1998).

DOI: 10.1520/d3807-98r19

[12] ASTM, Standard test method for lap shear adhesion for fiber reinforced plastic (FRP) bonding D5868-01 (2001).

DOI: 10.1520/d5868-01

[13] ASTM, Standard test method for shear adhesion of pressure-sensitive tapes 3654/D3654M (2000).

[14] E.E. Ehabe, F. Bonfils, J. Sainte-Beuve, A. Collet, F. Schue, High-temperature mastication of raw natural rubber: Changes in macrostructure and mesostructure. Polym. Eng. Sci. 46 (2006) 222-227.

DOI: 10.1002/pen.20433

[15] K.O. Nwanorh, M.E. Enyiegbulam, Enhancement of resistance to oxidative degradation of natural rubber through latex degradation. Chin. J. Polym. Sci. 16 (1998) 170-175.

[16] R. Jaratrotkamjorn, C. Khaokong, V. Tanrattanakul, Toughness enhancement of poly(lactic acid) by melt blending with natural rubber. J. Appl. Polym. Sci. 124 (2012) 5027-5036.

DOI: 10.1002/app.35617

[17] I. Khan, B.T. Poh, Natural rubber-based pressure-sensitive adhesives: A review, J. Polym. Environ. 19 (2011) 793-811.

DOI: 10.1007/s10924-011-0299-z

[18] I. Khan, B.T. Poh, Effect of molecular weight and testing rate on peel and shear strength of epoxidized natural rubber (ENR 50)-based adhesives. J. Appl. Polym. Sci. 120 (2011) 2641-2647.

DOI: 10.1002/app.33492

[19] S.A. Riyajan, N. Pheweaw, Modification of skim rubber blended with poly (vinyl alcohol) to be applied as a biodegradable pressure-sensitive adhesive: effect of 2, 6-di-t-butyl-4-methylphenol and hydrocarbon resin. Rubber Chem. Technol. 85 (2012).

DOI: 10.5254/rct.12.88946

[20] A. Tortum, C. Celik, A.C. Aydin, Determination of the optimum conditions for tire rubber in asphalt concrete. Build. Environ. 40 (2005) 1492-1504.

DOI: 10.1016/j.buildenv.2004.11.013