Search tips
Search criteria 


Logo of aapspharmspringer.comThis journalToc AlertsSubmit OnlineOpen Choice
AAPS PharmSciTech. 2005 December; 6(4): E586–E593.
Published online 2005 December 1. doi:  10.1208/pt060473
PMCID: PMC2750606

Comparison between gamma and beta irradiation effects on hydroxypropylmethylcellulose and gelatin hard capsules


The effects of electron beam or λ-irradiation on technological performances (capsule hardness, expressed as deforming work and dissolution time) of empty 2-shell capsules made of gelatin or hydroxypropylmethylcellulose (HPMC) were studied. Capsule structural changes induced by radiation treatment were investigated by capillary viscometry and atomic force microscopy (AFM). The capsules were irradiated in the air at 5, 15, and 25 kGy. The deforming work of nonirradiated HPMC capsules (0.06±0.01 J) was lower than that of gelatin capsules (0.10±0.01 J). The dissolution time of the HPMC capsules (414±33 seconds) was slightly higher than that determined for gelatin hard capsules (288±19 seconds). The hardness and dissolution time of gelatin and HPMC capsules were not significantly influenced by the irradiation type and the applied irradiation dose. As the viscometry analyses are concerned, irradiation caused a reduction of the intrinsic viscosity and water and dimethyl sulfoxide solvent power in both the cases. AFM analysis showed that the radiation treatment did not appreciably affect the surface roughness of the samples nor induce structural changes on capsule surface. However, measurements of force-distance curves pointed out a qualitative parameter for the identification of the irradiated capsules. On the bases of these preliminary results, empty gelatin or HPMC hard capsules can be sanitized/sterilized by ionizing radiation.

Keywords: gelatin capsule, HPMC capsule, electron beam irradiation, gamma irradiation, AFM

Full Text

The Full Text of this article is available as a PDF (208K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Woo L, Sandford CL. Comparison of electron beam irradiation with gamma processing for medical packaging materials. Radiat Phys Chem. 2002;63:845–850. doi: 10.1016/S0969-806X(01)00664-8. [Cross Ref]
2. Yamamoto T, Abe K, Matsuura S, inventors. Hard capsule for pharmaceutical drugs and method for producing the same. US patent 5 264 223. November 23, 1993.
3. Vieira FF, Mastro NL. Comparison of γ-radiation and electron beam irradiation effects on gelatin. Radiat Phys Chem. 2002;63:331–332. doi: 10.1016/S0969-806X(01)00522-9. [Cross Ref]
4. Sebert P, Andrianoff N, Rollet M. Effect of gamma irradiation on hydroxypropylmethylcellulose powder: consequences on physical, rheological, and pharmaco-technical properties. Int J Pharm. 1993;99:37–42. doi: 10.1016/0378-5173(93)90320-F. [Cross Ref]
5. Maggi L, Segale L, Ochoa Maciste E, Buttafava A, Faucitano A, Conte U. Chemical and physical stability of hydroxypropylmethylcellulose matrices containing diltiazem hydrochloride after gamma irradiation. J Pharm Sci. 2003;92:131–141. doi: 10.1002/jps.10271. [PubMed] [Cross Ref]
6. Aliste AJ, Vieira FF, Mastro NL. Radiation effects on agar, alginates and carrageenan to be used as food additives. Radiat Phys Chem. 2000;57:305–308. doi: 10.1016/S0969-806X(99)00471-5. [Cross Ref]
7. The Use of Ionizing Radiation in the Manufacture of Medicinal Products. Gare, Luxembourg: Official Publications of the European Communities; 1992. European Guideline 3AQ4a.
8. Pilati F, Toselli M.Masse e Dimensioni di Macromolecole Proceedings of the 15th Symposium of the Associazione Italiana di Scienza e Tecnologia delle Macromolecole; May 1993; Gargnano, Italy. 127.
9. Shroff RN. Single-point determination of intrinsic viscosity. J Appl Polym Sci. 1965;9:1547–1551. doi: 10.1002/app.1965.070090429. [Cross Ref]
10. Bohidar HB. Hydrodynamic properties of gelatin in dilute solutions. Int J Biol Macromol. 1998;23:1–6. doi: 10.1016/S0141-8130(98)00003-8. [PubMed] [Cross Ref]
11. Cragg LH, Bigelow CC. The viscosity slope constant k′-ternary systems: polymer-polymer-solvent. J Polym Sci [B] 1955;16:177–191. doi: 10.1002/pol.1955.120168208. [Cross Ref]
12. Cilurzo F, Minghetti P, Casiraghi A, Montanari L. Evaluation of compatibility of methacrylic copolymers by capillary viscometry. J Appl Polym Sci. 2000;76:1662–1668. doi: 10.1002/(SICI)1097-4628(20000613)76:11<1662::AID-APP7>3.0.CO;2-T. [Cross Ref]
13. Chiwele I, Jones BE, Podezeck F. The shell dissolution of various empty hard capsules. Chem Pharm Bull (Tokyo) 2000;48:951–956. [PubMed]

Articles from AAPS PharmSciTech are provided here courtesy of American Association of Pharmaceutical Scientists