Application of Starch as Partial substitutute for Gelatin in the production of Hard Capsule shell by Dip Moulding method

Abstract

Starches are extensively produced in Thailand which are also not expensive materials. Gelatin, imported material, has been used widely in hard capsule industries, therefore, the cost of production can be reduced if gelatin is partial substituted by starches. This study is to find out the suitable substituted starches, the maximum amount of substituted starches, the amount of appropriate plasticizer, the percentage of sodium lauryl sulfate (SLS) used to produce hard gelatin capsules by using dipping method. The appropriate starch-gelatin films and capsules were selected by using the appearance, the physical properties such as the maximum stress and extension at break, the viscosity, weight, thickness and the moisture content. Eight starches i.e. rice starch, glutinous rice starch, tapioca starch, fully pregelatinized starch (Eragel®), pregelatinized tapioca starch (Alpha starch®), Elastigel 1000J®, Elastigel 2000C® and Elastigel 3000M®, which represent three groups of starch namely native starch, pregelatined starch and modified starch were used. Results showed that 35% w/w substitution with Elastigel 2000C® with 0.1% w/w SLS, 25% w/w substitution with Eragel® with 0.1% w/w SLS and 1% w/w glycerin, 20% w/w substitution with Elastigel 3000M® with 2% w/w glycerin were selected as three best formulations. The starch-gelatin hard capsule produced are slightly cloudy but other properties such as shape, flexibility, strength and disintegration time are similar to commercial gelatin capsules. Dicloxacillin was chosen as a model drug to compare the dissolution time between three starch-gelatin capsules and commercial gelatin capsules. It was found that all three starch-gelatin capsules were dissolved completely in 10 minutes which complied to USP XXV monograph. The recommended storage for three starch-gelatin capsules after three months stability test was 30℃, 75% RH inside low density polyethylene bags.