Suitability of Wurster-Fluid Bed technique for functional Eudragit L-100 coating on tablet cores

Introduction

Film coating of solid dosage forms in pharmaceutical manufacturing is carried out using range of equipment, process parameters and coating formulations to achieve the quality target profile of the dosage form. Besides for aesthetic reasons, film coatings are mostly applied to modify the dissolution behaviour of active pharmaceutical ingredients. Currently, a number of coater types are used in pharmaceutical industry, including drum, fluid bed, rotary and continuous coaters. The end-point of coating process is usually defined by the amount of applied coating dispersion or weight gain of coated dosage forms. However, these measurements provide little information on coating quality attributes such as coating thickness, uniformity etc. Other monitoring techniques are scanning electron microscopy, Near infrared (NIR) or Fourier transform infrared spectroscopy (FTIR) (Hasar et al., 2013).

The aim of this research was to examine the suitability of Wurster-Fluid bed technique for functional Eudragit L-100 coating on tablet cores by monitoring critical attributes during the process.

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Materials

Coating: Eudragit L-100 is an anionic copolymer of methacrylic acid and methyl methacrylate, insoluble at pH<6, therefore it is suitable for enteric-coating. Triethyl citrate (TEC) and Polyethylene glycol (PEG 400) were used as plasticizers, to improve the flexibility and processability of the polymer film. Ammonia Solution 25% was used to promote dispersion of the anionic copolymer in water.

Preparation of Aqueous Enteric Coating Dispersion: Eudragit L-100 (20g) was added in purified water (108,53g) slowly, with constant stirring and suspension was stirred approximately for 10 minutes. Strong Ammonia Solution (1.20g) was slowly added to dispersion and the mixture was stirred for 30 minutes. Triethyl citrate (4.99g) and Polyethylene glycol (0.71g) were added to dispersion and moderately stirred for 20 minutes. (United States of America Patent No. US 6,224,911 B1, 2001).

Production of tablet cores: A mixture of 65% αLactose monohydrate (FlowLac 100, MEGGLE Wasserburg GmbH & Co. KG), 33% Microcrystalline cellulose (Avicel PH102, DuPont Nutrition & Health), and 2% Magnesium stearate (Faci S.p.A) was prepared using Erweka AR 400 drum hoop mixer (ERWEKA GmbH).
The lubricated final blend was tablet compressed on Korsch Xl 100 Pro rotary tablet press (Korsch AG), equipped with four 6 mm flat punches and gravity feeder configuration, at a production rate of 50 rpm. The main compression pressure was 6 kN and the pre-compression was fixed at 0.1 kN. Tablet compressing was performed on constant production speed and compression pressure. The filling depth was adjusted so that the resulting tablets have an average mass of 80 mg. Tablet cores weight was measured by use of analytical balance Sartorius model SECURA224-1CEU (Sartorius AG), and hardness and thickness were measured using Erweka TBH 425 multitester (ERWEKA GmbH).

Sanja Dukovska, Elizabeta Atanaskova, Maja Simonoska Crcarevska, Marija Glavas Dodov, Katerina Goracinova, Nikola Geskovski, Suitability of Wurster-Fluid Bed technique for functional Eudragit L-100 coating on tablet cores
Macedonian pharmaceutical bulletin, 69 (Suppl 1) 293 – 294 (2023), Online ISSN 1857 – 8969, DOI: 10.33320/maced.pharm.bull.2023.69.03.142