Floating Hard Egg Albumin Matrix Tablets with Gastroretentive Properties

INTRODUCTION

Floating, swelling, expansion, bioadhesion, sinking, and magnetic anchoring were evaluated for delaying of pyloric passage by the dosage form, as an opportunity to deliver drugs in controlled manner into narrow absorption window and locally in the stomach. Some of these highly unconventional delivery systems may in fact increase the bioavailability of drugs¹. In the present study an ovalbumin-based tablet with immediate buoyancy, high swelling properties, and high mechanical strength was developed, in aspiration that these three mechanisms tuned together may result in improved performance in gastric retention. A model drug gabapentin – a significant narrow-absorption-window molecule with high dose – was chosen to test the limits of the system.

METHODS

Denaturative granulations were performed in a mortar and pestle, drying in a temperature-controlled oven. Tablets were compressed using IR press. Elongated caplet die was used for gabapentin tablets. Swelling and buoyancy test was carried out at 37°C in simulated gastric fluid USP, without enzymes. Mechanical compression tests were performed with flat-head 20-mm probe, at 0.5 mm/s and 1-g trigger force.

RESULTS

With no denaturation the tablets disintegrated rapidly under the action of gas-forming couple. At lower amount of isopropanol but not ethanol for denaturative granulation and modest drying the tablets became immediately buoyant. Yield strength of the swollen tablets was above 5 kg, and the swelling of over 350% by weight, > 250% by volume and >150% by dimensions. The presence of a detergent during the denaturation probably improves the process and stabilizes the denaturated structure. An addition of 25% hypromellose caused yet better swelling and still the yield strength of 2.9 kg. Gabapentin was released in pseudo-first order kinetics, unaffected by the pH of the medium or even the presence of the hydrogel (1:1). The only parameter that affected the release kinetics was the drug loading. At 30% loading the release was sustained for 24 hours, at 50% for 12 hours.

CONCLUSION

The denaturated ovalbumin may serve as a non-erodible scaffold for gastroretentive tablets` matrices.

REFERENCES

1. Carla M. Lopes, et al, Overview on gastroretentive drug delivery systems for improving drug bioavailability, Int J Pharm, 510, 144-158 (2016).