ENHANCEMENT OF THE IMMEDIATE RELEASE OF PARACETAMOL FROM ALGINATE BEADS

Samah Hamed,Abd Almonem Doolaanea,Farah Amalina Ayob,Mulham Alfatama

doi:10.22159/ijap.2017v9i2.15672

Abstract

Objective: Alginate beads are not soluble in the acid leading to small portion released in the stomach. This may not be favourable for drugs administered for fast action like paracetamol. So, this study was aimed to increase the immediate release of paracetamol from alginate beads, i.e. the release in the acidic pH.Methods: The beads were prepared by dropwise paracetamol/alginate suspension in divalent cation solution. Two attempts were used to increase the dissolution of paracetamol in the acidic pH. First attempt was by only changing preparation variables: needle size, alginate viscosity and drug loading using 23 full factorial design. The second approach was by adding excipients like carbopol, tween and polyethylene glycol. The beads were characterized for their size, encapsulation efficiency and release profile.Results: First approach, changing preparation variables without excipient adding, helped to increase the drug release in the acid but to a maximum of 26% using a smaller needle, lower drug loading and higher alginate viscosity. However, optimising the formulation with suitable excipients increased the drug release in the acid to 77.3%. The optimised formulation included carbopol 940 (pH sensitive polymer) and tween 80 (facilitates water entry) in the beads, with using barium chloride instead of calcium chloride together with PEG 400 in the complexing solution.Conclusion: To achieve immediate release of paracetamol from alginate beads in the acidic pH, excipients need to be added. Rational selection of excipients is critical to achieve the desired drug release.

Highlights

The field of natural polysaccharides of marine origin is already large and expanding for the biomedical purpose
The favorable properties of alginates like biocompatibility, non-toxicity and ease of gelation led to their wide use in food and pharmaceutical industries as tablet disintegrant, thickening, and suspending agent, but the interest increased toward alginate gel beads as controlled-release devices for conventional drugs, proteins, microbial and biological cells [3]
Alginates with a high content of guluronic acid blocks give gels of considerably higher strength compared to alginates rich in mannuronate, as the G residues exhibit a stronger affinity for divalent ions than the M residues

Summary

Introduction

The field of natural polysaccharides of marine origin is already large and expanding for the biomedical purpose. Alginates are heteropolymer carboxylic acids linked by 1,4glycosidic bonds of p-D-mannuronic (M) and a-L-guluronic acid (G) units [4]. The most important feature of alginate’s physical properties is the selective binding of multivalent cations that is the basis for gel formation. The gelation occurs by cross-linking of the uronic acid units with divalent cations to form the so-called 'eggbox' structure. Alginate’s affinity is different toward the various divalent ions [5]. Alginates isolated from different sources can vary both in monomer composition and block arrangement and these variations are reflected in the properties of the alginate. Alginates with a high content of guluronic acid blocks give gels of considerably higher strength compared to alginates rich in mannuronate, as the G residues exhibit a stronger affinity for divalent ions than the M residues. The stiffness of alginate solution increases when the chain blocks increased in the order MG

Methods

Results

Conclusion