Effect of the Surface Hydrophobicity Degree on the In Vitro Release of Polar and Non-Polar Drugs from Polyelectrolyte Matrix Tablets.

Cristhian Yarce,Juan Echeverri,Constain Salamanca

doi:10.3390/polym10121313

Abstract

This work is the continuation of a series of studies focused on establishing the relationship between the surface thermodynamic properties of polyelectrolyte matrix tablets and drug release mechanisms. In this case, two model drugs with different polarity features, such as carbamazepine (non-polar) and metoprolol succinate (polar) were used in combination with polymeric material hydroxypropyl-methyl cellulose (HPMC) and two polyelectrolytes derived from maleic anhydride corresponding to the sodium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene) named PAM-0Na and PAM-18Na, respectively. The polymers were obtained and characterized as reported previously. Surface studies were performed by the sessile drop method, whilst the surface free energy was determined through Owens, Wendt, Rable and Kaeble (OWRK) semi-empirical model. By contrast, the drug release studies were performed by in vitro dissolution tests, where data were analyzed through dissolution efficiency. The results showed that, depending on the drug polarity, type and polymer proportion, surface properties and drug release processes are significantly affected.

Highlights

The polymers derived from maleic anhydride correspond to a class of materials that have shown an interesting potential as pharmaceutical excipients due to their biocompatibility and diversity of applications in product formulation [1]
The third and current research are focused on determining the effect of the polarity of the drug released, with respect to the surface hydrophobicity degree and the proportion of polymeric material in the binary matrix tablets
The structural changes of the PAM-0 and PAM-18 precursors and the PAM-0Na and PAM-18Na polymer derivatives were analyzed by comparing the Fourier transform infrared (FT-IR) spectra

Summary

Introduction

The polymers derived from maleic anhydride correspond to a class of materials that have shown an interesting potential as pharmaceutical excipients due to their biocompatibility and diversity of applications in product formulation [1] Some of these materials are the salts of poly(maleic acid-alt-octadecene), which have described several interesting properties, such as (i) the capability to form hydrophobic “pseudo-phases” in aqueous media, useful for the inclusion of drugs, [2] and (ii) the capability to generate surface with different hydrophobicity degrees, useful in the development of modified-release matrix systems [3].

Methods

Results

Conclusion