Novel Pharmaceutical Gels Containing Glyccerihizic Acid Ammonium Salt for Chronic Wounds

Abstract

Aims: This study aimed at preparing pharmaceutical gels containing Glyccerihizic Acid Ammonium Salt (GAM) for healing of chronic wounds followed by in-vitro and in-vivo characterization of the prepared gels to ensure their suitability, efficacy and safety. Place and Duration of Study: Department of Pharmaceutics, faculty of Pharmacy (El-Minia University) and Department of Histology, Faculty of medicine, El-Minia University, from September 2011 to June 2012. Methodology: Preformulation studies including infra-red and differential scanning calorimetry were performed on the drug and the polymers to confirm their physicochemical compatibility. Pluronic F-127, Carbomer 940, sodium alginate and hydroxypropyl methyl cellulose were used as gelling agents. The gel formulations were evaluated for in-vitro release and characterized for their physicochemical properties. The base that exhibited the highest release rate was subjected to further histological studies in wounded rats to demonstrate the effect of drug concentration on the histopathological changes post applications. Results: Physicochemical compatibility studies demonstrated the absence of interaction between the drug and the polymers. The physical appearance of the prepared gel was accepted. Microscopic examinations confirmed the absence of any particles or grittiness. Sodium alginate-based gels exhibited the highest drug release rate. Statistical analysis showed high significant differences as compared to other formulations (P<0.001). Kinetic studies showed that all formulations exhibited first-order release rate. Histopathological studies demonstrated that wound closure was faster in animals treated with 3% (w/w) drug as compared to those treated with 1% (w/w) drug. No signs of irritation were noticed among all treated animals Conclusion: GAM prepared in sodium alginate base gave the highest in-vitro release pattern, which followed first-order release rate. A concentration of 3% w/w GAM of this base would give better healing effect in a shorter time.