Metronidazole [1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole) is a broad spectrum antimicrobial agent used for the eradication of Helicobacter pylori. Due to the short biological half-life (6 to 8 h) and bitter taste which may lead to non-compliance issue; the purpose of this study was to develop and evaluate metronidazole loaded carbopol 934P mucoadhesive microcapsules for sustained drug release at the gastric mucosa. Metronidazole mucoadhesive microcapsule was formulated by ion gelation technique using 32 factorial designs. A 32 full factorial design was used to derive a statistical equation, ANOVA analysis, contour plots and 3D response surface plots. FT-IR spectroscopy result showed interaction between the drug and polymers combined. The optimized formulation exhibited a high drug entrapment efficiency of 87.74±0.01%, particle size of 845.40±0.02 (μm), percentage yield of 97.80±0.02%, swelling index of 102.33±0.03%, % mucoadhesion after 8 h was 64.00±0.01% and the drug release 52.30±0.01%. The microcapsules adhered more strongly to the gastric mucous layer and could be retained in the gastric mucosa for an extended period of time consequently increasing bioavailability, improving patients compliance and reducing dosing frequency; which is more effectively used for sustained drug release to the gastric mucosa in the treatment of upper GIT infection.
Key words: Metronidazole, Mucoadhesive drug delivery, Sustained drug release, Ion gelation technique, ANOVA analysis