Stability analysis and quantitative evaluation of metronidazole suspension.

Suspension is a heterogeneous mixture including solid particles that are satisfactorily bulky for sedimentation. Generally they must be larger than one micrometer. It is when particles are left floating around freely in a solvent. The inner phase (solid) is discrete all through the external phase (fluid) during mechanical stir, with utilizing of certain excipients or suspending agents. Metronidazole or 2-(2 methyl-5 nitro-1 H –imidazol-1 yl) ethanol belongs to the nitro imidazole group of antibiotics whose antimicrobial property through derive from the formation of toxic free radicals by intracellular reduction. The objective of present study was to prepare suspension of Metronidazole by using different suspending agents and stability testing was to provide evidence on how the quality of suspensions varies with the time under of influence of environmental factors such as temperature, light, oxygen, moisture, other ingredient or excipients in the dosage form, particle size of drug, microbial contamination etc. and to establish a recommended storage condition. The FTIR and DSC techniques are use for characterization of active ingredient MBZ. This suspension was evaluated for appearance, pH, sedimentation volume and dissolution study for in vitro drug release. Result of evaluation indicates 1% w/v xanthan gum give optimal characteristic suspension. Suspension containing 1% w/v was exposed for the stability studies as per ICH guidelines. The suspensions were evaluated for their physicochemical parameter, particle size, drug release, drug content and microbiological assessment. The suspension shows good stability at 25ºC ± 2 ºC /60%± 5% RH, 30 ºC ± 2 ºC /65%± 5% RH and good quantitative analysis result throughout the period of study. Suspension stored at 40 ºC ± 2 ºC /75%± 5% RH shows noncompliance with the analysis parameter after 4 week of storage. This indicate high temperature storage was shows degradation of the suspension which results in crystal growth in formulation and affect the physicochemical parameter as Appearance, pH, viscosity, specific gravity, drug dissolution profile and drug content.