PREPARATION AND EVALUATION OF DIFFERENT POLYMERS BASED DRY ADSORBED EMULSIONS OF CHLORPHENIRAMINE MALEATE AS A SUSTAINED DRUG-DELIVERY SYSTEM

Dry adsorbed emulsions containing chlorpheniramine maleate and differe nt polymers as adsorbent were chlorpheniramine Hydrophobic silica was used to cover the oil phase, while the aqueous phase was adsorbed by e ither pectin, Eudragit S, chitosan or hydrophilic silica. The physical properties of the prepared dry adsorbed emulsion, such as drug conten t, mean particle diameter, flowability and porosity, were evaluated. T he release rate of the drug was investigated in dissolution media of v arying pH. The stability of the hydrophilic silica based dry adsorbed emulsion was also studied. The results revealed that the physical prop erties of the prepared dry adsorbed emulsions were within the pharmace utical working range. The release rate of chlorpheniramine maleate was affected by the properties of both the drug and the polymers. The hig hest sustained release rate was obtained from the silica based dry ads orbed emulsion. The temperature and relative humidity affected the phy sical properties and increased there release rate of the drug from the stored samples.