Erythromycin stearate

In this present work Erythromycin stearate nanosuspension has been formulated. Since Erythromycin stearate is insoluble in water, it has been formulated as nanosuspension to improve bioavailability of the drug. The formulation was carried out using High Pressure Homogenization method using different variables like drug-surfactants ratio, stirring speed and rotation time, to optimize the final formulation while keeping the quantities of active ingredient constant. An optimized final formulation was prepared by using drug, poloxamer 188 and tween20 in 1:2:2 ratios with stirring speed of 25000 rpm for 25 minutes using High Pressure Homogenizer (Polytron PT 1600E) followed by lyophilisation. The optimized final formulation was subjected to in-vitro parameters such as compatibility, drug content, particle size analysis, zeta-potential, SEM, in-vitro release profile. All the in vitro evaluation parameters complied the limits. Stability studies were also conducted as per ICH guidelines and from the result it may be concluded that the optimized formulation is stable. Finally, it is concluded that the drug is compatible and stable with the excipients, hence Erythromycin stearate can be formulated as nanosuspension by this method. Key words: Erythromycin stearate, Poloxamer 188, Nanosuspension, Zeta potential, DSC, SEM.    

The concept of controlled release tablet can be utilized to provide a long lasting and more reliable release of drug in GIT to ultimately develop a once daily formulation. Thus, they prolong the dosing intervals, but also increase patient compliance beyond the level of existing conventional dosage forms. Erythromycin, macrolide antibiotics is used in the treatment of Mycoplasma pneumoniae infections, Chlamydial infections, etc. It is a drug with short biological half-life 1.5 hrs and dosing frequency more than one per day which makes it an ideal candidate for controlled release. The present investigation was planned to formulate the Erythromycin stearate once daily controlled release tablets. The tablets were prepared by direct compression method and were subjected for in vitro drug release studies. The mechanism of drug release was determined using various kinetic models. The results revealed that all the formulated tablets had acceptable physical properties and showed release up to 24 hrs. The kinetic studies revealed that all the formulations followed Zero order release kinetics. The tablets were prepared by Direct Compression technique and evaluated for various parameters. The optimized formulation contains Erythromycin Stearate as active ingredient, HPMC K15M, Chitosan and Xanthan gum as rate retarding polymers.