Formulation and Evaluation of Solid Dispersion Capsules Containing Erythromycin Stearate

No Thumbnail Available



Journal Title

Journal ISSN

Volume Title


Addis Ababa University


Erythromycin stearate is a macrolide and belong to one of the most commonly used families of clinically important antibiotics used to treat infections caused by Gram-positive bacteria such as Staphylococcus aureus, Streptococcus pneumonia and Streptococcus pyogenes. The objective of this study was to increase the solubility of the poorly water soluble drug erythromycin stearate, by the formation of solid dispersion. Solubility is an important physicochemical factor affecting absorption of drug and its therapeutic effectiveness. In the present investigation, an attempt was made to improve the solubility and dissolution rate of a poorly soluble drug, Erythromycin stearate. The dispersion carriers used for the study were PEG4000, PEG 6000 and PVP K30. Fusion method, Solvent Evaporation method and Kneading methods in 2:1, 1:1 and 1:2 ratios of drug to polymer were used to prepare the solid dispersion. The formulation were characterized for drug-polymer interaction using FTIR spectrum and DSC, solubility parameters, drug content studies, drug release studies. The interaction studies showed no interaction between the drug and the polymers. Formulations containing 1:2 ratio of drug: PEG4000, drug:PEG6000 prepared by fusion method showed the best release with a cumulative release of 97.55% and 101.78% respectively as compared to 54.62% for the pure drug. The flow property studies like angle of repose , hausner's ratio and carr's index showed the solid dispersion preparation had good flow. The practical yield was found to be above 90% for all the formulations. Similarly the drug content was also above 90% for all the formulation except, the solid dispersion prepared by kneading method. The XRD studies showed the crystallinity of the solid dispersion reduced compared to the drug alone. Drug to PVPK30 1:2 ratio prepared by solvent evaporation method showed cumulative release of 96.31%. The results of short term stability studies showed good stability within the studied period of 3 months at the temperature 40C and relative humidity of 75%.



Staphylococcus aureus; Streptococcus pneumonia; Streptococcus pyogenes