A comparative study of approaches used to improve solubility of roxithromycin - Spray Drying

A comparative study of approaches used to improve solubility of roxithromycin
Received 16 November 2005; revised 25 July 2006; accepted 25 July 2006. Available online 11 September 2006.
Shailesh V. Biradara, Arpana R. Patila, Guditi V. Sudarsana and Varsha B. Pokharkar, a
Powder Technology
Volume 169, Issue 1 , 24 October 2006
ScienceDirect
Copyright ? 2006 Elsevier B.V. All rights reserved.
aDepartment of Pharmaceutics, Poona College of Pharmacy, Bharati Vidyapeeth Deemed University, Erandwane, Pune, Maharashtra State, India
Abstract
Roxithromycin (ROX), a class IV drug has 50% absolute oral bioavailability due to poor aqueous solubility. The present study deals with exploring the effect of homogenization, homogenization followed by freeze drying and homogenization followed by spray drying in the presence of solubilizers on drug solubility and dissolution rate. Homogenization and subsequent freeze drying resulted in 3?4 fold increase in saturation solubility and 18 times faster dissolution as compared to the pure drug. In this study, a more preferred aqueous system was developed for enhancement of the saturation solubility and dissolution rate and compared with the non-aqueous system. Interestingly the aqueous system was found equally effective and comparatively more stable. Enhancement of the saturation solubility and dissolution rate was a result of significant particle size reduction, improved hydrophilicity and complete or partial transformation to amorphous form as evidenced by DSC and XRPD studies. The study focused on utilization of solubilizer to synergistically enhance the efficiency of the processing techniques. The effect of processing and formulation variables on the saturation solubility, in vitro dissolution, drug crystallinity, physical interaction, antimicrobial activity and stability was also monitored.
Keywords: Freeze drying; Spray drying; Roxithromycin; Ultra turrax; Homogenization

Corresponding author. Tel.: +91 20 25437237; fax: +91 20 25439383.
You can view the abstract online. A subscription is required to view the full text or it can be purchased online.