Introduction

1. DEVELOPMENT, OPTIMIZATION AND PROCESS VALIDATION OF THE MODIFIED QUASSI EMULSION SOLVENT DIFFUSION METHOD FOR THE PREPARATION OF MICROSPONGES RishabhSrivastava*, KamlaPathakDepartment of Pharmaceutics, Rajiv Academy for Pharmacy, Mathura, Uttar Pradesh- 281001

2. Introduction • Microsponges are porous microspheres having numerous interconnected voids in the particle, loaded with an active ingredient within a collapsible structure along with the large porous surface. • These microparticles have characteristic feature in the form of their capacity to ‘adsorb on its surface’ and/or ‘load into the bulk’ of the particle, the high quantity of active pharmaceutical ingredients. • In spite of using conventional technique to prepare microsponges we had developed the method to prepare microsponges using porogen incorporation technique and used sodium chloride as porogen.

3. OBJECTIVE • The objective of this study is to develop, optimize and validate a novel technique for preparation of microsponges by incorporating a porogen to modify the quassi emulsion solvent diffusion method.

4. Outline for the developed technique organic solution of the polymer aqueous solution of the porogen 2% v/v Span 80 vigorous stirring internal aqueous phase porogen 1% w/w equivalent to the polymer emulsified properly to form a w/o emulsion The prepared w/o emulsion is redispersed in 1% w/v PVA solution to form w/o/w emulsion and stirred continuously, filtered, dried and kept in dessicator

5. Optimization of the process variables Parameters optimized • PVA concentration • Volume of the external phase • Porogen content • Concentration of internal phase stabilizing agent • Temperature • Stirring time These have been optimized for particle shape, aggregation and for better cross-linking of microparticles

7. Fig. 1: Photomicrograph of the prepared microsponges showing spherical shape Fig. 2: SEM of the prepared microsponges showing porous surface

8. Validation • The developed technology has been validated for the reproducibility in the result. It has been done by repeating the developed methodology for various times.

9. Result • Various process variables had been optimized for the developed technique. Porogen content of 1% w/w provided no disruption to the shape. Span 80 was selected as stabilizing agent for internal w/o emulsion. It can stabilize the internal phase when used in the concentration of 2% v/v. A concentration of 1% w/v of PVA gives spherical particles. Low temperature was required for better cross-linking. While a stirring time of 24 hrs and high volume of external continuous phase provided better deaggregation of the particles.

10. Conclusion • An optimized and validated novel technique for the preparation of the microsponges has been developed. These microsponges can be used as the drug carriers for the rate modulated drug delivery of a poorly water soluble drug.

11. Presented at • 26th ANNUAL CONFERENCE OF INDIAN PHARMACY GRADUATES ASSOCIATION • PHARMACEUTICAL OPPORTUNITIES AND CHALLENGES OF THE NEW DECADE • 2nd APRIL 2011 • NEW DELHI