Tsz Hei Kwong1, Sarah Clymans1, Arvind B Bhome2, Patricia Tang1, Hak-Kim Chan1 & Philip Chi Lip Kwok1
1Advanced Drug Delivery Group, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia
2Proposed PGI, YCM Hospital, PCMC, Pimpri, Pune 411018, India
Introduction
Seretide® metered dose inhaler (MDI) is a combination product containing fluticasone propionate and salmeterol xinafoate. Although its generic products are commonly used in India, there is yet no published studies comparing them.
Aim
The objective of the study was to compare the in vitro aerosol performance between Seretide, Esiflo®, and Seroflo® MDIs.
Methods
Two inhalers of each product were examined. The life of each inhaler was divided into beginning, middle, and end phases. Ten dose uniformity and three aerodynamic particle size measurements were randomly performed on each inhaler in each phase. The tests were measured by the Dose Uniformity Sampling Apparatus and the Next Generation Impactor, respectively. The dispersed drugs were analysed by high performance liquid chromatography.
Results and discussion
There was no significant difference in the delivered dose uniformity and aerodynamic particle size distribution in the beginning phase. In the middle phase, the ex-actuator fraction of both drugs from Seroflo was significantly higher than those from Seretide. Seroflo emitted 26-27% more drugs than Seretide but both generic products produced significantly lower fine particle fractions < 5 µm. Differences in aerosol performance were more pronounced in the end phase. The ex-actuator fraction of fluticasone propionate for both generics were significantly lower (Seretide: 88.7%; Esiflo: 62.4%; Seroflo: 68%). Seroflo produced a significantly lower fine particle fraction < 5 µm of salmeterol xinafoate (Seretide: 37.6%; Esiflo: 32.0%; Seroflo: 25.3%).
Conclusions
Both generics performed differently to Seretide. In vivo studies are required to test their bioequivalence and compare their therapeutic effects.