A survey on IVIVC/IVIVR development in the pharmaceutical industry - Past experience and current perspectives.

The present work aimed to describe the current status of IVIVC/IVIVR development in the pharmaceutical industry, focusing on the use and perception of specific approaches as well as successful and failed case studies. Two questionnaires have been distributed to 13 EFPIA partners of the Oral Biopharmaceutics Tools Initiative and to the Pharmacokinetics Working Party of the European Medicines Agency in order to capture the perspectives and experiences of industry scientists and agency members, respectively. Responses from ten companies and three European Agencies were received between May 21st 2014 and January 19th 2016. The majority of the companies acknowledged the importance of IVIVC/IVIVR throughout the drug development stages and a well-balanced rate of return on investment. However, the IVIVC/IVIVR approach seemed to be underutilized in regulatory submissions. Four of the ten companies stated to have an internal guidance related to IVIVC/IVIVR modelling, whereas three felt that an overall strategy is not necessary. Successful models mainly served to support formulation development and to provide a better mechanistic understanding. There was not yet much experience with safe-space IVIVRs as well as the use of physiologically based modelling in the field of IVIVC. At the same time, the responses from both industry and agencies indicated that there might be a need for a regulatory framework to guide the application of these novel approaches. The relevance of IVIVC/IVIVR for oral IR drug products was recognized by most of the companies. For IR formulations, relationships other than Level A correlation were more common outcomes among the provided case studies, such as multiple Level C correlation or safe-space IVIVR, which could be successfully used for requesting regulatory flexibility. Compared to the responses from industry scientists, there was a trend towards a higher appreciation of the BCS among the regulators, but a less positive attitude towards the utility of non-compendial dissolution methods for establishing a successful IVIVC/IVIVR. The lack of appropriate in vivo data and regulatory uncertainty were considered the major difficulties in IVIVC/IVIVR development. The results of this survey provide unique insights into current IVIVC/IVIVR practices in the pharmaceutical industry. Pursuing an IVIVC/IVIVR should be generally encouraged, considering its high value from both industry and regulators' perspective.

Setting accelerated dissolution test for PLGA microspheres containing peptide, investigation of critical parameters affecting drug release rate and mechanism.

The objective of this study was development of accelerated in vitro release method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug release rate and mechanism. Accelerated release conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while release rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, release rate showed three-fold deceleration without significant change in release mechanism. Effect of medium composition on drug release was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug release rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide release. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the release process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for accelerated in vitro dissolution testing for a given formulation.