We present an integrated omnichannel framework designed for coordinating and improving shopping experience in the Health and Pharma (H&P) sector. The architecture of this unified purchasing system is composed by macros and subsystems designed for the scalability and flexibility of the framework in the specific context of H&P. In addition, we introduce an optimization algorithm specifically designed for the storage operations in a dark-store, with the aim of optimizing operational efficiency and reducing related costs. In the present study we propose two product allocation strategies in a vertical carousel warehouse, based on correlations between products. We show that the proposed optimized allocation strategy significantly reduces picking times compared to the random allocation strategy. Moreover, these results indicate that taking into account the correlation between products in past orders and the optimization of product arrangements within the warehouse can significantly improve the efficiency of the picking process.