Assembled modules technology for site-specific prolonged delivery of norfloxacin.

The aim of this research was to design and study norfloxacin (NFX) release in floating conditions from compressed hydrophilic matrices of hydroxypropylmethylcellulose (HPMC) or poly(ethylene oxide) (PEO). Module assembling technology for drug delivery system manufacturing was used. Two differently cylindrical base curved matrix/modules, identified as female and male, were assembled in void configuration by friction interlocking their concave bases obtaining a floating release system. Drug release and floatation behavior of this assembly was investigated. Due to the higher surface area exposed to the release medium, faster release was observed for individual modules compared to their assembled configuration, independently on the polymer used and concentration. The release curves analyzed using the Korsmeyer exponential equation and Peppas & Sahlin binomial equation showed that the drug release was controlled both by drug diffusion and polymer relaxation or erosion mechanisms. However, convective transport was predominant with PEO and at low content of polymers. NFX release from PEO polymeric matrix was more erosion dependent than HPMC. The assembled systems were able to float in vitro for up to 240min, indicating that this drug delivery system of norfloxacin could provide gastro-retentive site-specific release for increasing norfloxacin bioavailability.

Artesunate-clindamycin multi-kinetics and site-specific oral delivery system for antimalaric combination products.

The aim of this work was to study a multi-kinetics and site-specific oral antimalaria drug delivery system (MKS_DDS), containing artesunate and clindamycin, based on the Dome Matrix module assembly technology. The MKS_DDS assembled system comprises of four modules, i.e., two controlled release (CR) modules for delivery of 160 mg of clindamycin phosphate, one immediate release module containing 50 mg of artesunate and one immediate release module containing 80 mg of clindamycin phosphate. These modules have been assembled in stacked and void configurations. The void configuration is able to float and showed gastro-retentive behavior. The MKS_DDS was investigated for its mechanical characteristics, system behavior during release, drug release rate and mechanism. A bioavailability study (dogs) showed that the clindamycin plasma curve of the MKS_DDS system exhibited a quasi constant release rate, up to 8 h. The MKS_DDS system containing clindamycin and artesunate allows the use of one tablet containing one immediate release dose of artesunate and of clindamycin and a portion of clindamycin released over a prolonged time, by exploiting the gastro-retentive properties of a floating system.