ABSTRACT-PURPOSE.Comparative drug release kinetics from nanoparticles was carried out using conventional and our novel models with the aim of finding a general model applicable to multi mechanistic release. Theoretical justification for the two best general models was also provided for the first time. METHODS. Ten conventional models and three models developed in our laboratory were applied to release data of 32 drugs from 106 nanoparticle formulations collected from literature. The accuracy of the models was assessed employing mean percent error (E) of each data set, overall mean percent error (OE) and number of Es less than 10 percent. RESULTS. Among the models the novel reciprocal powered time (RPT), Weibull (W) and log-probability (LP) ones produced OE values of 6.47, 6.39 and 6.77, respectively. The OEs of other models were higher than 10%. Also the number of errors less than 10% for the models was 84.9, 80.2 and 78.3 percents of total number of data sets. CONCLUSIONS. Considering the accuracy criteria the reciprocal powered time model could be suggested as a general model for analysis of multi mechanistic drug release from nanoparticles. Also W and LP models were the closest to the suggested model RPT.

Gelatin is a natural, biocompatible, nontoxic, edible, and inexpensive macromolecule. These properties result in its wide application in pharmaceutical, medical, and cosmetic products. Recently, it has been used for the delivery of such gene therapeutic entities as plasmid DNA. This review discusses the in vivo and in vitro studies using gelatin for delivery of therapeutic genes to cancerous cells. Recent studies show that present cancer gene therapy using gelatin is lacking in both efficiency and specificity in comparison with viral vectors, whereas complexes of therapeutic DNA with modified gelatin possibly offer a safe and efficient strategy for systemic administration of therapeutic genes to solid tumors compared to injection of naked plasmid DNA. The future of these promising approaches lies in the development of better techniques for preparing gelatin-gene complexes with the aim of a gelatin-based cancer gene therapy with comparable efficiency to viral vectors but with the added advantage of biosafety for patients.

Rapid and sensitive detection techniques for indicator pathogens are important in pharmaceutical industry. However, common detection methods rely on bacterial culture in combination with biochemical tests, a process that typically takes 5–6 days to complete. Thus, the aim of this study was to develop a multiplex polymerase chain reaction (mPCR) assay for simultaneous detection and identification of four indicator pathogenic bacteria in a single reaction. Specific primers for indicator bacteria, namely Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosaand Salmonella, were applied to allow simultaneous detection of them, and the sensitivity and specificity of each primer pairs were determined. In the mPCR with mixed DNA samples, specific bands for corresponding bacteria were simultaneously detected. Agarose gel electrophoresis of PCR products revealed 100% specificity of mPCR with single bands in the expected sizes. Low levels of microbial contamination less than 10 cfu per milliliter or gram of product were detected using mPCR assay. The detection of all four indicator pathogenic bacteria were completed in less than 8 h with this novel mPCR method, whereas the conventional United States Pharmacopeia methods and uniplex PCR required 5–6 days and 27 h for completion, respectively. Using mPCR assay, the microbial quality control of nonsterile pharmaceutical products can be performed in a cost‐effective and timely manner in pharmaceutical industry. PRACTICAL APPLICATIONS Detection of pathogenic indicatiors of Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa is one of the mandatory tests in microbial quality of nonsterile pharmaceutical products; therefore, rapid and sensitive detection of the contaminations is of great importance for product release. According to the results of the present study, simultaneous detection of low levels of four major potential pathogenic bacteria in pharmaceutical finished products can be performed using mPCR in a cost‐effective and timely manner, and upon these properties of the mPCR assay it could have potential applications in pharmaceutical industry.

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