Studies on Dissolution Enhancement of Prednisolone, a Poorly Water-Soluble Drug by Solid Dispersion Technique

Introduction: Prednisolone is a class II substance according to the Biopharmaceutics Classification System. It is a poorly water soluble agent. The aim of the present study was to improve dissolution rate of a poorly water-soluble drug, prednisolone, by a solid dispersion technique. Methods: Solid dispersion of prednisolone was prepared with PEG 6000 or different carbohydrates such as lactose and dextrin with various ratios of the drug to carrier i.e., 1:10, 1:20 and 1:40. Solid dispersions were prepared by coevaporation method. The evaluation of the properties of the dispersions was performed using dissolution studies, Fourier-transform infrared spectroscopy and x-ray powder diffractometery. Results: The results indicated that lactose is suitable carriers to enhance the in vitro dissolution rate of prednisolone. The data from the x-ray diffraction showed that the drug was still detectable in its solid state in all solid dispersions except solid dispersions prepared by dextrin as carrier. The results from infrared spectroscopy showed no well-defined drug–carrier interactions for coevaporates. Conclusion: Solid dispersion of a poorly water-soluble drug, prednisolone may alleviate the problems of delayed and inconsistent rate of dissolution of the drug

Kinetic analysis of drug release from nanoparticles

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

Isolation and Identification of Antibiotic-Producing Halophilic Bacteria from Dagh Biarjmand and Haj Aligholi Salt Deserts, Iran

Background: Halophilic bacteria are potent organisms in production of novel bioactive antimicrobial compounds which might be considered in drug innovation and control of plant pathogens. Salt deserts in Semnan province are of the most permanent hypersaline areas in the North of Iran. Despite the importance of these areas, there is no scientific report regarding the biodiversity and potency of their halophilic bacteria. Thus, aforementioned areas were selected to detect the halophilic bacteria. Methods: Here, seven strains were isolated and cultured on their molecular and biochemical properties were characterized. To determine the antibiotic potency of the isolates, agar well diffusion method was conducted. Phylogenetic analysis was done to reveal the isolates relationship with previously known strains. Results: As a result, growth of the strains in the medium containing 5 to 20% (w/v) NaCl determined that the majority of the isolates were moderately halophile. Catalase activity of all strains was positive. The results represented that D6A, Dar and D8B have antimicrobial effects against different plant and human pathogens. Phylogenic tree analysis also showed that two strains of D6A and Dar are belonged to Bacillus subtilis and D8B is belonged to Virgibacillus olivae. The bacteria extracts were evaluated for their antifungal and antibacterial activities on human and Plant pathogenic strains. The MIC of the extract B. subtilis against was found active against human pathogenic fungi and Plant pathogenic bacteria and fungi, ranging from 12.5 to 25 µg/mL. Conclusion: This study highlights the therapeutic and prophylactic potential of B. subtilis extracts as antibacterial and antifungal agents

Intraperitoneal delivery of nanoparticles for cancer gene therapy

Nanoparticle-based gene delivery systems may be more efficient for administration of therapeutic genes to solid tumors and cancer metastases, owing to the numerous advantages in terms of enhanced tissue penetrability, improved cellular uptake and targeted gene delivery to the cells of interest compared with other gene delivery systems. Intraperitoneal (IP) delivery of therapeutic agents offers special merits because of the anatomical situation of peritoneum for local cancer therapy. Via the IP administration route, it is possible to target the therapeutic agents exactly to the target cells and protect healthy tissues outside the peritoneal cavity from side effects. IP delivery could be applicable for the treatment of disorders of organs in the peritoneal cavity covered with peritoneum and subperitoneal connective tissue, including cancers such as ovarian and gastric. The goal of this article is to review the current state of IP delivery of nanoparticles for cancer gene therapy

Delivery of nanoparticulate drug delivery systems via the intravenous route for cancer gene therapy

While the systemic route of administration enables therapeutic genes to spread through the bloodstream and access target cells, it is a challenge to achieve this. Several studies demonstrate that systemic administration of therapeutic genes or other nucleic acid-based constructs such as siRNA to solid tumors as well as cancer metastases are better with nanoparticulate systems compared to administration of free (uncomplexed) nucleic acids. Nanoparticle-based nucleic acid delivery systems might be more pertinent, due to the several privileges in terms of enhanced tissue penetrability, improved cellular uptake and to a lesser extent, targeted gene delivery to the cells of interest provided targeting ligands are used. Systemic delivery of nanoplexes has already been reported with different nanoparticles containing DNA via various routes of administration. The goal of the present article is to review the current state of intravenous delivery of nanoparticles for gene therapy of cancer

Nanoparticle-mediated interleukin-12 cancer gene therapy

Interleukin-12 (Il-12) is a heterodimeric cytokine which has been proved to possess antitumor effects in various animal models via stimulating the immune system. The main problem associated with Il-12 protein delivery is its instability as well as cytotoxicity subsequent to systemic administration in rodents and in human clinical trials. However, gene delivery can be used to deliver genes of interest to the tumor site. Hence, a large number of studies have been undertaken to deliver genes of interest to the tumor site through viral or non-viral vectors. Viral DNA delivery systems suffer from safety concern due to the toxicity of the viruses and strong immune response; while non-viral gene delivery systems proffer lower transfection efficiency. Nevertheless, nanometer-size complex of therapeutic DNA may demonstrate more efficient for administration of therapeutic genes to solid tumors compared to administration of naked plasmid DNA. Nanoparticle-based gene delivery systems might be more pertinent, due to the enhanced tissue penetrability, improved cellular uptake. Il-12 gene delivery has already been reported with different nanoparticles containing DNA. This article provides a review on the in vivo and in vitro studies using various nanoparticles, for delivery of the Il-12 genes to neoplastic cells. The future of these promising approaches lies in the development of better techniques for preparing il-12 gene delivery systems with complete efficiency of viral vectors in addition to the highest safety for cancer patients