Emulgel-loaded mannosylated thiolated chitosan-coated silver nanoparticles for the treatment of cutaneous leishmaniasis.

Topical treatment of cutaneous leishmaniasis holds great promise for decreasing drug associated side effects and improving efficacy. This study was aimed to develop mannosylated thiolated chitosan-coated silver nanoparticles (MTCAg) loaded emulgel for the treatment of cutaneous leishmaniasis. MTC-Ag were synthesized via a chemical reduction method and were loaded into the emulgel. The nanoparticles had a zeta potential of +19.8 mV, an average particle size of 115 nm and a narrow polydispersity index of 0.26. In-vitro release profiles showed controlled release of silver ions from both the MTC-Ag and the emulgel-loaded MTC-Ag nanoparticles after 24 h. An ex-vivo retention study indicated 5 times higher retention of silver by the emulgel-loaded MTC-Ag than by the MTC-Ag nanoparticles. The in-vitro anti-leishmanial assay revealed that MTC-Ag had an excellent inhibitory effect on intracellular amastigotes, leading to ~90 % inhibition at the highest concentration tested. A 4-fold reduction in the IC50 value was found for MTC-Ag compared to blank Ag nanoparticles. Cytotoxicity assay showed 83 % viability of macrophages for MTC-Ag and 30 % for Ag nanoparticles at a concentration of 80 µg/mL, demonstrating the improved biocompatibility of the polymeric nanoparticles. Drug release and retention studies corroborate the great potential of MTC-Ag-loaded emulgel for the treatment of cutaneous leishmaniasis.

A Multifunctional Polymeric Micelle for Targeted Delivery of Paclitaxel by the Inhibition of the P-Glycoprotein Transporters.

P-glycoprotein (P-gP) efflux-mediated multidrug resistance is a fundamental aspect of chemotherapeutic failure in oncology. The current study aims to deliver paclitaxel (PTX) specifically at the target site with improved in vivo efficacy of poorly permeable PTX against solid tumors. Multifunctional polymeric micelles as targeted delivery have been devised for loading and release of PTX. Mucoadhesion, permeation enhancement, oral pharmacokinetics, biodistribution, and toxicological studies were carried out to fully elucidate the therapeutic outcomes of the polymeric micelles. Ex vivo permeation studies indicated a 7.89-fold enhancement in the permeation of PTX with mucopermeating papain functionalized thiolated redox micelles (PT-R-Ms) compared to the pure PTX. Moreover, PT-R-Ms exhibited a higher percentage of apoptotic cells (42.9 ± 0.07%) compared to pure PTX. Biodistribution studies revealed that fluorotagged PT-RMs accumulated in excised tumors and organs. The higher fluorescence intensity indicated the mucopermeation of micelles across the intestine. The orally administered PT-R-Ms efficiently overcome intestinal barriers and inhibit the P-gP efflux pump, resulting in increased bioavailability of PTX (up to 8-fold) in comparison to pure PTX. The enhanced anti-tumor efficacy and reduced toxic effects are key aspects of efficient cancer therapy. This study demonstrates that the use of mucopermeating PT-R-Ms is an encouraging approach to overwhelm the permeation barrier in cancer treatment.

Tuberculosis Resistance and Nanoparticles: Combating the Dual Role of Reactive Oxygen Species in Macrophages for Tuberculosis Management.

Increasing drift in antimicrobial therapy failure against Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), and the advent of extended resistant strains strongly demand discovery of mechanisms underlying development of drug resistance. The emergence of resistance against anti-TB drugs has reached an alarming level in various parts of the world, providing an active platform for the design of new targeted drug delivery. Reactive oxygen species (ROS) have an important role in controlling TB pathogenesis. At macrophage activation, ROS that are produced inside macrophages directly kill resident bacteria. These ROS possess a dual character because they can kill macrophages along with the resident bacteria. Targeting these ROS can play a remarkable part in overcoming resistance of conventional drugs. Nanoparticles (NPs) have evolved as a potential drug carrier for targeted delivery and elimination of various resistance mechanisms against antimicrobials. Receptor-mediated targeting of macrophages via different NPs may be a promising strategy for combating drug resistance and enhancing efficacy of old-fashioned antimycobacterial agents.

Microbiological quality control of some non-sterile preparations commonly used in Pakistan.

The quality of medicines in some developing countries including Pakistan is not very satisfactory regarding safety and efficacy. In addition to sterile preparations, the microbial contamination of non sterile preparations should also be monitored according to USP microbial limits for these preparations. This study was designed to check the microbial quality of some commonly used non-sterile preparations available in Pakistan. Total 133 samples containing national and multinational brands of different dosage forms were collected from retail setups of Sargodha, Khushab and Chakwal cities. The total aerobic bacterial count and fungal contamination was tested by pour plate method. The absence of objectionable microorganisms was confirmed by using selective media, biochemical testing and microscopy. Bioburden of these preparations was also tested after a storage period of six months. The bio burden varied among all the selected non-sterile preparations whether of local or multinational brands. The highest load was observed in syrups, among which syrup number 1 showed maximum aerobic count (8.4×106). Lowest count was observed in tablets, among which tablet preparation number 1 contained 1.5×103aerobic bacteria. Creams and capsules produced no recovered bacteria. The fungal contaminants were also observed in all dosage forms except tablets. The isolated organisms included Gramnegative bacteria which contained objectionable ones such as Salmonella, Shigella, Pseudomonas and E.coli and some airborne moulds including Aspergillus spp., Penicillium spp., Fusarium spp. and Acremonium spp. Several measures such as GMPs, monitoring programs and SOPs should be followed by the pharmaceutical companies to reduce the microbial contamination level in the non sterile preparations. The regulatory agencies have to implement strict analysis strategy to check the microbial quality of the medicines before their release for sale in the market.