Effect of production variables on the physical characteristics of ibuprofen-loaded polystyrene microparticles.

Ibuprofen-loaded polystyrene microparticles were prepared by the emulsion-solvent evaporation method from an aqueous system containing methylcellulose as the emulsion stabilizer. The effect of production variables on the formation and the physical characteristics of the microparticles were studied. While an increase in stirring speed, concentration of emulsion stabilizer up to a critical value and disperse phase volume decreased the mean diameter of the particles, increase in drug loading and concentrations of emulsion stabilizer beyond the critical value tended to increase in size. The microparticles, except those prepared at higher stirring speeds, and with higher disperse phase volumes and drug-loads, were found to be spherical.     

Non-systemic delivery of topical brimonidine to the brain: A neuro-ocular tissue distribution study

To date, the risks of central nervous system (CNS) side effects of topically administered ophthalmic therapeutic agents are thought to be the consequence of systemic absorption of these drugs. This paper envisions the possibility of drug delivery to the CNS following ocular application through non-systemic routes. After single instillation of 50 μl of ³H-radiolabeled Alphagan® solution (0.2%) in the cul de sac of the right eye, three male albino rabbits (2–2.5 kg) were sacrificed at each time point (5, 15, 30 and 60 min). Both sides (eyes) specimens of aqueous humor, cornea, iris, lens, vitreous, conjunctiva, sclera, ciliary body, choroid, retina, optic nerve, optic tract and olfactory bulb were weighed, and blood samples were measured, before combustion in tissue oxidizer and radioactive liquid scintillation counting. Significant ³H-brimonidine levels were found in right and left optic nerves and tracts with extremely low corresponding drug levels in blood. Uveal tract (ciliary body, iris and choroid tissues) brimonidine levels were relatively high in the treated eye, and the highest among contralateral eye tissues. Our data provide the first case of good CNS availability after ocular application of conventional ophthalmic therapeutic agent, through non-systemic routes. Similar neuro-ocular pharmacokinetic studies should be adopted as a routine ocular therapeutics evaluation study.     

Manufacturing techniques and excipients used during the design of biodegradable polymer-based microspheres containing therapeutic peptide/protein for parenteral controlled drug delivery

In the last couple of decades, use of biodegradable polymer-based microspheres has been recognized as an interesting and promising approach for parenteral controlled delivery of therapeutic peptide/protein, including antigens. The main objectives of this review are (i) to update the current state of art of manufacturing of peptide/protein-loaded microspheres through both conventional and newer microencapsulation techniques, and (ii) to bring into focus the various possible instability problems, and the investigated mechanistic ways to obviate the instability problems of peptide/protein drug during microspheres preparation as well as its release from the microspheres. The solubilization, stabilization, and preservation enhancing excipients that are used in peptide/protein-loaded microspheres are briefly overviewed.     

Studies on the in vitro release characteristics of ibuprofenloaded polystyrene microparticles

Ibuprofen-loaded polystyrene microparticles were prepared by the emulsionsolvent evaporation process from an aqueous system. The effects of different parameters on the drug content and on the release of the drug from the microparticles were investigated. The drug content, in all the formulations, was less than the theoretical drug loading. The lower drug content was due to drug partitioning to the external aqueous phase during formulation. Statistical analysis revealed that the variation in the concentrations of the emulsion stabilizer and the organic disperse phase volume did not significantly alter the release of the drug. Although an increase in drug loading increased drug release from the microparticles, a biphasic linear relationship was observed between the time required for 50% drug release and the drug loading. The effect of size of the microparticles on drug release was more important for the low drug-loaded microparticles than that for the high drug-loaded microparticles. Such release behaviour from the microparticles was explained on the basis of the morphological structure of the microparticles.     

Rare cause for short stature--Kallmann's syndrome--a case report

Kallmann's syndrome is a neuroendocrine disorder, characterized by hypogonadotropic hypogonadism with hyposmia. We report a 27 year old male who presented with short stature and pain in the lumbar region. On detailed evaluation he had growth retardation, features of hypothalamic hypogonadism as evidenced by endocrimological tests and anosmia since birth. He had co-existent caries spine T10,T11 causing pain in the lumbar region-MRI brain showed normal olfactory pathway while the response to nasal stimulants was markedly attenuated. We present this case for its very care occurrence in the eastern part of the world and the typical feature being normal MRI brain with functional defect of the olfactory pathway.     

Outcome of partial internal biliary diversion for intractable pruritus in children with cholestatic liver disease

Purpose

Children with cholestatic disorders have undergone liver transplantation for intractable pruritus unresponsive to medical therapy even in the absence of liver failure. Biliary diversion procedures interrupt the entero-hepatic circulation of bile acids allowing them to be excreted in the feces thereby lowering the total bile acid pool. We evaluated the outcome of partial internal biliary diversion (PIBD) in children with intractable pruritus from inherited cholestatic disorders.

Methods

The records of children who underwent PIBD over a 4-year period were reviewed for etiology of liver disease, demographic data, preoperative and postoperative biochemical profile and improvement of pruritus. Standard statistical methods were used for analysis.

Results

Of the 12 children, 10 had progressive familial intrahepatic cholestasis (PFIC) and 2 had Alagille syndrome (AS). PIBD was done using an isolated jejunal loop as a conduit from gall bladder to mid ascending colon. Median period of follow up was 30 months. Pruritus resolved in nine children with significant reduction of serum bile acids (P < 0.02).

Conclusion

To our knowledge, this is the largest reported series of children with PIBD. PIBD is a safe, well-tolerated and effective alternative to liver transplant in children with PFIC and AS who have intractable pruritus in the absence of synthetic liver failure.     

THE PHARMACOKINETIC QUESTION OF TOPICAL NEURO－PROTECTIVE AGENTS： HOW DOES A TOPICALLY APPLIED DRUG PENETRATE TO THE BACK OF THE EYE？

Purpose: To evaluate the efficiency and the route of topical bri-monidine penetration to the back of the eye. Methods: After single instillation of 50μ1 of 3H -radiolabeled Alphagan solution (0.2%) in the cul-de-sac of the right eye, three male albino rabbits (2-2.5 kg) were sacrificed at each time point (5, 15, 30 and 60 min). Both eyes were dissected. Eyes specimens of aque-     

The potential of lipid- and polymer-based drug delivery carriers for eradicating biofilm consortia on device-related nosocomial infections

Microbial biofilms are microcosm attaching irreversibly to abiotic or biotic surfaces and they are promulgated as congregate of single or multiple populations. The potential of lipid- and polymer-based drug delivery carriers for eradicating biofilm consortia on device-related nosocomial infections is explored in this review. Liposomes-loaded with antimicrobial agents could effectively be applied as anti-biofilm coating to reduce microbial adhesion/colonisation onto medical devices and as drug delivery carriers to biofilm interfaces and in intracellular infection. Many polymer-based carrier systems have also been proposed, including those based on biodegradable polymers such as poly(lactide co-glycolide) as well as fibrous scaffolds and thermoreversible hydrogels and surface (properties) modified polymeric catheter materials such as antimicrobial, antiseptic or metallic substances-coated polymeric materials. Their contribution to the prevention/resolution of infection is reviewed.