Recent advances and novel strategies in pre-clinical formulation development: an overview.

Preclinical profiling for a New Chemical Entity (NCE), if carried out carefully, can be a good predictor of human clinical outcome. Along with the pre-clinical study design a thorough understanding of the physico-chemical properties of the drug candidate and a careful selection of the formulation development strategy are of high importance. The study scientist can experience various challenges in executing a pre-clinical study.

Controlled release application of multilamellar vesicles: a novel drug delivery approach.

A novel multilamellar vesicular delivery system was developed for the controlled release application. Multilamellar vesicles were prepared by thin film hydration and converted into proliposomes by freeze-drying. A model drug metoclopramide, a highly hydrophilic drug, was successfully encapsulated into proliposomes.

Chitosan nanoparticles for prolonged delivery of timolol maleate.

Timolol maleate-loaded chitosan (CS) nanoparticles were prepared by desolvation method. Experimental variables such as molecular weight of CS and amount of crosslinking agent were varied to study their effect on drug entrapment efficiency, size and release rates of nanoparticles. Chemical stability of timolol maleate (TM) and crosslinking of CS were confirmed by Fourier transform infrared spectroscopy.

Development of polysaccharide-based colon targeted drug delivery systems for the treatment of amoebiasis.

The main focus of this study is to develop colon targeted drug delivery systems for metronidazole (MTZ). Tablets were prepared using various polysaccharides or indigenously developed graft copolymer of methacrylic acid with guar gum (GG) as a carrier. Various polysaccharides such as GG, xanthan gum, pectin, carrageenan, beta-cyclodextrin (CD) or methacrylic acid-g-guar (MAA-g-GG) gum have been selected and evaluated.

Development and evaluation of novel biodegradable microspheres based on poly(d,l-lactide-co-glycolide) and poly(epsilon-caprolactone) for controlled delivery of doxycycline in the treatment of human periodontal pocket: in vitro and in vivo studies.

This study reports on the development of novel biodegradable microspheres prepared by water-in-oil-water (W/O/W) double emulsion technique using the blends of poly(d,l-lactide-co-glycolide) (PLGA) and poly(epsilon-caprolactone) (PCL) in different ratios for the controlled delivery of doxycycline (DXY). Doxycycline encapsulation of up to 24% was achieved within the polymeric microspheres. Blend placebo microspheres, drug-loaded microspheres and pristine DXY were analyzed by Fourier transform infrared spectroscopy (FT-IR), which indicated no interaction between drug and polymers.

Evaluation and controlled release characteristics of modified xanthan films for transdermal delivery of atenolol.

The present study was performed to evaluate the possibility of using modified xanthan films as a matrix system for transdermal delivery of atenolol (ATL), which is an antihypertensive drug. Acrylamide was grafted onto xanthan gum (XG) by free radical polymerization using ceric ion as an initiator. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated the formation of the graft copolymer.

Novel interpenetrating network chitosan-poly(ethylene oxide-g-acrylamide) hydrogel microspheres for the controlled release of capecitabine.

This paper describes the synthesis of capecitabine-loaded semi-interpenetrating network hydrogel microspheres of chitosan-poly(ethylene oxide-g-acrylamide) by emulsion crosslinking using glutaraldehyde. Poly(ethylene oxide) was grafted with polyacrylamide by free radical polymerization using ceric ammonium nitrate as a redox initiator. Capecitabine, an anticancer drug, was successfully loaded into microspheres by changing experimental variables such as grafting ratio of the graft copolymer, ratio of the graft copolymer to chitosan, amount of crosslinking agent and percentage of drug loading in order to optimize process variables on drug encapsulation efficiency, release rates, size and morphology of the microspheres.

Controlled release of cephalexin through gellan gum beads: effect of formulation parameters on entrapment efficiency, size, and drug release.

Gellan gum beads containing cephalexin were prepared by extruding the dispersion of cephalexin and gellan gum into a solution containing a mixture of calcium and zinc ions (counterions). Beads were prepared by changing experimental variables such as pH of the counterion solution and amount of cephalexin loading in order to optimize process variables on the final % drug entrapment efficiency, release rates, size, and morphology of the beads. Absence of chemical interactions between drug, anionic polymer, and counterions after production of beads was confirmed by Fourier transform infrared spectroscopy.

Development of novel interpenetrating network gellan gum-poly(vinyl alcohol) hydrogel microspheres for the controlled release of carvedilol.

Novel interpenetrating polymeric network microspheres of gellan gum and poly(vinyl alcohol) were prepared by the emulsion cross-linking method. Carvedilol, an antihypertensive drug, was successfully loaded into these microspheres prepared by changing the experimental variables such as ratio of gellan gum:poly(vinyl alcohol) and extent of cross-linking in order to optimize the process variables on drug encapsulation efficiency, release rates, size, and morphology of the microspheres. Formation of interpenetrating network and the chemical stability of carvedilol after preparing the microspheres was confirmed by Fourier transform infrared spectroscopy.

Recent advances on chitosan-based micro- and nanoparticles in drug delivery.

Considerable research efforts have been directed towards developing safe and efficient chitosan-based particulate drug delivery systems. The present review outlines the major new findings on the pharmaceutical applications of chitosan-based micro/nanoparticulate drug delivery systems published over the past decade. Methods of their preparation, drug loading, release characteristics, and applications are covered.

Controlled release of clozapine through chitosan microparticles prepared by a novel method.

A simple and commercially viable method of preparation of chitosan microparticles (MPs) was adopted for the entrapment of clozapine, which can be easily scaled-up to controlled drug delivery dosage form. This method is devoid of tedious processes like emulsification in oil phase, spray-drying, etc. MPs have been prepared by changing the experimental variables such as extent of crosslinking and amount of clozapine loading in order to optimize the process variables on the final percent drug entrapment efficiency, size of MPs and release rates.