Marine Enzymes in Cancer: A New Paradigm.

Over the last decades, the vast chemical and biodiversity of marine environment has been identified as an important source of new anticancer drugs. The evolution of marine life is a result of competition among microorganisms for space and nutrients in the marine environment, which drives marine microorganisms to generate diverse enzyme systems with unique properties to adapt to harsh conditions of ocean. Therefore, marine-derived sources offer novel enzymes endowed with extraordinary properties. Recent advances in cancer therapy have facilitated enzyme therapy as a promising tool. But, the available information on the use of enzymes derived from marine sources as therapeutic agents for cancer therapy is scanty. The potential utility of marine enzymes in cancer therapy will be discussed in this chapter.

Design and optimization of a novel method for extraction of genistein.

Genistein, an isoflavone, has been demonstrated to promote the health of human beings by reducing the incidence of specific chronic diseases, namely, cancer and atherosclerosis. The present investigation explores a novel method of extraction of genistein from soy source which consists of a bioconversion reaction using fermentation by microorganism namely Streptomyces roseolus NRRL B-5424. In situ bioconversion of genistein glycoside to aglycone was carried out by the microbe. Such methodology has not been reported hitherto. Optimization of upstream and downstream parameters was done for maximum extraction of genistein. Genistein was isolated in a powder form by column chromatography and preparative thin layer chromatography and was characterized using massspectrometry, nuclear magnetic resonance and infrared spectroscopy and its purity determined using high performance liquid chromatography. Genistein was extracted with 91.04% purity and extraction efficiency was 67.01%.

Novel cosmetic delivery systems: an application update.

World consumers are nowadays more focused on their health and appearance. This trend is creating heightened demand for products formulated with natural and nutraceutical ingredients. Functional ingredients and innovative delivery systems are driving the new product development in the field of cosmetics. A significant number of innovative formulations are now being used in personal care with real consumer-perceivable benefits and optimized sensory attributes, resulting in an economic uplift of cosmetic industry. In fact, the U.S. market alone for novel cosmetic delivery systems has been projected to be more than $41 billion for the year 2007. Novel cosmetic delivery systems reviewed here possess enormous potential as next-generation smarter carrier systems.

Microemulsions: applications in transdermal and dermal delivery.

Microemulsions have gained much interest as second-generation colloidal carrier systems for the dermal/transdermal delivery of the various hydrophilic and lipophilic drugs. The advantages associated with microemulsions include spontaneity of formation, ease of manufacturing, high solubilization capacity, and improved drug stability. This review focuses on the excipients available for the formulation of topical microemulsions and the potential mechanisms responsible for improvements in the dermal/transdermal delivery of therapeutic agents. It also describes the in vitro and in vivo investigations reported for the various classes of therapeutic agents, along with the recent developments.

Exploring the potential of N-methyl pyrrolidone as a cosurfactant in the microemulsion systems.

The effect of N-methyl pyrrolidone (NMP) on the phase behavior of two ternary systems, viz. PEG-35-castor oil (CremophoreEL)-glyceryl caprylate/caprate (Capmul MCM)-water and PEG-35-castor oil (CremophoreEL)-isopropyl myristate-water was studied. The study indicated that NMP has considerable influence on the phase behavior of both the systems. NMP increased the area of microemulsion formation in both the systems. Moreover, it also led to reduction/disappearance in the gelling region of the CremophoreEL-isopropyl myristate-water system. These observations allowed us to conclude that NMP can be considered as a cosurfactant for the development of biocompatible microemulsions.

Nanosuspensions: a promising drug delivery strategy.

Nanosuspensions have emerged as a promising strategy for the efficient delivery of hydrophobic drugs because of their versatile features and unique advantages. Techniques such as media milling and high-pressure homogenization have been used commercially for producing nanosuspensions. Recently, the engineering of nanosuspensions employing emulsions and microemulsions as templates has been addressed in the literature. The unique features of nanosuspensions have enabled their use in various dosage forms, including specialized delivery systems such as mucoadhesive hydrogels. Rapid strides have been made in the delivery of nanosuspensions by parenteral, peroral, ocular and pulmonary routes. Currently, efforts are being directed to extending their applications in site-specific drug delivery.

Study of solid lipid nanoparticles with respect to particle size distribution and drug loading.

This work deals with the formulation and development of Solid Lipid Nanoparticles (SLN) using pressure homogenization technique, nimesulide being used as the model drug. Main emphasis of the work was to study the effect of individual process parameters (homogenization pressure and homogenization cycles) and formulation parameters (lipid concentration and surfactant concentration) on particle size distribution and drug loading. Particle size distribution data indicate that by optimizing the homogenization process and formulation parameters it is possible to produce SLN within a desired size range as required for carrier mediated drug targeting. Approaches to improve drug loading efficiency indicate that drug loading was higher in case of SLN prepared from glyceryl beheanate, palmitostearate and glyceryl tristearate + span 60 as compared to monoacid triglyceride (MAT) tristearate. Thermal analysis by differential scanning calorimetry of the drug loaded SLN indicates the solid nature of the lipid carrier as required for sustained drug release.

HPTLC determination of nimesulide from pharmaceutical dosage forms.

A simple, rapid, reproducible and stability indicating high performance thin-layer chromatographic method for the analysis of Nimesulide both the bulk drug and from pharmaceutical formulations is reported. The mobile phase selected consists of Cyclohexane-Ethylacetate [60:40, v/v]. It gave compact spots both for Nimesulide and its degraded products at Rf values 0.44 and 0.712, respectively. Densitometric analysis of nimesulide was carried out at 295 nm. The calibration curve of Nimesulide in methanol was linear in the range of 100-900 ng. The mean value of correlation coefficient, slope and intercept were 0.9989+/-0.0011, 504.655+/-0.0013 and 85331.56+/-0.0253, respectively. The limits of detection and quantitation were 60 and 100 ng, respectively. The drug content was within the limits (+/-5% of the labelled content of the formulations). The recovery of Nimesulide was about 99.5%.

High performance thin layer chromatographic determination of nifedipine from bulk drug and from pharmaceuticals.

A stability indicating high performance thin layer chromatographic (HPTLC) method for quantification of nifedipine, as bulk drug and from solid oral dosage forms has been developed. The extraction solvent was methanol and the mobile phase was chloroform:ethyl acetate:cyclohexane (19:2:2, v/v/v). The calibration curve of nifedipine in methanol was linear in the concentration range of 180-720 ng. The mean values of correlation coefficient, slope and intercept were 0.995 +/- 1.02, 1.467 +/- 0.56 and 184.16 +/- 2.15. The limit of detection for nifedipine was 20 ng and limit of quantification was 40 ng. No interference was found from photodecomposition products. The percent recovery of nifedipine using the described procedure was 99.08 +/- 1.51. The coefficient of variation for within day and between day analysis was 0.60 and 0.84% for 480 ng and 0.47 and 0.25% for 720 ng nifedipine concentration. The method was utilized to monitor concentration of nifedipine from sustained release marketed solid oral dosage forms as also from the developed sustained release liquid filled and multi unit hard gelatin capsules.

Fluorodensitometric evaluation of gentamicin from plasma and urine by high-performance thin-layer chromatography.

High-performance thin-layer chromatographic (HPTLC) analysis of gentamicin by in situ fluorodensitometric evaluation of its 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) derivative is presented. The aminoglycoside components separated on silica gel plates using chloroform-methanol-20% ammonium hydroxide (2.4:2.2:1.5, v/v/v) as the mobile phase were reacted with NB-Cl to yield highly fluorescent derivatives. The calibration curves of gentamicin in water, plasma and urine were linear in the range 40-200 ng. The mean values of intercept, slope and correlation coefficient were 16.82 +/- 0.473, 6.83 +/- 0.015 and 0.9968 +/- 0.0017 for standard curves in water, 17.35 +/- 0.375, 6.85 +/- 0.018 and 0.9941 +/- 0.0012 for standard curves in plasma and 14.35 +/- 0.286, 6.86 +/- 0.002 and 0.9933 +/- 0.0011 for standard curves in urine respectively. The analytical technique was validated for within-day and day-to-day variation. The results indicate that HPTLC, coupled with in situ fluorodensitometry, is a reliable and valuable technique for quantitative analysis of the bulk drug gentamicin and gentamicin from urine and plasma.