Therapeutic Significance of Polymeric Nano Particles as Carriers for Sustained Ocular Therapy: An Overview

ABSTRACT Effective delivery of drug to the eye poses many problems through conventional eye drops due to its poor ocular retention and bioavailability. The use of nanocarriers provides interesting opportunities for topical ocular drug delivery. The association of an active drug to nanocarriers allows the drug to closely interact with specific ocular structures, also to overcome ocular barriers and to prolong its residence in the target area. Hence delivery of a drug through nanoparticles can accomplish main benefits like enhancement of drug permeation, controlled release, and targeting. Though several non polymeric and colloidal drug delivery systems, such as Prodrugs, Polymeric micelles, liposomes, neosome, nanoemulsions, nanocrystals and nanoparticles have been largely investigated and reported to enhance ocular bioavailability of ocular drugs. Owing to the submicron size of polymeric nanoparticles they are well tolerated and have the tendency to deposit in the cul-de-sac for prolonged period. In the present review our objective is focused on the fundamental aspects of polymeric nanoparticles as carrier for ocular drugs and its therapeutic applications with special emphasis to research studies in ocular delivery of polymeric nanoparticles with anti-infectious and anti inflammatory drugs

Pharmacokinetic evaluation of newly developed isradipine sustained release formulation

A specific and efficient method using High Performance Liquid Chromatography (HPLC) has been developed to validate the pharmacokinetics of sustained-release formulation containing Isradipine. The objective of the present study is to develop and validate PK of sustained release formulation containing Isradipine. The plasma samples of Isradipine were extracted using the protein precipitation technique (PPT). The detection wavelength of Isradipine, which was 325nm, was determined using UV spectrophotometer. Reversed phase Thermos c18 column was used for separation. 10mM ammonium acetate buffer (pH 4) and acetonitrile at a ratio of 20:80% v/v was used as the mobile phase with the flow rate of 1.0 ml/min. The linearity achieved in this method was in the range of 10-120 ng/ml. HPLC method provides extremely precise results and is an excellent and efficient method compared to others. The development of a sustained release formulation offers advantages such as prolonged blood levels of the drug and improved patient compliance. The formulated sustained release tablets containing Isradipine is capable of exhibiting sustained release properties, stable and feasible for industrial scale production. Thus they are capable of reducing the dose intake, minimize the blood level oscillations, dose related adverse effects, cost and ultimately improve the patient compliance in the hypertension

Targeted drug delivery system:- formulation and evaluation of chitosan nanospheres containing doxorubicin hydrochloride

A chitosan molecule form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site. Chemical attachment of drug to chitosan throughout the functional linker has possibility to produce useful prodrugs, exhibiting biological activity at target site. In vivo residence time of the dosage form in the gastrointestinal tract and bioavailability of various drugs increases by mucoadhesive and absorption enhancement properties of chitosan. Antitumour activity of doxorubicin(DOX)-incorporated nanoparticles in vitro on DOX- resistant C6 glioma cells. Nanoparticles showed increased cytotoxicity compared to DOX alone. These results suggest that doxorubicin (DOX) was unable to penetrate into cells and did not effectively inhibit cell proliferation. In contrast, nanoparticles can penetrate into cells and effectively inhibit cell proliferation. There are 3 batches of drug loaded nanospheres in which 2.5mg,5mg and 10mg of DOX were loaded into nanospheres where the concentration of chitosan is 1%w/v. Anticancer drugs without targeting a specific site cause side effects. The objective of this research is to reduce side effects. HPLC device was used to quantitatively analyze amount of doxorubicin loaded in nanospheres. The result had showed concentration of anticancer drug loaded in nanospheres is directly proportional to the drug payload capacity until saturation point. The in vitro drug release studies was carried out for 48 hours to obtain a more precise result by carrying out this studies in a medium resembling our body environment such as pH7.4, 37ºC with analytical grade water for this studies. In vitro release of doxorubicin is of zero order kinetic. This shows that release is independent of the concentration of drug loaded in the nanospheres. Besides that, the graphs also show a sustained release manner, indicating these nanospheres formulation are suitable for targeting drug delivery system and for efficient treatment of cancerous cells

Targeted drug delivery system:- formulation and evaluation of chitosan nanospheres containing doxorubicin hydrochloride

A chitosan molecule form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site. Chemical attachment of drug to chitosan throughout the functional linker has possibility to produce useful prodrugs, exhibiting biological activity at target site. In vivo residence time of the dosage form in the gastrointestinal tract and bioavailability of various drugs increases by mucoadhesive and absorption enhancement properties of chitosan. Antitumour activity of doxorubicin(DOX)-incorporated nanoparticles in vitro on DOX- resistant C6 glioma cells. Nanoparticles showed increased cytotoxicity compared to DOX alone. These results suggest that doxorubicin (DOX) was unable to penetrate into cells and did not effectively inhibit cell proliferation. In contrast, nanoparticles can penetrate into cells and effectively inhibit cell proliferation. There are 3 batches of drug loaded nanospheres in which 2.5mg,5mg and 10mg of DOX were loaded into nanospheres where the concentration of chitosan is 1%w/v. Anticancer drugs without targeting a specific site cause side effects. The objective of this research is to reduce side effects. HPLC device was used to quantitatively analyze amount of doxorubicin loaded in nanospheres. The result had showed concentration of anticancer drug loaded in nanospheres is directly proportional to the drug payload capacity until saturation point. The in vitro drug release studies was carried out for 48 hours to obtain a more precise result by carrying out this studies in a medium resembling our body environment such as pH7.4, 37ºC with analytical grade water for this studies. In vitro release of doxorubicin is of zero order kinetic. This shows that release is independent of the concentration of drug loaded in the nanospheres. Besides that, the graphs also show a sustained release manner, indicating these nanospheres formulation are suitable for targeting drug delivery system and for efficient treatment of cancerous cells

Formulation of Sodium Alginate Nanospheres Containing Amphotericin B for the Treatment of Systemic Candidiasis

Purpose: The aim of this work was to formulate sodium alginate nanospheres of amphotericin B by controlled gellification method and to evaluate the role of the nanospheres as a "passive carrier" in targeted antifungal therapy. Methods: Sodium alginate nanospheres of amphotericin B were prepared by controlled gellification method, and the particle size analysis was carried out by scanning electron microscopy. The carrier capacity of sodium alginate was evaluated in terms of drug to polymer ratio. In vitro release study was carried out on all drug loaded nanospheres by the dialysis method. Release kinetics of drug from different drug loaded nanospheres was also determined. The in vivo antifungal efficacy of nanospheres bound drug vis-à-vis the free drug was evaluated in candidiasis- induced mice models. Results: Preparation of nanospheres through controlled gellification method yielded particles with a size range of 419.6 ± 0.28 nm. Studies on drug to polymer ratio showed a linear relationship between concentration of drug and drug loading capacity. In vitro release kinetic study revealed that the release of drug from the nanospheres followed Fickian diffusion. In vivo studies showed that the nanospherebound drug produced a higher antifungal efficacy than the free drug. Conclusion: The formulated sodium alginate nanospheres containing amphotericin B was found to have better antifungal activity when compared to the free drug and also yielded sustained in vitro release