Acquired Immuno Deficiency Syndrome (AIDS) is a disease caused by the human immunodeficiency virus (HIV). AIDS patients are generally treated with nucleoside or nucleotide reverse transcriptase inhibitors (nRTI) which inhibit reverse transcription. Stavudine, a nucleoside analogue used as reverse transcriptase inhibitor, has severe side effects due to higher dose related problems with short half-life and poor bioavailability. Nanoparticles may be used for delivery of drugs that exhibit the problems of short half-life, poor bioavailability, and strong side-effects. Nanoparticles are transport carrier for various drugs and proteins in the nanometer size range (10nm–1000nm). Nanoparticles as drug delivery system are rapidly expanding area in drug delivery sciences.

Objectives

The primary objectives of this research work was to :-

Develop and evaluate different formulations of poly (d,l-lactic-co-glycolic acid) (PLGA) (50:50) based nanoparticles containing anti-AIDS drug Stavudine prepared by Nanoprecipitation

To study the uptake of FITC incorporated nanoparticles by macrophages in vitroas HIV viruses hide themselves in macrophages at the early stage of infection.

Method of preparation

.

Aqueous phase containing Drug

Primary Dispersion

Magnetic Stirring

Final Dispersion

Organic Phase containing Polymer in nonsolvent

Distilled water Containing 0.5% PVA

Magnetic Stirring

Added drop wise

Added drop wise

Nanoparticles recovered

Evaporation of organic phase

Results

1. Drug-excipient interaction (FTIR) study

Fig 3. FESEM of various formulations at different magnification

Discussion

FESEM photograph (Fig.3) shows that the prepared particles were spherical in shape and a major portion of the particle distribution was occupied by very small particles in nano (200 to 600nm) range with some even below 200nm.

Drug loading was found to be approximately 5.5-31.5 % w/w with an entrapment efficiency of 56-70% . Drug loading is found to vary due to formulation compositions, methodology, process parameters etc. The variation of loading capacity in different samples might be due to formation of smaller particles in nanosizes which could only entrap a smaller amount of stavudine containing solvent.

Drug release(Fig.4, Table 2) is being carried out for 63 days to test for the drug release pattern. The initial results show sustained release.

FTIR data (Fig.1)shows that there is no interaction between the excipients.

The initial results show a positive outcome in the attainment of sustained release of Stavudine from the formulated nanoparticles. Thus, the present study supports the fact that drugs may be safely formulated in the biodegradable polymer such as PLGA to maintain their stability and integrity to achieve a sustain action from them.

Preparation and Evaluation of Stavudine loaded PLGA nanoparticle using nanoprecipitation method

Saikat Ghosh*, Samrat Roy Chowdhury and Biswajit Mukherjee.Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700032.

Introduction

Nanoparticles formed

Centrifugation at different RPM

Fig 1: Brief outline of method of nanoparticle preparation

Future Course of Work

Conclusion

In the method, various process parameters such as drug-polymer ratio, magnetic stirring time, centrifugation speeds were varied. The samples were centrifuged at 5000rpm, 10000 rpm, 15000rpm and 30000rpm.

A

C

B

E

D

Fig. 2: FTIR spectra of PLGA(A), PVA (B), Stavudine (C), Excipients only (D) and Stavudine-excipients (E).

2. Field Emission Scanning electron microscopy (FESEM) study of Stavudine loaded PLGA Nanoparticles

A B

C D

PLGA (50:50) IN CHLOROFORM

Stavudine in Ethanol-Water mixture

3. Drug Loading studyFormulation PLGA(mg) Drug(mg) Magnetic

stirring time 1: Magnetic stirring time 2

Theoretical Loading(%)

Practical Loading(%)

Encapsulation Efficiency(%)

S1 100 10 10:20 9.0909 5.3657 59.823

S2 100 10 20:20 9.0909 6.3109 69.419

S3 100 100 10:20 50.0000 28.1055 56.211

S4 100 100 20:20 50.0000 31.4827 62.965

Table 1. Drug Loading of various formulations (S1, S2, S3,S4)

4. Invitro Drug Release study

Further studies like PDI, Zeta Potential measurements for stability testing as well as particle size distribution is to be done. The best formulation is intended to be FITC labeled to study the uptake of FITC incorporated nanoparticles by macrophages in vitro or in vitro cell line studies as well in vivo study in mice.

Days S1 S2 S3 S4

1 5.0639 4.359 5.316 5.573

2 10.521 9.738 9.763 10.951

7 29.722 23.872 30.511 31.023

14 37.841 38.133 39.179 40.357

21 45.479 44.088 43.949 46.173

Table 2: In vitro Drug release of various formulations (S1, S2, S3,S4) .

Fig.4: In vitro Drug release of various formulations (S1, S2, S3,S4) .

Percentage release(%)