Nanotechnology

Nanotechnology in designing
Drug Delivery systems
Friends, I want to tell you all about some interesting things that I learnt when I went to Chandigarh to attend a conference on nanotechnology in February 2006 in NIPER.
Nanotechnology is immensely useful in designing drug delivery systems that can be used in targeting. Nanoparticles or nanoemulsions help in targeting drugs to a specific site, in reducing the dose to be administered and in reducing unnessary side effects.
When materials are broken down into nano size they look and behave differently.

Points on nanoparticles :
1.Surface to volume ratio increases
2.Surface properties change
3.Their optical, electrical and magnetic properties change.
4.Nanoparticles look and behave differently.
5.High chemical reactivity
6.Site specificity
7.They can be used as carriers for small drug molecules.

Dr. Murali Sastry is preparing gold nanoparticles and then attaching to them, enzymes such as pepsin and studying them. He found that pepsin bound to Gold nanoparticles showed much enhanced activity at all pHs but particularly at acidic pH.

Dr. Murali Sastry developed nanoparticles. He studied insulin loaded bare gold nanoparticles and insulin loaded aspartic acid capped gold nanoparticles. He tested these products on Wistar rats. He observed a significant fall in blood glucose levels

Dr. Khullar presented a study on nanotechnology based Anti TB Chemotherapy. (Isoniazied + rifampicin + pyrazinamide + ethambutol) for 2 months and (isoniazid + rifampicin) for 2 months in TB treatment. They prepared PLG [Poly (DL – lactide – 10 – glycolide) [biodegradable, biocompatible, approved by FDA) nanoparticles of four drugs, by multiple emulsion technique. 28 doses got reduced to 3 doses. Dose can be reduced to ½ of therapeutic dose. Nanoparticle based therapy appears to prevent latent bacilli from reproducing. These nanoparticles had no toxicity.
Dr.Khullar reported that high drug encapsulation efficiency was achieved with synthetic / natural polymers. In animal studies it was found that sustained drug release was obtained and drug dose to be administered could be reduced.

With this technique the dose to be administered and dosing frequency can be reduced and duration of chemotherapy can also be reduced. Hence the cost of treatment may also be reduced. When he was reporting these results, i.e. in February 2006, acute subacute and chronic toxicity studies were finished, the product got FDA approval for phase I studies and they were proceeding for it. Dr. Khullar expressed the opinion that nanotechnology based drug delivery systems might be a promising approach which can give improved patient compliance in tuberculosis chemotherapy.
Several groups of researchers are working on nanoparticles in India presently. Let us hope we will have some breakthroughs soon and we will have wonderful site specific inexpensive medicines for dreadful diseases.