Solid dispersion: A promising technique to enhance solubility of poorly water soluble drug

Poorly water soluble compounds have solubility and dissolution related bioavailability problems. The present review deals in detail about solid dispersion technology and its manufacturing techniques at laboratory and industrial level. This highlight about various hydrophilic polymers used in this technique to enhance solubility of poorly soluble drugs. It also discusses about modern characterization technique to characterize solid dispersion. In this review, it is intended to discuss the recent advances related on the area of solid dispersion technology.Keywords: Solid dispersion; Carriers; Solubility; Dissolution; Bioavailability

ENHANCING OF ORAL BIOAVAILABILITY OF POORLY WATER-SOLUBLE ANTIHYPERTENSIVE DRUGS

Among various routes of drug delivery, Oral administration is the most convenient route because of its high patient compliance. Although oral drug delivery is effective for drugs with high aqueous solubility and epithelial permeability; however for poorly aqueous soluble drug the membrane permeability, chemical, and enzymatic stability of drugs are the major limitations in successful oral drug delivery. Almost 70% of the new drug candidates which shows poor bioavailability, the antihypertensive drugs are among those. Novel drug delivery systems are available in many areas to overcome the problems associated with hydrophobic drugs and the nanotechnology-based drug delivery system is the most potential to beat the challenges related to the oral route of administration with some important advantages such as the colloidal size, biocompatibility, lowered dose size, reduced toxicity, patient compliance and drug targeting. The foremost common nanotechnology-based strategies utilized in the development of delivery systems are nano-emulsions, nano-suspensions, dendrimers, micelles, liposomes, solid lipid nanoparticles, polymeric nanoparticles, carbon nanotubes, Self-Nano-emulsifying Drug Delivery System, proliposomes, nano-crystals, and so forth, which give controlled, sustained, and targeted drug delivery. The appliance of those systems within the treatment of hypertension continues to broaden. This review focuses on various nano-carriers available in oral drug administration for improving solubility profile, dissolution, and consequently bioavailability of hydrophobic antihypertensive drugs

Investigations on noval method for the formulation of solid dispersions part- I Formulation, characterization and selection

The solid dispersions of indomethacin with hydrophilic polymers were prepared by lyophilization. The polymers used in the investigation were HPMC, PVP K30, CBR and PLF 127. The solubility and dissolution of indomethacin from prepared lyophilized solid dispersions were investigated in 0.1 N HCl, purified water and USP-NF dissolution media.  Out of fifteen lyophilized formulations from F1 to F15, five formulations F2, F5, F8, F12 and F14 showed highest solubility in purified water. Formulation F2, F8 failed to comply with the USP-NF dissolution test for indomethacin capsules. Formulation F14 showed maximum dissolution in the respective dissolution media within 60 min.  Sustained drug release was observed for 6 h with formulations F2 and F8 in USP-NF media. The formulations F2, F5, F8, F12 and F14 were characterized by modulated DSC and FT-IR spectroscopy. Some Formulations on stability testing were found physico-chemically stable at accelerated temperature conditions

Development and Characterization of Irbesartan Nanoparticles

INTRODUCTION:Nanoparticles are defined as particulate dispersions or solid particles with a size in the range of 10-1000nm. The drug is dissolved, entrapped, encapsulated or attached to a nanoparticle matrix. Depending upon the method of preparation, nanoparticles, nanospheres or nanocapsules can be obtained. Nanocapsules are systems in which the drug is confined to a cavity surrounded by a unique polymer membrane, while nanospheres are matrix systems in which the drug is physically and uniformly dispersed. In recent years, biodegradable polymeric nanoparticles, particularly those coated with hydrophilic polymer such as poly(ethylene glycol) (PEG) known as long-circulating particles, have been used as potential drug delivery devices because of their ability to circulate for a prolonged period time target a particular organ, as carriers of DNA in gene therapy, and their ability to deliver proteins, peptides and genesAIM OF WORK:Development of nanoparticles are one of the emerging fields of nanotechnology with several potential application in drug delivery, clinical medicine and research as well as in other discipline. The use of nanoparticles as drug carrier system is a very attractive controlled drug release. Irbesartan is an angiotensin receptor blockers used mainly for the treatment of hypertension. It belongs to class Π drug according to biopharmaceutical classification system. The bioavailability of the valsartan after oral administration is low (60%) with higher variability. The present study was aimed at developing nanoparticle of irbesartan in order to improve the bioavailability and efficacy in treatment of hypertension. Irbesartan is a poorly water soluble drug. To increase solubility of the drug and reduce the dose frequency and improve the bioavailability the study was aimed at nanoparticle of Irbesartan. Thus the present work is to Develop and characterize a nanoparticulate drug delivery system of antihypertensive drug (Irbesartan) and also 1. To increase the solubility 2. To overcome variable systemic availability. 3. To overcome side effect. 4. To overcome the drug resistance on long term. 5. Specific site drug delivery at controlled rate. 6. Prolonged systemic circulation.PLAN AND SCOPE OF WORK:1. Preformulation studies involve observation of physical and chemical data available. The identification of raw materials and compatibility studies between drug and polymer is to be done by using Infrared spectrophotometry. 2. Preparation of Irbesatran Nanoparticles prepared by Precipitation Method. 3. Formulation of Irbesartan Nanoparticles in various ratios of drug and polymer. 4. The best formulation will be selected based on the results of following parameters. The prepared nanoparticles is to be evaluated by following chemical characteristics Drug entrapment efficiency, In vitro drug release of formulated nanoparticles. 5. Surface morphology of formulation (SEM) of the optimized formulation. 6. Zeta potential analysis of the optimized formulation. 7. Stability studies for the best formulation at different temperature. 8. Drug release kinetics.SUMMARY AND CONCLUSION:The present study was aimed to develop a nanoparticulate drug delivery system of antihypertensive drug irbesartan using polymer ( poly vinyl alcohol).The polymer enhances the binding of irbesartan nanoparticles in specific or targeted site with sustained release of drug increasing therapeutic efficacy. These nanoparticles may also reduce the dose frequency with desired therapeutic response. All batches of nanoparticles (F1-F10) were prepared by nano precipitation method. The entrapment efficiency of the optimized formulation F7 (drug 50mg, polyvinyl alcohol 75mg, β –cyclodextin 10 mg) was 99.38 ±0.08 and invitro drug release was 98.46% after 24 hours. It also obey the zero order, follows diffusion and erosion mechanism of release. Surface morphology of optimized formulation (F7) indicated that lrbesartan nanoparticles were found to be in average nanometer range(358.4nm) and showed ideal surface morphology. The stability test performed revealed that the formulation (F7) showed no change in its characters. The optimized formulation (F7) was also examined for zeta potential determinations. The formulation(F7) showed maximum deviation of 9.16 mV which demonstrated that the particles are separate and highly repelling property found to be more useful in decreasing opsonization and favors target specificity. The developed irbesartan nanoparticle formulation increases water solubility, reduces the dose frequency and improves the bioavailability of drug