Abhijeet Joshi

pH and Urea Estimation in Urine Samples using Single Fluorophore and Ratiometric Fluorescent Biosensors

Kidney diseases remain often undiagnosed due to inefficient screening methods available at patient’s disposal. Early diagnosis and effective management of kidney problems can best be addressed by the development of biosensors for commonly occurring clinical biomarkers. Here we report the development of single fluorophore and dual fluorophore ratiometric biosensors based on alginate microspheres for pH and urea analysis in urine samples. A facile method of air driven atomization was used for developing these polymeric fluorophore and enzyme based biosensors. Ratiometric biosensors were developed using layer-by-layer coating of polyelectrolyte conjugated to reference fluorophores. Biosensing studies using these biosensors showed that samples in pathophysiological range can be measured having pH range of 4–8 and urea levels between 0–50u2009mM. Testing of urine samples using these biosensors showed that both pH and urea detection can be accurately performed without interference. Thus, we believe that FITC-Dextran and FITC-Dextran/RuBpy based pH and urea biosensors show a great potential to be translated as a point of care device for pH and urea biosensing in early detection and continuous monitoring of kidney diseases.

MULTIPLE UNIT PELLET SYSTEM (MUPS TECHNOLOGY) FOR DEVELOPMENT OF MODIFIED RELEASE FAST DISINTEGRATING TABLETS: A REVIEW

Oral drug delivery system becomes challenging when the drug product needs to be delivered in modified release pattern in elderly patients, especially since it is difficult to swallow for them. Multiparticulates are the choice of dosage form when fast disintegration is desirable without loss of original release profile. Compressed multi-particulate system prepared by using pellets have several pharmacokinetic, pharmacodynamic, commercial and other advantages as mentioned henceforth in this review article. It includes not only different types of modified release pellets that can be compressed into Multiple Unit Pellet System (MUPS) but also factors regulating the compression behavior of pellets including properties of pellets, core material, and compressible excipients. This review also presents detailed explanation on physicochemical properties of pellets and formulation strategies of

On-Demand Controlled Drug Delivery

Spatial and temporal control of drug delivery is of prime importance for establishing the therapeutic compliance of drugs for various diseases. Conventional approaches to drug delivery for temporal control of drug delivery include encapsulation, entrapment and conjugation to polymeric materials for obtaining the controlled release. Several macro, micro and nanoformulations have been researched and commercialized for producing controlled release of drugs. Apart from the control over the rate of release, a regional delivery would be highly desirable for increasing the efficacy of the drugs and reducing the undue side effects pertaining to the therapy. Some developments in region specific delivery have been utilizing physiological differences of various sites in the body. Topical formulations have been extensively explored for their region specific delivery due to ease of access of these organs like eye, ear, nasal, oral, vaginal and rectal cavities or parts of gastro-intestinal tract like mouth, stomach, intestine and colon. Several sites of the body have not been reached using drug delivery formulations to selectively deliver the drugs to particular organs due to several physiological barriers. Recent developments and approaches in material chemistry, novel polymers, and technology advancements have led to new avenues in the development of nano/micro-carriers or materials for on-demand controlled drug delivery or stimuli responsive drug delivery. On-demand drug release although complex has become possible due to materials which recognize the microenvironments and react in a dynamic way altering properties to cause release of encapsulated drugs within. The current chapter reviews different approaches of developing on-demand drug release using different materials and techniques.

Targeted Drug Delivery for Personalized Cure

Human population bears a similarity to an extent of 99.9%, however mere 0.1% of variability also creates large differences in personal make-up owing to several hereditary and environmental factors. Conventionally, development of healthcare modalities like diagnostics and therapeutics has been by mass production assuming uniformity in characteristics of recipient population. Due to the inherent variability in each individual clinical response to diagnostic and therapeutic products vary greatly ranging from inefficient therapeutic compliance, adverse reactions and hypersensitivity reactions. Personalization of medications is the need of hour to avoid perils of both modalities so that efficient healthcare is provided to human population. Advances in delivery like targeted drug formulations, companion diagnostics and triggered drug formulations provide necessary dimensions to personalized medicines. Formulations with these capabilities can be described as theranostics and have been instrumental in this decade to establish the field of personalized medicine. The current chapter reviews different types, mechanisms of targeted and triggered drug delivery systems that have helped to improve the diagnostic and therapeutic compliance in disease management.

Nanoengineered uric acid biosensor based on chemiluminescence

Uric acid (UA) is a nitrogenous end product of the purine catabolism in humans. Excessive production of UA may lead to gout, hyperuricemia and kidney disorders. The research here aims at developing an indirect enzyme based UA biosensor where UA is sensed from the amount of hydrogen peroxide (H2O2) produced. Pentacene loaded nanoparticles encapsulated in uricase loaded alginate microspheres (nano-in-micro) particles were synthesized. All formulations were characterized using DLS and imaged using Optical, SEM, TEM, CLSM and FTIR. These nano-in-micro particles were used for H2O2 and UA sensing. UA sensing with nano-in-micro system showed regression constant 0.977 in range of 0–0.1mg/ml. Thus chemiluminescent nano-in-micro particles can act as diagnostic markers for detection of UA.