Venkata Srikanth Meka

A comprehensive review on polyelectrolyte complexes

Global research on polyelectrolytes at a fundamental and applied level is intensifying because the advantages of sustainability are being accepted in academia and industrial research settings. During recent decades, polyelectrolytes became one of the most attractive subjects of scientific research owing to their great potential in the areas of advanced technologies. Polyelectrolytes are a type of polymer that have multitudinous ionizable functional groups. Ionized polyelectrolytes in solution can form a complex with oppositely charged polyelectrolytes - a polyelectrolyte complex (PEC). The present article provides a comprehensive review on PECs and their classification, theory and characterization, as well as a critical analysis of the current research.

Statistical optimization of a novel excipient (CMEC) based gastro retentive floating tablets of propranolol HCl and it’s in vivo buoyancy characterization in healthy human volunteers

The objective of the present investigation is to formulate gastro retentive floating drug delivery systems (GRFDDS) of propranolol HCl by central composite design and to study the effect of formulation variables on floating lag time, D1hr (% drug release at 1 hr) and t90 (time required to release 90% of the drug). 3 factor central composite design was employed for the development of GRFDDS containing novel semi synthetic polymer carboxymethyl ethyl cellulose (CMEC) as a release retarding polymer. CMEC, sodium bicarbonate and Povidone concentrations were included as independent variables. The tablets were prepared by direct compression method and were evaluated for in vitro buoyancy and dissolution studies. From the polynomial model fitting statistical analysis, it was confirmed that the response floating lag time and D1hr is suggested to quadratic model and t90 is suggested to linear model. All the statistical formulations followed first order rate kinetics with non-Fickian diffusion mechanism. The desirability function was used to optimize the response variables, each having a different target, and the observed responses were highly agreed with experimental values. Statistically optimized formulation was characterized by FTIR and DSC studies and found no interactions between drug and polymer. The results demonstrate the feasibility of the model in the development of GRFDDS containing a propranolol HCl. Statistically optimized formulation was evaluated for in vivo buoyancy studies in healthy humans for both fed and fasted states. From the results, it was concluded that gastric residence time of the floating tablets were enhanced at fed stage but not in fasted state.

Preparation and in vitro characterization of non-effervescent floating drug delivery system of poorly soluble drug, carvedilol phosphate

Abstract The objective of the study was to enhance the solubility of carvedilol phosphate and to formulate it into non-effervescent floating tablets using swellable polymers. Solid dispersions (SD) of carvedilol were prepared with hydrophilic carriers such as polyvinylpyrrolidone and poloxamer to enhance solubility. Non-effervescent floating tablets were prepared with a combination of optimized solid dispersions and release retarding polymers/swellable polymers such as xanthan gum and polyethylene oxide. Tablets were evaluated for physicochemical properties such as hardness, thickness and buoyancy. SD prepared with the drug to poloxamer ratio of 1:4 by melt granulation showed a higher dissolution rate than all other dispersions. Formulations containing 40 mg of polyethylene oxide (C-P40) and 50 mg xanthan gum (C-X50) were found to be best, with the drug retardation up to 12 hours. Optimized formulations were characterized using FTIR and DSC and no drug and excipient interactions were detected.

Lipid based nanocarriers system for topical delivery of photosensitizers

Topical photodynamic therapy (PDT) is a non-invasive technique used in the treatment of malignant and non-malignant skin diseases. It offers great promise because of its simplicity, enhanced patient compliance, localisation of the photosensitizer, as well as the use of light and oxygen to achieve photocytotoxicity. Despite progress in photosensitizer-mediated topical PDT, its clinical application is limited by poor penetration of photosensitizers through the skin. Therefore, much effort has been made to develop nanocarriers that can tackle the challenges of conventional photosensitizer-mediated PDT for topical delivery. This review discusses recent data on the use of different types of lipid-based nanocarriers in delivering photosensitizer for topical PDT.

Recent Advances in Non-Invasive Delivery of Macromolecules using Nanoparticulate Carriers System.

BACKGROUND The drug delivery of macromolecules such as proteins and peptides has become an important area of research and represents the fastest expanding share of the market for human medicines. The most common method for delivering macromolecules is parenterally. However parenteral administration of some therapeutic macromolecules has not been effective because of their rapid clearance from the body. As a result, most macromolecules are only therapeutically useful after multiple injections, which causes poor compliance and systemic side effects. METHOD Therefore, there is a need to improve delivery of therapeutic macromolecules to enable non-invasive delivery routes, less frequent dosing through controlled-release drug delivery, and improved drug targeting to increase efficacy and reduce side effects. RESULT Non-invasive administration routes such as intranasal, pulmonary, transdermal, ocular and oral delivery have been attempted intensively by formulating macromolecules into nanoparticulate carriers system such as polymeric and lipidic nanoparticles. CONCLUSION This review discusses barriers to drug delivery and current formulation technologies to overcome the unfavorable properties of macromolecules via non-invasive delivery (mainly intranasal, pulmonary, transdermal oral and ocular) with a focus on nanoparticulate carrier systems. This review also provided a summary and discussion of recent data on non-invasive delivery of macromolecules using nanoparticulate formulations.

Production, Characterization and Evaluation of Kaempferol Nanosuspension for Improving Oral Bioavailability

CONTEXT Kaempferol has a large particle size and poor water solubility, leading to poor oral bioavailability. The present work aimed to develop a kaempferol nanosuspension (KNS) to improve pharmacokinetics and absolute bioavailability. METHODS A nanosuspension was prepared using high pressure homogenization (HPH) techniques. The physico-chemical properties of the kaempferol nanosuspension (KNS) were characterized using photon correlation spectroscopy (PCS), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and x-ray diffractometry (XRD). A reversephase high performance liquid chromatography (RP-HPLC) method for the analysis of the drug in rat plasma was developed and validated as per ICH guidelines. In vivo pharmacokinetic parameters of oral pure kaempferol solution, oral kaempferol nanosuspension and intravenous pure kaempferol were assessed in rats. RESULTS AND DISCUSSION The kaempferol nanosuspension had a greatly reduced particle size (426.3 ± 5.8 nm), compared to that of pure kaempferol (1737 ± 129 nm). The nanosuspension was stable under refrigerated conditions. No changes in physico-chemical characteristics were observed. In comparison to pure kaempferol, kaempferol nanosuspension exhibited a significantly (P<0.05) increased in Cmax and AUC(0-∞) following oral administration and a significant improvement in absolute bioavailability (38.17%) compared with 13.03% for pure kaempferol. CONCLUSION These results demonstrate enhanced oral bioavailability of kaempferol when formulated as a nanosuspension.

Preparing Kaempferol Nanosuspension (KNS) using High Pressure Homogenization (HPH) technique

Background During the last decades, researchers have provided a plethora of therapeutic uses of kaempferol, including anticancer, anti-inflammatory, neuroprotective, anti-oxidative and anti-oestrogenic activities, making kaempferol a valuable compound [1]. However, being a poor water-soluble compound, kaempferol often has insufficient solubility and bioavailability [2].To find a solution for this limitation, this research project mainly focuses on formulating a kaempferol nanosuspension (KNS) using High Pressure Homogenisation (HPH), followed by performing physiological characterization. Kaempferol nanosuspensions are supposed to have a better bioavailability in animal models or even human subjects in future experiments, thereby reducing oral drug dosage required by consumers.

Design and statistical optimization of an effervescent floating drug delivery system of theophylline using response surface methodology

Abstract The aim of this research was to formulate effervescent floating drug delivery systems of theophylline using different release retarding polymers such as ethyl cellulose, Eudragit® L100, xanthan gum and polyethylene oxide (PEO) N12K. Sodium bicarbonate was used as a gas generating agent. Direct compression was used to formulate floating tablets and the tablets were evaluated for their physicochemical and dissolution characteristics. PEO based formulations produced better drug release properties than other formulations. Hence, it was further optimized by central composite design. Further subjects of research were the effect of formulation variables on floating lag time and the percentage of drug released at the seventh hour (D7h). The optimum quantities of PEO and sodium bicarbonate, which had the highest desirability close to 1.0, were chosen as the statistically optimized formulation. No interaction was found between theophylline and PEO by Fourier Transformation Infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) studies.

Development of a Validated HPLC Method for the Estimation of Metformin HCl and Propranolol HCl

The present investigation targets to develop a simple, specific, sensitive and accurate reverse phase high performance liquid chromatographic (RP-HPLC) method in human plasma for the estimation of metformin HCl and propranolol HCl from bulk drug and also from the marketed products. Human plasma samples were subjected to correct procedure for protein precipitation by methanol and protein free plasma samples were directly injected into HPLC C18 column. Chromatographic determination was performed on a reversed phase C18 column (3.9 mm X 300 mm, particle size 5 μm) using a mixture of acetonitrile and 0.1M pH 4.5 potassium dihydrogenortho phosphate buffer (mL) (40:60) at a flow rate of 0.8 mL/min and maintained at a pressure of 140 to 150 Kg/cm. The retention time for metformin HCl and propranolol HCl was found to be 9.084 min and 6.132 min respectively at 232 nm without any interference of endogenous compounds in Original Research Article British Journal of Pharmaceutical Research, 4(15): 1909-1922, 2014 1910 the plasma. The method was linear in the range between 50-2000 ng/mL. The peak areas were reproducible as indicated by low coefficient of variation. It was found that the excipients in the tablet dosage form do not interfere in the quantification of active drug by proposed method.

Comparative Quality Control Evaluation of Atenolol Tablets Marketed in Kuala Lumpur, Malaysia

Background: The emergent of many pharmaceutical companies producing their own generic type of drugs after the patent of innovator drugs expired can improve the general healthcare delivery systems as well as de creasing the healthcare costs. But it also raises a few issues with one of it is the widespread of substandard and counterfeit product. Post surveillance study to assess product parameter of various generics drug marketed is