Parameswara Rao Vuddanda

Berberine: a potential phytochemical with multispectrum therapeutic activities

Importance of the field: The use of traditional medicines of natural origin is being encouraged for the treatment of chronic disorders, as synthetic drugs in such cases may cause unpredictable adverse effects. Berberine, a traditional plant alkaloid, is used in Ayurvedic and Chinese medicine for its antimicrobial and antiprotozoal properties. Interestingly, current clinical research on berberine has revealed its various pharmacological properties and multi-spectrum therapeutic applications. Areas covered in this review: An extensive search in three electronic databases (Unbound Medline, PubMed and ScienceDirect) and internet search engines (Scirus and Google Scholar) were used to identify the clinical studies on berberine, without any time constraints. This review elaborates the recent studies which reveal that with time, the drug has evolved with superior therapeutic activities. In addition, this review will also attract the attention of formulation scientists towards the issues and challenges associated in its drug delivery and the probable approaches that may be explored to help patients reap the maximum benefit of this potentially useful drug. What the reader will gain: A relatively large number of studies discussed here have revealed the possible areas where this phytochemical constituent can exhibit its therapeutic activities in the treatment of chronic ailments or diseases including diabetes, cancer, depression, hypertension and hypercholesterolemia. Take home message: The potential of the drug remains to be harvested by designing a suitable formulation that could overcome its inherent low bioavailability.

Development and Evaluation of Solid Lipid Nanoparticles of Raloxifene Hydrochloride for Enhanced Bioavailability

Raloxifene hydrochloride (RL-HCL) is an orally selective estrogen receptor modulator (SERM) with poor bioavailability of nearly 2% due to its poor aqueous solubility and extensive first pass metabolism. In order to improve the oral bioavailability of raloxifene, raloxifene loaded solid lipid nanoparticles (SLN) have been developed using Compritol 888 ATO as lipid carrier and Pluronic F68 as surfactant. Raloxifene loaded SLN were prepared by solvent emulsification/evaporation method, and different concentrations of surfactant, and homogenization speed were taken as process variables for optimization. SLN were characterized for particle size, zeta potential, entrapment efficiency, surface morphology, and crystallinity of lipid and drug. In vitro drug release studies were performed in phosphate buffer of pH 6.8 using dialysis bag diffusion technique. Particle sizes of all the formulations were in the range of 250 to 1406 nm, and the entrapment efficiency ranges from 55 to 66%. FTIR and DSC studies indicated no interaction between drug and lipid, and the XRD spectrum showed that RL-HCL is in amorphous form in the formulation. In vitro release profiles were biphasic in nature and followed Higuchi model of release kinetics. Pharmacokinetics of raloxifene loaded solid lipid nanoparticles after oral administration to Wistar rats was studied. Bioavailability of RL-HCL loaded SLN was nearly five times than that of pure RL-HCL.

Cefuroxime axetil loaded solid lipid nanoparticles for enhanced activity against S. aureus biofilm

The present research work is focused on the development of solid lipid nanoparticles of cefuroxime axetil (CA-SLN) for its enhanced inhibitory activity against Staphylococcus aureus produced biofilm. CA-SLN was prepared by solvent emulsification/evaporation method using single lipid (stearic acid (SA)) and binary lipids (SA and tristearin (TS)). Process variables such as volume of dispersion medium, concentration of surfactant, homogenization speed and time were optimized. The prepared SLN were characterized for encapsulation efficiency, drug polymer interaction studies (DSC and FT-IR), shape and surface morphology (SEM and AFM), in vitro drug release, stability studies and in vitro anti biofilm activity against S. aureus biofilm. Among the process variables, increased volume of dispersion medium, homogenization speed and time led to increase in particle size whereas increase in surfactant concentration decreased the particle size. SLN prepared using binary lipids exhibited higher entrapment efficiency than the single lipid. DSC and FT-IR studies showed no incompatible interaction between drug and excipients. CA-SLN showed two folds higher anti-biofilm activity in vitro than pristine CA against S. aureus biofilm.

Utilization of adsorption technique in the development of oral delivery system of lipid based nanoparticles.

The objective of the present study was to employ suitable adsorbent with free flowing characteristics for improving the stability and physical properties of solid lipid nanoparticles (SLN) for oral administration. Stearic acid based nanoparticles of carvedilol phosphate were fabricated by solvent emulsification evaporation technique in sodium taurocholate solution prepared in pH 7.2 buffers (I-KH2PO4/NaOH or II-NaH2PO4/Na2HPO4) with 1% polyvinyl alcohol. Nanoparticles were then adsorbed by passing the nanodispersion through a Neusilin US2 (adsorbent) column. Interestingly, scanning electron microscopy revealed round deformed and even collapsed nanoparticles in Buffer-I and discrete spherical to ellipsoidal nanoparticles in Buffer-II which indicates the inability of nanoemulsion to crystallize and form SLN in Buffer-I. The successful formation of SLN in Buffer-II was confirmed by differential scanning calorimetry and X-ray diffraction. The retention of SLN from the nanodispersion by adsorption on the adsorbent imparted good flow property and resulted in a marked stability improvement of the formulation in terms of drug retention efficiency and release profile as compared to the simple nanosuspension. In conclusion, the adsorbent technology would be instrumental in imparting additional features to the existing conventional colloidal system for pharmaceutical application which would ease the process of capsule filling at industrial scale, simplify the handling of formulations by patients and can significantly improve the shelf life of the product for a longer period of time as compared to liquid formulations.

Targeting of diacerein loaded lipid nanoparticles to intra-articular cartilage using chondroitin sulfate as homing carrier for treatment of osteoarthritis in rats

UNLABELLED Targeted delivery of antiosteoarthritic drug diacerein to articular tissue could be a major achievement and soluble polysaccharide chondroitin sulfate (ChS) may be a suitable agent for this. Therefore, diacerein loaded solid lipid nanoparticles modified with ChS (ChS-DC-SLN) were prepared for synergistic effect of these agents to combat multidimensional pathology of osteoarthritis (OA). Prepared formulation were of size range 396±2.7nm, showed extended release up to 16h and increased bioavailability of diacerein by 2.8 times. ChS-DC-SLN were evaluated for their effect on histopathology of femoro-tibial joint of rat knee and amount of ChS and rhein (an active metabolite of diacerein) at targeted site. Concentration of rhein was significantly higher in case of ChS-DC-SLN (7.8±1.23μg/ml) than that of drug dispersion (2.9±0.45μg/ml). It can be stated that ChS served as homing to articular cartilage for targeting of drug. Thus, ChS-DC-SLN have great potential to enhance the overall efficacy of treatment for OA. FROM THE CLINICAL EDITOR This study demonstrates the feasibility of targeted delivery of diacerein to articular tissue using soluble polysaccharide chondroitin sulfate as the targeting vector. This approach has the potential to significantly increase anti-arthritic drug concentration in joints without leading to systemic toxicity.

Intranasal delivery of asenapine loaded nanostructured lipid carriers: formulation, characterization, pharmacokinetic and behavioural assessment

The aim of the present research work was to develop asenapine (ASM) loaded nanostructured lipid carriers (ANLC) for the delivery of drugs in the brain by an intranasal route to enhance therapeutic efficacy. A quality by design approach was used for development and optimization of ANLC. A total of five independent variables were selected, in which three were compositions and two were process variables, while particle size and entrapment efficiency were selected as response variables. The final optimized batch was evaluated by various in vitro characterizations as well as in vivo brain and plasma pharmacokinetic studies. Finally, the ANLC was assessed for efficacy and safety profiling for upto three weeks by a behavior model viz. catalepsy, induced locomotor and paw test in Charles Foster rats. The observed particle size, entrapment efficiency and zeta potential of ANLC was found to be 167.30 ± 7.52 nm, 83.50 ± 2.48% and −4.33 ± 1.27 mV, respectively. Surface characterization studies demonstrated a spherical shape with a smooth surface of ANLC which follows the Korsmeyer–Peppas in vitro release kinetic model (r2 = 0.9911, n = 0.53). A brain pharmacokinetic study indicated a significantly higher (p < 0.05) peak drug concentration (Cmax: 74.13 ± 6.73 ng mL−1), area under the drug concentration–time curve (AUC0–24 h: 560.93 ± 27.85 h ng mL−1) and mean residence time (MRT: 7.1 ± 0.13 h) of ANLC compared to ASM in the brain via an intranasal route. The results of behaviour studies of ANLC showed a significant decrease in extra-pyramidal side effects with increasing antipsychotic effect after 1–2 week(s) of treatment. These findings demonstrate that nanostructured lipid carriers could be a new promising drug delivery system for intranasal delivery of asenapine in the treatment of schizophrenia.

Intestinal Lymphatic Delivery of Praziquantel by Solid Lipid Nanoparticles: Formulation Design, In Vitro and In Vivo Studies

The aim of the present work was to design and develop Praziquantal (PZQ) loaded solid lipid nanoparticles (PZQ-SLN) to improve the oral bioavailability by targeting intestinal lymphatic system. PZQ is practically insoluble in water and exhibits extensive hepatic first-pass metabolism. PZQ SLN were composed of triglycerides, lecithin and various aqueous surfactants; were optimized using hot homogenization followed by ultrasonication method. The optimized SLN had particle size of  nm, EE of %. The drug release of PZQ-SLN showed initial burst release followed by the sustained release. Inspite of zeta potential being around −10 mV, the optimized SLN were stable at storage conditions (°C and °C/% RH) for six months. TEM study confirmed the almost spherical shape similar to the control formulations. Solid state characterization using differential scanning calorimeter (DSC) and powder X-ray diffraction (PXRD) analysis confirmed the homogeneous distribution of PZQ within the lipid matrix. The 5.81-fold increase in , after intraduodenal administration of PZQ-SLN in rats treated with saline in comparison to rats treated with cycloheximide (a blocker of intestinal lymphatic pathway), confirmed its intestinal lymphatic delivery. The experimental results indicate that SLN may offer a promising strategy for improving the therapeutic efficacy and reducing the dose.

A Comparison between Use of Spray and Freeze Drying Techniques for Preparation of Solid Self-Microemulsifying Formulation of Valsartan and In Vitro and In Vivo Evaluation

The objective of the present study was to develop self micro emulsifying formulation (SMEF) of valsartan to improve its oral bioavailability. The formulations were screened on the basis of solubility, stability, emulsification efficiency, particle size and zeta potential. The optimized liquid SMEF contains valsartan (20% w/w), Capmul MCM C8 (16% w/w), Tween 80 (42.66% w/w) and PEG 400 (21.33% w/w) as drug, oil, surfactant and co-surfactant, respectively. Further, Liquid SMEF was adsorbed on Aerosol 200 by spray and freeze drying methods in the ratio of 2 : 1 and transformed into free flowing powder. Both the optimized liquid and solid SMEF had the particle size <200 nm with rapid reconstitution properties. Both drying methods are equally capable for producing stable solid SMEF and immediate release of drug in in vitro and in vivo conditions. However, the solid SMEF produced by spray drying method showed high flowability and compressibility. The solid state characterization employing the FTIR, DSC and XRD studies indicated insignificant interaction of drug with lipid and adsorbed excipient. The relative bioavailability of solid SMEF was approximately 1.5 to 3.0 folds higher than marketed formulation and pure drug. Thus, the developed solid SMEF illustrates an alternative delivery of valsartan as compared to existing formulations with improved bioavailability.

Intravenous administration of trans-resveratrol-loaded TPGS-coated solid lipid nanoparticles for prolonged systemic circulation, passive brain targeting and improved in vitro cytotoxicity against C6 glioma cell lines

trans-Resveratrol (RSV), a natural molecule isolated from red wine, is widely known for several therapeutic potentials. RSV is proved for cardioprotective, vasodilation, anti-inflammatory, and anticancer effects. Recently, anticancer potential against glioma cells has also been reported. However, the clinical application of RSV in glioma treatment is largely limited because of its rapid metabolism and elimination from systemic circulation thereby exhibiting low biological half-life and poor brain distribution as well. Therefore, the main objective of this study was to enhance the circulation time, biological half-life and passive brain targeting of RSV using D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS)-coated solid lipid nanoparticles (RSV-TPGS-SLN). RSV-TPGS-SLN formulations were prepared by a solvent emulsification evaporation method and evaluated for several nanoparticulate characteristics. In vitro anticancer potential and cellular internalization of nanoparticles were also investigated in C6 glioma cell lines. Pharmacokinetics and biodistribution studies were carried out following intravenous administration in healthy Charles Foster rats. RSV-TPGS-SLN showed significantly higher in vitro cytotoxicity against C6 glioma cell lines and excellent cellular internalization. RSV-TPGS-SLN showed 11.12 and 9.37 times higher area under the curve and plasma half-life than RSV solution, respectively. Moreover, brain distribution of RSV-TPGS-SLN was found to be 9.23 times higher in comparison to that of RSV alone. Thus, we anticipate that the RSV-TPGS-SLN formulation can be applied as a potential tool for improving circulation time, biological half-life and passive brain targeting of RSV, thereby being immensely useful in the treatment of glioma.

Effect of plasticizers on the physico-mechanical properties of pullulan based pharmaceutical oral films

&NA; The effect of different plasticizers (glycerol, vitamin E TPGS and triacetin) and their concentrations on the physico‐mechanical properties of pullulan based oral films was studied. A full factorial (32) design of experiments was used. Elastic modulus, tensile strength, elongation at break and disintegration time were selected as response variables. Modulated differential scanning calorimeter (MDSC) was used for determining glass transition temperature (Tg) of pullulan films. The surface morphology of films was evaluated by SEM, while ATR‐FTIR was used to obtain a molecular level understanding of polymer‐plasticizer interactions. The DoE analysis allowed for the modelling of tensile strength and elongation at break. The highest elongations were observed in glycerol at 20% w/w. Majority of the films disintegrated within one minute without significant differences. ATR‐FTIR spectra of pullulan alone and different plasticizer blend films show characteristic molecular interactions. The present study concluded that glycerol is suitable plasticizer compared to others for manufacturing pullulan based oral films. Graphical abstract Figure. No caption available.