Spanlastics: a novel elastic drug delivery system with potential applications via multifarious routes of administration

Drug delivery systems (DDS) based on nanocarriers are designed to transport therapeutic agents to specific areas of the body where they are required to exhibit pharmacodynamic effect. These agents rely on an appropriate carrier to protect them from rapid degradation or clearance and enhance their concentration in target tissues. Spanlastics, an elastic, deformable surfactant-based nanovesicles have the potential to be used as a drug delivery vehicle for wide array of drug molecules. Spanlastics are formed by the self-association of non-ionic surfactants and edge activators in an aqueous phase and have gained attention as promising drug carriers due to their biodegradable, biocompatible, and non-immunogenic structure. In recent years, numerous scientific journals have published research articles exploring the potential of spanlastics to serve as a DDS for various types of drugs as they offer targeted delivery and regulated release of the drugs. Following brief introduction to spanlastics, their structure and methods of preparation, this review focuses on the delivery of various drugs using spanlastics as a carrier via various routes viz. topical, transdermal, ototopical, ocular, oral and nasal. Work carried out by various researchers by employing spanlastics as a carrier for enhancing therapeutic activity of different moieties has been discussed in detail.

Neuroprotective effect of Berberine Nanoparticles Against Seizures in Pentylenetetrazole Induced Kindling Model of Epileptogenesis: Role of Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Mechanisms

There is an unmet need to develop alternative therapeutic strategies to not only restrain seizures but also to alleviate the underlying pathologies and sequelae. Berberine (BBR), an isoquinoline alkaloid, has shown promising effect in the kindling model of epileptogenesis, but due to the poor oral bioavailability its clinical application is limited. So, the present study was designed to study the neuroprotective effect of BBR nanoparticles (enhanced bioavailability as compared to BBR) against seizures in pentylenetetrazole (PTZ) induced kindling model of epileptogenesis. Kindling model was established in male Wistar rats by intraperitoneal (i.p.) administration of PTZ (30 mg/kg) on every alternate day till the animal became fully kindled or till 6 weeks. Three doses of BBR (50, 100, and 200 mg/kg) and nano-BBR (25, 50, 100 mg/kg) were studied for seizure score, percentage of animal kindled, histopathological score, oxidative stress, inflammation, and apoptosis in PTZ treated rats by conducting cytokines, gene expression and protein expression analysis. BBR nanoparticles showed significant effect on the seizure score and percentage of animal kindled, histopathological score, neurobehavioral parameters (Forced swim test, Rotarod), oxidative (MDA, SOD, GSH, GPx) and inflammatory (IL-1beta, TNF-alpha) parameters, apoptotic parameters (Bax and iNOS), and gene (Nrf2, NQO1, HO1) and protein expression (Nrf2) as compared to both PTZ and BBR. BBR nanoparticles showed neuroprotective effect in PTZ induced kindling model of epileptogenesis and proves to be a promising antiepileptogenic therapy for the patients who are at high risk of developing seizures.

Preclinical Investigation of Transdermal Route for Enhanced Bio-performance of Duloxetine HCl

The aim of the study was to develop and optimise drug-in-adhesive (DIA) transdermal patch of duloxetine HCl for enhanced drug delivery. DIA patch so developed reduced the dose and dosing frequency by enhancing bio-performance of the drug. A transdermal DIA patch having Duro-Tak 87-2287 as DIA polymer and Transcutol P as permeation enhancer loaded with 40% drug previously complexed with MeβCD duly characterised (FTIR, DSC, and SEM) was developed for in vivo study. Pharmacokinetic parameters of developed formulation were assessed and compared with oral route of administration. Among various permeation enhancers (PEs), Transcutol P exhibited most enhanced permeation (ER ≈ 1.99) in terms of flux and Q24 compared to control group having. Mean of maximum plasma concentration (Cmax) and area under time-concentration curve (AUC0-72) in Wistar rats (n = 6) for transdermal patch (10 mg/kg) was found to be 70.31 ± 11.2 ng/ml and 2997.29 ± 387.4 ng/ml*h, respectively, and were considerably higher than oral dose of DLX (20 mg/kg and 10 mg/kg). Albeit, T1/2 was higher in case of transdermal delivery, but this was due to sustained behaviour of delivery system. These findings highlight the significance of both inclusion complexation and transdermal delivery of DLX using DIA patch for efficient drug absorption.

Levofloxacin loaded clove oil nanoscale emulgel promotes wound healing in Pseudomonas aeruginosa biofilm infected burn wound in mice

Owing to their tolerance to antibiotics, bacterial biofilms continue to pose a threat to mankind and are leading cause for non-healing of burn wounds. Within the biofilm matrix, antibiotics become functionally inactive due to restricted penetration and enzymatic degradation leading to rise of antimicrobial resistance. The objective of present investigation was to develop and characterize levofloxacin (LFX) loaded clove oil nanoscale emulgel (LFX-NE gel) and evaluate its in vivo therapeutic efficacy in Pseudomonas aeruginosa biofilm infected burn wound in mice. The optimized emulgel was found to possess good texture profile and showed shear thinning behavior. In vitro release study demonstrated complete drug release in 8 h and emulgel was found to be stable for 3 months at 25 °C and 40 °C. In vivo study revealed biofilm dispersal, complete wound closure, re-epithelialization and collagen deposition by LFX-NE gel in comparison to various control groups. LFX-NE gel was able to clear the infection within 7 days of treatment and promote wound healing as well. Therefore, administration of LFX-incorporated NE gel could be a beneficial treatment strategy for P. aeruginosa biofilm-infected burn wounds.

Advancements in redox-sensitive micelles as nanotheranostics: A new horizon in cancer management

World Health Organisation (WHO) delineated cancer as one of the foremost reasons for mortality with 10 million deaths in the year 2020. Early diagnosis and effective drug delivery are of utmost importance in cancer management. The entrapment of both bio-imaging dyes and drugs will open novel avenues in the area of tumor theranostics. Elevated levels of reactive oxygen species (ROS) and glutathione (GSH) are the characteristic features of the tumor microenvironment (TME). Researchers have taken advantage of these specific TME features in recent years to develop micelle-based theranostic nanosystems. This review focuses on the advantages of redox-sensitive micelles (RSMs) and supramolecular self-assemblies for tumor theranostics. Key chemical linkers employed for the tumor-specific release of the cargo have been discussed. In vitro characterisation techniques used for the characterization of RSMs have been deliberated. Potential bottlenecks that may present themselves in the bench-to-bedside translation of this technology and the regulatory considerations have been deliberated.

Forging Ahead the Repositioning of Multitargeted Drug Ivermectin

With the advent of ivermectin, tremendous improvement in public health has been observed, especially in the treatment of onchocerciasis and lymphatic filariasis that created chaos mostly in rural, sub-Saharan Africa and Latin American countries. The discovery of ivermectin became a boon to millions of people that had suffered in the pandemic and still hold its pharmacological potential against these. Ivermectin continued to surprise scientists because of its notable role in the treatment of various other tropical diseases (Chagas, leishmaniasis, worm infections, etc.) and is viewed as the safest drug with the least toxic effects. The current review highlights its role in unexplored avenues towards forging ahead of the repositioning of this multitargeted drug in cancer, viral (the evaluation of the efficacy of ivermectin against SARS-Cov-2 is under investigation) and bacterial infection and malaria. This article also provides a glimpse of regulatory considerations of drug repurposing and current formulation strategies. Due to its broad-spectrum activity, multitargeted nature and promising efforts are put towards the repurposing of this drug throughout the field of medicine. This single drug originated from a microbe, changed the face of global health by proving its unmatched success and progressive efforts continue in maintaining its bequestnin the management of global health by decreasing the burden of various diseases worldwide.

Pharmaceutical strategies for the treatment of bacterial biofilms in chronic wounds

Biofilms are sessile communities of microorganisms, mainly bacteria, that grow on biotic and abiotic surfaces. These microorganisms are embedded within an extracellular polymeric substance that provides enhanced protection from antimicrobials. Chronic wounds provide an ideal habitat for biofilm formation. Bacteria can easily attach to wound debris and can infect the wound due to an impaired host immune response. This review highlights the mechanism of biofilm formation and the role of biofilms in the pathophysiology of chronic wounds. Our major focus is on various formulation strategies and delivery systems that are employed to eradicate or disperse biofilms, thereby effectively managing acute and chronic wounds. We also discuss clinical research that has studied or is studying the treatment of biofilm-infected chronic wounds. Teaser: Innovative pharmaceutical strategies such as hydrogels, nanofibers, films and various nanoscale materials can provide promising approaches for the treatment of biofilm-mediated chronic wound infections, offering the potential to improve therapeutic outcomes.

Long Acting Polycaprolactone Based Parenteral Formulation of Aripiprazole Targeting Behavioural and Biochemical Deficit in Schizophrenia

Schizophrenia is a neurodevelopmental disorder which is expressed in the form of disturbed behaviour and abnormal mental functions. Patient's non-adherence to the medicine is the main cause of failure of drug therapy and increases incidence of relapses. Thus, for successful management of disease long acting parenteral formulations were developed. Aripiprazole was encapsulated in biocompatible polycaprolactone microsphere by o/w emulsion solvent-evaporation method in order to achieve sustained release of the drug for several weeks after single subcutaneous administration. They were optimised on the basis of various parameters such as physical appearance, particle size (49.4 μm-387.1 μm), encapsulation efficiency (70%-95%), percentage yield (33%-75%) and drug loading (25.9%-47.5%). The surface topography and sphericity of the microspheres was determined by scanning electron microscopy which revealed that the microspheres formed were spherical and non-porous in nature. The in vitro releases from the selected formulations were found to be 87% and 95% respectively after 45 days of dissolution. In vivo efficacy of optimised formulation showed significantly (p < 0.05) amelioration of various positive, negative and cognitive symptoms associated with schizophrenia and oxidative stress markers in ketamine-induced schizophrenia model in rats for 30 days.

Engineered Site-specific Vesicular Systems for Colonic Delivery: Trends and Implications

Steering drug-loaded, site-specific, coated lipid vesicles to the target receptor sites have the potential of plummeting adverse effects and improving the pharmacological response in diverse pathologies of the large bowel, especially the colon. Colonic delivery via oral route has its own challenges, often governed by several glitches such as drug degradation or absorption in the upper GIT, instability of proteins/peptides due to high molecular weight, and peptidase activity in the stomach. Consequently, colon-specific coated liposomal systems (CSLS) offer a potential alternate for not only site-specificity, but protection from proteolytic activity, and prolonged residence time for greater systemic bioavailability. On the other hand, liposomal delivery via the oral route is also cumbersome owing to several barriers such as instability in GIT, difficulty in crossing membranes, and issues related to production at the pilot scale. New advancements in the field of CSLS have successfully improved the stability and permeability of liposomes for oral delivery via modulating the compositions of lipid bilayers, adding polymers or ligands. Despite this ostensible propitiousness, no commercial oral CSLS has advanced from bench to bedside for targeted delivery to the colon as yet. Nevertheless, CSLS has quite fascinated the manufacturers owing to its potential industrial viability, simplistic and low-cost design. Hence, this review aims to decipher the convolutions involved in the engineering process of industrially viable CSLS for colonic delivery.

Impact of cyclodextrin derivatives on systemic release of duloxetine HCl via buccal route

Aim: The aim of this work was to develop buccoadhesive tablets for the systemic delivery of duloxetine HCl (DXT) using more soluble derivatives of β-cyclodextrin, i.e. hydroxypropyl-β-cyclodextrin (HPβCD) and sulfobutylether-β-cyclodextrin (SBEβCD) and to investigate enhanced cellular uptake of inclusion complexed drug.Materials and methods: Freeze dried and spray dried complexes of both cyclodextrin derivatives with DXT (1:1 molar) were prepared and characterized with DSC, FTIR, and PXRD techniques. C971 and PC, on the basis of swelling behavior, erosion and in vitro residence time, were selected for further study at different levels (-1, 0, +1) to optimize the formulation in terms of enhanced drug release and ex vivo permeation.Results: SBEβCD based complexes show more aqueous solubility of DXT (0.782 and 0.958 mM) and more complexation efficiency compared to HPβCD at 25 °C and 37 °C, respectively. Apparent stability constant was reported to be higher (1109.94 and 1693.25 M^-1) for DXT-SBEβCD at 25 °C and 37 °C, respectively, than the corresponding values for DXT-HPβCD systems. Enhanced cellular uptake using fibroblast cells was revealed for complexed drug compared to free drug .Conclusion: Both cyclodextrin derivatives are able to enhance drug release and permeation in vitro and ex vivo.

In Situ Forming Depot as Sustained-Release Drug Delivery Systems

In situ forming systems can serve as promising alternative to existing long acting injectables like disperse systems and microspheres, owing to their biocompatibility, stability, ease of administration and scale up. Microspheres based on long-acting parenteral systems pose challenges in scaling up and process changes with the drug and polymer selected. In situ gelling systems are having low viscosity which is very conducive during various manufacturing unit operations and passing the formulation through hypodermic needle with lower applied pressure. Different mechanisms such as physical or physiological stimuli and cross linking reactions are involved in the gelling of in situ forming systems at the site of injection. Drug release from in situ forming systems can be altered according to the need by using different polymers, lipids and fatty acids. In situ forming systems can be evaluated by sol-gel transition time, temperature and pH, rheology, gel strength, texture analysis, syringeability and injectability. The present paper is an overview of the various in situ gelling polymers and their application in the preparation of depot formulations. Numerous products based on in situ forming systems such as Eligard®, Atridox® are available in market.

A New Therapeutic Approach for Brain Delivery of Epigallocatechin Gallate: Development and Characterization Studies

Background:

Blood-brain permeability is the primary concern when dealing with the biodistribution of drugs to the brain in neurological diseases.

Objective:

The purpose of the study is to develop the nanoformulation of Epigallocatechin gallate (EGCG) in order to improve its bioavailability and penetration into the brain.

Methods:

EGCG loaded Solid Lipid Nanoparticles (SLNs) have been developed using microemulsification method and pharmacological assessments were performed.

Results:

Surface morphology and micromeritics analysis showed the successful development of EGCG loaded solid lipid nanoparticles with an average size of 162.4 nm and spherical in shape. In vitro release studies indicated a consistent and slow drug release. Pharmacological evaluation of SLN-EGCG demonstrated a significant improvement in cerebral ischemia-induced memory impairment.

Conclusion:

The results indicate that the EGCG loaded SLNs provide a potential drug delivery system for improved delivery of EGCG to the brain, hence, enhancing its brain bioavailability.

Use of thermal and non thermal techniques for assessing compatibility between mirtazapine and solid lipids

The present investigation was aimed at the evaluation of possible interactions between mirtazapine and selected solid lipids that are commonly used to develop solid lipid nanoparticles (SLNs) and nanostructured lipidic carriers (NLCs). The solids lipids explored were palmitic acid, stearic acid, glycerylmonostearate, cutina CPPH, sterotex NF, gelucire 50/13, hydrogenated castor oil and compritol 888 ATO. The techniques used were Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Hot Stage Microscopy (HSM) and Isothermal Stress Testing (IST) studies. In some cases, the DSC results indicated the possibility of drug-solid lipid interactions which was further ruled out by performing HSM studies. Moreover, IST studies were also used to further confirm the compatibility between the drug and selected solid lipids. And the findings from these studies indicated compatibility between mirtazapine and solid lipids that can further be used to develop SLNs or NLCs.

Enhancement of In Vivo Efficacy and Oral Bioavailability of Aripiprazole with Solid Lipid Nanoparticles

Aripiprazole (ARP), a second-generation or atypical antipsychotic, is poorly soluble and undergoes extensive hepatic metabolism and P-glycoprotein efflux which lead to reduced in vivo efficacy and increased dose-related side effects. To enhance in vivo efficacy and oral bioavailability of aripiprazole, aripiprazole-loaded solid lipid nanoparticles (SLNs) were developed using tristearin as solid lipid. Tween 80 and sodium taurocholate were used as surfactants to prepare SLNs using microemulsification method. SLNs were characterized for particle size, zeta potential, entrapment efficiency, and crystallinity of lipid and drug. In vitro release studies were performed in water containing 0.5% sodium dodecyl sulfate. Pharmacodynamic evaluation was carried out in laca mice using dizocilpine-induced schizophrenic model where behavioral evaluation revealed better in vivo efficacy of SLNs. Pharmacokinetics of aripiprazole-loaded SLNs after oral administration to conscious male Wistar rats was studied. Bioavailability of aripiprazole was increased 1.6-fold after formulation of aripiprazole into SLNs as compared to plain drug suspension. The results indicated that solid lipid nanoparticles can improve the bioavailability of lipophilic drugs like aripiprazole by enhancement of absorption and minimizing first-pass metabolism.

Antidepressants as antipruritic agents: A review

Pruritus is a concomitant symptom of various underlying disorders viz. dermatological, systemic and psychiatric disorders that provoke the person to scratch the skin. Many natural as well as, antipruritic therapies are usually practiced in the treatment of pruritus including general preventive measures, topical therapies such as cooling agents, antihistamines, anesthetics, capsaicin, corticosteroids, immunomodulators and; systemic therapies including administration of antihistamines, opioid antagonists/agonists, antiepileptic drugs/neuroleptics (e.g., gabapentin and pregabalin), antidepressants (e.g., doxepin, amitriptyline, paroxetine, fluvoxamine, sertraline, escitalopram and mirtazapine) (Patel and Yosipovitch, 2010; Reich et al., 2011; Martín and Padilla, 2015; Eskeland et al., 2016). Topical therapies are the mainstay of treatment of delicate and localized pruritus while other systemic drug therapies are used to treat stern and generalized pruritus. The reported antipruritic activity of some antidepressant drugs has intrigued this review to focus on the types of pruritus, pruritus mechanism, the antipruritic mechanism of antidepressants and to comprehend the role of antidepressants in the management of pruritus.

Liquid Nanosize Emulsion-Filled Enteric-Coated Capsules for Colon Delivery of Immunosuppressant Peptide

Present study aims at solubilizing slightly water-soluble peptide into a nanosize emulsion which is filled into a hard gelatin capsule in the form of preconcentrate. Further, liquid-filled capsule was dip-coated with ethyl cellulose and Eudragit S100 for colon targeting. An in vitro release profile was studied for selected formulations, i.e., Formulation A (5 mg ethyl cellulose and 40 mg Eudragit S100), Formulation B (10 mg ethyl cellulose and 30 mg Eudragit S100), and Formulation C (10 mg ethyl cellulose and 20 mg Eudragit S100). Formulations B and A showed an immediate release after 5 and 6 h, respectively, which represents ileo-ceacal transit time. The nanosize of emulsion, i.e., below 100 nm, was confirmed by transmission electron microscopy. Also, a phase transition of nanosize emulsion from water in oil to oil in water on dilution with water was observed through TEM. This novel approach of filling poorly water-soluble protein in solubilized form of nanosize emulsion preconcentrate into coated hard gelatin capsules for colon targeting has been reported first time. This approach could be a breakthrough for the better management of local intestinal pathologies.

Effect of mesenchymal stem cells and galantamine nanoparticles in rat model of Alzheimer's disease

AIM

The present study investigated the efficacy of bone marrow-derived mesenchymal stem cells (BM-MSCs) in combination with galantamine hydrobromide-loaded solid lipid nanoparticles (GH-SLNs) in intracerebroventricular (ICV)-isoproterenol-induced rat model of Alzheimer's disease.

MATERIALS & METHODS

BM-MSCs were harvested by dissecting femur and tibia of 8-10-week-old Wistar rats. 1 × 10(6) cells were administered intravenously once in ICV-isoproterenol-induced rats followed by GH-SLNs (5 mg/kg) for 3 weeks.

RESULTS & CONCLUSION

ICV-isoproterenol resulted in significant memory deficit. The results demonstrated rapid regain of memory in isoproterenol-induced amnesic rats, following single intravenous administration of BM-MSCs and oral administration of GH-SLNs for 21 days. The combination of BM-MSCs and GH-SLNs produced a more pronounced protective effect, therefore, could be explored for the management of Alzheimer's disease.

Emerging Potential of Nanosuspension-Enabled Drug Delivery: An Overview

Poor aqueous solubility is one of the key concerns of the majority of new drug molecules. One of the important problems associated with such drugs is that they often lead to low bioavailability. Researchers have used various techniques, but little success has been achieved due to poor stability and industrial viability, including technique cost. Of the numerous techniques, nanosuspensions (NSs) have drawn interest in improving solubility. NSs are dispersions of nanosized drug particles stabilized with the aid of appropriate agents. Stabilizers for NSs are generally recognized as safe (GRAS) excipients that can be chosen from a number of surfactants and/or polymers to food proteins. The commonly used techniques for preparation of NSs including top-down and bottom-up methods, along with new fabrication techniques based on supercritical (SC) fluids, are reviewed. This review also includes preparatory techniques, characterization, potential applications, and recent advancements in the field of NSs.

Solid lipid nanoparticle: an efficient carrier for improved ocular permeation of voriconazole

This research focuses on the fabrication and evaluation of solid lipid nanoparticles (SLNs) for improved ocular delivery of voriconazole (VCZ). Compritol and palmitic acid were selected as lipid carriers based on drug solubility and partitioning behavior. Poloxamer and soya lecithin were the choice for surfactant, while sodium taurocholate was used as a co-surfactant. The particle sizes of the SLNs determined by zetasizer and transmission electron microscopy (TEM) were found within the desired range. The in vitro release study of SLNs exhibited a sustained-release property of the drug. The ex vivo studies displayed enhanced corneal drug permeation from SLNs in comparison to the drug suspension. Further, the corneal hydration studies, histopathology and Hen's Egg Test Chorio Allantoic Membrane (HETCAM) assay confirmed the non-irritancy of the nano-formulation. The in vivo study confirmed the higher availability of VCZ (from SLN) in aqueous humor with minimal nasolacrymal drainage in contrast to the drug suspension. A good in-vitro in-vivo correlation (IVIVC) further confirmed the potential of SLN as an effective carrier for ocular delivery.

Preparation and evaluation of floating tablets of pregabalin

Floating tablets of pregabalin were prepared using different concentrations of the gums (xanthan gum and guar gum), Carbopol 974P NF and HPMC K100. Optimized formulations were studied for physical tests, floating time, swelling behavior, in vitro release studies and stability studies. In vitro drug release was higher for tablet batches containing guar and xanthan gum as compared to the batches containing Carbopol 974P NF. Tablet batches were subjected to stability studies and evaluated by different parameters (drug release, drug content, FTIR and DSC studies). The optimized tablet batch was selected for in vivo pharmacodynamic studies (PTZ induced seizures). The results obtained showed that the onset of jerks and clonus were delayed and extensor phase was abolished with time in treated groups. A significant difference (p > 0.05) was observed in control and treated group behavior indicating an excellent activity of the formulation for a longer period (>12 h).

Modified Release Biodegradable Polymeric Microspheres of Stavudine: Cell Viability, Cellular Uptake, Hemolysis Studies and In Vivo Pharmacokinetics

Family of retroviruses which replicates through the use of the reverse transcriptase enzyme or the enzyme needed to convert RNA to DNA for replication bears Human Immunodeficiency Virus (HIV). It causes irreversible destruction of the immune system leading to the occurrence of opportunistic infections and malignancies. The eradication of HIV is highly unlikely as the cells of the mononuclear phagocyte system (MPS) besides CD4 T lymphocytes are the specific hosts for HIV which need to be targeted even after extended blood plasma profile of antiviral drug to maintain viral suppression and reduced disease progression. Aiming the current goal, biodegradable polymeric microspheres of PLGA 50: 50 (RESOMER(®) 505H) were developed and evaluated. These polymeric particles encapsulating Stavudine (d4T) exhibited nearly 100% cell viability during cytotoxicity studies in comparison to pure d4T. The histological studies have revealed the in vivo biocompatibility while hemolysis studies certified the liability of formulation to be used parenteraly exhibiting no significant hemolytic toxixicty. The in vivo pharmacokinetics has shown the extended drug release from microsphere matrix upto a month. The calculated AUCtotal for d4T loaded polymeric microspheres was found to be 3341.656 μM h/ml; which was nearly 54 times than the total AUC of free d4T injected subcutaneously to the control group of animals; exhibiting the stable d4T concentration in blood avoiding fluctuation of the same indicating decreased probabilities of development of resistance against the treatment. Combination of targeted and subcutaneous administration of d4T will not only provide the stable and extended release of drug but also eradicate the hidden HIV hosted by macrophages. The concomitant regimen will potentially enhance the therapeutic efficacy with patient compliance; renewing new hopes for complete cure and improved quality of life in the AIDS patient.

Pioglitazone hydrochloride: chemopreventive potential and development of site-specific drug delivery systems

The aim of this study was to investigate the potential of pioglitazone hydrochloride as a promising anticancer agent and then to design and evaluate the colon-targeted delivery system. The role of pioglitazone hydrochloride as a promising anticancer agent was evaluated by in vitro cell line studies and in vivo 1,2-dimethylhydrazine-induced colon carcinogenesis in rats. In order to deliver the drug at site of action, i.e. colon, drug embedded in matrices containing a release retarding polymer (HPMC K4M) and a polysaccharide (locust bean gum) were prepared. These matrix systems were further enteric coated with Eudragit®S100 to minimize the premature drug release in the upper segments of the GIT. In vitro dissolution studies were performed in absence and presence of rat caecal contents on selected batches and samples were analyzed using a validated RP-HPLC method. Hence, the studies led to the conclusion that successful site-specific delivery systems of pioglitazone hydrochloride were developed to improve its therapeutic efficacy in the management of colorectal cancer.

Emergence of nanomedicine as cancer targeted magic bullets: recent development and need to address the toxicity apprehension

Multi drug resistance and non specific targeting is a major problem with conventional therapy. To overcome this problem, nanoparticles (NPs) have emerged as an important tool to deliver conventional drugs, recombinant proteins, vaccines and more recently, nucleotides. NPs modify the drug release pattern, absorption, distribution, metabolism, excretion (ADME) and therapeutic response. This review focuses on the potential of nanotechnology in cancer and discusses the different nanoparticulate drug-delivery systems including quantum dot, iron oxide nanoparticles, gold nanoparticles, carbon nanotubes, silica nanoparticles, dendrimer, graphene and polymeric nanoparticles with their applications in therapeutics, diagnostics, and imaging pattern. Further, the recent development and progress of theranostic nanoparticles in the treatment of cancer and toxicity associated with nanoparticles is also covered here.

Critical aspects in rationale design of fluorouracil-based adjuvant therapies for the management of colon cancer

The strategic goal behind adjuvant therapy is to open novel avenues for colon cancer treatment by specifically inactivating pathways needed for the growth of tumor cells. 5-Fluorouracil (5-FU) therapy is a prominent conventional treatment for colon cancer that has been used for five decades. Among the rich diversity of chemotherapeutics, 5-FU has been extensively manipulated as an anticancer drug. The pharmacology of 5-FU has spawned myriad alternatives to achieve low-toxicity treatment for better colon cancer management. The existing highly toxic chemotherapeutic regimens, lack of new congeners with significant efficacy, and drug resistance to cancer cells have prompted scientists to manipulate conventional treatments. These factors make it imperative to rationalize the current 5-FU therapy in combination with synthetic or natural compounds by optimizing the dose with respect to pharmacokinetic and preclinical data. To attempt to tailor effective conventional 5-FU regimens, novel therapeutic perspectives associated with the 5-FU-based colon cancer chemotherapy currently available in clinical settings have been summarized. This review presents comprehensive summary of a dedicated literature search of databases (i.e., PUBMED, CAPLUS, and MEDLINE) for adjuvant approaches such as NSAIDs (COX-II inhibitors), natural compounds, viral vectors, novel agents/molecules, and various targeted therapies, in combination with 5-FU in developing treatment alternatives for colon cancer.

In silico predicative studies for cytotoxic potential of NSAIDs using self-organizing molecular field analysis

Antiproliferative potential of nonsteroidal anti-inflammatory drugs (NSAIDs) has generated an immense interest among the scientific fraternity to assess its broader role in the chemoprevention of colon cancer. Due to serious adverse events associated with the chemotherapy, NSAIDs have been exploited as adjuvants to synergize the cytotoxic potential of conventional chemotherapeutic agents at low-dose regimens. The present investigation has been focused on in silico model generation for in vitro cytotoxicity activity of the clinically active NSAIDs using self-organizing molecular field analysis (SOMFA) studies. A statistically validated robust model for a diverse group of NSAIDs having flexibility in structure and cytotoxicity activity was obtained using SOMFA. The statistical measures having good cross-validated correlation coefficient r (2) (cv) (.8291), noncross-validated correlation coefficient r (2) values (.8686), and high F test value (41.8722) proved significance in the generated model. Analysis of 3-dimensional quantitative structure activity relationship (3D-QSAR) models through electrostatic and shape grids provided additional valuable information regarding shape and electrostatic potential influence on in vitro cytotoxicity profile. The analysis of SOMFA results provided a better insight about the generation of molecular architecture of novel NSAIDs yet to be synthesized, with optimum in vitro cytotoxicity activity and improved therapeutic profile.

A novel synergistic galactomannan-based unit dosage form for sustained release of acarbose

In the current study, the potential of a novel combination of a galactomannan with acarbose (100 mg) was evaluated for attaining a desired hypoglycaemic effect over a prolonged period of time. Three major antidiabetic galactomannans viz., fenugreek gum, Boswellia gum, and locust bean gum were selected in order to achieve a synergistic effect in the treatment along with retardation in drug release. In vitro studies indicated that batches containing various proportions of fenugreek gum (AF40-60) were able to control drug release for a longer duration of approximately 10-12 h. In contrast, the matrices prepared using Boswellia and locust bean gum were able to sustain the release for relatively shorter durations. Drug release mainly followed first-order release kinetics owing to the highly soluble nature of the drug. In vivo study depicted a significant reduction (p < 0.001) in the postprandial blood glucose and triglyceride levels in the diabetic rats on treatment with formulation AF40. Thus, the developed system provides a better control of the postprandial glycaemic levels and it also obviates the need of conventional multiple dosing of acarbose. Furthermore, it also reduces the occurrence of side effects like diarrhea and loss of appetite.

Utility of an oxidation reaction for the spectrophotometric determination of acarbose in controlled release tablets at various simulated gastrointestinal media

A sensitive kinetic method for spectrophotometric determination of acarbose is developed and validated for the determination of the drug in bulk and pharmaceutical formulations. The drug was estimated in simulated gastrointestinal media i.e., 0.1 M HCl (pH 1.2) and phosphate buffer (pH 6.8). The method involves the oxidation of acarbose by treating it with a strong oxidizing agent (potassium permanganate (1 x 10(-2) M)) in alkaline media. The reaction kinetics was determined for 20 min at room temperature. The reaction followed first order kinetics and the absorbance of the corresponding manganate ions produced was determined at 610 nm. The absorbance-concentration plot was found to be rectilinear over the concentration range of 2-20 microg/mL. The proposed method was used for estimation of the drug in a novel controlled release dosage form. Thus, the method developed was simple, reproducible and can be successfully applied for the determination of the drug in simulated gastrointestinal fluid.

A Stability-Indicating RP-HPLC Assay Method for 5-Fluorouracil

The present study describes the development of a validated RP-HPLC method for the determination of 5-fluorouracil in presence of its degradation products or other pharmaceutical excipients. Stress studies were performed on 5-fluorouracil and it was found that it degrades sufficiently in alkaline conditions, while negligible degradation was observed in acidic, neutral, oxidative and photolytic conditions. The peaks of the degradation products were not observed in the chromatogram due to the nonchromophoric nature of the degradation moiety formed. The separations were carried out on a C-18 reversed phase column (Phenomenex; Prodigy ODS3V, 250x4.6 mm, 5 mu) using 50mM KH(2)PO(4) (pH, 5.0) as mobile phase at a flow rate of 1.2 ml/min and temperature of 30 degrees . The wavelength of detection was 254 nm. A retention time of nearly 6 minutes was obtained. Analytical validation parameters such as specificity and selectivity, linearity, accuracy and precision were evaluated. The calibration curve for 5-fluorouracil was linear (r(2)=0.999+/-0.0005) from range of 10 mug/ml to 100 mug/ml. Relative standard deviation values for all the key parameters, was less than 2.0 %. The recovery of the drug after standard addition to the degraded sample was found to be 104.69%. Thus, the developed RP-HPLC method was found to be suitable for the determination of 5-fluorouracil in bulk as well as stability samples of the pharmaceutical dosage forms containing various excipients.

Molecular simulation of hydroxypropyl-beta-cyclodextrin with hydrophobic selective Cox-II chemopreventive agent using host-guest phenomena

The present investigation outlays the host-guest penetration of hydrophobic selective Cox-II chemopreventive agent, celecoxib (CXB), with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) using inclusion complexation phenomena. Phase solubility studies conducted at 37 degrees C and 25 degrees C revealed typical A(L)-type curve for the HP-beta-CD indicating the formation of soluble complexes. The inclusion complexes in the molar ratio of 1:1 and 2:1 (CXB-HP-beta-CD) were prepared by kneading technique. The formation of inclusion complexes and the molecular simulation of CXB protons with HP-beta-CD cavity in all samples were testified by 1H-NMR, DSC, powder-XRD, SEM and FTIR and UV/visible spectroscopy. The results of these studies indicated that complex (prepared by kneading method) in molar ratio of 1:1 exhibited better improvement in in vitro dissolution profiles as compared to 1:2 complex. Mean in vitro dissolution time indicated significant difference in the release profiles of CXB from complexes and physical mixtures as compared to pure CXB.

Formulation, Characterization, and Evaluation of Ketorolac Tromethamine-Loaded Biodegradable Microspheres

Ketorolac tromethamine has to be given every 6 hr intramuscularly in patients for acute pain, so to avoid frequent dosing and patient inconvenience we found it to be a suitable candidate for parenteral controlled delivery by biodegradable microspheres for the present study. Ketorolac tromethamine-loaded microspheres were prepared by o/w emulsion solvent evaporation technique using different polymers: polycaprolactone, poly lactic-co-glycolic acid (PLGA 65/35), and poly lactic-co-glycolic acid (PLGA 85/15). To tailor the release profile of drug for several days, blends of PLGA 65/35 and PLGA 85/15 were prepared with polycaprolactone (PCL) in different ratios. The results revealed that microspheres made with 1:3 (PLGA65/35:PCL) blend released 97% of the drug in 5 days as compared 97% in 30 days in with pure PLGA65/35 microspheres. Microspheres made with 1:1 (PLGA65/35:PCL) and 3:1 (PLGA65/35:PCL released 98% of the drug in 30 days. In microspheres made with 1:3 (PLGA85/15:PCL), almost the entire drug was released in a week whereas in batches made with pure PLGA85/15 and 3:1 (PLGA 85/15:PCL) more than 80% of the drug was released in 60 days as compared with 96% in 60 days in 1:1 (PLGA85/15:PCL). Higher encapsulation efficiency was obtained with microspheres made with pure PLGA 65/35. These formulations were characterized for particle size analysis by Malvern mastersizer that revealed particle size in range of 12-15 micron and 12-22 micron for microspheres made with polymer blends of PLGA 65/35:PCL and PLGA85/15:PCL, respectively. In pure PLGA65/35 and PLGA85/15, particle size was 28 micron and 8 micron, respectively. Surface topography was studied by scanning electron microscopy that revealed a spherical shape of microspheres. From our study it as concluded that with careful selection of different polymers and their combinations, we can tailor the release of ketorolac tromethamine for long periods.

In vivo bioavailability and therapeutic assessment of host-guest inclusion phenomena for the hydrophobic molecule etodolac: pharmacodynamic and pharmacokinetic evaluation

The aim of present investigation was 1) to evaluate the in vivo bioavailability of an Etodolac (ETD)-β-cyclodextrin (β-CD) inclusion complex system prepared by kneading and spray drying techniques in rats, 2) to study the pharmacodynamic parameters in various animal models for analyzing the therapeutic response and, 3) to evaluate the pharmacokinetic profile of the drug administered. Inclusion complexation with β-CD enhanced the solubility of the drug, improved bioavailability and reduced ulcerogenicity of ETD in rats. Pharmacodynamic studies were carried out in normal LACA mice and pharmacokinetic evaluation was done in male Wistar rats. Pharmacokinetic parameters evaluated for the inclusion complexes revealed good correlation. The minimum dose necessary to produce analgesic or anti-arthritic activity was also decreased, indicating that the host-guest strategy that uses β-CD and ETD was very effective and could be successfully employed in the preparation of pharmaceutical formulations of anti-arthritics and analgesics.

Stress degradation studies on duloxetine hydrochloride and development of an RP-HPLC method for its determination in capsule formulation

Duloxetine hydrochloride (HCl) is an antidepressant drug prescribed for major depressive disorders, pain related to diabetic peripheral neuropathy, and stress urinary incontinence. In the present study, degradation behavior of duloxetine HCl was studied by subjecting the drug to various International Conference on Harmonization-recommended stress conditions. Also, a stability-indicating high-performance liquid chromatography method was established for analysis of the drug in the presence of various degradation products. An acceptable separation of the drug and its degradation products was achieved on a C-8 column at 40 degrees C using a mobile phase comprised of phosphate buffer (pH 2.5)-methanol-tetrahydrofuran in the ratio of 50:40:10 at a flow rate of 1 mL/min. The detection wavelength was 232 nm. The method was validated for linearity, precision, accuracy, selectivity, specificity, and robustness. The method was found to be linear over a concentration range of 1-100 microg/mL (n = 6). The value of slope was found to be 85.735 mV/s ppm with correlation coefficient of 0.9994 and relative standard deviation (RSD) of 0.87%. RSD values ranged from 0.20% to 0.82% in the case of intra-day precision studies, whereas the values ranged from 0.63% to 1.57% in the case of inter-day precision. The drug was found to be stable on exposure of 30% H(2)O(2) for 48 h. It was found to be highly unstable in acidic conditions, as 41.35% degradation was observed in 0.01N HCl at 40 degrees C after 8 h. Degradation was also observed in alkaline and neutral conditions (2.83% and 42.75%, respectively) on refluxing the drug for 1 h. The drug was stable under photolytic and thermal stress on exposure in solid form but showed considerable degradation in solution form.

Development of Pulsatile Systems for Targeted Drug Delivery of Celecoxib for Prophylaxis of Colorectal Cancer

The aim of the present study was to formulate fast release enteric-coated tablets for drug delivery to the colon. Two different approaches were used for the preparation of these tablets. The first included making use of superdisintegrant (SD) in the tablet. The amount of super disintegrant (cross-linked PVP) in the tablet and the coat weight were varied to formulate a suitable time-controlled release system, that would provide colon-specific drug delivery. The second approach consisted of development of osmogen-based tablets for drug delivery into the tracts of the colon. Two different osmogens, sodium chloride and potassium chloride, were used. These also were coated at different coat levels. Celecoxib was used as a model drug. In vitro drug release studies showed that superdisintegrants were more effective in showing burst effect in the tablets and therefore showed a rapid drug release as compared with osmogens, which would show a sustained drug release all through the colon. Osmotic tablets were formulated making use of a high concentration of osmogen sodium chloride (OM-SC) and potassium chloride (OM-KC) were further enteric-coated. These also were found to be useful in providing a sustained delivery of nearly 80-90% of the drug into the colonic region. The coat weight required in these tablets for protection in the upper gastrointestinal conditions varied from 9.69% in OM-KC tablets to 4.65% in OM-SC tablets.

A simple and sensitive stability-indicating RP-HPLC assay method for the determination of aceclofenac

The aim of the present study is to develop a stability-indicating assay method for the determination of aceclofenac after being subjected to different International Conference on Harmonization prescribed stress conditions, such as hydrolysis, oxidation, heat, and photolysis. Aceclofenac (2-[2-[2-(2,6-dichlorophenyl)aminophenyl]acetyl]oxyacetic acid) is decomposed under hydrolytic stress (neutral, acidic, and alkaline) and also on exposure to light (in solution form). The compound is stable to oxidative stress, heat, and photolytic stress (in solid form). The major degradation product is diclofenac, which is confirmed through comparison with the standard. Separation of the drug from major and minor degradation products is achieved on a C-18 column using methanol-0.02% of ortho phosphoric acid in a ratio of 70:30. The method is linear over the concentration range of 17-100 microg/mL (r(2) = 0.9988). The detection wavelength is 275 nm. The method is validated for linearity, range, precision, accuracy, specificity, and selectivity.

Stress Studies on Acyclovir

Acyclovir is an antiviral drug of choice in the treatment of many types of herpes virus infections, including genital herpes simplex infections, herpetic conjunctivitis, herpes simplex encephalitis, etc. The present study describes the degradation behavior of acyclovir under different International Conference on Harmonization recommended stress conditions (hydrolysis, oxidation, photolysis, and thermal decomposition) in order to establish a validated stability-indicating high-performance liquid chromatography method. Acyclovir is found to degrade extensively in acidic conditions and oxidative stress. Mild degradation of the drug occurs in alkaline and neutral conditions. The drug is stable to dry heat. The drug is found to be sufficiently stable after light exposure in a solid state; however, photolytic degradation is observed when the drug is exposed as a solution in water. The major degradation product in acidic hydrolysis and photolysis is identified as guanine through comparison with the standard. Separation of drug and the degradation products under various conditions is successfully achieved on a C-18 column utilizing water-methanol in the ratio of 90:10. The flow rate is 1 mL/min, and the detection wavelength is 252 nm. The method is validated with respect to linearity, precision, accuracy, selectivity, specificity, and robustness. The mean values of slope and correlation coefficient are 39.307 and 0.9998 with relative standard deviation values less than 2%. The recovery of the drug is found to be in the range of 97.34% to 102.35%. From the previous study it is concluded that the stability-indicating method developed for acyclovir can be used for analysis of the drug in various stability samples.

Compression coated systems for colonic delivery of 5-fluorouracil

Compression coating is one of the approaches for delaying the release of drugs. The aim of this study was to develop colon-specific compression coated systems of 5-fluorouracil (5-FU) for the treatment of colorectal cancer using xanthan gum, boswellia gum and hydroxypropyl methylcellulose (HPMC) as the coating materials. Core tablets containing 50 mg of 5-FU were prepared by direct compression. The coating of the core tablets was done using different coat weights (230, 250, 275 and 300 mg) and different ratios (1:2, 2:1, 1:3, 1:7 and 3:4) of boswellia gum and xanthan gum and different ratios (1:1, 1:2, 2:1, and 2:3) of boswellia gum and HPMC. In-vitro release studies were carried out using simulated gastric and intestinal fluids, with and without rat caecal contents. Among the different ratios used for coating with boswellia:xanthan gum combination, ratio 1:3 gave the best release profile with the lowest coating weights of 230 mg (7.47 +/- 1.56% in initial 5 h). Further increase in the coat weights to 250, 275 and 300 mg led to drug release of 5.63 +/- 0.53%, 5.09 +/- 1.56% and 4.57 +/- 0.88%, respectively, in the initial 5 h and 96.90 +/- 0.66%, 85.05 +/- 1.01% and 80.22 +/- 0.35%, respectively, in 24 h. When coating was carried out using different ratios of the combination boswellia gum and HPMC, the ratio 2:3 gave the best results among the initial trial batches (7.80 +/- 0.57% in 5 h). Increasing the coat weights to 250, 275 and 300 mg led to drug release of 6.5 +/- 0.27%, 3.70 +/- 2.3% and 2.99 +/- 0.72%, respectively, in the initial 5 h and 96.90 +/- 0.66%, 85.05 +/- 1.01% and 80.22 +/- 0.35%, respectively, in 24 h. In-vitro studies were further carried out in the presence of 2% w/v rat caecal contents, which led to complete release of the drug from the tablets. Therefore, this study lays a basis for use of compression coating of 5-FU as a tool for delaying the release of the drug, which ensures better clinical management of the disease.

Biodegradable microspheres for parenteral delivery

Nowadays, emphasis is being laid to development of controlled release dosage forms. Interest in this technology has increased steadily over the past few years. Although oral administration of drugs is a widely accepted route of drug delivery, bioavailability of drug often varies as a result of gastrointestinal absorption, degradation by first-pass effect, and hostile environment of gastrointestinal tract. Transdermal administration for percutaneous absorption of drug is limited by the impermeable nature of the stratum corneum. Ocular and nasal delivery is also unfavorable because of degradation by enzymes present in eye tissues and nasal mucosa. Hence, the parenteral route is the most viable approach in such cases. Of the various ways of achieving long-term parenteral drug delivery, biodegradable microspheres are one of the better means of controlling the release of drug over a long time. Because of the lipidic nature of liposomes, problems such as limited physical stability and difficulty of freeze-drying are encountered. Similarly, for emulsions, stability on long-term basis and in suspensions, rheological changes during filling, injecting, and storage poses limitation. Also, in all these systems, the release rate cannot be tailored to the needs of the patient. Parenteral controlled-release formulations based on biodegradable microspheres can overcome these problems and can control the release of drug over a predetermined time span, usually in the order of days to weeks to months. Various FDA-approved controlled-release parenteral formulations based on these biodegradable microspheres are available on the market, including Lupron Depot Nutropin Depot and Zoladex. This review covers various molecules encapsulated in biodegradable microspheres for parenteral delivery.

Bioavailability of Immediate- and Extended-Release Formulations of Glipizide in Healthy Male Volunteers

BACKGROUND AND OBJECTIVE

An extended-release glipizide formulation using a hydrophilic matrix system containing hydrophilic polymers has been developed for use in diabetes mellitus. This study compared the pharmacokinetic parameters of immediate- and extended-release formulations of glipizide 5mg in healthy male volunteers.

METHODS

In a single-dose, four-period, four-treatment, Latin-square crossover study, the bioavailability of immediate-release glipizide 5mg (Glynase) [GL], extended-release glipizide 5mg (Glynase) XL [GLXL], Glucotrol XL [GTXL], and the new formulation developed in our laboratory [GLPF]) was compared. Plasma glipizide levels of the four formulations were determined at different time intervals, and pharmacokinetic parameters were analysed using a two-compartment body model.

RESULTS

The mean peak plasma concentration (C(max)) of the immediate-release formulation (523+/-60 ng/mL) was significantly higher (p<0.05) than those of the three extended-release formulations (403+/-24, 349+/-37 and 426+/-55 ng/mL for GLXL, GTXL and GLPF, respectively). Mean time to reach C(max) was 1.83+/-0.3 hours for GL, 4.41+/-1.2 hours for GLXL, 3.21+/-0.8 hours for GTXL and 3.24+/-0.4 hours for GLPF. The order of magnitude of area under the plasma concentration-time curve was GTXL (5591 ng . h/mL)>GLXL (4,771 ng . h/mL)>GLPF (4,537 ng . h/mL)>GL (1,897 ng . h/mL). The mean residence time was 3.14+/-0.59 hours for GL, 8.26+/-0.81 hours for GLXL, 9.70+/-2.70 hours for GTXL and 7.87+/-1.93 hours for GLPF. Extended-release glipizide formulations maintained effective plasma drug concentrations for approximately 24 hours. Plasma levels of glipizide fluctuated less with GTXL than with the other two extended-release formulations.

CONCLUSION

The newly developed formulation (GLPF) maintained effective levels of glipizide for a period of more than 20 hours, with quicker onset of action than the other two formulations. This formulation may be more economical than glipizide GITS.

Complexation of celecoxib with beta-cyclodextrin: characterization of the interaction in solution and in solid state

Inclusion complexation between celecoxib, a specific cyclooxygenase II inhibitor, and beta-cyclodextrin (beta-CD) was studied in solution and solid state. Drug cyclodextrin complexes were prepared by spray drying while physical mixtures were obtained by simple blending. Inclusion complexes were characterized by nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), X-ray diffractometry (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), and polarimetry. Phase solubility analysis was carried out to determine the stability constant. Solubility studies revealed the existence of a 1:1 complex between celecoxib and beta-CD. NMR studies suggested a strong interaction between celecoxib and beta-CD prepared by spray drying. XRD and SEM analysis illustrated that celecoxib existed as an amorphous complexed form in spray-dried complexes. Dissolution studies showed that the celecoxib entrapped in spray-dried complexes dissolved much faster than the uncomplexed drug and physical mixtures. The data obtained suggest that celecoxib forms an inclusion complex with beta-CD in solution and solid state, which was confirmed by various analytical techniques. A shorter t50% of dissolution is found for the formulation prepared by spray drying when compared on a weight basis in a USP II apparatus.