An approach for lacidipine loaded gastroretentive formulation prepared by different methods for gastroparesis in diabetic patients

The present work deals with various attempts to prepare a gastroretentive formulation of lacidipine for treating gastroparesis. High density sucrose beads were modified by coating with certain polymers, but unfortunately sustained release could not be achieved. Granules were prepared by wet granulation technology using different combinations of polymers and a release of the drug was observed. The method failed to release the drug as per desired specifications. Polymeric coating followed by wet granulation was thought to be a better process to sustain the dissolution rate. The release rate can be modified by the incorporation of different polymeric coatings, but the mucoadhesive potential of granules was only 4.23% which might be due to its large size and the presence of other ingredients. Further, the lacidipine loaded microparticles were prepared by different methods such as compression, ionic gelation with TPP, ionic gelation with TPP and glutaraldehyde, spray drying and coacervation techniques. The formulations were evaluated for average particle size, surface morphology, entrapment efficiency, % yield and mucoadhesive potential. The microparticles prepared by compression method using HPMC K4M and SCMC as mucoadhesive polymers and BaSO4 as high density diluent showed poor bioadhesion (8.3%) and poor release characteristics (100% in 120 min). Ionic gelation with tripolyphosphate yielded microspheres with poor mechanical strength. In order to improve its mechanical strength, TPP ionic gelation was combined with step-wise cross-linking with glutaraldehyde. The additional solidification step to improve mechanical strength left this procedure tedious, time consuming and cytotoxic. Spray drying method gave a very low yield with 46.67% bioadhesion. The method using CaCl2 for ionotropic gelation showed the best results with regard to physical characteristics (well formed discrete, spherical surface microcapsule), particle size (88.57 ± 0.51), in vitro bioadhesion (67.33%), yield (>85%) and loading (>70%).

Aerodynamics and deposition effects of inhaled submicron drug aerosol in airway diseases

Particle engineering is the prime focus to improve pulmonary drug targeting with the splendor of nanomedicines. In recent years, submicron particles have emerged as prettyful candidate for improved fludisation and deposition. For effective deposition, the particle size must be in the range of 0.5-5 μm. Inhalers design for the purpose of efficient delivery of powders to lungs is again a crucial task for pulmonary scientists. A huge number of DPI devices exist in the market, a significant number are awaiting FDA approval, some are under development and a large number have been patented or applied for patent. Even with superior design, the delivery competence is still deprived, mostly due to fluidisation problems which cause poor aerosol generation and deposition. Because of the cohesive nature and poor flow characteristics, they are difficult to redisperse upon aerosolization with breath. These problems are illustrious in aerosol research, much of which is vastly pertinent to pulmonary therapeutics. A technical review is presented here of advances that have been utilized in production of submicron drug particles, their in vitro/in vivo evaluations, aerosol effects and pulmonary fate of inhaled submicron powders.

Application of a liquid chromatography-electrospray mass spectrometry (LC/MS) method to the biodistribution and excretion studies of novel 5'-chloro-2, 3-didehydroindolo (2', 3': 2, 3) betulinic acid (DRF-4012) in tumour-bearing mice

Novel betulinic acid derivative 5'-chloro-2, 3-didehydroindolo [2', 3': 2, 3] betulinic acid (DRF-4012) is a new effective lupane type triterpenes with greater anticancer activity and efficacy than betulinic acid and currently under advanced preclinical investigation phase. In this study, a sensitive and rapid liquid chromatography-electrospray mass spectrometric (LC/MS) method has been developed for the determination of DRF-4012 in tumour-bearing mice plasma, urine, feces and tissues (liver, brain, lungs, heart, spleen, stomach, thigh muscle, kidneys, urinary bladder, small intestine and tumour). Biodistribution and excretion studies were performed for DRF-4012 nanoparticle (30 mg/kg body weight) after intravenous (i.v.) injection in tumour-bearing mice. DRF-4012 rapidly distributed throughout the body. After 0.5 h, tumour showed the second highest concentration, which was nearly half of the liver. After 4 and 24 h, the highest concentration of DRF-4012 was found in tumour indicating its retention in tumour site for a longer time. Excretion studies revealed that very low amount of unchanged DRF-4012 was observed in urine and primarily excreted through fecal route. This study may be useful to explain the manner in which DRF-4012 can inhibit tumour growth without apparent toxicity and preclinical/clinical evaluation of this potential antitumour agent.

Role of CD44 in tumour progression and strategies for targeting

CD44 or hyaluronan receptor is a transmembrane receptor associated with aggressive tumour growth, proliferation, and metastasis. In normal physiology, this receptor has a crucial role in cell adhesion, inflammation, and repair processes. However, many tumour cells over-express this receptor and abuse it to become progressive and perpetual units. The article comments from common functioning of the CD44 receptor, to its diabolic multi-dimensional effects in promotion of malignant cells. It also illuminates the relations of CD44 endorsed processes with other biomolecular events in cancer progression. In an end, the review focuses comprehensively at ongoing researches to exploit the CD44 over-expression as a probable target in treatment, management, and diagnosis of malignancy.

Development and evaluation of thymoquinone-encapsulated chitosan nanoparticles for nose-to-brain targeting: a pharmacoscintigraphic study

Chitosan (CS) nanoparticles of thymoquinone (TQ) were prepared by the ionic gelation method and are characterized on the basis of surface morphology, in vitro or ex vivo release, dynamic light scattering, and X-ray diffractometry (XRD) studies. Dynamic laser light scattering and transmission electron microscopy confirmed the particle diameter was between 150 to 200 nm. The results showed that the particle size of the formulation was significantly affected by the drug:CS ratio, whereas it was least significantly affected by the tripolyphosphate:CS ratio. The entrapment efficiency and loading capacity of TQ was found to be 63.3% ± 3.5% and 31.23% ± 3.14%, respectively. The drug-entrapment efficiency and drug-loading capacity of the nanoparticles appears to be inversely proportional to the drug:CS ratio. An XRD study proves that TQ dispersed in the nanoparticles changes its form from crystalline to amorphous. This was further confirmed by differential scanning calorimetry thermography. The flat thermogram of the nanoparticle data indicated that TQ formed a molecular dispersion within the nanoparticles. Optimized nanoparticles were evaluated further with the help of scintigraphy imaging, which ascertains the uptake of drug into the brain. Based on maximum concentration, time-to-maximum concentration, area-under-curve over 24 hours, and elimination rate constant, intranasal TQ-loaded nanoparticles (TQ-NP1) proved more effective in brain targeting compared to intravenous and intranasal TQ solution. The high drug-targeting potential and efficiency demonstrates the significant role of the mucoadhesive properties of TQ-NP1.

Validated HPLC method for the simultaneous determination of taxol and ellagic acid in a Punica granatum fruit extract containing combination formulation

A simple, rapid, precise and accurate isocratic reversed-phase high performance liquid chromatography (HPLC) method was developed and validated for the simultaneous determination of paclitaxel and ellagic acid in a combination nanoformulation. Separation was achieved using a 25 x 4.6 mm column, particle size 5 microm C18 reverse phase column (Luna), with a mobile phase consisting of methanol and 0.05% H3PO4, in gradient elution mode with a mobile phase flow rate of 1 mL/min, using UV visible detection at 230 nm. Sharp and well defined peaks were obtained at retention times of 13.75 min. and 11.6 min. for paclitaxel and ellagic acid, respectively. Regression analysis showed a good linear relationship (r2 = 0.996 +/- 0.0011) and (r2 = 0.993 +/- 0.0011) over wide ranges of 5-500 microg/ml and 1-500 microg/ml for paclitaxel and ellagic acid, respectively. LOD and LOQ of paclitaxel were 30 ng/ml and 100 ng/ml, respectively, while for ellagic acid LOD and LOQ were 300 ng/ml and 1 microg/ml, respectively. The accuracy of the method was determined by recovery studies using the standard addition method and was found to be in the range of 99.61-101.21% and 98.70-102.22% for paclitaxel and ellagic acid, respectively. The relative standard deviation (% RSD) for precision, repeatability and robustness was less than 2%. The ellagic acid content in fruits of Punica granatum and combination formulation with paclitaxel was analyzed and found to be 0.04% w/w and 0.0012%w/w, respectively. The proposed, developed and validated HPLC method for the simultaneous quantification of ellagic acid and paclitaxel can be used for the quality control and standardization of several crude drugs and different combination formulations, in which ellagic acid is present.

Contemporary overview on clinical trials and future prospects of hepato-protective herbal medicines

Till date the synthetic hepato-protective agents used in clinical practices are therapeutically non-promising and may itself lead to hepatotoxicity. Herbal medicines and their bioactives are considered to be relatively safe and have been used in the treatment of liver diseases for a long time. The 21st century has seen a paradigm shift towards therapeutic standardization of herbal drugs in hepatic disorders by evidence-based randomized controlled clinical trials to support their clinical efficacy. Even so, the specific hepato-protective clinical trial protocols for herbal medicines are not established till now. So, the efficacy of herbal medicines needs to be evaluated through rigorously designed multicentre clinical studies. In this review, we have enlightened the clinically evaluated hepatoprotective herbals and herbal formulations with respect to their status in different trial stages. Moreover, the problems and their strategic solutions during the development of clinical trial protocol for hepatoprotective herbal medicine are also addressed.

Efficacy of Mycobacterium indicus pranii immunotherapy as an adjunct to chemotherapy for tuberculosis and underlying immune responses in the lung

BACKGROUND

The 9-month-long chemotherapy of tuberculosis often results in poor compliance and emergence of drug-resistant strains. So, improved therapeutic strategy is urgently needed. Immunotherapy could be beneficial for the effective management of the disease. Previously we showed the protective efficacy of Mycobacterium indicus pranii (MIP) when given as prophylactic vaccine in animal models of tuberculosis.

METHODS

We sought to investigate whether MIP can be used as an adjunct to the chemotherapy in guinea pig models of tuberculosis. Efficacy of MIP was evaluated when given subcutaneously or by aerosol.

RESULTS

MIP-therapy as an adjunct to the chemotherapy was found to be effective in accelerating bacterial killing and improving organ pathology. MIP-immunotherapy resulted in higher numbers of activated antigen-presenting cells and lymphocytes in the infected lungs and also modulated the granulomatous response. Early increase in protective Th1 immune response was observed in the immunotherapy group. Following subsequent doses of MIP, decrease in the inflammatory response and increase in the immunosuppressive response was observed, which resulted in the improvement of lung pathology.

CONCLUSION

MIP immunotherapy is a valuable adjunct to chemotherapy for tuberculosis. Aerosol route of immunotherapy can play a crucial role for inducing immediate local immune response in the lung.

Development and validation of a stability-indicating method for determination of free sterols in the Asian medicinal leech Hirudo manillensis

A rapid, simple, sensitive, selective, precise and robust thin-layer chromatography densitometric method for the determination of free sterols in leech was developed and validated on silica gel layer using carbon tetrachloride-methanol-formic acid (9.5:1.5:0.55, v/v/v). Spectrodensitometric scanning was carried using a Camag TLC scanner III at 366 nm after spraying 2% methanolic sulphuric acid, which gave compact spots for cholesterol (R(F) = 0.35 ± 0.02). The regression analysis data for calibration plot implied a good linear relationship (r(2) = 0.99958) between response and concentration over the range 100-600 ng per spot with respect to peak area. The limits of detection and quantification were found to be 13.8 ± 0.51 and 45.01 ± 1.29 ng per spot, respectively. Validation was in accordance to the International Conference on Harmonization guidelines. Cholesterol was subjected to forced stress conditions of oxidation, hydrolysis and heat. Degradation products resulting from the forced stress did not interfere with detection because the degradant peaks were well separated from the cholesterol peak. The densitometric method can be regarded as stability-indicating and can be used for quality control assay of cholesterol in leech extract.

Stabilized terbutaline submicron drug aerosol for deep lungs deposition: drug assay, pulmonokinetics and biodistribution by UHPLC/ESI-q-TOF-MS method

Terbutaline submicron particles (SμTBS) were prepared by nanoprecipitation technique followed by spray drying for deep lungs deposition. Inhalable SμTBS particles were 645.16 nm of diameter with 0.11μm of MMAD, suggested for better aerosol effects. Both submicron and micron-sized TBS particles were administered in rodents administered via major delivery routes, and their biological effects were compared by using UHPLC/ESI-q-TOF-MS method. TBS was found stable in all exposed conditions with 96.28-99.0% of recovery and <4.34% of accuracy (CV). An inhalation device was designed and validated to deliver medicines to lungs, which was found best at dose level of 25mg for 30 min of fluidization. Both submicron and micron particles were compared for in vivo lung deposition and a 1.67 fold increase in concentration was observed for SμTBS exposed by inhalation. Optimized DPI formulation contained lesser fraction of ultrafine particle (<500 nm) with the major fraction of submicron particles (>500 nm), advocated for better targeting to lungs. UHPLC/ESI-q-TOF-MS confirmed that designed submicron particles has been successfully delivered to the lungs. From tongue to lungs, the landing of pulmonary medicines can be improved by submicronization technology.

Simultaneous HPTLC determination of strychnine and brucine in strychnos nux-vomica seed

OBJECTIVE

A simple, sensitive, and specific thin layer chromatography (TLC) densitometry method has been developed for the simultaneous quantification of strychnine and brucine in the seeds of Strychnos nux-vomica.

MATERIALS AND METHODS

The method involved simultaneous estimation of strychnine and brucine after resolving it by high performance TLC (HPTLC) on silica gel plate with chloroform-methanol-formic acid (8.5:1.5:0.4 v/v/v) as the mobile phase.

RESULTS

The method was validated as per the ICH guidelines for precision (interday, intraday, intersystem), robustness, accuracy, limit of detection, and limit of quantitation. The relationship between the concentration of standard solutions and the peak response was linear within the concentration range of 50-1000 ng/spot for strychnine and 100-1000 ng/spot for brucine. The method precision was found to be 0.58-2.47 (% relative standard deviation [RSD]) and 0.36-2.22 (% RSD) for strychnine and brucine, respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.75% for strychnine and 100.52% for brucine, respectively.

CONCLUSIONS

The HPTLC method for the simultaneous quantification of strychnine and brucine was found to be simple, precise, specific, sensitive, and accurate and can be used for routine analysis and quality control of raw material of S. nux-vomica and several unani and ayurvedic formulations containing this as an ingredient.

Formulation of PEG-ylated L-asparaginase loaded poly (lactide-co-glycolide) nanoparticles: influence of Pegylation on enzyme loading, activity and in vitro release

The present paper describes the advantage of PEG-ylation of L-asparaginase before encapsulation over its incorporation in the native form. During encapsulation a considerable amount of native protein undergoes denaturation and forms insoluble aggregates. In an effort to overcome this problem, L-asparaginase was PEG-ylated before subjecting it to the harsh conditions as encountered during double emulsion solvent evaporation technique. L-asparaginase was conjugated with succinimidyl succinate derivative of polyethylene glycol (SS-PEG, MW 5000) followed by characterization of the formed conjugate using size exclusion-HPLC and SDS PAGE. The PEG-ylated L-asparaginase consisted of different isomers from mono to multi PEG-ylated depending upon the number of Lysine residues (14 in case of L-asparaginase) with about 5% as native protein. The specific activity as retained after PEG-ylation was 62.84 +/- 8.2% and further about 82.7% of activity was recovered from the particles. Imitated studies with the native protein confirmed the enhanced stability of the conjugated protein when exposed to the organic solvent and sonication and showed comparatively less encapsulation efficiency due to increased hydrophilicity. Release profiles for native as well as conjugated proteins consisted of sustained release of about 66.66% and 44.45% in 28 days, respectively. The decrease in the release can be attributed to the increase in the molecular weight of the conjugated protein. The study finally proved that PEG-ylation protected the enzyme and prevented it from denaturation during encapsulation.

Aqueous synthesis and concentration-dependent dermal toxicity of TiO2 nanoparticles in Wistar rats

A number of dermal toxicological studies using TiO(2) nanoparticles exist which are based on the study of various animal models like mice, rabbits etc. However, a well-defined study is lacking on the dermal toxic effects of TiO(2) nanoparticles on rats, which are the appropriate model for systemic absorption study of nanoparticles. Furthermore, toxicity of TiO(2) nanoparticles varies widely depending upon the size, concentration, crystallinity, synthesis method etc. This study was conducted to synthesize TiO(2) nanoparticles of different sizes (∼15 to ∼30 nm) by aqueous method, thereby evaluating the concentration-dependent toxicological effects of the ∼20-nm sized nanoparticles on Wistar rats. Characterization of the particles was done by transmission electron microscope, dynamic light scattering instrument, X-ray diffractrometer, and ultraviolet spectrophotometer. The toxicity study was conducted for 14 days (acute), and it is observed that TiO(2) nanoparticles (∼20 nm) at a concentration of 42 mg/kg, when applied topically showed toxicity on rat skin at the biochemical level. However, the histopathological studies did not show any observable effects at tissue level. Our data suggest that well-crystallized spherical-shaped ∼20 nm anatase TiO(2) nanoparticles synthesized in aqueous medium can induce concentration-dependent biochemical alteration in rat skin during short-term exposure.

Nano-vectors for the Ocular Delivery of Nucleic Acid-based Therapeutics

Nucleic acid-based therapeutics have gained a lot of interest for the treatment of diverse ophthalmic pathologies. The first to enter in clinic has been an oligonucleotide, Vitravene^® for the treatment of cytomegalovirus infection. More recently, research on aptamers for the treatment of age related macular degeneration has led to the development of Macugen^®. Despite intense potential, effective ocular delivery of nucleic acids is a major challenge since therapeutic targets for nucleic acid-based drugs are mainly located in the posterior eye segment, requiring repeated invasive administration. Of late, nanotechnology-based nano-vectors have been developed in order to overcome the drawbacks of viral and other non-viral vectors. The diversity of nano-vectors allows for ease of use, flexibility in application, low-cost of production, higher transfection efficiency and enhanced genomic safety. Using nano-vector strategies, nucleic acids can be delivered either encapsulated or complexed with cationic lipids, polymers or peptides forming sustained release systems, which can be tailored according to the ocular tissue being targeted. The present review focuses on developments and advances in various nano-vectors for the ocular delivery of nucleic acid-based therapeutics, the barriers that such delivery systems face and methods to overcome them.

Design and in vitro characterization of buccoadhesive drug delivery system of insulin

A buccoadhesive drug delivery system of Insulin was prepared by solvent casting technique and characterized in vitro by surface pH, bioadhesive strength, drug release and skin permeation studies. Sodium carboxymethylcellulose-DVP was chosen as the controlled release matrix polymer. The optimized formulation J₄ contained Sodium carboxy methyl cellulose-DVP 2% (w/v), insulin (50 IU/film), propylene glycol (0.25 ml) and Isopropyl alcohol: water (1:4) as solvent system. Bioadhesive strength of the prepared patches was measured on a modified physical balance using bovine cheek pouch as the model membrane. In vitro release studies were carried out at 37 ± 2° using phosphate buffer pH 6.6, in a modified dissolution apparatus fabricated for the purpose. Cumulative amount of drug released from the optimized formulation J₄ was 91.64% in 6 hours. In vitro permeation studies were carried out on J₄ at 37 ± 2° using Franz diffusion cell. Cumulative amount of drug permeated from J₄ was 6.63% in 6 hours. In order to enhance the permeation of protein drug, different permeation enhancers were evaluated. The results suggested that sodium deoxycholate 5% (w/v) was the best permeation enhancer among those evaluated. It enhanced the permeation of insulin from 6.63% to 10.38% over a period of 6 hours. The optimized patches were also satisfactory in terms of surface pH and bioadhesive strength. It can also be easily concluded that the system is a success as compared to the conventional formulations with respect to invasiveness, requirement of trained persons for administration and most importantly, the first pass metabolism.

Antiepileptic intranasal Amiloride loaded mucoadhesive nanoemulsion: development and safety assessment

Current investigation aimed to develop a novel Amiloride loaded mucoadhesive nanoemulsion formulation for nose-to-brain delivery. Furthermore, nasal irritation study and histopathological examination of the nasal mucosa were also carried out to assess nonirritant nature of the nanoemulsion. The optimized formulation, surface epithelium lining and the granular cellular structure of the nasal mucosa were totally intact, whereas KCl caused major changes in the ultrastructure of mucosa. Amiloride loaded mucoadhesive nanoemulsion formulations are non toxic on nasal mucosa and can be administered by intranasal route for effective treatment of epilepsy.

Assessment of ocular pharmacokinetics and safety of Ganciclovir loaded nanoformulations

Ganciclovir (GCV) plays an important role in the treatment of ocular viral infections. A high dose results in dose-related toxicity including bone marrow suppression and neutropenia. The aim of the present study was to investigate the comparative potential of different mucoadhesive nano formulations for the topical ocular delivery of Ganciclovir. GCV mucoadhesive Nanoemulsions (GCV-NEs), chitosan nanoparticles (GCV-NPs), GCV mucoadhesive niosomal dispersion (GCV-NDs) were prepared by the reverse-phase evaporation technique. All of the three formulations were evenly round in shape with mean particle size in the range of 23-200 nm. These results indicated the nonirritant and nontoxic nature of the developed formulations. The achieved results may be useful for formulation development of GCV, which could be effective in the treatment of ocular infections by topical instillation.

A validated HPTLC method for determination of terbutaline sulfate in biological samples: Application to pharmacokinetic study

Terbutaline sulfate (TBS) was assayed in biological samples by validated HPTLC method. Densitometric analysis of TBS was carried out at 366 nm on precoated TLC aluminum plates with silica gel 60F254 as a stationary phase and chloroform-methanol (9.0:1.0, v/v) as a mobile phase. TBS was well resolved at RF 0.34 ± 0.02. In all matrices, the calibration curve appeared linear (r (2) ⩾ 0.9943) in the tested range of 100-1000 ng spot(-1) with a limit of quantification of 18.35 ng spot(-1). Drug recovery from biological fluids averaged ⩾95.92%. In both matrices, rapid degradation of drug favored and the T 0.5 of drug ranged from 9.92 to 12.41 h at 4 °C and from 6.31 to 9.13 h at 20 °C. Frozen at -20 °C, this drug was stable for at least 2 months (without losses >10%). The maximum plasma concentration (Cpmax) was found to be 5875.03 ± 114 ng mL(-1), which is significantly higher than the maximum saliva concentration (Csmax, 1501.69 ± 96 ng mL(-1)). Therefore, the validated method could be used to carry out pharmacokinetic studies of the TBS from novel drug delivery systems.

Microscopic and spectroscopic evaluation of novel PLGA-chitosan Nanoplexes as an ocular delivery system

The interaction of PLGA-chitosan Nanoplexes with ocular mucosa was investigated ex vivo and in vivo to assess their potential as ocular delivery system. Fluorescent Rhodamine Nanoplexes (Rd-Nanoplexes) were prepared by ionotropic gelation method. The size and morphology of Nanoplexes was investigated by TEM, SEM and PCS. The corneal retention, uptake and penetration of Nanoplexes were analyzed by spectrofluorimetry and confocal microscopy. Corneas from Rd-Nanoplexes-treated rabbits were evaluated for the in vivo uptake and ocular tolerance. The Nanoplexes prepared were round with a mean diameter of 115.6±17nm and the encapsulation efficiency of Rd was 59.4±2.5%. Data from ex vivo and in vivo studies showed that the amounts of Rd in the cornea were significantly higher for Nanoplexes than for a control Rd solution, these amounts being fairly constant for up to 24h. Confocal microscopy of the corneas revealed paracellular and transcellular uptake of the Nanoplexes. The uptake mechanism postulated was adsorptive-mediated endocytosis and opening of the tight junctions between epithelial cells. No alteration was microscopically observed after ocular surface exposure to Nanoplexes. Taken together, these data demonstrate that Nanoplexes are potentially useful as ocular drug carriers.

Quantitative analysis of safranal in saffron extract and nanoparticle formulation by a validated high-performance thin-layer chromatographic method

INTRODUCTION

Safranal is an effective anticonvulsant shown to act as an agonist at GABA(A) receptors. Nose to brain delivery via nanoparticle formulation might improve its brain delivery. A selective and sensitive analytical method is required for evaluation of safranal-based novel drug delivery systems.

OBJECTIVE

To develop and validate a high-performance thin-layer chromatographic (HPTLC) method for the quantitative analysis of safranal as bulk, in saffron extract and in developed safranal-loaded nanoparticle formulation.

METHODOLOGY

Chromatographic separation was achieved on silica gel pre-coated TLC aluminium plates 60F-254, using n-hexane:ethyl acetate (9 : 1, v/v) as the mobile phase. Quantitative analysis was carried out by densitometry at a wavelength of 310 nm. The method was validated and applied to detect related impurities, to analyse safranal in saffron extract and to evaluate safranal-loaded nanoparticles.

RESULTS

Compact spots of safranal were observed at R(f) value 0.51 +/- 0.02. The method was linear (r = 0.9991) between 0.5 and 5.0 ng/spot. The intra- and inter-day precisions were 1.08-2.17 and 1. 86-3.47%, respectively. The limit of detection was 50 ng/spot and the limit of quantification was 150 ng/spot. The method proved to be accurate (recovery 97.4-102.0%) and was selective for safranal. Evaluation of safranal-loaded nanoparticle formulation demonstrated drug loading of 23.0%, encapsulation efficiency of 42.0% and sustained drug release following biphasic pattern.

CONCLUSION

The present method is useful for the quantitative and qualitative analysis of safranal and safranal-loaded nanoparticle formulation. It provides significant advantages in terms of greater specificity and rapid analysis.

Advances and potential applications of chitosan derivatives as mucoadhesive biomaterials in modern drug delivery

Pharmaceutical technologists have been working extensively on various mucoadhesive polymeric systems to create an intimate and prolonged contact at the site of administration. Chitosan is one of the most promising polymers because of its non-toxic, polycationic biocompatible, biodegradable nature, and particularly due to its mucoadhesive and permeation enhancing properties. Due to its potential importance in controlled drug delivery applications, pharmaceutical scientists have exploited this mucoadhesive polymer. However, chitosan suffers from limited solubility at physiological pH and causes presystemic metabolism of drugs in intestinal and gastric fluids in the presence of proteolytic enzymes. These inherent drawbacks of chitosan have been overcome by forming derivatives such as carboxylated, various conjugates, thiolated, and acylated chitosan, thus providing a platform for sustained release formulations at a controlled rate, prolonged residence time, improved patient compliance by reducing dosing frequency, enhanced bioavailability and a significant improvement in therapeutic efficacy. We have explored the potential benefits of these improved chitosan derivatives in modern drug delivery.

Potential prospects of chitosan derivative trimethyl chitosan chloride (TMC) as a polymeric absorption enhancer: synthesis, characterization and applications

In recent years, researchers have been working extensively on various novel properties of polymers to develop increased efficiency of drug delivery and improve bioavailability of various drug molecules, especially macromolecules. Chitosan, a naturally occurring polysaccharide, because of its protonated/polymeric nature, provides effective and safe absorption of peptide and protein drugs. Its transmucosal absorption is, however, limited to acidic media because of its strong intermolecular hydrogen bonds. A new partially quaternized chitosan derivative, N-trimethyl chitosan chloride (TMC), has been synthesized with improved solubility, safety and effectiveness as an absorption enhancer at neutral pH and in aqueous environment. It enhances the absorption, especially of peptide drugs, by reversible opening of tight junctions in between epithelial cells, thereby facilitating the paracellular diffusion of peptide drugs. This derivative thus opens new perspectives as a biomaterial for various pharmaceutical applications/drug delivery systems. This review deals with the potential use of the quaternized chitosan derivative as a permeation enhancer for the mucosal delivery of macromolecular drugs along with its other biomedical applications.

Techniques to develop and characterize nanosized formulation for salbutamol sulfate

The present study relates to enhancing the dosing efficiency of pharmaceutical dry powder formulations administered by pulmonary inhalation. In particular, the study relates to the provision of dry powder inhalers (DPI) by forming nanosized particles of salbutamol sulfate (SBM) in order to augment the drug penetrability and deposition in the lungs. SBM, an antiasthmatic was selected to be developed into a nanosized formulation by different techniques like solvation, high-pressure homogenization, and spray drying, which were then compared on the basis of particle shape, particle size, and particle size distribution. In case of solvation method the nanosuspension was prepared by dispersing SBM into a nonsolvent and adding Tween-80 as a surfactant to prevent the agglomeration, the particles obtained therein were in the range of 2-10 mu. The second attempt was made by passing the suspension of SBM through high-pressure homogenizer at 10,000-15,000 psi. A treatment of six cycles of homogenization in presence of a Tween-80 as surfactant was found to give a nanosuspension within a size range 50-100 nm. The only drawback seemed with this technique was the low-product yield and high-processing time (3-4 h). In order to overcome this drawback spray-drying technique was further explored; the solution of SBM containing Tween-80 was stirred on magnetic stirrer at 1,200 rpm and finally dried by using spray dryer at an inlet and outlet temperature of 75 degrees C and 56 degrees C, respectively. The feed rate for spray dryer was kept to be 91 ml/h. The sample was collected and analyzed for particle size distribution which was found to be in the range of 50-100 nm. Keeping in view the positive outcomes in terms of higher yield and lower processing time, the spray-drying technique was taken to give the optimized formulation. Nanosized particles, thus obtained were evaluated for particle size, surface topology and particles size distribution, by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Quasi-elastic light scattering (QELS) technique, respectively. The nanosized particles were subjected to investigate changes on the physical stability of the powder, for this different analytical method was used as: Fourier transform infrared spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and X-ray diffraction (XRD) analysis and thus the result indicates that there was no physical disparity when compared with the commercial SBM sample.

Exploration of skin permeation mechanism of frusemide with proniosomes

The present study explored the transdermal permeation enhancing mechanism of non-ionic surfactant vesicles (proniosomes) of frusemide across rat skin. Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), activation energy and histological examination were carried out to study the mode of action of the optimized proniosome formulations PGS [Span 40:soyalecithin:cholesterol (4.5:4.5:1)] and PGD [Span 40:dicetylphosphate:cholesterol (4.5:4.5:1)]. The IR spectra showed a prominent decrease in peak areas and heights of CH2 stretchings but did not show shift of these peaks and shift in amide bands. DSC studies also confirmed the IR findings. It was concluded that the proniosomes disrupted the lipid bilayer by extracting the lipids thereby creating pathways for drug penetration. The significant decrease in activation energy for frusemide permeation across rat skin indicated the SC lipid bilayers were significantly disrupted (p<0.05). Histological investigations were carried out. Disruption and extraction of lipid bilayers as distinct voids and empty spaces were visible in the epidermal region. Overall, our findings suggested that proniosomal formulations offer a promising means for non-invasive delivery of frusemide, especially due to their ability to modulate drug transfer and serve as non-toxic permeation enhancers.

Nanocarrier for the transdermal delivery of an antiparkinsonian drug

The purpose of the present study was to investigate the potential of nanoemulsions as nanodrug carrier systems for the percutaneous delivery of ropinirole. Nanoemulsions comprised Capryol 90 as the oil phase, Tween 20 as the surfactant, Carbitol as the cosurfactant, and water as an external phase. The effects of composition of nanoemulsion, including the ratio of surfactant and cosurfactant (Smix) and their concentration on skin permeation, were evaluated. All the prepared nanoemulsions showed a significant increase in permeation parameters such as steady state flux (Jss) and permeability coefficient (Kp) when compared to the control (p<0.01). Nanoemulsion composition (NEL3) comprising ropinirole (0.5% w/w), Capryol 90 (5% w/w), Smix 2:1 (35% w/w), and water (59.5% w/w) showed the highest flux (51.81+/-5.03 microg/cm2/h) and was selected for formulation into nanoemulsion gel. The gel was further optimized with respect to oil concentration (Capryol 90), polymer concentration (Carbopol), and drug content by employing the Box-Behnken design, which statistically evaluated the effects of these components on ropinirole permeation. Oil and polymer concentrations were found to have a negative influence on permeation, while the drug content had a positive effect. Nanoemulsion gel showed a 7.5-fold increase in skin permeation rate when compared to the conventional hydrogel. In conclusion, the results of the present investigation suggested a promising role of nanoemulsions in enhancing the transdermal permeation of ropinirole.

Dental therapeutic systems

The recognition of periodontal diseases as amenable to local antibiotherapy has resulted in a paradigmatic shift in treatment modalities of dental afflictions. Moreover the presence of antimicrobial resistance, surfacing of untoward reactions owing to systemic consumption of antibiotics has further advocated the use of local delivery of physiologically active substances into the periodontal pocket. While antimicrobials polymerized into acrylic strips, incorporated into biodegradable collagen and hollow permeable cellulose acetate fibers, multiparticulate systems, bio-absorbable dental materials, biodegradable gels/ointments, injectables, mucoadhesive microcapsules and nanospheres will be more amenable for direct placement into the periodontal pockets the lozenges, buccoadhesive tablets, discs or gels could be effectively used to mitigate the overall gingival inflammation. Whilst effecting controlled local delivery of a few milligram of an antibacterial agent within the gingival crevicular fluid for a longer period of time, maintaining therapeutic concentrations such delivery devices will circumvent all adverse effects to non- oral sites. Since the pioneering efforts of Goodson and Lindhe in 1989, delivery at gingival and subgingival sites has witnessed a considerable progress. The interest in locally active systems is evident from the patents being filed and granted. The present article shall dwell in reviewing the recent approaches being proffered in the field. Patents as by Shefer, et al. US patent, 6589562 dealing with multicomponent biodegradable bioadhesive controlled release system for oral care products, Lee, et al. 2001, US patent 6193994, encompassing a locally administrable, biodegradable and sustained-release pharmaceutical composition for periodontitis and process for preparation thereof and method of treating periodontal disease as suggested by Basara in 2004via US patent 6830757, shall be the types of intellectual property reviewed and presented in the current manuscript.

Emerging role of microemulsions in cosmetics

Microemulsions represent a promising carrier system for cosmetic active ingredients due to their numerous advantages over the existing conventional formulations. They are capable of solubilizing both hydrophilic and lipophilic ingredients with relatively higher encapsulation. There is growing recognition of their potential benefits in the field of cosmetic science in addition to the drug delivery. They are now being widely investigated for preparing personal care products with superior features such as having improved product efficiency, stability or appearance. They are well suited for the preparation of various cosmetic products for use as moisturizing and soothing agents, as sunscreens, as antiperspirants and as body cleansing agents. They are also valuable for use in hair care compositions which ensure a good conditioning of the hair as well as good hair feel and hair gloss. They have also found application in after shave formulations which upon application to the skin provide reduced stinging and irritation and a comforting effect without tackiness. These newer formulations elicit very good cosmetic attributes and high hydration properties with rapid cutaneous penetration which may accentuate their role in topical products. These smart systems are also suitable for perfuming purposes where minimum amount of organic solvents is required, such as for perfuming skin or hair. This article highlights the recent innovations in the field of microemulsion technology as claimed by different patents which can bring unique products with great commercial prospects in a very competitive and lucrative global cosmetic market.

Microemulsions: a novel approach to enhanced drug delivery

Microemulsions are isotropic, thermodynamically stable transparent (or translucent) systems of oil, water and surfactant, frequently in combination with a cosurfactant with a droplet size usually in the range of 20-200 nm. They can be classified as oil-in-water (o/w), water-in-oil (w/o) or bicontinuous systems depending on their structure and are characterized by ultra low interfacial tension between oil and water phases. These versatile systems are currently of great technological and scientific interest to the researchers because of their potential to incorporate a wide range of drug molecules (hydrophilic and hydrophobic) due to the presence of both lipophilic and hydrophilic domains. These adaptable delivery systems provide protection against oxidation, enzymatic hydrolysis and improve the solubilization of lipophilic drugs and hence enhance their bioavailability. In addition to oral and intravenous delivery, they are amenable for sustained and targeted delivery through ophthalmic, dental, pulmonary, vaginal and topical routes. Microemulsions are experiencing a very active development as reflected by the numerous publications and patents being granted on these systems. They have been used to improve the oral bioavailability of various poorly soluble drugs including cyclosporine and paclitaxel as professed by Hauer et al., US patent 7235248, and Gao et al., US patent 7115565, respectively. Furthermore, they can be employed for challenging tasks such as carrying chemotherapeutic agents to neoplastic cells and oral delivery of insulin as diligently described by Maranhao, US patent 5578583 and Burnside et al., US patent 5824638 respectively. The recent commercial success of Sandimmune Neoral (Cyclosporine A), Fortovase (Saquinavir), Norvir (Ritonavir), etc. also reflects the tremendous potential of these newer drug therapeutic systems. A critical evaluation of recent patents claiming different approaches to improve the drug delivery is the focus of the current review.