Nanocrystals as an emerging nanocarrier for the management of dermatological diseases

Skin conditions are amongst the most prevalent health issues in the world and come with a heavy economic, social, and psychological burden. Incurable and chronic skin conditions like eczema, psoriasis, fungal infections are linked to major morbidity in the manner of physical pain and a reduction in quality life of patients. Several drugs have difficulties for penetrating the skin due to the barrier mechanism of the skin layers and the incompatible physicochemical characteristics of the drugs. This has led to the introduction of innovative drug delivery methods. Currently, formulations depend on nanocrystals have indeed been researched for topical administration of drugs and have resulted in enhanced skin penetration. This review focuses on skin penetration barriers, modern methods to enhance topical distribution, and the use of nanocrystals to overcome these barriers. By means of mechanisms such as adherence to skin, creation of diffusional corona, targeting of hair follicles, and the generation of a greater concentration gradient throughout the skin, nanocrystals could enhance transport across the skin. Scientists working on product formulations incorporating chemicals that are "challenging-to-deliver" topically may find the most current findings to be of relevance.

Role of phytoconstituents in the management of COVID-19

BACKGROUND

COVID-19, a severe global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged as one of the most threatening transmissible disease. As a great threat to global public health, the development of treatment options has become vital, and a rush to find a cure has mobilized researchers globally from all areas.

SCOPE AND APPROACH

This review focuses on deciphering the potential of different secondary metabolites from medicinal plants as therapeutic options either as inhibitors of therapeutic targets of SARS-CoV-2 or as blockers of viral particles entry through host cell receptors. The use of medicinal plants containing specific phytomoieties could be seen in providing a safer and long-term solution for the population with lesser side effects. Key Findings and Conclusions: Considering the high cost and time-consuming drug discovery process, therapeutic repositioning of existing drugs was explored as treatment option in COVID-19, however several molecules have been retracted as therapeutics either due to no positive outcomes or the severe side effects. These effects call for exploring the alternate treatment options which are therapeutically effective as well as safe. Keeping this in mind, phytopharmaceuticals derived from medicinal plants could be explored as important resources in the development of COVID-19 treatment, as their role in the past for treatment of viral diseases like HIV, MERS-CoV, and influenza has been well reported. Considering this fact, different phytoconstituents such as flavonoids, alkaloids, tannins and glycosides etc. Possessing antiviral properties against coronaviruses and possessing potential against SARS-CoV-2 have been reviewed in the present work.

Antimicrobial activity of a novel polyherbal combination for the treatment of vaginal infection

The present study evaluated the antimicrobial activity of Azadirachta indica (AI), Cichorium intybus (CI), and Trigonella foenum-graecum (TFG) against bacterial and fungal pathogens responsible for the vaginal infections. The AI, CI, and TFG were selected to include antimicrobial and antifungal action against wide range of microbes. The different extracts of the herbs were evaluated for antibacterial and antifungal activity by well diffusion assays. Based on the results, the combination was selected and evaluated, "polyherbal antimicrobial (PHA)." The developed PHA extract demonstrated synergistic broad-spectrum antimicrobial activities including antibacterial and antifungal activity (minimum inhibition concentration: 5-7 mg/ml).

Lungs deposition and pharmacokinetic study of submicron budesonide particles in Wistar rats intended for immediate effect in asthma

The purpose of the present investigation was to study the aerosolization, lungs deposition and pharmacokinetic study of inhalable submicron particles of budesonide in male Wistar rats. Submicron particles were prepared by antisolvent nanoprecipitation method and freeze-dried to obtain free flowing powder. The freeze-drying process yielded dry powder with desirable aerodynamic properties for inhalation therapy. An in-house model inhaler was designed to deliver medicine to lungs, optimized at dose level of 10 mg for 30 sec of fluidization. The in vitro aerosolization study demonstrates that submicron particles dissolve faster with improved aerosolization effect as compared to micronized budesonide. Both submicron and micron particles were compared for in vivo lungs deposition. The results showed that relatively high quantity of submicron particles reaches deep into the lungs as compared to micron particles. Most pronounced effect observed with submicron particles from pharmacokinetic parameters was the enhancement in peak plasma concentration (C_max) by 28.85 %, and increase in area under concentration curve (AUC_0-8h) by 30.33 % compared to micron sized particles. The results suggested that developed submicronized formulation of budesonide can be used for pulmonary drug delivery for high deposition to deep lungs tissues.

Physiologically active hydrogel (in situ gel) of sparfloxacin and its evaluation for ocular retention using gamma scintigraphy

Objective:

Due to the structure and physiological barrier of eye, only 1% of instilled dose is available for action on the corneal surface. In this work, we developed and evaluated chitosan (pH sensitive) and gellan gum (ion sensitive) in situ gel of sparfloxacin to improve precorneal residence time.

Materials and Methods:

A protocol for radiolabeling of sparfloxacin with Tc-99m was optimized to study the ocular retention using gamma scintigraphy technique.

Results:

The clear formulation was developed. In vitro release showed a sustained and prolonged release compared to plain eye drop solution. Dynamic and static gamma scintigraphy showed better retention than plain eye drops. The ocular tolerance test (hen's egg test-chorioallantoic membrane test and infra-red study) showed that the formulation is nonirritant and can be used as ocular vehicle.

Conclusion:

Radiolabel protocol for sparfloxacin was successfully developed and evaluated on ocular retention studies of developed in situ gel. The developed in situ gel is non irritant and can go further with clinical evaluation.

Current scenario of spurious and substandard medicines in India: a systematic review

Globally, every country is the victim of substandard or spurious drugs, which result in life threatening issues, financial loss of consumer and manufacturer and loss in trust on health system. The aim of this enumerative review was to probe the extent on poor quality drugs with their consequences on public health and the preventive measures taken by the Indian pharmaceutical regulatory system. Government and non-government studies, literature and news were gathered from journals and authentic websites. All data from 2000 to 2013 were compiled and interpreted to reveal the real story of poor quality drugs in India. For minimizing spurious/falsely-labelled/falsified/counterfeit drugs or not of standard quality drugs, there is urgent requirement of more stringent regulation and legal action against the problem. However, India has taken some preventive steps in the country to fight against the poor quality drugs for protecting and promoting the public health.

Modulation of liver and kidney toxicity by herb Withania somnifera for silver nanoparticles: a novel approach for harmonizing between safety and use of nanoparticles

In the present study, toxicity of nanoparticles is evaluated for assessing their effect on liver and kidney. We have synthesized highly mono-disperse spherical and rod-shaped silver nanoparticles using reverse microemulsion and aqueous phase methods. These were characterized by UV-vis spectrophotometer, dynamic light scattering, and transmission electron microscope confirming the formation of different sizes of spherical-shaped and rod-shaped silver nanoparticles (Ag NPs). Acute toxicity of different shapes and sizes of Ag NPs and their modulations by using Withania somnifera were evaluated through biochemical and histopathological changes in liver and kidney tissues of Wistar rats. We also evaluated cytotoxicity in specific murin macrophages through confocal microscopy. Cytotoxicity analysis indicates that median lethal dose (LD50) for 20, 50, and 100-nm size spherical and 100-nm rod-shaped Ag NPs was 0.25, 0.35, 0.35, and 0.35 mg/ml, respectively. We also calculated clinically important protein concentration to illustrate the efficacy of Ag nanomaterials. These studies indicated that 20, 50, and 100-nm spherical Ag NPs (35 mg/kg, 23 days) increased the biochemically important enzymes and substrate levels glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), creatinine, and urea concentration in serum, showing liver and kidney tissue damage. After 23 days of treatment of Ag NPs (20, 50, and 100 nm spherical), along with W. somnifera, toxicity of Ag NPs significantly decreased and marginalized. However, no significant changes were observed for 100-nm rod-shaped Ag NPs on normal liver and kidney architecture. Given their low toxic effects and high uptake efficiency, these have a promising potential as to lower the toxicity of Ag NPs.

An alternative in situ gel-formulation of levofloxacin eye drops for prolong ocular retention

Introduction:

Delivering drugs to ocular region is a challenging task. Eye physiological barriers lead to relatively less therapeutic and bioavailability effect by the conventional eye drops. This may be overcome by the use of in situ gel delivery system.

Objective:

The objective of our work was to formulate an ocular delivery system of levofloxacin, based on the concept of ion (sodium alginate) and pH (chitosan) activated in situ gelation concept. Due to its elastic properties, in situ gels resist the ocular drainage of drug leading to longer contact times with ocular surface.

Materials and Methods:

The formulation was evaluated for physicochemical characteristics, in vitro drug release. Ocular retention studies were carried out by Gamma scintigraphy. Time activity curve was plotted between marketed formulation and developed formulation for comparing drug drainage from the eye with time. Ocular tolerance test was performed by handheld infra-red camera.

Results and Discussion:

The formulations showed a first-order release pattern over 12 h. Both in vitro release studies and in vivo gamma scintigraphy precorneal retention studies indicated better therapeutic efficacy compared with standard eye drops.

Conclusion:

The results demonstrated that the developed in situ gel of levofloxacin is nonirritant, has prolonged action and is a better option in terms of retention, ocular bioavailability and patient compliance when compared with plain eye drops formulation.

Dorzolamide-loaded PLGA/vitamin E TPGS nanoparticles for glaucoma therapy: Pharmacoscintigraphy study and evaluation of extended ocular hypotensive effect in rabbits

Poor drug penetration and rapid clearance after topical instillation of a drug formulation into the eyes are the major causes for the lower ocular bioavailability from conventional eye drops. Along with this, poor encapsulation efficiency of hydrophilic drug in polymeric nanoparticles remains a major formulation challenge. Taking this perspective into consideration, dorzolamide (DZ)-loaded PLGA nanoparticles were developed employing two different emulsifiers (PVA and vitamin E TPGS) and the effects of various formulation and process variables on particle size and encapsulation efficiency were assessed. Nanoparticles emulsified with vitamin E TPGS (DZ-T-NPs) were found to possess enhanced drug encapsulation (59.8±6.1%) as compared to those developed with PVA as emulsifier (DZ-P-NPs). Transcorneal permeation study revealed a significant enhancement in permeation (1.8-2.5 fold) as compared to solution. In addition, ex vivo biodistribution study showed a higher concentration of drug in the aqueous humour (1.5-2.3 fold). Histological and IR-camera studies proved the non-irritant potential of the formulations. Pharmacoscintigraphic studies revealed the reduced corneal clearance, as well as naso-lachrymal drainage in comparison to drug solution. Furthermore, efficacy study revealed that DZ-P-NPs and DZ-T-NPs significantly reduced the intraocular pressure by 22.81% and 29.12%, respectively, after a single topical instillation into the eye.

Nanoparticles laden in situ gel for sustained ocular drug delivery

Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%). To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG) as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

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.

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.

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.

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.

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.

Novel polymer coupled lipid nanoparticle of paclitaxel with synergistic enhanced efficacy against cancer

This study was aimed to develop chitosan coupled lipid nanoparticle (Ch-Ptx-Lip), where immunomodulatory activity of chitosan and chemotherapeutic effect of paclitaxel can synergistically enhance efficacy of this novel drug delivery system. Particle size, zeta potential and % Entrapment Efficiency (%EE) of Ch-Ptx-Lip was found to be 113.3 +/- 4.5 nm (PDI: 0.38), (+)35.7 +/- 2.9 mV and 96.4 +/- 1.8% respectively. Morphological evaluation of these particles by TEM shows circular bilayer structure along with outer polymer layers. Ch-Ptx-Lip showed significantly enhanced cytotoxicity (p < 0.05) compared with marketed formulation (Ptx Solution) and Ptx-Lip when evaluated in-vitro by MTT assay on MCF-7 cell lines. Improved efficacy with lower dose of drug can be a new strategy against cancer with minimum side effects and shorter treatment duration.

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.

Development, characterization and in vitro assessement of stearylamine-based lipid nanoparticles of paclitaxel

The objective of the study was to design and evaluate a solid lipid nanoparticle (SLN) drug delivery system for delivery of paclitaxel. Components of the SLN were lipid (stearylamine) and surfactants (Pluronic F68 and Soya lecithin). The paclitaxel loaded nanoparticles were prepared by a modified solvent injection method. Experiments were carried out with excipients, where surfactants, lipid and drug molar ratios were varied to optimize the formulation characteristics. The in vitro drug release profile from the nanoparticles followed a diffusion controlled mechanism. The modified solvent injection method ensured high entrapment efficiency (approximately 75%), produced smaller, stable nanoparticles with a narrow size distribution and proved to be a reproducible and fast production method. The present study describes the feasibility and suitability of stearylamine based SLN produced using a mixture of surfactants to develop a clinically useful system with targeting potential for poorly soluble antineoplastic drugs.

Gastroretentive drug delivery system of acyclovir-loaded alginate mucoadhesive microspheres: formulation and evaluation

In the present study, mucoadhesive alginate microspheres of acyclovir were prepared to prolong the gastric residence time using a simple emulsification phase separation technique. The particle size of drug-loaded formulations was measured by SEM and the particle size distribution was determined using an optical microscope and mastersizer. The release profile of acyclovir from microspheres was examined in simulated gastric fluid (SGF pH 1.2). The particles were found to be discreet and spherical with the maximum particles of an average size (70.60 ± 2.44 µm). The results indicated that the mean particle size of the microspheres increased with an increase in the concentration of polymer and decreased with increase in stirring speed. The entrapment efficiency was found to be in the range of 51.42-80.46%. The concentration of the calcium chloride (% w/v) of 10% and drug-polymer ratio of 1:4 resulted in an increase in the entrapment efficiency and the extent of drug release. The optimized alginate microspheres were found to possess good mucoadhesion (66.42 ± 1.01%). The best fit model with the highest regression coefficient values (R²) was predicted by Peppas model (0.9813). In Gamma scintigraphy analysis, the section of GIT was critically analyzed and much differentiation was present at each time point after oral administration, which revealed that the optimized formulation demonstrated gastroretention in vivo for more than 4 h, which revealed that optimized formulation could be a good choice for gastroretentive 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.

Self-emulsifying drug delivery systems: an approach to enhance oral bioavailability

Self-emulsifying drug delivery systems are a vital tool in solving low bioavailability issues of poorly soluble drugs. Hydrophobic drugs can be dissolved in these systems, enabling them to be administered as a unit dosage form for per-oral administration. When such a system is released in the lumen of the gastrointestinal tract, it disperses to form a fine emulsion (micro/nano) with the aid of GI fluid. This leads to in situ solubilization of drug that can subsequently be absorbed by lymphatic pathways, bypassing the hepatic first-pass effect. This article presents an exhaustive account of various literature reports on diverse types of self-emulsifying formulations with emphasis on their formulation, characterization and in vitro analysis, with examples of currently marketed preparations.

Biodegradable levofloxacin nanoparticles for sustained ocular drug delivery

Drug delivery to ocular region is a challenging task. Only 1-2% of drug is available in eye for therapeutic action, rest of the drug is drained out through nasolachrymal drainage system and other ocular physiological barriers. To overcome these problems of conventional dosage form, novel drug delivery systems are explored like nanoparticles. In our present work, levofloxacin encapsulated poly(lactic-co-glycolic acid) nanoparticles were developed and evaluated for various parameters like particle size, ζ potential, in vitro drug release and ex vivo transcorneal permeation. Microbiological efficacy was tested against Staphylococcus aureus using cup-plate method. Precorneal residence time was studied on albino rabbits by γ scintigraphy after radiolabeling of levofloxacin by Tc-99m. Ocular tolerance was evaluated using hen's egg chorioallantoic membrane (HET-CAM) test. The developed nanoparticles were of spherical shape with a mean particle size of 190-195 nm with a ζ potential of -25 mV. The drug entrapment efficiency was found to be near 85%. In vitro drug release profile shows initial burst release followed by extended release up to 24 h. Microbiological assay showed equivalent zone of inhibition compared to marketed formulation. γ Scintigraphy images of developed formulation, suggested a good spread and good retention over precorneal area. The nanosuspension thus developed was retained for the longer time and drained out from the eye very slowly compared to marketed formulation as significant radioactivity was recorded in later in kidney and bladder. The developed nanosuspension with a mean score of 0.33 up to 24 h in HET-CAM assay, showed the nonirritant efficacy of developed formulation. The stability studies yielded a degradation constant less then 5 × 10(-4), proving a stable formulation with an arbitrary shelf life of 2 years.

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.

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.

Sparfloxacin-loaded PLGA nanoparticles for sustained ocular drug delivery

Poor ocular bioavailability of drugs (<1%) from conventional eye drops (ie, solution, suspension, and ointments) is mainly due to the physiologic barriers of the eye. In general, ocular efficacy is closely related to ocular drug bioavailability, which may be enhanced by increasing corneal drug penetration and prolonging precorneal drug residence time. In our current work, we develop and evaluate a new colloidal system, that is, poly(dl-lactide-co-glycolide) (PLGA) nanoparticles for sparfloxacin ophthalmic delivery, to improve precorneal residence time and ocular penetration. Nanoparticles were prepared by nanoprecipitation technique and characterized for various properties such as particle size, zeta potential, in vitro drug release, statistical model fitting, stability, and so forth. Microbiological assay was carried out against Pseudomonas aeruginosa using the cup-plate method. Precorneal residence time was studied in albino rabbits by gamma scintigraphy after radiolabeling of sparfloxacin by Tc-99m. Ocular tolerance of the developed nanosuspension was also studied by the Hen Egg Test-Chorioallantoic Membrane (HET-CAM) method. The developed nanosuspension showed a mean particle size in the range of 180 to 190 nm, suitable for ophthalmic application with zeta potential of -22 mV. In vitro release from the developed nanosuspension showed an extended release profile of sparfloxacin according to the Peppas model. Acquired gamma camera images showed good retention over the entire precorneal area for the developed nanosuspension compared with that of a marketed formulation. The marketed drug formulation cleared very rapidly from the corneal region and reached the systemic circulation through the nasolacrimal drainage system, as significant radioactivity was recorded in kidney and bladder after 6 hours of ocular administration, whereas the developed nanosuspension cleared at a very slow rate (P < .05) and remained at the corneal surface for longer duration, as no radioactivity was observed in the systemic circulation. HET-CAM assay with 0 score in 8 hours indicates the nonirritant property of the developed nanosuspension. The developed lyophilized nanosuspension was found to be stable for a longer duration of time than the conventional marketed formulation with a good shelf life.

FROM THE CLINICAL EDITOR

Poor ocular bioavailability of drugs (<1%) from conventional eye drops is mainly due to the eye physiological barriers. In this study, a new colloidal system, PLGA nanoparticle for sparfloxacin ophthalmic delivery was demonstrated to improve precorneal residence time and ocular penetration. The developed lyophilized nanosuspension was found to be stable for longer duration of time than conventional marketed formulations.