Search

Nanoparticles range in size from 1-100 nm although much larger nanoparticles i.e. up to 300 nm, are widely reported for medical application. Current trends in drug delivery research have shifted focus toward the designing of the “smart” drug delivery systems (DDS) for spacial and temporal control of the drug delivery. When a magnetic moiety is added to a DDS i.e. nanoparticle or liposome, it can be retained in a specific part of the body through localized magnetic field. These magnetically modulated drug delivery systems (MDDS) can also carry payload to deep lying tumor tissues which are difficult to target with other targeting modalities. MDDS are also used as hyperthermic agents under the influence of externally applied alternating magnetic field. Not only the magnetic hyperthermia can kill cancer cells but also causes phase-change in nanoparticles to induce abrupt drug release. Magnetic resonance imaging (MRI) is a diagnostic techniques used to image disease specific changes in tissues using contrast agents such as iron oxide nanoparticles. When iron oxide nanoparticles are loaded with drugs, they act as a contrast agent and carrier for targeted drug delivery which is revolutionizing medical field. In addition to drug delivery applications, magnetic nanoparticles are also being used in biosensors for identification and separation of target molecules/cells from complex mixture. However, challenges associated with optimized particle size, selection of biocompatible materials, and fate of MDDS after in vivo application need to be addressed. Emerging literature also points towards interaction of magnetic field with human body. Thus, carefully tailored magnetic modulated nanoparticles are expected to emerge as a key player in medical field due to their unique diagnostic, therapeutic, sensing and multifunctional application.

Transfersomes (TFS) are the promising carriers for transdermal delivery of various low and high molecular weight drugs, owing to their self-regulating and self-optimizing nature. Herein, we report synthesis and characterization of TFS loaded with meloxicam (MLX), an NSAID, and dexamethasone (DEX), a steroid, for simultaneous transdermal delivery. The different formulations of TFS containing varying amounts of lecithin, Span 80, and Tween 80 (TFS-1 to TFS-6) were successfully prepared by thin-film hydration method. The size of ranged between 248 and 273 nm, zeta potential values covering from -62.6 to -69.5 mV, polydispersity index (PDI) values in between 0.329 and 0.526, and entrapment efficiency of MLX and DEX ranged between 63-96% and 48-81%, respectively. Release experiments at pH 7.4 demonstrated higher cumulative drug release attained with Tween 80 compared to Span 80-based TFS. The scanning electron microscopy (SEM) of selected formulations -1 and TFS-3 revealed spherical shape of vesicles. Furthermore, three optimized transfersomal formulations (based on entrapment efficiency, TFS-1, TFS-3, and TFS-5) were incorporated into carbopol-940 gels coded as TF-G1, TF-G3, and TF-G5. These transfersomal gels were subjected to pH, spreadability, viscosity, homogeneity, skin irritation

Transfersomes (TFS) are the promising carriers for transdermal delivery of various low and high molecular weight drugs, owing to their self-regulating and self-optimizing nature. Herein, we report synthesis and characterization of TFS loaded with meloxicam (MLX), an NSAID, and dexamethasone (DEX), a steroid, for simultaneous transdermal delivery. The different formulations of TFS containing varying amounts of lecithin, Span 80, and Tween 80 (TFS-1 to TFS-6) were successfully prepared by thin-film hydration method. The size of ranged between 248 and 273 nm, zeta potential values covering from –62.6 to –69.5 mV, polydispersity index (PDI) values in between 0.329 and 0.526, and entrapment efficiency of MLX and DEX ranged between 63-96% and 48-81%, respectively. Release experiments at pH 7.4 demonstrated higher cumulative drug release attained with Tween 80 compared to Span 80-based TFS. The scanning electron microscopy (SEM) of selected formulations -1 and TFS-3 revealed spherical shape of vesicles. Furthermore, three optimized transfersomal formulations (based on entrapment efficiency, TFS-1, TFS-3, and TFS-5) were incorporated into carbopol-940 gels coded as TF-G1, TF-G3, and TF-G5. These transfersomal gels were subjected to pH, spreadability, viscosity, homogeneity, skin irritation, in vitro drug release, and ex vivo skin permeation studies, and the results were compared with plain (nontransfersomal) gel having MLX and DEX. TFS released 71.72% to 81.87% MLX in 12 h; whereas, DEX release was quantified as 74.72% to 83.72% in same time. Nevertheless, TF-based gels showed slower drug release; 51.54% to 59.60% for MLX and 48.98% to 61.23% for DEX. The TF-G systems showed 85.87% permeation of MLX (TF-G1), 68.15% (TF-G3), and 68.94% (TF-G5); whereas, 78.59%, 70.54%, and 75.97% of DEX was permeated by TF-G1, TF-G3, and TF-G5, respectively. Kinetic modeling of release and permeation data indicated to follow Korsmeyer-Peppas model showing diffusion diffusion-based drug moment. Conversely, plain gel influx was found mere 26.18% and 22.94% for MLX and DEX, respectively. These results suggest that TF-G loaded with MLX and DEX can be proposed as an alternate drug carriers for improved transdermal flux that will certainly increase therapeutic outcomes.

Background: Lipid polymer hybrid nanoparticles (LPHNPs) for the controlled delivery of hydrophilic doxorubicin hydrochloride (DOX.HCl) and lipophilic DOX base have been fabricated by the single step modified nanoprecipitation method. Materials and methods: Poly (D, L-lactide-co-glicolide) (PLGA), lecithin, and 1,2-distearoyl-Sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000 (DSPE-PEG 2000) were selected as structural components. Results: The mean particle size was 173-208 nm, with an encapsulation efficiency of 17.8±1.9 to 43.8±4.4% and 40.3±0.6 to 59. 8±1.4% for DOX.HCl and DOX base, respectively. The drug release profile was in the range 33-57% in 24 hours and followed the Higuchi model (R2=0.9867-0.9450) and Fickian diffusion (n

Pentazocine (PTZ) is a narcotic analgesic used to manage moderate to severe, acute and chronic pains. In this study, PTZ loaded Ethyl cellulose microsphere has been formulated for sustained release and improved bioavailability of PTZ. These microspheres were fabricated by oil in water emulsion solvent evaporation technique. A three factorial, three levels Box-Behnken design was applied to investigate the influence of different formulation components and process variables on the formulation response using the numeric approach through the design expert® software. All the formulations were characterized for the morphology, different physicochemical properties and the results were supported with the ANOVA analysis, three dimensional contour graphs and regression equations. The maximum percentage yield was 98.67% with 98% entrapment of PTZ. The mean particle size of the formulations ranges from 50–148μm, which directly relates to the concentration of polymer and inversely proportional to the stirring speed. SEM revealed the spherical shape of PTZ microspheres with porous structures. These are physically, chemically and thermally stable as confirmed through Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and thermal gravimetric (TG) analysis respectively. The microspheres provided a sustained release of the PTZ for more than 12 hours, following zero order with fickian and non fickian diffusion. The results indicate that prepared microspheres can be a potential drug delivery system (DDS) for the delivery of PTZ in the management of pains.

Many countries have been facing the problem of bank insolvency across the globe. Asset deterioration is one of the main reasons for insolvency of banks. The objective of the paper is to ascertain the determinants of nonperforming loans (NPLs) in the banking sector of Pakistan for the period 2006-16. Other than the bank specific and macro variables proposed by the literature, the roles of weighted maturity and output gap are for the first time examined. We find significant impact of output gap on NPLs however weighted maturity has insignificant role in shaping the future NPLs. Bank specific drivers of NPLs include bank size and capital adequacy ratio.

Background Lipid-polymer hybrid nanoparticles (LPHNP) are suitable for co-delivery of hydrophilic and lipophilic drugs. The structural advantages of polymers and biomimetic properties of lipids enable higher encapsulation of drugs and controlled release profile. Lipid-polymer hybrid nanoparticles have been prepared for co-delivery of curcumin and cisplatin for enhanced cytotoxicity against ovarian cancer. Material and Methods Chitosan, cisplatin, curcumin, Lipoid S75 were selected as structural components and ionic gelation method was used for preparation of LPHNPs. Nanoparticles were formed via ionic interaction of positively charged chitosan and negatively charged lipid. Results The optimized nanoparticles were of 225 nm with cationic charge. The encapsulation efficiency was greater than 80% with good drug loading. The drug release profile showed controlled release behavior of both curcumin and cisplatin simultaneously and the absence of burst release. The in vitro therapeutic efficacy and cellular association was evaluated using A2780 ovarian cell lines. To further investigate therapeutic efficacy, we developed 3D spheroids as tumor model to mimic the in vivo conditions. The cytotoxicity and uptake of co-loaded LPHNPs were evaluated on 3D spheroids and results indicated increased chemosensitization and enhanced therapeutic efficacy of co-loaded LPHNPs. Conclusion Lipid-polymer hybrid nanoparticles could be a suitable platform for co-delivery of curcumin and cisplatin for enhanced cytotoxic effect on ovarian cell lines.

Biological half-life and volume of distribution of the drug are the key parameters in understanding the pharmacokinetics of the drugs within the body as they affect all the pharmacokinetic processes including absorption, distribution, metabolism and elimination of drugs and also associated with each other, ultimately effecting the Pharmacological action of the drug on its target site. Given study elaborates the various aspects of half-life, i.e., Alpha & beta half-lives, the contribution of Zero-order and first-order kinetics in ADME and interrelation among the volume of distribution & half-life along with the distribution & redistribution of the drug within the body. Moreover, the importance of half-life & Vd and the idea of Steady-state concentration is also discussed. Various types of physiological barriers, including the blood-brain barrier, placental barrier, blood-CSF barrier, affect the distribution of drugs.

Graphene, the mother of all carbon materials, has unlocked a new era of biomedical nanomaterials due to its exceptional biocompatibility, physicochemical and mechanical properties. It is a single atom thick, nanosized, two-dimensional structure and provides high surface area with adjustable surface chemistry to form hybrids. The present article provides a comprehensive review of ever-expanding application of graphene nanomaterials with different inorganic and organic materials in drug delivery and theranostics. Methods of preparation of nanomaterials are elaborated and biological and physicochemical characteristics of biomedical relevance are also discussed. Graphene form nanomaterials with metallic nanoparticles offer multiscale application. First, graphene act as a platform to attach nanoparticles and provide excellent mechanical strength. Second, graphene improves efficacy of metallic nanoparticles in diagnostic, biosensing, therapeutic and drug delivery application. Graphene-based polymeric nanocomposites find wider application in drug delivery with flexibility to incorporate hydrophilic, hydrophobic, sensitive and macromolecules. In addition, grapheme quantum dots and graphene hybrids with inorganic nanocrystal and carbon nanotubes hybrids have shown interesting properties for diagnosis and therapy. Finally, we have pointed out research trends that may be more common in future for graphene-based nanomaterials.

Proniosomes (PN) are the dry water-soluble carrier systems that may enhance the oral bioavailability, stability, and topical permeability of therapeutic agents. The low solubility and low oral bioavailability due to extensive first pass metabolism make Pentazocine as an ideal candidate for oral and topical sustained release delivery. The present study was aimed to formulate the PNs by quick slurry method that are converted to niosomes (liquid dispersion) by hydration, and subsequently formulated to semisolid niosomal gel. The PNs were found in spherical shape in the SEM and stable in the physicochemical and thermal analysis (FTIR, TGA, and XRD). The quick slurry method produced high recovery (> 80% yield) and better flow properties (θ = 28.1–37.4°). After hydration, the niosomes exhibited desirable entrapment efficiency (44.45–76.23%), size (4.98–21.3 μm), and zeta potential (− 9.81 to − 21.53 mV). The in vitro drug release (T100%) was extended to more than three half-lives (2–4 h) and showed good fit to Fickian diffusion indicated by Korsmeyer-Peppas model (n = 0.136–0.365 and R2 = 0.9747–0.9954). The permeation of niosomal gel was significantly enhanced across rabbit skin compared to the pure drug-derived gel. Therefore, the PNs are found promising candidates for oral as dissolution enhancement and sustained release for oral and topical delivery of pentazocine for the management of cancer pain.

Lung cancer is the leading cause of cancer-related deaths in the world. Conventional therapy for lung cancer is associated with lack of specificity and access to the normal cells resulting in cytotoxicity, reduced cellular uptake, drug resistance and rapid drug clearance from the body. The emergence of nanotechnology has revolutionized the treatment of lung cancer. The focus of nanotechnology is to target tumor cells with improved bioavailability and reduced toxicity. In the recent years, nanoparticulate systems have extensively been exploited in order to overcome the obstacles in treatment of lung cancer. Nanoparticulate systems have shown much potential for lung cancer therapy by gaining selective access to the tumor cells due to surface modifiability and smaller size. In this review, various novel nanoparticles (NPs) based formulations have been discussed in the treatment of lung cancer. Nanotechnology is expected to grow fast in future, and it will provide new avenues for the improved treatment of lung cancer. This review article also highlights the characteristics, recent advances in the designing of NPs and therapeutic outcomes.

Lipid-polymer hybrid nanoparticles (LPHNPs) are emerging platforms for drug delivery applications. In the present study, methotrexate loaded LPHNPs consisted of PLGA and Lipoid S100 were fabricated by employing a single-step modified nanoprecipitation method combined with self-assembly. A three factor, three level Box Behnken design using Design-Expert® software was employed to access the influence of three independent variables on the particle size, drug entrapment and percent drug release. The optimized formulation was selected through numeric optimization approach. The results were supported with the ANOVA analysis, regression equations and response surface plots. Transmission electron microscope images indicated the nanosized and spherical shape of the LPHNPs with fair size distribution. The nanoparticles ranged from 176 to 308nm, which increased with increased polymer concentration. The increase in polymer and lipid concentration also increased the drug entrapment efficiency. The in vitro drug release was in range 70.34-91.95% and the release mechanism follow the Higuchi model (R2=0.9888) and Fickian diffusion (n

Lipid-polymer hybrid nanoparticles (LPHNP) are delivery systems for controlled drug delivery at tumor sites. The superior biocompatible properties of lipids and structural advantages of polymers can be obtained using this system for controlled drug delivery. In this study, cisplatin-loaded lipid-chitosan hybrid nanoparticles were formulated by the single step ionic gelation method based on ionic interaction of positively charged chitosan and negatively charged lipid. Formulations with various chitosan to lipid ratios were investigated to obtain the optimal particle size, encapsulation efficiency, and controlled release pattern. Transmission electron microscope and dynamic light scattering analysis demonstrated a size range of 181–245 nm and a zeta potential range of 20–30 mV. The stability of the formulation was demonstrated by thermal studies. Cytotoxicity and cellular interaction of cisplatin-loaded LPHNP were investigated using in vitro cell-based assays using the A2780 ovarian carcinoma cell line. The pharmacokinetics study in rabbits supported a controlled delivery of cisplatin with enhanced mean residence time and half-life. These studies suggest that cisplatin loaded LPHNP have promise as a platform for controlled delivery of cisplatin in cancer therapy.

Objective: The purpose of study is to determine relationship of anemia n pregnancy with the birth weight of new born. Comparison between anemic and non-anemic pregnant females was done. Methodology: The study design is comparative, cross sectional conducted at Lady Aitchison hospital, Lahore from to January 2019 to March 2019. The permission was granted to authors from the hospital ethical committee. Total 200 patients were enrolled and were stratified into two groups, consisting of 100 patients each. Patients with single fetus at term and till gravida 5 were included in study while those suffering from other causes of low birth weight like, grand multipara, multiple pregnancies, intra-uterine growth retardation (IUGR), preterm and any other co-morbidity which can possibly lead to low birth weight were excluded. Maternal complete blood count was performed. Blood sample was collected at the time of enrollment. Data was collected on a pre-designed form after taking informed written consent. Data analysis was done by using SPSS version 10. Results: The mean birth weight of newborns of anemic mothers was 2338± 266 grams while in non-anemic mothers birth weight was 3081±307 grams. The p value was 0.000. The patients in anemic group were stratified into mild, moderate and severe which were 25%, 65% and 10% respectively. The moderately anemic mothers had 2184 ± 89 grams birth weight of their newborn while severely anemics had 1990±73 grams, p value was 0.000. Conclusion: The study shows that mothers with anemia i.e. hemoglobin level less than 11 g/dl had low birth weight babies while those with HB equals or more than 11g/dl had normal birth weight babies. Key Words: Birth weight, New born, Anemia, Pregnancy

Objectives: To study deficiency of vitamin “D” and its effects on human body. Material & Methods: The study was conducted in a local private clinic situated in HML Hospital Lahore from January 2019 to March 2019. Five hundred subjects were included in the sample which consisted of 250 males and 250 females. These subjects presented to the hospital due to any major or minor illness. These subjects also included those who had or had no body aches. Samples of blood were also collected from these patients by venipuncture by disposable syringe after overnight fasting in mooring. 4 ml of blood sample was taken which was stored at -18°C till the time the sample was analyzed. The variables which were studied are age, gender, serum levels of vitamin “D”, serum calcium levels and past history of any pain in bones. SPSS-version-10 for windows was used to analyze the study. P value of Results: In 75.5% of the patients included in sample had vitamin “D” deficiency, 9.5% of them were having levels of vitamin “D” within normal range while 15% among the sample patients were in the category of vitamin “D” insufficiency. There was a prevalence of 90.5% of vitamin “D” deficiency and insufficiency overall. 163 (32.6%) patients were presented with the complaints of body aches while remaining 337 (67.4%) patients were having no complaints of body aches. Serum calcium levels were in normal range in all patients which were included in the sample. Conclusion: The dietary insufficiency and lack of exposure to sunlight being the major causes of vitamin D deficiency in humans. Key Words: Vitamin ‘’D’’ deficiency, Risk factors.

Lipid polymer hybrid nanoparticles (LPHNPs) have been merged as potential nanocarriers for treatment of cancer. In the present study, LPHNPs loaded with Sorafenib (SFN) were prepared with PLGA, Lecithin and DSPE-PEG 2000 by using the bulk nanoprecipitation and microfluidic (MF) co-flow nanoprecipitation techniques. Herein, a glass capillary microfluidic device was primed to optimize the LPHNPs and compared to the bulk nanoprecipitation method. The morphological analysis of prepared LPHNPs revealed the well-defined spherical nano-sized particles in bulk nanoprecipitation method. Whereas, core shell morphology was observed in the MF method. The formulation prepared by the MF method (MF1-MF3) indicated relatively higher % EE (95.0%, 93.8% and 88.7%) and controlled release of the SFN from the particles as compared to the LPHNPs obtained by the bulk nanoprecipitation method. However, the release of SFN from all LPHNP formulation followed Higuchi model (R2 = 0.9901–0.9389) with Fickian diffusion mechanism. Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and powder X-rays diffraction (pXRD) studies depicted the compatibility of SFN with all the structural components. In addition, the colloidal stability, in vitro cytotoxicity and cell growth inhibition studies of LPHNPs also demonstrated stability in biological media, biocompatibility and safety with enhanced anti-proliferative effects than the free SFN in breast cancer and prostate cancer cells. In conclusion, LPHNPs provided a prospective platform for the cancer chemotherapy and substantially improved the knowledge of fabrication and optimization of the hybrid nanoparticles.

A simple and cost effective RPLC-UV bio-analytical method was developed and used for tenoxicam quantification on ODS Hypersil C-18 column using classical liquid-liquid extraction technique for sample preparation. Acetonitrile was used as precipitating agent for plasma proteins and supernatant was taken for injection without any further modification. The bio-analytical method depends upon isocratic elution using binary mixture of aqueous 0.1 M potassium dihydrogen phosphate and acetonitrile in 6 : 4 ratio. The pH of mobile phase was adjusted to 2.8 which favor tenoxicam to remain undissociated throughout the analysis. The optimized flow rate of 1.0 mL/min provided proper separation of peaks and column clean up within 5 min. The UV detection was achieved at 381 nm and 4.29 min. Reproducible calibration curve gave 0.325 μg/mL LOQ, linear dynamic range from 0.325 to 20 μg/mL and recovery from plasma was 98.5% with %CV 0.2314 achieved. After validation, the method was applied in pharmacokinetic study in healthy human volunteers (n = 8). The pharmacokinetic parameters were evaluated using kinetica version 4.1.1. The values of C. and area under curve for current study were 1.776 ± 0.003 pg/mL and 179.97 ± 0.0681 (mean ± SEM) pg x h/mL. The values of t, and volume of distribution for tenoxicam in current study were 74.103 0.167 h (mean ± SEM) and 11.962 ± 0.0677 L/kg (mean ± SEM), respectively. This method was simple, sensitive and successfully applied in pharmacokinetic studies. It can be extended to bioequivalence studies and evaluation of tenoxicam in different clinical situations.

Tuberculosis (TB) is an infectious disease that is communicable from one person to another. Pakistan stands forefront among few unfortunate countries that still have heavy burden of TB infection. Being a developing country, TB patients in Pakistan have to face different socio-economic constraints that upset life of the patients as well as their families. A cross sectional survey was conducted in three selected districts, Lodharan, Bahawalpur and Bahawalnagar during February 2011 to June 2011. From three hundred selected patients 210 were enrolled in study after receiving written consents. Data were collected though structured questionnaire and verbal interviews and statistically analyzed by using the univariate analysis. The survey results showed that the low educational status (p0.0012, CI 95%), unawareness of disease (88.7%), crowded population (p =0.0000, CI, 95%), poverty, high treatment cost and distant access to public health facilities were directly related to prevalence of TB. Different disease related constraints including poor attitude of family members, colleagues, society and even health care professionals (p = 0.0000, CI 95%) were also found to be major social factors leading to non-compliance and denial of TB treatment. Socio-economic constraints such as low literacy rate, unemployment, unawareness of disease, high treatment cost, poor attitude of family, society and health care professionals were directly related to noncompliance and should be given high priority consideration for achieving better TB management and mitigation.

Thermoresponsive targeting is used to deliver therapeutic agents at hyperthermic conditions (39–45 °C). However, available thermoresponsive drug delivery systems (TDDS), including liposomes, have a complex method of preparation involving toxic solvents and reagents. The objective of this in vitro study was to prepare and characterize thermoresponsive lipid nanoparticles (TLN) for treating glioblastoma, the most aggressive brain tumor whose treatment is limited by a low blood brain barrier (BBB) permeability of drugs. Thermoresponsive lipids were prepared by mixing liquid and solid fatty acids (0.1 : 1 to 2 : 1 ratio) and lipid mixtures exhibiting a solid–liquid phase transition at 39 °C were identified by plotting melting point against liquid contents. TLN were prepared by a hot melt encapsulation method using mono- or double-surfactant systems. TLN showed desirable size (

The current study aimed to develop novel pH independent microparticles loaded with ropinirole (ROP) for sustained drug release. Eudragit RS 100 was used as release retardant and microparticles were fabricated by oil-in-oil emulsion solvent evaporation method. A three-factor three-level Box-Behnken design using Design-Expert software was employed to optimize formulation variables. Ropinirole loaded microparticles were evaluated with respect to morphology, particle size, encapsulation efficiency, and in vitro release profile. Optical microscopy and SEM micrographs indicated spherical shape with smooth surface and well-defined boundary. The particle size was in the range of 98.86 to 236.29 μm, being significantly increased with increasing polymer concentration. Higher polymer load also increased the thickness of internal polymer network, which led to reduced drug loss and higher entrapment efficiency (89%). The cumulative in vitro release was found to be in the range of 54.96 to 99.36% during the release studies (12 h) following zero order release kinetics and non-Fickian diffusion pattern. The developed microparticles have the potential to sustain the release of ropinirole, which may lead to a reduction in its adverse effects and improved management of Parkinson’s disease.

Liposomes are lipid based vesicular systems that offer novel platform for versatile drug delivery to target cell. Liposomes were first reported by Bangham and his co-workers in 1964 (1). Since then, liposomes have undergone extensive research with the prime aim to optimize encapsulation, stability, circulation time and target specific drug delivery. Manipulation of a liposome’s lipid bilayer and surface decoration with selective ligands has transformed conventional liposomes into adaptable and multifunctional liposomes. Development of liposomes with target specificity provide the prospect of safe and effective therapy for challenging clinical applications. Bioresponsive liposomes offer the opportunity to release payload in response to tissue specific microenvironment. Incorporation of novel natural and synthetic materials has extended their application from stable formulations to controlled release targeted drug delivery systems. Integration and optimization of multiple features into one system revolutionized research in the field of cancer, gene therapy, immunotherapy and infectious diseases. After 50 years since the first publication, this review is aimed to highlight next generation of liposomes, their preparation methods and progress in clinical applications. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.