Three-Dimensional Printing as a Progressive Innovative Tool for Customized and Precise Drug Delivery

While using three-dimensional printing, materials are deposited layer by layer in accordance with the digital model created by computer-aided design software. Numerous research teams have shown interest in this technology throughout the last few decades to produce various dosage forms in the pharmaceutical industry. The number of publications has increased since the first printed medicine was approved in 2015 by Food and Drug Administration. Considering this, the idea of creating complex, custom-made structures that are loaded with pharmaceuticals for tissue engineering and dose optimization is particularly intriguing. New approaches and techniques for creating unique medication delivery systems are made possible by the development of additive manufacturing keeping in mind the comparative advantages it has over conventional methods of manufacturing medicaments. This review focuses on three-dimensional printed formulations grouped in orally disintegrated tablets, buccal films, implants, suppositories, and microneedles. The various types of techniques that are involved in it are summarized. Additionally, challenges and applications related to three-dimensional printing of pharmaceuticals are also being discussed.

Pulmonary Fibrosis: Unveiling the Pathogenesis, Exploring Therapeutic Targets, and Advancements in Drug Delivery Strategies

Idiopathic pulmonary fibrosis (IPF) is an ailment with no cure and a very high rate of progression that ultimately leads to death. The exact reason for this disease is still not acknowledged. Many underlying mechanisms of wound healing and various types of stimuli that trigger the pathogenesis of IPF continue to be intensively explored. The exact therapy for the reversal of this disease is not yet known and is constantly in progress. Existing treatments only slow down the process or mitigate the symptoms to enhance the patient's healthcare system. The only two Food and Drug Administration-approved oral medications include pirfenidone and nintedanib whose high dose and systemic circulation can have side effects to a greater extent. Further research on restorative and extra-curative therapies for IPF is necessary due to the absence of viable therapeutic choices. To assure minimum off-targeted site delivery and longer duration of action, techniques that offer a sustainable release of the drug, better bioavailability, and patient compliance can be used.The work is an overview of the main therapeutic targets and pertinent developing therapies for the management of IPF. This study is an attempt to focus on various drug delivery systems that are responsible for showing effectiveness in defense mechanisms against IPF.

The Electronic Tongue: an advanced taste-sensing multichannel sensory tool with global selectivity for application in the pharmaceutical and food industry

Taste is a crucial organoleptic characteristic that determines whether a substance will be accepted for delivery through the mouth. However, the vast majority of medications have an unpleasant taste. Drugs with a bitter taste are often depicted using a variety of flavouring compounds to increase patient acceptance and compliance. Human panellists are the principal means of assessing the flavour of medication ingredients and formulations. Due to the toxicity of medications and subjectivity of taste panellists, as well as issues with hiring taste panellists and panel upkeep when working with unpleasant items, the use of sensory panellists in the industry is particularly challenging and troublesome. Furthermore, tests cannot be conducted on compounds that have not received FDA approval.As a result, the analytical taste-sensing multichannel sensory system known as the electronic tongue (also known as the artificial tongue or e-tongue) helps in reducing the number of samples that are ought to be assessed by trained sensory panels and also when the sample to be tasted is injurious or harmful for the concerned person. Therefore, e-tongue has advantages like lowering reliance on human panels. The working theory, the sensors used, and the pharmaceutical and food applications are covered, along with the major software used, difficulties, and future scope are also highlighted.

Recent Advances and Prospects for Plant Gum-Based Drug Delivery Systems: A Comprehensive Review

This work is an effort to first introduce plant-based gums and discussing their drug delivery applications. The composition of these plant gums and their major characteristics, which make them suitable as pharmaceutical excipients are also described in detail. The various modifications methods such as physical and chemical modifications of gums and polysaccharides have been discussed along with their applications in different fields. Consequently, plant-based gums modification such as etherification and grafting is attracting much scientific attention to satisfy industrial demand. The evaluation tests to characterize gum-based drug delivery systems have been summarized. The release behavior of drug from plant-gum-based drug delivery is being discussed. Thus, this review is an attempt to critically summarize different aspect of plant-gum-based polysaccharides to be utilized in drug delivery systems having potential industrial applications.

COVID-19 associated rhino-orbital-cerebral mucormycosis-an institutional series

Mucormycosis is almost always confined to the patients with altered host defenses amongst which diabetes is considered as the strongest risk factor. COVID-19 only been seen in severe cases but also in mild and moderate cases of SARS-CoV-2 infections. After preliminary clinical and radiological diagnosis, surgical management in the form of endoscopic sinus surgery, debridement, and orbital exenteration (8) was performed. Medical management in the form of antifungal therapy (amphotericin-B, posaconazole, and isavuconazole) was initiated. In this case series, 79 proven cases of COVID-19 associated rhino-orbital-cerebral mucormycosis were analyzed retrospectively from mid-April 2021 to mid-September 2021. 67 patients were known diabetics, whereas rest 12 had new onset diabetes mellitus. Of these 79 cases, 27 cases had the disease limited to sinuses (rhino-mucormycosis), 43 had orbital involvement also (rhino-orbital mucormycosis), and 9 had cerebral involvement as well (rhino-orbital-cerebral mucormycosis). During this time-period, a total of 14 mortalities occurred. Most of the patients were discharged after completion of amphotericin-B therapy and rest stayed little longer till their general condition improved. COVID-19 causes dysregulation and alteration of immune response in the body which predispose to invasive fungal infections. In addition, uncontrolled diabetes mellitus and corticosteroid treatment increase the risk of mucormycosis by many folds.

A Critical Review on Floating Tablets as a Tool for Achieving Better Gastric Retention

Most of the oral drug delivery systems demand better retention of drug in the gastrointestinal tract (GIT) for better bioavailability. One of the tools for better gastric retention of the drug is to administer it as a floating drug delivery system (FDDS) by reducing its density, compared to the gastric fluids. This system is helpful to overcome the problems associated with the conventional pharmaceutical dosage forms. The present work is an effort to systematically review the latest advancements in FDDS with a major spotlight on how these systems act to make the dosage form float in the gastric fluid for the slow release, better gastric retention, and improved bioavailability of the orally administered drug. As managing diseases through medicines is going in a new age in which innovative delivery system is being used as well as made accessible for remedial use. The excipients used for making such oral gastro-retention dosage forms (GRDF) to provide sustained release profile of drugs along with the work done so far by different scientists in the past two decades; the patents filed in this area; the evaluation methods for checking the quality of FDDS; and their applications are the major highlights of this work.

In vivo Evaluation of Nanostructured Lipid Carrier System in Rats Bearing Breast Tumor

The aim of this work is to study the anti-proliferative potential of two anticancer drugs loaded in nanostructured lipid carriers (NLCs).The maximal inhibition of cell growth by Raloxifene (RLX) & Curcumin (CUM) nanostructured lipid carriers (RLX-CUM-NLCs) was determined by assessing the viability of MDA-MB 231 cells. As far as we know, this is the first research to look at the effects of RLX-CUM-NLCs on DMBA-induced breast carcinogenesis in a rat model. RLX-CUM-NLCs reduced the number of tumors in an in-vivo investigation. After 14 weeks of induction, we discovered a tumor with a 100% incidence rate. The incidence of experimental breast cancer was decreased to 83.33% in the RLX-treated group. In contrast, RLX-CUM-NLCs demonstrated a significant anticancer effect with a 50% incidence in the RLX-CUM-NLCs group. Compared to controls, the RLX-CUM-NLCs therapy did not cause any toxicity in the animals in terms of food intake, body weight, or activity levels until 300 mg/kg BW. The current research shows that the RLX-CUM-NLCs has a chemopreventive impact on DMBA-induced breast cancer in rats by decreasing tumor burden and restoring marker enzymes activity.

Ellagic acid-loaded, tween 80-coated, chitosan nanoparticles as a promising therapeutic approach against breast cancer: In-vitro and in-vivo study

AIMS

Among polyphenolic phytoconstituents with anticancer properties, Ellagic acid (EA) is widely reported for its translational potential in vitro but efficient in vivo delivery of EA has been a challenge. We, for the first time, used a tween 80 coated nano delivery of Ellagic acid to evaluate its preclinical efficacy in vitro and in vivo for breast cancer.

MAIN METHODS

To overcome the challenges of in vivo delivery, two batches of chitosan-based nanoformulations of EA (with and without tween 80 coating) were prepared by the ionotropic gelation method. The nanoformulations were characterized and further evaluated in vitro against breast cancer cells (MCF7) and in vivo with EAC tumor-bearing mice for establishing their anticancer efficacy compared to Ellagic acid alone. A quantitative simulation study was undertaken to understand if the observed antitumor efficacy is due to the synergistic efficacy of the Chitosan-Ellagic acid combination.

KEY FINDINGS

Results revealed that nanoformulations consist of good nano-sized encapsulation of EA and showed good drug entrapment-release capacity. Nano-encapsulated EA is biocompatible and exhibited higher cytotoxicity in vitro compared to EA alone. Similarly, significantly higher tumor regression was observed in nano-EA treated mice compared to EA alone, and best efficacy was observed with the nanoformulation with tween 80 coating. Furthermore, nanoformulations showed higher apoptosis in tumor tissues with no significant tissue toxicity in vital organs.

SIGNIFICANCE

We report synergism of Chitosan-Ellagic acid combination in the tween 80 coated nanoparticles of Ellagic acid resulting in enhanced anti-breast tumor efficacy that may be of translational value for other tumor types, too.

Emerging Pathophysiological Targets of Psoriasis for Future Therapeutic Strategies

Psoriasis is a chronic autoimmune skin disorder which involves complex interactions between genes, keratinocytes, T-cells and inflammatory cells. It affects 2-3% population worldwide. Molecular biology and cellular immunology of psoriasis, when linked with biotechnology and genetic studies can help researchers to understand the pathophysiology of psoriasis. T-cells activation, keratinocyte hyperproliferation, and angiogenesis are the core mechanisms entailed in the development of psoriasis lesion. Investigators are trying to overcome the challenges of complex pathophysiology pathways involved in this disorder. The different possible hypotheses for its pathophysiology such as growth factors, enzymes, inflammation, and genetic factors mediated pathophysiology have been described in the present review paper in detail. Clinically available drugs only control the symptoms of psoriasis but are not effective for the treatment of the disorder completely and are also associated with some side effects such as itching, renal disorders, hematologic, nonmelanoma skin cancer, pulmonary, gastrointestinal toxicity, etc. This paper made an effort to understand the pathophysiological targets, discuss the research done so far and the treatments available for the effective management of psoriasis.

Critical Reviews on Pediatric Dosage Form Developments and Medical Devices

The pediatric population is generally considered as "miniature adults," but they actually differ from adults due to their different body compositions and varied stages of organ development, which alter essential biopharmaceutical parameters. The physiological differences between the pediatric population and the adult population alter the essential kinetics and dynamics of the same drug administered at the same dose. For pediatric patients, the drug dose is generally calculated using different formulas based on age, body surface area, or weight, or is simply reduced to half of adult dose. This, however, is not the correct practice. New approaches have emerged for designing customized formulations and medical devices for the pediatric population. Examples of customized formulations are "mini-tablets" and "oro-dispersible films," which attempt to ease the administration of solid oral dosage forms. These specially designed medical devices have shown the ability to overcome many challenges in dose administration to children. One such medical device is the "oral solid dosage pen," which allows for dose adjustment by cutting a tablet-like drug carrier at a predefined height and offers flexibility and convenience for dose administration to the pediatric population. Other medical devices, such as the Nipple Shield Delivery System (NSDS) and Medibottle also aid in efficient drug delivery to pediatrics. This review summarizes the challenges in dosage form design and advances in suitable medical devices for better administration to the pediatric population to overcome accidents due to medical errors, incomplete absorption, and toxicity.

Emerging Biomarkers and Contributing Factors of Prostate Cancer

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Prostate Cancer (PC) is one the most prominent cause of deaths in males worldwide especially in western countries. The exhaustive research into prostate cancer to date has demonstrated ELAC2, RNASEL, MSR1, NBS1, CHEK2, MYC, BCL-2, c-Kit, tumor suppressor genes, BRCA1, BRCA2, PACE4, GSTP1, PTEN,CDKN1B, NKX3.1, KLF6, FOXA1, Retinoblastoma, p53, androgen receptor, kallikreins, ETS, CYP17, SRD5A2, E-cadherin, KAI1/CD82, hepsin, AMACR, PIM1, MTA-1, EZH2, EPHB2, growth factors & its receptors, cannabinoid receptors, annexins, oxidative stress and inflammation are entailed changes underlying the initiation, development, and progression of PC. Furthermore, oncology would shift from a reactive to proactive discipline so exploring these targets open new area of research. Therefore, the present review is focused on molecular pathophysiology biomarkers for the progression of PC that would encourage the researchers and pharmaceutical industries to investigate potential therapeutic strategy to overcome demerits of currently available clinically therapies.

Dendrimers for Therapeutic Delivery: Compositions, Characterizations, and Current Status

Dendrimers, commonly referred to as arborols, offer tremendous opportunities for drug delivery, diagnostics, and treatment applications. This may be attributed to the characteristic features of their three architectural components: core, branches, and terminal groups. These components provide vast flexibility to designers. They act as highly moldable platforms that can be modified to suit the needs of application designers. Effectively, the type, length, and molecular weight of the core, branches and terminal groups may be customized to achieve desired characteristics and satisfy the demands of numerous applications. These perfectly designed multifunctional structures are reviewed in the current paper, focusing on their complex archetypical design for interphase applications; novel drug delivery applications, especially oral, ocular, pulmonary, transdermal; targeted, and controlled-release; and diagnosis and treatment of diseases like cancer, diabetes, and autoimmune disorders.

Anti-inflammatory, Analgesic and Antiulcer properties of Porphyra vietnamensis

OBJECTIVES

Aim of the present work was to investigate the anti-inflammatory, analgesic and antiulcer effects of red seaweed Porphyra vietnamensis (P. vietnamenis).

MATERIALS AND METHODS

Aqueous (POR) and alcoholic (PE) fractions were successfully isolated from P. vietnamenis. Further biological investigations were performed using a classic test of paw edema induced by carrageenan, writhing induced by acetic acid, hot plate method and naproxen induced gastro-duodenal ulcer.

RESULTS

Among the fractions POR showed better activity. POR and PE significantly (p < 0.05) reduced carrageenan induced paw edema in a dose dependent manner. In the writhing test POR significantly (p < 0.05) reduced abdominal writhes than PE. In hot plate method POR showed better analgesic activity than PE. POR showed comparable ulcers reducing potential (p<0.01) to that of omeprazole, and has more ulcer reducing potential then PE.

CONCLUSIONS

The results of this study demonstrated that P. vietnamenis aqueous fraction possesses biological activity that is close to the standards taken for the treatment of peripheral painful or/and inflammatory and ulcer conditions.

Minocycline encapsulated chitosan nanoparticles for central antinociceptive activity

The purpose of the study is to explore the central anti-nociceptive activity of brain targeted nanoparticles (NP) of minocycline hydrochloride (MH). The NP were formulated using the modified ionotropic gelation method (MHNP) and were coated with Tween 80 (T80) to target them to brain (cMHNP). The formulated nanoparticles have already been characterized for particle size, zeta potential, drug entrapment efficiency and in vitro drug release. The nanoparticles were then evaluated for pharmacodynamic activity using thermal methods. The pure drug and the formulation, MHNP were not able to show a statistically significant central analgesic activity. cMHNP on the other hand evidenced a significant central analgesic activity. Animal models evidenced that brain targeted nanoparticles may be utilized for effective delivery of central anti-nociceptive effect of MH. Further clinical studies are required to explore the activity for mankind.

Comparative release profile of sustained release matrix tablets of verapamil HCl

Introduction:

Verapamil hydrochloride (VH) is a calcium channel blocking agent used in the treatment of hypertension, cardiac arrhythmia and angina pectoris. The short half-life and high frequency of administration of VH makes it a suitable candidate for designing sustained drug delivery system. The aim of the present investigation was to develop a sustained release matrix tablet of verapamil hydrochloride (VH) using ethyl cellulose, methyl cellulose, Eudragit RS 100, hydroxypropyl methylcellulose and carboxymethyl cellulose and to evaluate the drug release kinetics.

Materials and Methods:

In order to achieve the required sustained release profile, the tablets were prepared by a wet granulation method using avicel PH 101 and magnesium stearate as binder and lubricant, respectively.

Results:

The formulated tablets were characterized for pre-compression and post-compression parameters and they were in the acceptable limits. The drug release data obtained after an in vitro dissolution study was fitted to various release kinetic models in order to evaluate the release mechanism and kinetics. The criterion for selecting the best fit model was linearity (coefficient of correlation). Drug release mechanism was found to follow a complex mixture of diffusion, swelling and erosion. Furthermore, to minimize the initial burst drug release, batches were coated by using Eudragit RS100 polymer. After coating the tablets, a better release profile of the formulated tablets was expected and the release rate of the drug was compared with the marketed SR tablet of VH.

Conclusion:

The dosage form holds the potential to control the release rate of drug and extend the duration of action of a drug.

Influence of the formulation on the maximum tolerated doses of brain targeted nanoparticles of gallic acid by oral administration in Wistar rats

Objectives

The objective of the present investigation was to study the effect of pure gallic acid (GA) and its Tween 80 coated chitosan nanoparticles (cGANP) on the maximum tolerated dose (MTD) using Wistar rats.

Methods

The animals were administered with increasing doses (dose increasing rate = 10%) of GA and cGANP orally for 28 consecutive days until the MTD was found. The animals were monitored for bodyweight, weight indices, behavioural, biochemical and histopathological changes.

Key findings

The MTD was found to be 750 mg/kg for GA and was increased to 825 mg/kg for cGANP, which indicated a significantly greater tolerance of cGANP. Slight behavioural and biochemical changes were observed above the MTD. At the MTD no significant behavioural, biochemical, histopathological changes were observed.

Conclusions

The brain targeted nanoparticles displayed considerable improvement in the tolerance profile of the drug as compared with the free drug.

Nanoparticle mediated brain targeted delivery of gallic acid: in vivo behavioral and biochemical studies for improved antioxidant and antidepressant-like activity

CONTEXT

Gallic acid had been reported to possess antidepressant like activity, which may be attributed to its CNS effects like increase in reduced glutathione levels, increased catalase activity and decreased malonaldehyde levels in brain.

OBJECTIVE

This study was designed to enhance the antidepressant-like activity of gallic acid (GA) using nanoparticulate delivery system in swiss male albino mice and to explore the possible underlying mechanisms for this activity.

METHODS

GA loaded chitosan nanoparticles (GANP) and corresponding tween 80 coated batch (cGANP) were formulated for brain targeting of GA and characterized for physicochemical parameters, morphology, differential scanning calorimetry and in vitro drug release. GA, GANP, cGANP (dose equivalent to GA 10 mg/kg, i.p.) and positive control drug, Fluoxetine (10 mg/kg, i.p.) were administered for successive seven days to male swiss albino mice. Then, the in vivo antidepressant-like activity was evaluated using Despair Swim Test (DST) and Tail Suspension Test (TST); along with the evaluation of MAO-A activity, reduced glutathione, malonaldehyde level, catalase and locomotor activity in mice. KEYFINDINGS: cGANP (equivalent to 10 mg/kg, i.p.) significantly decreased immobility period of mice in DST and TST, indicating significant antidepressant-like activity. There was no significant effect on locomotor activity of the mice by GA and its nanoparticle formulations. cGANP (10 mg/kg, i.p.) significantly decreased Monoamine oxidase-A (MAO-A) activity, malondialdehyde levels, and catalase activity in mice.

CONCLUSIONS

GA possess significant antidepressant like activity and ligand coated nanoparticle approach with improved brain targeting may serve as an effective approach to enhance such effect.

Azithromycin novel drug delivery system for ocular application

Background:

Azithromycin (AZT) is a macrolide antibiotic derived from and similar in structure to erythromycin. Oral administration of AZT is effective for the treatment of trachoma; however, topical formulations are difficult to develop because of the drug's hydrophobicity. The aim of this study is to formulate a novel topical ophthalmic delivery system of AZT.

Materials and Methods:

In the present study, ocular inserts of AZT are prepared using alginate, carbopol, and hydroxypropyl methylcellulose (HPMC) to solve the said formulation problem of drug and to facilitate ocular bioavailability. Ocular inserts were prepared by film casting method and the prepared films were subjected to investigations for their physical and mechanical properties, swelling behaviors, ex vivo bioadhesion, and in vitro drug release. Ocular irritation of the developed formulation was also checked by hen's egg chorioallantoic membrane test for ocular irritation potential.

Results:

The physicochemical, bioadhesive, and swelling properties of films were found to vary significantly depending on the type of polymers used and their combinations. The alginate films exhibited greater bioadhesion and showed higher tensile strength and elasticity than the carbopol films. HPMC addition to the films significantly affected the properties of ocular inserts. Carbopol:HPMC (30:70)-based ocular inserts sustained drug release for longest span of 6 h. The release profile of AZT showed that drug release was by both diffusion and swelling. The formulation was found to be practically nonirritant in ocular irritation studies.

Conclusion:

AZT can therefore be developed as an ocular insert delivery system for the treatment of ocular surface infections.

Dissolution enhancement of glimepiride using modified gum karaya as a carrier

OBJECTIVE

The aim of present investigation is to enhance in vitro dissolution of poorly soluble drug glimepiride by preparing solid dispersions using modified gum karaya.

MATERIALS AND METHODS

Solid dispersions of drug were prepared by solvent evaporation method using modified gum karaya as carrier. Four batches of solid dispersion (SD1, SD4, SD9, and SD14) and physical mixture (PM1, PM4, PM9, and PM14) were prepared and characterized by differential scanning colorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, powder X-Ray diffraction (X-RD), and scanning electron microscopy (SEM) studies. Equilibrium solubility studies were carried out in shaker incubator for 24 h and in vitro drug release was determined using USP Dissolution Apparatus-II.

RESULTS

Maximum solubility and in vitro dissolution were observed with Batch SD4. No significant enhancement of dissolution characteristics were observed in the corresponding physical mixture PM4. Low viscosity with comparable swelling characteristics as compared to GK of modified form of gum karaya may lead to improvement in dissolution behavior of solid dispersion batches. Also, the conversion of crystalline form of drug to amorphous form may be a responsible factor, which was further confirmed by DSC, FTIR studies, and X-RD studies. SEM photographs of batch SD4 revealed porous nature of particle surface.

CONCLUSION

Modified forms of natural carriers prove beneficial in dissolution enhancement of poorly soluble drugs and exhibited a great potential in novel drug delivery systems.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Chitosan nanoparticles: a promising system in novel drug delivery

The ability of nanoparticles to manipulate the molecules and their structures has revolutionized the conventional drug delivery system. The chitosan nanoparticles, because of their biodegradability, biocompatibility, better stability, low toxicity, simple and mild preparation methods, offer a valuable tool to novel drug delivery systems in the present scenario. Besides ionotropic gelation method, other methods such as microemulsion method, emulsification solvent diffusion method, polyelectrolyte complex method, emulsification cross-linking method, complex coacervation method and solvent evaporation method are also in use. The chitosan nanoparticles have also been reported to have key applications in parentral drug delivery, per-oral administration of drugs, in non-viral gene delivery, in vaccine delivery, in ocular drug delivery, in electrodeposition, in brain targeting drug delivery, in stability improvement, in mucosal drug delivery in controlled drug delivery of drugs, in tissue engineering and in the effective delivery of insulin. The present review describes origin and properties of chitosan and its nanoparticles along with the different methods of its preparation and the various areas of novel drug delivery where it has got its application.

Improved bioavailability through floating microspheres of lovastatin

BACKGROUND AND THE PURPOSE OF THE STUDY

Lovastatin is an antihyperlipidemic agent which has low bioavailability due to the extensive first pass metabolism. It was sought to increase gastric retention of lovastatin by development of a sustained release gastroretentive drug delivery system leading to reduced fluctuation in the plasma concentration and improved bioavailability. MEHODS: Floating microspheres were prepared by emulsion solvent diffusion technique, using various polymers and their blends. The in vitro performance was evaluated for drug-polymer compatibility, percent yield, particle size, drug entrapment efficiency, in vitro onset and duration of floatation, in vitro drug release as well as in vivo determination of serum cholesterol level.

RESULTS

The mean particle size of microspheres was observed to be between 6.9 to 9.5 µm and the maximum particle size was around 50 µm. In vivo studies of the selected batches indicated lower level of serum cholesterol compared to the marketed tablet at the same dose but was not significant.

MAJOR CONCLUSION

The data obtained in this study suggested that a microparticulate floating dosage form of lovastatin can be successfully designed to yield controlled delivery with improved therapeutic efficacy.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Sex hormone receptors in the human eye

Dissimilarities in ocular physiopathology exist between human males and females. These differences can be observed in the lacrimal and other eye-associated glands, the ocular surface, the crystalline lens, and the retinochoroid complexes. Literature on the subject revealed that because of sex steroid hormone (estrogen, progesterone, and androgen) actions, various physiological conditions, such as age, menstrual cycles, pregnancy, and menopause or andropause, where the hormone milieu changes, affect vision. Well-designed scientific studies are lacking on the subject, although such studies hold much potential value. This review analyzes the relatively new area of hormones and vision.