The Use of Nanoneedles in Drug Delivery: an Overview of Recent Trends and Applications

Nanoneedles (NN) are growing rapidly as a means of navigating biological membranes and delivering therapeutics intracellularly. Nanoneedle arrays (NNA) are among the most potential resources to achieve therapeutic effects by administration of drugs through the skin. Although this is based on well-established approaches, its implementations are rapidly developing as an important pharmaceutical and biological research phenomenon. This study intends to provide a broad overview of current NNA research, with an emphasis on existing approaches, applications, and types of compounds released by these systems. A nanoneedle-based delivery device with great spatial and temporal accuracy, minimal interference, and low toxicity could transfer biomolecules into living organisms. Due to its vast potential, NN has been widely used as a capable transportation system of many therapeutic active substances, from cancer therapy, vaccine delivery, cosmetics, and bio-sensing nanocarrier drugs to genes. The use of nanoneedles for drug delivery offers new opportunities for the rapid, targeted, and exact administration of biomolecules into cell membranes for high-resolution research of biological systems, and it can treat a wide range of biological challenges. As a result, the literature has analyzed existing patents to emphasize the status of NNA in biological applications.

Development and Characterization of Pullulan-Based Orodispersible Films of Iron

Iron deficiency is the principal cause of nutritional anemia and it constitutes a major health problem, especially during pregnancy. Despite the availability of various non-invasive traditional oral dosage forms such as tablets, capsules, and liquid preparations of iron, they are hard to consume for special populations such as pregnant women, pediatric, and geriatric patients with dysphagia and vomiting tendency. The objective of the present study was to develop and characterize pullulan-based iron-loaded orodispersible films (i-ODFs). Microparticles of iron were formulated by a microencapsulation technique, to mask the bitter taste of iron, and ODFs were fabricated by a modified solvent casting method. Morphological characteristics of the microparticles were identified by optical microscopy and the percentage of iron loading was evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES). The fabricated i-ODFs were evaluated for their morphology by scanning electron microscopy. Other parameters including thickness, folding endurance, tensile strength, weight variation, disintegration time, percentage moisture loss, surface pH, and in vivo animal safety were evaluated. Lastly, stability studies were carried out at a temperature of 25 °C/60% RH. The results of the study confirmed that pullulan-based i-ODFs had good physicochemical properties, excellent disintegration time, and optimal stability at specified storage conditions. Most importantly, the i-ODFs were free from irritation when administered to the tongue as confirmed by the hamster cheek pouch model and surface pH determination. Collectively, the present study suggests that the film-forming agent, pullulan, could be successfully employed on a lab scale to formulate orodispersible films of iron. In addition, i-ODFs can be processed easily on a large scale for commercial use.

Development and Evaluation of Solid Lipid Nanoparticles for the Clearance of Aβ in Alzheimer's Disease

Aggregation of Amyloid-β (Aβ) leads to the formation and deposition of neurofibrillary tangles and plaques which is the main pathological hallmark of Alzheimer's disease (AD). The bioavailability of the drugs and their capability to cross the BBB plays a crucial role in the therapeutics of AD. The present study evaluates the Memantine Hydrochloride (MeHCl) and Tramiprosate (TMPS) loaded solid lipid nanoparticles (SLNs) for the clearance of Aβ on SHSY5Y cells in rat hippocampus. Molecular docking and in vitro Aβ fibrillation were used to ensure the binding of drugs to Aβ. The in vitro cell viability study showed that the M + T SLNs showed enhanced neuroprotection against SHSY5Y cells than the pure drugs (M + T PD) in presence of Aβ (80.35µM ± 0.455 µM) at a 3:1 molar ratio. The Box-Behnken Design (BBD) was employed to optimize the SLNs and the optimized M + T SLNs were further characterized by %drug entrapment efficiency (99.24 ± 3.24 of MeHCl and 89.99 ± 0.95 of TMPS), particle size (159.9 ± 0.569 nm), PDI (0.149 ± 0.08), Zeta potential (-6.4 ± 0.948 mV), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM) and in vitro drug release. The TEM & AFM analysis showed irregularly spherical morphology. In vitro release of SLNs was noted up to 48 h; whereas the pure drugs released completely within 3 hrs. M + T SLNs revealed an improved pharmacokinetic profile and a 4-fold increase in drug concentration in the brain when compared to the pure drug. Behavioral tests showed enhanced spatial memory and histological studies confirmed reduced Aβ plaques in rat hippocampus. Furthermore, the levels of Aβ decreased in AlCl₃-induced AD. Thus, all these noted results established that the M + T SLNs provide enhanced neuroprotective effects when compared to pure and individual drugs and can be a promising therapeutic strategy for the management of AD.

3-Methoxy Carbazole Impedes the Growth of Human Breast Cancer Cells by Suppressing NF-κB Signaling Pathway

Breast cancer represents the most frequently occurring cancer globally among women. As per the recent report of the World Health Organization (WHO), it was documented that by the end of the year 2020, approximately 7.8 million females were positively diagnosed with breast cancer and in 2020 alone, 685,000 casualties were documented due to breast cancer. The use of standard chemotherapeutics includes the frontline treatment option for patients; however, the concomitant side effects represent a major obstacle for their usage. Carbazole alkaloids are one such group of naturally-occurring bioactive compounds belonging to the Rutaceae family. Among the various carbazole alkaloids, 3-Methoxy carbazole or C13H11NO (MHC) is obtained from Clausena heptaphylla as well as from Clausena indica. In this study, MHC was investigated for its anti-breast cancer activity based on molecular interactions with specific proteins related to breast cancer, where the MHC had predicted binding affinities for NF-κB with −8.3 kcal/mol. Furthermore, to evaluate the biological activity of MHC, we studied its in vitro cytotoxic effects on MCF-7 cells. This alkaloid showed significant inhibitory effects and induced apoptosis, as evidenced by enhanced caspase activities and the cellular generation of ROS. It was observed that a treatment with MHC inhibited the gene expression of NF-kB in MCF-7 breast cancer cells. These results suggest that MHC could be a promising medical plant for breast cancer treatment. Further studies are needed to understand the molecular mechanisms behind the anticancer action of MHC.

A Comprehensive Review of Patented Technologies to Fabricate Orodispersible Films: Proof of Patent Analysis (2000–2020)

Orodispersible films (ODFs)are ultra-thin, stamp-sized, rapidly disintegrating, and attractive oral drug delivery dosage forms best suited for the pediatric and geriatric patient populations. They can be fabricated by different techniques, but the most popular, simple, and industrially applicable technique is the solvent casting method (SCM). In addition, they can also be fabricated by extrusion, printing, electrospinning, and by a combination of these technologies (e.g., SCM + printing). The present review is aimed to provide a comprehensive overview of patented technologies of the last two decades to fabricate ODFs. Through this review, we present evidence to adamantly confirm that SCM is the most popular method while electrospinning is the most recent and upcoming method to fabricate ODFs. We also speculate around the more patent-protected technologies especially in the domain of printing (two or three-dimensional), extrusion (ram or hot-melt extrusion), and electrospinning, or a combination of the methods thereof.

Can manipulation of gut microbiota really be transformed into an intervention strategy for cardiovascular disease management?

Recent advancement in manipulation techniques of gut microbiota either ex vivo or in situ has broadened its plausible applicability for treating various diseases including cardiovascular disease. Several reports suggested that altering gut microbiota composition is an effective way to deal with issues associated with managing cardiovascular diseases. However, actual translation of gut microbiota manipulation-based techniques into cardiovascular-therapeutic approach is still questionable. This review summarized the evidence on challenges, opportunities, recent development, and future prospects of gut microbiota manipulation for targeting cardiovascular diseases. Initially, issues associated with current cardiovascular diseases treatment strategy, association of gut microbiota with cardiovascular disease, and its influence on cardiovascular drugs were discussed, followed by applicability of gut microbiota manipulation as a cardiovascular disease intervention strategy along with its challenges and future prospects. Despite the fact that the gut microbiota is rugged, interventions like probiotics, prebiotics, synbiotics, fecal microbiota transplantation, fecal virome transplantation, antibiotics, diet changes, and exercises could manipulate it. Advanced techniques like administration of engineered bacteriophages and bacteria could also be employed. Intensive exploration revealed that if sufficiently controlled approach and proper monitoring were applied, gut microbiota could provide a compelling answer for cardiovascular therapy.

Fabrication and Characterization of Paclitaxel and Resveratrol Loaded Soluplus Polymeric Nanoparticles for Improved BBB Penetration for Glioma Management

Gliomas are one of the prominent cancers of the central nervous system with limited therapeutic modalities. The present investigation evaluated the synergistic effect of paclitaxel (PAX) and resveratrol (RESV)-loaded Soluplus polymeric nanoparticles (PNPs) against glioma cell lines along with in vivo pharmacokinetics and brain distribution study. PAX-RESV-loaded PNPs were prepared by the thin film hydration technique and optimized for different dependent and independent variables by using DoE (Design-Expert) software. The in vitro physiochemical characterization of prepared PAX-RESV-loaded PNPs exhibited appropriate particle size, PDI and % encapsulation efficiency. Cytotoxicity assay revealed that PTX-RESV loaded PNPs had a synergistic antitumor efficacy against C6 glioma cells compared with single and combined pure drugs. Finally, the pharmacokinetic and brain distribution studies in mice demonstrated that the PNPs significantly enhanced the bioavailability of PTX-RESV PNPs than pure PAX and RESV. Thus, the study concluded that PAX-RESV PNPs combination could significantly enhance anti-glioma activity, and this could be developed into a potential glioma treatment strategy.

Prospection of chitosan and its derivatives in wound healing: Proof of patent analysis (2010-2020)

Disruption in the normal anatomy and physiology of the skin often leads to wound formation. Its healing is a pretty complex and dynamic biological process with different phases. While there are many biopolymers (and their derivatives) for wound healing purposes. One of the most popular, promising, progressive and attention-grabbing biopolymers is 'chitosan'. It is a polysaccharide biopolymer that has tremendous potential in augmenting the process of wound healing. Most importantly, the derivatives of chitosan have heavily attracted the scientific community's attention to employing them in various formulations for wound healing applications. The prime focus of the present review is to provide scientific and technological prospection about chitosan and its derivatives for wound healing activity, starting from 2010 to 2020. Besides, the review also focuses about toxicity, different formulations and products of chitosan that are currently under clinical trials for wound healing purposes are described. Through this review, we present evidence that abundantly confirms that there is a growing interest in the domain of wound healing using novel, inventive, useful and patent protected chitosan derivatives. We speculate the possibility of more patent protected chitosan derivatives in the future for wound healing applications.

Printing Methods in the Production of Orodispersible Films

Orodispersible film (ODF) formulations are promising and progressive drug delivery systems that are widely accepted by subjects across all the age groups. They are traditionally fabricated using the most popular yet conventional method called solvent casting method. The most modern and evolving method is based on printing technologies and such printed products are generally termed as printed orodispersible films (POFs). This modern technology is well suited to fabricate ODFs across different settings (laboratory or industrial) in general and in a pharmacy setting in particular. The present review provides an overview of various printing methods employed in fabricating POFs. Particularly, it provides insight about preparing POFs using inkjet, flexographic, and three-dimensional printing (3DP) or additive manufacturing techniques like filament deposition modeling, hot-melt ram extrusion 3DP, and semisolid extrusion 3DP methods. Additionally, the review is focused on patenting trends in POFs using ESPACENET, a European Patent Office search database. Finally, the review captures future market potential of 3DP in general and ODFs market potential in particular.

Nanodelivery Systems Targeting Epidermal Growth Factor Receptors for Glioma Management

A paradigm shift in treating the most aggressive and malignant form of glioma is continuously evolving; however, these strategies do not provide a better life and survival index. Currently, neurosurgical debulking, radiotherapy, and chemotherapy are the treatment options available for glioma, but these are non-specific in action. Patients invariably develop resistance to these therapies, leading to recurrence and death. Receptor Tyrosine Kinases (RTKs) are among the most common cell surface proteins in glioma and play a significant role in malignant progression; thus, these are currently being explored as therapeutic targets. RTKs belong to the family of cell surface receptors that are activated by ligands which in turn activates two major downstream signaling pathways via Rapidly Accelerating Sarcoma/mitogen activated protein kinase/extracellular-signal-regulated kinase (Ras/MAPK/ERK) and phosphatidylinositol 3-kinase/a serine/threonine protein kinase/mammalian target of rapamycin (PI3K/AKT/mTOR). These pathways are critically involved in regulating cell proliferation, invasion, metabolism, autophagy, and apoptosis. Dysregulation in these pathways results in uncontrolled glioma cell proliferation, invasion, angiogenesis, and cancer progression. Thus, RTK pathways are considered a potential target in glioma management. This review summarizes the possible risk factors involved in the growth of glioblastoma (GBM). The role of RTKs inhibitors (TKIs) and the intracellular signaling pathways involved, small molecules under clinical trials, and the updates were discussed. We have also compiled information on the outcomes from the various endothelial growth factor receptor (EGFR)-TKIs-based nanoformulations from the preclinical and clinical points of view. Aided by an extensive literature search, we propose the challenges and potential opportunities for future research on EGFR-TKIs-based nanodelivery systems.

Microneedles Drug Delivery Systems for Treatment of Cancer: A Recent Update

Microneedles (MNs) are tiny needle like structures used in drug delivery through layers of the skin. They are non-invasive and are associated with significantly less or no pain at the site of administration to the skin. MNs are excellent in delivering both small and large molecules to the subjects in need thereof. There exist several strategies for drug delivery using MNs, wherein each strategy has its pros and cons. Research in this domain lead to product development and commercialization for clinical use. Additionally, several MN-based products are undergoing clinical trials to evaluate its safety, efficacy, and tolerability. The present review begins by providing bird's-eye view about the general characteristics of MNs followed by providing recent updates in the treatment of cancer using MNs. Particularly, we provide an overview of various aspects namely: anti-cancerous MNs that work based on sensor technology, MNs for treatment of breast cancer, skin carcinoma, prostate cancer, and MNs fabricated by additive manufacturing or 3 dimensional printing for treatment of cancer. Further, the review also provides limitations, safety concerns, and latest updates about the clinical trials on MNs for the treatment of cancer. Furthermore, we also provide a regulatory overview from the "United States Food and Drug Administration" about MNs.

Design and formulation of polymeric nanosponge tablets with enhanced solubility for combination therapy

Three drugs namely caffeine, paracetamol, and aceclofenac are commonly used for treating various acute and chronic pain related ailments. These 3 drugs have varied solubility profiles, and formulating them into a single tablet did not have the desired dissolution profile for drug absorption. The objective of the present research was to tailor the drug release profile by altering drug solubility. This was achieved by loading the drug into nanosponges. Here, three-dimensional colloidal nanosponges were prepared using β-cyclodextrin with dimethyl carbonate as a cross-linker using the hot-melt compression method. The prepared nanosponges were characterized by FTIR, ¹H NMR spectroscopy, DSC, XRPD studies and SEM. The FTIR and DSC results obtained indicated polymer-drug compatibility. The ¹H NMR spectroscopy results obtained indicated the drug entrapment within nanosponges with the formation of the inclusion complex. XRPD studies showed that the loaded drug had changed crystalline properties altering drug solubility. SEM photographs revealed the porous and spongy texture on the surface of the nanosponge. Box–Behnken experimental design was adopted for the optimization of nanosponge synthesis. Among the synthesized nanosponges containing paracetamol, aceclofenac and caffeine, batch F3–P31, F3–A31 and F3–C31 were considered optimized. Their particle size was 185, 181 and 199 nm with an entrapment efficiency of 81.53, 84.96, and 89.28% respectively. These optimized nanosponges were directly compressed into tablets and were studied for both pre and post-compression properties including in vitro drug release. The prepared tablet showed desired drug dissolution properties compared to the pure drug. The above outcomes indicated the applicability of nanosponges in modulating the drug release with varied solubility for combination therapy.

Polymeric nanosponges as potential carriers for successful combination therapy of poorly soluble drugs (paracetamol, aceclofenac, caffeine).

Patent Perspective on Orodispersible Films

The traditional oral dosage forms (tablets, capsules, syrups, and elixirs) suffer from various disadvantages. They are pretty challenging to administer to patients with dysphagia, mucositis, and vomiting tendency. Therefore, gaining patient compliance using conventional dosage forms is highly cumbersome. One of the most transformative and innovative approaches to overcome such challenges is Orodispersible Films, a Novel Drug Delivery System. They are easy to consume, no need to chew or swallow and they do not even require water for consumption. Therefore, several drugs have been converted into orodispersible films to gain patient compliance. With the advent of these film formulations, new innovations are erupting and accordingly, companies in India are actively protecting them by filing ordinary patent applications in India and internationally under the Patent Cooperation Treaty. Patenting in India poses unique patentability challenges when compared with rest of the world. Nonetheless, meeting all the challenges and obtaining a valid patent not only help in recouping the cost involved in developing new drugs and its novel drug delivery systems but also helps in taking legal action against alleged infringers. This review article identifies key active Indian players in the domain of ODF based on their patent filings in India (and abroad) and also identifies the challenges they face to obtain a grant.

A Paradigm Shift in the Development of Anti-Candida Drugs

BACKGROUND

The considerable increase in the incidence of Candida infection in recent times has prompted the use of numerous antifungal agents, which has resulted in the development of resistance towards various antifungal agents. With rising Candida infections, the need for design and development of novel antifungal agents is in great demand. However, new therapeutic approaches are very essential in preventing the mortality rate and improving the patient outcome in those suffering from Candida infections.

OBJECTIVE

The present review objective is to describe the burden, types of Candidiasis, mechanism of action of antifungal agents and its resistance and the current novel approaches used to combat candidiasis.

METHODS

We have collected and analyzed 135 different peer-reviewed literature studies pertinent to candidiasis. In this review, we have compiled the major findings from these studies.

RESULTS AND CONCLUSION

The review describes the concerns related to candidiasis, its current treatment strategy, resistance mechanisms and imminent ways to tackle the problem. The review explored that natural plant extracts and essential oils could act as sources of newer therapeutic agents, however, the focus was on novel strategies, such as combinational therapy, new antibodies, utilization of photodynamic therapy and adaptive transfer primed immune cells with emphasis on the development of effective vaccination.

Current Perspectives on Novel Drug Carrier Systems and Therapies for Management of Pancreatic Cancer: An Updated Inclusive Review

Pancreatic cancer (PC) is one of the most fatal solid tumors, resulting in more than 250,000 deaths per year globally. It is the eighth leading cause of death from cancer in men and women throughout the world and is now third leading cause of cancer-related deaths in the United States. In addition, the worldwide occurrence of PC ranges from 1 to 10 cases per 100,000 people, indicating a higher incidence in developed countries. Most patients with locally advanced or metastatic disease are not candidates for curative resection due to enormously poor prognosis. Substantial efforts have been taken during the past decade to distinguish better treatments in the absence of efficient screening methods. Regardless of wide-ranging efforts, various systems and therapies have shown insufficient efficacy for PC patients. Therefore, the development of novel drug delivery systems, strategies, and diverse therapeutic approaches to improve the range of active molecules for the treatment of PC is critical. Currently, cancer research focuses on improving the treatment of PC via diverse novel drug delivery systems of chemotherapeutic agents. These novel drug delivery systems consist of nanoparticles and liposomes. Strategies or therapeutic approaches intended for PC include radiation therapy, ablation therapy, and gene therapy. These systems and approaches can carry the drug molecules to targeted cancer cells to enhance the effectiveness of tumor penetration. The present review encloses existing novel drug carrier systems and approaches for PC management.

Development and Efficacy Assessment of an Enteric Coated Porous Tablet Loaded With F4 Fimbriae for Oral Vaccination of Piglets against F4+ Escherichia coli Infections

Enterotoxigenic Escherichia coli (ETEC) infection is one of the major causes contributing to the development of diarrhoea and mortality in new born, suckling and newly weaned piglets. To date, no preventive/treatment strategy showed promising results, which could be due to the lack of potent vaccines, and/or due to the development of resistance of ETEC to antibiotics. Therefore, in the present investigation, a novel porous sodium alginate (SA) tablet formulation loaded with F4 fimbriae antigen was developed and tested for efficacy against ETEC infections in piglet models. Precompression parameters of the powder mixes and post compression parameters of tablets have been evaluated and results were found to be satisfactory. Loading of F4 fimbrial antigens into the tablets was achieved by inducing pores in the tablets via the sublimation of camphor followed by incubation with purified F4 fimbriae. The loaded tablets have been coated with Eudragit L100 to protect the F4 fimbriae from (a) highly acidic gastric environment; (b) proteolytic cleavage by pepsin; and (c) to promote subsequent release in the intestine. Evaluation of developed F4 fimbrial tablets in a Pig model demonstrated induction of mucosal immunity, and a significant reduction of F4+ E. coli in faeces. Therefore, F4 fimbriae loaded porous tablets could be a novel oral vaccination candidate to induce mucosal and systemic immunity against ETEC infections.

Mucosal vaccines: a paradigm shift in the development of mucosal adjuvants and delivery vehicles

Mucosal immune responses are the first-line defensive mechanisms against a variety of infections. Therefore, immunizations of mucosal surfaces from which majority of infectious agents make their entry, helps to protect the body against infections. Hence, vaccinization of mucosal surfaces by using mucosal vaccines provides the basis for generating protective immunity both in the mucosal and systemic immune compartments. Mucosal vaccines offer several advantages over parenteral immunization. For example, (i) ease of administration; (ii) non-invasiveness; (iii) high-patient compliance; and (iv) suitability for mass vaccination. Despite these benefits, to date, only very few mucosal vaccines have been developed using whole microorganisms and approved for use in humans. This is due to various challenges associated with the development of an effective mucosal vaccine that can work against a variety of infections, and various problems concerned with the safe delivery of developed vaccine. For instance, protein antigen alone is not just sufficient enough for the optimal delivery of antigen(s) mucosally. Hence, efforts have been made to develop better prophylactic and therapeutic vaccines for improved mucosal Th1 and Th2 immune responses using an efficient and safe immunostimulatory molecule and novel delivery carriers. Therefore, in this review, we have made an attempt to cover the recent advancements in the development of adjuvants and delivery carriers for safe and effective mucosal vaccine production.

Fabrication and characterization of carboxymethylated bael fruit gum with potential mucoadhesive applications

Carboxymethylation of bael fruit gum was achieved through its reaction with monochloroacetic acid in the presence of sodium hydroxide as a catalyst at different reaction conditions.

Design of phosphated cross-linked microspheres of bael fruit gum as a biodegradable carrier

Present work was aimed at designing of phosphated cross-linked microspheres of bael fruit gum (BFG) by emulsification method using sodium-tri-meta phosphate as a cross-linking agent for treatment of colon cancer using 5-fluorouracil as model drug. Stirring speed was found to be 1,000 rpm for about 5 h to be optimal to obtain reproducible microspheres. It was found that there is an increase in particle size as polymer concentration is increased whereas a reduction in particle size was observed as there is increase in stirring speed. Cross-linked BFG microspheres were successfully prepared by emulsification method. Optimum surfactant concentration was found to be 2 % w/w. Scanning electron microscopy studies showed that the drug-loaded microspheres were non-aggregated and in spherical shape. Differential scanning calorimetry and Fourier transform infrared-spectroscopy studies showed that drug and excipients are compatible. Release studies showed that drug release was more profound in cecal medium induced with enzymes causing degradation of the cross linked BFG than that of the release showed in simulated intestinal fluid. Stability studies showed that there were no significant changes in the drug content and physical appearance of microspheres.

Calcipotriol delivery into the skin as emulgel for effective permeation

The objective of this work is to formulate and evaluate an emulgel containing calcipotriol for treatment of psoriasis. Emulgels have emerged as a promising drug delivery system for the delivery of hydrophobic drugs. Isopropyl alcohol and polyethylene glycol have been employed as permeation enhancers. Formulation chart is made with seven formulations, evaluated for physical parameters, drug content, viscosity, thixotropy, spreadability, extrudability, mucoadhesion, diffusion studies, skin irritation test along with short term stability studies. Carbopolis is reported to have a direct influence on appearance and viscosity of final formulation. The photomicroscopic evaluations showed the presence of spherical globules in size range of 10–15 μm. Rheograms revealed that all the formulations exhibited pseudoplastic flow. Optimized formulation (F6) had shown 86.42 ± 2.0% drug release at the end of 8 h study. The release rate through dialysis membrane and rat skin is higher when compared to commercial calcipotriol ointment. Hence it is concluded that calcipotriol can be delivered topically with enhanced penetration properties when formulated as emulgel.

Development and evaluation of microporous osmotic tablets of diltiazem hydrochloride

Microporous osmotic tablet of diltiazem hydrochloride was developed for colon targeting. These prepared microporous osmotic pump tablet did not require laser drilling to deliver the drug to the specific site of action. The tablets were prepared by wet granulation method. The prepared tablets were coated with microporous semipermeable membrane and enteric polymer using conventional pan coating process. The incorporation of sodium lauryl sulfate (SLS), a leachable pore-forming agent, could form in situ delivery pores while coming in contact with gastrointestinal medium. The effect of formulation variables was studied by changing the amounts of sodium alginate and NaCMC in the tablet core, osmogen, and that of pore-forming agent (SLS) used in the semipermeable coating. As the amount of hydrophilic polymers increased, drug release rate prolonged. It was found that drug release was increased as the concentration of osmogen and pore-former was increased. Fourier transform infrared spectroscopy and Differential scanning calorimetry results showed that there was no interaction between drug and polymers. Scanning electron microscopic studies showed the formation of pores after predetermined time of coming in contact with dissolution medium. The formation of pores was dependent on the amount of pore former used in the semipermeable membrane. in vitro results showed acid-resistant, timed release at an almost zero order up to 24 hours. The developed osmotic tablets could be effectively used for prolonged delivery of Diltiazem HCl.

Preparation, evaluation and bioavailability studies of indomethacin-bees wax microspheres

The present study envisages the preparation of microspheres containing indomethacin (IM) as model drug and bees wax as carrier, and to compare the in vitro release and pharmacokinetics of prepared IM formulation with commercially available oral formulation MicrocidSR. The microsphere formulations were prepared by meltable emulsified dispersion and cooling induced solidification. Surface morphology of microspheres has been evaluated using scanning electron microscopy (SEM). The SEM images revealed the spherical shape of microspheres and more than 98.0% of the isolated microspheres were in the size range 115-855 mum. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy studies indicated that the drug after encapsulation with bees wax was stable and compatible. A single dose randomized complete cross over study of IM (75 mg) microspheres was carried out on 8 healthy Albino sheeps. Plasma IM concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The T (max), C (max), AUC(O-24) and T (1/2) values of MicrocidSR and optimized formulation were 3.0 h, 2038 +/- 51.31 ng/ml, 9528 +/- 129.65 ng/ml h(-1), and 2.59 +/- 0.02 h(-1); and 3.2 h, 1940 +/- 22.61 ng/ml, 8751 +/- 41.32 ng/ml h(-1), and 2.68 +/- 0.02 h(-1), respectively. Beeswax microspheres showed controlled release and it can be concluded that both the prepared formulation and MicrocidSR are bioequivalent.

Effect of hydrophilic natural gums in formulation of oral-controlled release matrix tablets of propranolol hydrochloride

In order to develop a controlled delivery of highly water-soluble propranolol hydrochloride (PPHCl) using hydrophilic natural gums (xanthan gum [X] and locust bean gum [LBG]) as cost-effective, nontoxic, easily available. The granules of PPHCl were prepared by wet granulation method using a different ratios drug: gum ratios of X, LBG and XLBG(X and LBG in 1:1 ratios). To increase the flowability and compressibility of the granules, and to prevent its adhesion to punch and die, magnesium stearate and talc were added to the granules in 1:2 ratios before punching. The tablet was analysed to determine hardness, friability, % assay and invitro release study was carried out. The release of PPHCl from a gelatinous swollen mass, which controls the diffusion of drug molecules through the polymeric material into aqueous medium. The XLBG matrice shows precise controlled release than the X and LBG matrice because of burst effect and fast release in case of X and LBG matrice respectively and there was no chemical interaction between drug and polymer in XLBG formulation as confirmed by FTIR studies. First pass effect of PPHCl can be avoided by these formulations. Matrices with XLBG show zero-order release via swelling, diffusion and relaxation mechanism. The XLBG matrice leads to more precise result than X and LBG alone by the utilization of synergistic interaction between two biopolymers and uniformity in the hydration layer in dissolution media. However, according to the similarity factor (f(2)) XLBG3 were the most similar formulations to Lol-SR as the reference standard.