Pharmacokinetics and pharmacodynamics of controlled release insulin loaded PLGA microcapsules using dry powder inhaler in diabetic rats

Taking leads out of nature, can nano deliver us from COVID-like pandemics?

The COVID-19 crisis has alerted the research community to re-purpose scientific tools that can effectively manage emergency pandemic situations. Researchers were never so desperate to discover a 'magic bullet' that has significant clinical benefits with minimal or no side effects. At the beginning of the pandemic, due to restricted access to traditional laboratory techniques, many research groups delved into computational screening of thousands of lead molecules that could inhibit SARS-CoV-2 at one or more stages of its infectious cycle. Several in silico studies on natural derivatives point out their potency against SARS-CoV-2 proteins. However, theoretical predictions and existing knowledge on related molecules reflect their poor oral bioavailability due to biotransformation in the gut and liver. Nanotechnology has evolved into a key field for precise and controlled delivery of various drugs that lack aqueous solubility, have low oral bioavailability and possess pronounced toxicity in their native form. In this review, we discuss various nanoformulations of natural products with favorable ADME properties, and also briefly explore nano-drug delivery to lungs, the primary site of SARS-CoV-2 infection. Natural products are also envisioned to augment nanotechnology-based 1) personnel protective equipment for ex vivo viral inactivation and 2) wearable sensors that perform rapid and non-invasive analysis of volatile organic compounds in exhaled breath of the infected person after therapeutic food consumption.

NANO-BIOTECHNOLOGY AND ITS INNOVATIVE PERSPECTIVE IN DIABETES MANAGEMENT

Diabetes occurs due to the imbalance of glucose in the body known as glucose homeostasis, thus leading to metabolic changes in the body. The two stages hypoglycemia or hyperglycemia classify diabetes into various categories. Various bio-nanotechnological approaches are coupled up with nano particulates, polymers, liposome, various gold plated and solid lipid particulates, regulating transcellular transport, non specific cellular uptake, and paracellular transport, leading to oral, trans-dermal , pulmonary, buccal , nasal , specific gene oriented administration to avoid the patient's non compliance with the parental routes of administration. Phytochemicals are emerging strategies for the future prospects of diabetes management.

A triple combination 'nano' dry powder inhaler for tuberculosis: in vitro and in vivo pulmonary characterization

Inhalation route of drug delivery is the most favorable for pulmonary infections wherein direct drug delivery is desired to the lungs. Tuberculosis is one such infection suffering from poor therapeutic efficacy because of low patient compliance due to high drug dosing and lengthy treatment protocols. The current research work was undertaken to develop a dry powder inhaler (DPI) for administration of three first-line antitubercular antibiotics directly to the lungs to improve the treatment rates. Nanoformulations of isoniazid, pyrazinamide, and rifampicin were prepared, spray-dried to obtain a dry powder system, and blended with inhalation grade lactose to develop the DPI. The DPI was evaluated for its flow properties, pulmonary deposition, dissolution profile, and stability. The DPI possessed excellent flow properties with a fine particle fraction of 45% and a mass median aerodynamic diameter of approximately 5 µm indicating satisfactory lung deposition. In vitro drug release exhibited a sustained release of the formulations. In vivo studies showed a prolonged deposition in the lung at elevated concentrations compared to oral therapy. Stability studies proved that the formulation remained stable at accelerated and long-term stability conditions. The DPI could complement the existing oral therapy in enhancing the therapeutic efficacy in patients.

Emerging Nano- and Micro-Technologies Used in the Treatment of Type-1 Diabetes

Type-1 diabetes is characterized by high blood glucose levels due to a failure of insulin secretion from beta cells within pancreatic islets. Current treatment strategies consist of multiple, daily injections of insulin or transplantation of either the whole pancreas or isolated pancreatic islets. While there are different forms of insulin with tunable pharmacokinetics (fast, intermediate, and long-acting), improper dosing continues to be a major limitation often leading to complications resulting from hyper- or hypo-glycemia. Glucose-responsive insulin delivery systems, consisting of a glucose sensor connected to an insulin infusion pump, have improved dosing but they still suffer from inaccurate feedback, biofouling and poor patient compliance. Islet transplantation is a promising strategy but requires multiple donors per patient and post-transplantation islet survival is impaired by inflammation and suboptimal revascularization. This review discusses how nano- and micro-technologies, as well as tissue engineering approaches, can overcome many of these challenges and help contribute to an artificial pancreas-like system.

In-vitro and in-vivo respiratory deposition of a developed metered dose inhaler formulation of an anti-migraine drug

Enhancement of zolmitriptan bioavailability through development of micronized zolmitriptan pressurized metered dose inhaler (MDI) as an alternative to its traditional drug delivery systems. A reversed phase HPLC method for zolmitriptan determination was developed and evaluated. Micronized zolmitriptan MDI formulations were prepared using two different propellants. The prepared formulations were evaluated for mean shot weight, drug content, and leakage rate in addition to in-vitro deposition using next generation impactor where mass median aerodynamic diameter (MMAD), geometric standard deviation (GSD), fine particle dose, fine particle fraction (FPF), emitted dose (ED), and dispersibility were determined. The selected formulation was evaluated for in-vivo bronchial absorption in rats. The physicochemical characters of the prepared formulations were found to be dependent mainly on the vapor pressure of the used propellant. MDI formulation prepared with HFA 134a propellant was found to have the lowest MMAD (3.47 ± 0.65) with GSD of 2.3 ± 0.4. It also had the highest FPF (41.9), ED (89.26 ± 2.35) with dispersibility of 46.9%. This formulation, when applied to rats, resulted in faster Tmax (27 ± 5 min) with higher Cmax (1236 ± 116 ng/mL) and AUC(0-12) (3375 ± 482 ng/mL·h) over the oral tablet. Its relative bioavailability was 72.7% which was 1.25 times higher than the oral tablet relative bioavailability. Zolmitriptan MDI formulation was developed using micronized zolmitriptan powder without further modification or particle engineering. The developed formulation using HFA 134a propellant could be favorable alternative, with enhanced bioavailability, to zolmitriptan oral tablet for acute migraine treatment.

Biopharmaceutical characterization of nebulized antimicrobial agents in rats: 1. Ciprofloxacin, moxifloxacin, and grepafloxacin

The aim of this study was to evaluate the biopharmaceutical characteristics of three fluoroquinolones (FQs), ciprofloxacin (CIP), moxifloxacin (MXF), and grepafloxacin (GRX), after delivery via a nebulized aerosol to rats. Bronchoalveolar lavages (BAL) were conducted 0.5, 2, 4, and 6 h after FQ intravenous administration and nebulized aerosol delivery to estimate epithelial lining fluid (ELF) drug concentrations. Plasma drug concentrations were also measured, and profiles of drug concentrations versus time after intravenous administration and nebulized aerosol delivery were virtually superimposable, attesting for rapid and complete systemic absorption of FQs. ELF drug concentrations were systematically higher than corresponding plasma drug concentrations, whatever the route of administration, and average ELF-to-unbound plasma drug concentration ratios post-distribution equilibrium did not change significantly between the ways of administration and were equal: 4.0 ± 5.3 for CIP, 12.6 ± 7.3 for MXF, and 19.1 ± 10.5 for GRX (means ± standard deviations). The impact of macrophage lysis on estimated ELF drug concentrations was significant for GRX but reduced for MXF and CIP; therefore, simultaneous pharmacokinetic modeling of plasma and ELF drug concentrations was only performed for the latter two drugs. The model was characterized by a fixed volume of ELF (VELF), passive diffusion clearance (QELF), and active efflux clearance (CLout) between plasma and ELF, indicating active efflux transport systems. In conclusion, this study demonstrates that ELF drug concentrations of these three FQs are several times higher than plasma drug concentrations, probably due to the presence of efflux transporters at the pulmonary barrier level, but no biopharmaceutical advantage of FQ nebulization was observed compared with intravenous administration.

Heuristic modeling of macromolecule release from PLGA microspheres

Dissolution of protein macromolecules from poly(lactic-co-glycolic acid) (PLGA) particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs), feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP) networks with a root-mean-square error (RMSE) of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE) of 14.3. The equation was characterized by four parameters, thus feasible (applicable) to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with comparable predictability to the ANN model.

Lactose engineering for better performance in dry powder inhalers

Dry powder inhaler (DPI) is generally formulated as a powder mixture of coarse carrier particles and micronized drug with aerodynamic diameters of 1-5 μm. Carrier particles are used to improve drug particle flowability, thus improving dosing accuracy, minimizing the dose variability compared with drug alone and making them easier to handle during manufacturing operations. Lactose is the most common and frequently used carrier in DPIs formulations and nowadays various inhalation grades of lactose with different physico-chemical properties are available on the market. Therefore, the purpose of this manuscript is to review evolution of lactose as a carrier in inhalable formulations, their production and the impact of its physico-chemical properties on drug dispersion. This review offers a perspective on the current reported studies to modify lactose for better performance in DPIs.

Controlled release of modified insulin glargine from novel biodegradable injectable gels

The objective of this study was to investigate the duration of biological effects of modified insulin glargine released from a novel biodegradable injectable gel in type II diabetic Zucker diabetic fatty (ZDF) rats. Modified insulin glargine was purified from the marketed formulation by process of dialysis followed by freeze-drying, and the purity was confirmed by the single peak, corresponding to insulin glargine in the HPLC chromatogram. To determine and to compare the biological activity of purified insulin glargine with marketed formulation, it was suspended in isotonic saline solutions and administered subcutaneously to ZDF rats at a dose of 10 IU/kg of insulin and the blood glucose levels were measured. The blood glucose levels of ZDF rats after a subcutaneous injection of a suspension of purified insulin glargine decreased below 200 mg/dL within 2 h and remained at this level up to 6 h, then steadily raised above 400 mg/dL in 12 h. Insulin glargine particles were loaded into a novel biodegradable injectable gel formulation prepared from a blend of polylactic-co-glycolic acid (PLGA) and biocompatible plasticizers. Approximately 0.1 mL of insulin glargine-loaded gel prepared with PLGA was administered subcutaneously to the ZDF rats, and blood glucose levels were measured. The PLGA gel formulations prepared with insulin glargine particles had duration of action of 10 days following a single subcutaneous injection. The addition of zinc sulfate to the formulations prepared with purified insulin glargine particles further slowed down the drop in blood glucose concentrations.