Development of press-coated, floating-pulsatile drug delivery of lisinopril

Glyceroniosomes for enhanced intestinal absorption of hydrochlorothiazide and lisinopril in their fixed dose combination

The objective was to investigate the effect of co-administration of hydrochlorothiazide and lisinopril as fixed dose combination on their intestinal absorption. The scope was extended to enhance intestinal absorption of both drugs. In situ rabbit intestinal absorption through the duodenum and jejuno-ileum was used to monitor membrane permeability of both drugs when perfused alone or in combination. Niosomes containing glycerols (glyceroniosomes) were loaded with both drugs. Glyceroniosomes comprised Span 60 or Tween 40 in combination with cholesterol and glycerol were prepared by bath sonication. Glyceroniosomes were characterized with respect to vesicle size, drug entrapment efficiency and were examined using transmission electron microscope (TEM). The prepared vesicles were nanosized spherical vesicles with average size of 202.4 nm and 108.8 nm for span free and span containing glyceroniosomes, respectively. The recorded Zeta potential values suggested good stability of the prepared formulations. Intestinal absorption studies reflected incomplete absorption of hydrocholothiazide and lisinopril correlating with their categorization as class IV and III drugs, respectively. Co-perfusion of both drugs reduced the intestinal absorption of lisinopril. Simultaneous encapsulation in glyceroniosomes enhanced the intestinal absorption of both drugs. Tween based systems were more efficient. The study introduced glyceroniosomes as carriers of simultaneous delivery of hydrochlorothiazide and lisinopril.

Pharmacokinetic and Bioequivalence Study of Lisinopril/Hydrochlorothiazide Tablet Under Fasting and Postprandial Conditions in Healthy Chinese Subjects

The objective of this research was to evaluate and compare the pharmacokinetic profiles and safety of lisinopril/hydrochlorothiazide (10 mg/12.5 mg) tablets in the test and reference formulations administered to participants in both fasting and postprandial states and to evaluate the bioequivalence of the 2 products in healthy Chinese volunteers. This study employed a single-center, randomized, open-label, single-dose dosing trial involving a cumulative 96 healthy adult participants (60 in the fasting group and 36 in the postprandial group). Each group comprised 2 sequence sets, and a 2-week washout period was implemented. There were no statistically significant differences in time to maximum concentration and terminal elimination half-life between the test and control groups under fasting and postprandial conditions (P > .05), and the 90% CIs for area under the plasma concentration-time curve and maximum plasma concentration were within the bioequivalence range of 80%-125%. Pharmacokinetic results indicate a large food effect for lisinopril, meaning that there is a loss of approximately 20%-25% of systemic exposure from fasting to postprandial administration for both preparations. The study demonstrated that a single oral dose of generic lisinopril/hydrochlorothiazide is bioequivalent to the reference product and well tolerated, with no significant adverse events observed, and that both products are similarly safe in a cohort of healthy Chinese male and female participants, following administration under fasting and postprandial conditions.

Optimization and evaluation of Lisinopril mucoadhesive sustained release matrix pellets: In-vitro and ex-vivo studies

Lisinopril (LIS) is antihypertensive drug, classified as a class III drug with high water solubility and low permeability. To overcome the low permeability, 3² factorial designs aimed to formulate LIS as a sustained-release (LIS-SR) matrix pellet by extrusion/spheronization. Matrix pellets were composed of wet mass containing Avicel® and polymeric matrix polymers (sodium alginate (SA) and chitosan (CS)). Evaluation of the effect of two independent variables, matrix-forming units (SA and CS) on mean line torque, on pellet size, dissolution rate after 6 h, and mucoadhesion strength of the pellets were assessed using Statgraphics software. The tested formulations (F1-F9) showed that mean line torque ranged from 1.583 to 0.461 Nm, with LIS content in the LIS-SR pellets ranged from 87.9 to 103%, sizes varied from 1906 to 1404 µm and high percentages of drug released from pellets formulations (68.48 to 74.18 %), while the mean zeta potential value of mucoadhesive range from -17.5 to -22.9 mV. The selection of optimized formulation must have the following desirability: maximum peak torque, maximum pellets' particle size, and minimum % LIS release after 6hr. LIS optimized sustained release pellet formula composed of 2,159 % SA and 0.357 % CS was chosen as optimized formula. It's showed a 1.055 Nm mean line torque was responsible for the increased pellet size to 1830.8 μm with decreased release rate 56.2 % after 6 hr, and -20.33 mV average mucin zeta potential. Ex-vivo mucoadhesion studies revealed that that the optimize formulation, exhibited excellent mucoadhesive properties, after 1 h, about 73% of the pellets were still attached to the mucus membrane. Additionally, ex-vivo permeation determination of LIS from the optimized LIS-SR formulation was found to be significantly higher (1.7-folds) as compared to free LIS. In conclusion: LIS-SR matrix pellets, prepared with an extrusion/spheronization have desirable excellent characteristics in-vitro and ex-vivo sustained-release pellet formulation of LIS-SR was able to sustain the release of LIS for up to 8 h.

Citric Acid: A Multifunctional Pharmaceutical Excipient

Citric acid, a tricarboxylic acid, has found wide application in the chemical and pharmaceutical industry due to its biocompatibility, versatility, and green, environmentally friendly chemistry. This review emphasizes the pharmaceutical uses of citric acid as a strategic ingredient in drug formulation while focusing on the impact of its physicochemical properties. The functionality of citric acid is due to its three carboxylic groups and one hydroxyl group. These allow it to be used in many ways, including its ability to be used as a crosslinker to form biodegradable polymers and as a co-former in co-amorphous and co-crystal applications. This paper also analyzes the effect of citric acid in physiological processes and how this effect can be used to enhance the attributes of pharmaceutical preparations, as well as providing a critical discussion on the issues that may arise out of the presence of citric acid in formulations.

Effect of the compaction parameters on the final structure and properties of a press-coated tablet (Tab-in-Tab): Experimental and numerical study of the influence of core and shell dimensions

With increasing interest in chronopharmaceutics, press-coated tablets have become a key technology in the field of modified release drug delivery systems. Although their benefits in terms of drug release have been largely studied, the comprehension of the compaction process of press-coated tablets is yet to complete. Particularly, the effects of geometrical parameters like the ratios between the thickness/diameter of the core and the thickness/diameter of the whole tablet were so far not much considered. Moreover, there is only few studies in the literature about the effect of the press-coating compression on the final structure and properties of the core. The present work consists in a joint experimental and numerical study that aims to assess these points. The study revealed high stress concentrations on the core during compression, causing high permanent deformations of the core, especially when the ratio between the core thickness and the total tablet thickness was high. The mechanical properties of the core tablet were also shown to be impacted: its density and strength were found to decrease before increasing again along the coating-compression. This effect was highlighted to be dependent on the triaxiality of the stress state (i.e. the ratio between the stresses in the different directions), itself depending on the two studied geometrical parameters. As the properties of the core affect the release attributes, ratios between the dimensions of the core and the dimensions of the whole tablet (thickness, diameter) should be taken into account as critical parameters for the manufacture of press-coated tablets.

Investigation of Pectin-Hydroxypropyl Methylcellulose-Coated Floating Beads for Pulsatile Release of Piroxicam

OBJECTIVES

The aim of the present study was to prepare pectin-hydroxypropyl methylcellulose-coated floating beads for pulsatile release of piroxicam in the treatment of early morning inflammation.

MATERIALS AND METHODS

Piroxicam-loaded beads were prepared from sodium alginate and hydroxypropyl methylcellulose (HPMC) in different concentrations of calcium carbonate using the ionotropic gelation method. In order to avoid drug release in the upper part of the gastrointestinal tract, the beads were coated with a pectin-HPMC layer using the dip coating method. Size analysis and encapsulation efficiency, drug loading, in vitro release, swelling behavior, and surface morphology studies of the beads were carried out.

RESULTS

The in vitro release study revealed that the pectin-HPMC coating of the beads prevented the release of the drug in an acidic medium and provided pulsed release of the drug after a lag time. Formulation CF4 (containing calcium carbonate in the ratio 3:4 with respect to sodium alginate) exhibited pulsed release of 95.55% at the end of 7 h in phosphate buffer, which was after the desired lag time of 6 h.

CONCLUSION

The study revealed that optimized floating pulsatile beads coated with pectin-HPMC can efficiently retain piroxicam in an acidic medium and that there is pulsed release in an alkaline medium after a lag time. It also showed that the beads prepared can potentially be used for chronotherapeutic treatment of the disease associated with early morning inflammation.

Prediction of lisinopril pediatric dose from the reference adult dose by employing a physiologically based pharmacokinetic model

Background

This study aimed to assess the pediatric lisinopril doses using an adult physiological based pharmacokinetic (PBPK) model. As the empirical rules of dose calculation cannot calculate gender-specific pediatric doses and ignores the age-related physiological differences.

Methods

A PBPK model of lisinopril for the healthy adult population was developed for oral (fed and fasting) and IV administration using PK-Sim MoBI® and was scaled down to a virtual pediatric population for prediction of lisinopril doses in neonates to infants, infants to toddler, children at pre-school age, children at school age and the adolescents. The pharmacokinetic parameters were predicted for the above groups at decremental doses of 20 mg, 10 mg, 5 mg, 2.5 mg, and 1.5 mg in order to accomplish doses producing the pharmacokinetic parameters, similar (or comparable) to that of the adult population. The above simulated pediatric doses were compared to the doses computed using the conventional four methods, such as Young’s rule, Clark’s rule, and weight-based and body surface area-based equations and the dose reported in different studies.

Results

Though the doses predicted for all subpopulations of children were comparable to those calculated by Young’s rule, yet the conventional methods overestimated the pediatric doses when compared to the respective PBPK-predicted doses. The findings of previous real time pharmacokinetic studies in pediatric patients supported the present simulated dose.

Conclusion

Thus, PBPK seems to have predictability potential for pediatric dose since it takes into consideration the physiological changes related to age and gender.

Green Synthetic Approach for Synthesis of Fluorescent Carbon Dots for Lisinopril Drug Delivery System and their Confirmations in the Cells

In this work, highly luminescent carbon dots (CDs) were synthesized by the hydrothermal method at 170 °C for 12 h using pasteurized milk as a carbon source. The prepared CDs exhibited bright blue fluorescence under UV light illumination at 365 nm. The CDs show fluorescence life time of ~4.89 ns at excitation wavelength of 370 nm. The effect of different solvents on the fluorescence property of CDs was also investigated. The lisinopril (Lis)-loaded CDs were fabricated by self-assembly of lisinopril on the surfaces of CDs, which were characterized by UV-visible and FT-IR spectroscopic techniques. The controlled release of lisinopril from the Lis-CDs was realized at pH values of 5.2, 6.2 and 7.4, respectively. The results of the cytotoxicity and confocal laser scanning microscopic images indicate that the Lis-CDs were successfully uptaken by HeLa cells without apparent cytotoxicity. The synthesized CDs show great potential as drug vehicles with good biocompatibility, sustained release of lisinopril from CDs, indicating that the CDs can act as a promising drug delivery system for therapeutic delivery and/or bioimaging applications.

Sulfated Seaweed Polysaccharides as Multifunctional Materials in Drug Delivery Applications

In the last decades, the discovery of metabolites from marine resources showing biological activity has increased significantly. Among marine resources, seaweed is a valuable source of structurally diverse bioactive compounds. The cell walls of marine algae are rich in sulfated polysaccharides, including carrageenan in red algae, ulvan in green algae and fucoidan in brown algae. Sulfated polysaccharides have been increasingly studied over the years in the pharmaceutical field, given their potential usefulness in applications such as the design of drug delivery systems. The purpose of this review is to discuss potential applications of these polymers in drug delivery systems, with a focus on carrageenan, ulvan and fucoidan. General information regarding structure, extraction process and physicochemical properties is presented, along with a brief reference to reported biological activities. For each material, specific applications under the scope of drug delivery are described, addressing in privileged manner particulate carriers, as well as hydrogels and beads. A final section approaches the application of sulfated polysaccharides in targeted drug delivery, focusing with particular interest the capacity for macrophage targeting.