Development and evaluation of controlled porosity osmotic pump for nifedipine and metoprolol combination

Osmotic Pump Drug Delivery Systems-A Comprehensive Review

In the last couple of years, novel drug delivery systems (NDDS) have attracted much attention in the food and pharmaceutical industries. NDDS is a broad term that encompasses many dosage forms, one of which is osmotic pumps. Osmotic pumps are considered to be the most reliable source of controlled drug delivery, both in humans and in animals. These pumps are osmotically controlled and release active agents through osmotic pressure. To a large extent, drug release from such a system is independent of gastric fluids. Based on such unique properties and advantages, osmotic pumps have made their mark on the pharmaceutical industry. This review summarizes the available osmotic devices for implantation and osmotic tablets for oral administration.

3D-Printed Wearable Personalized Orthodontic Retainers for Sustained Release of Clonidine Hydrochloride

Orthodontic retainers are wearable customizable medical devices for dental protection or alignment. Here, clonidine hydrochloride (CH)-loaded wearable personalized 3D printed orthodontic retainers were studied for local sustained-release of drugs. CH powders were mixed with PEG 4000, Tween 80, poly(lactic acid), and polycaprolactone. The mixture was hot-melt extruded to form a filament that was 3D printed to a customizable original orthodontic retainer with the fused deposition modeling (FDM) method. The original retainer showed a burst release of CH in the early stage of the dissolution process though a sustained release appeared in the late stage. The in vivo burst release of CH would lead to unexpected side effect. The original retainer was modified by coating with hydrophilic polymers or washing with buffered solutions to obtain the coated or washed retainer. The coated retainer still showed a burst release while the washed retainer showed an optimal sustained release. Many CH microparticles existed on the surface of original retainers according to the scanning electron microscopic image so that the burst release was unavoidable. The hydrophilic polymer coating method did not change the release profile because the polymer was also rapidly dissolved. However, most of the surface CH can be eliminated by washing so that the burst release dissappeared in the washed retainer. Furthermore, the simulated CH concentration-time profiles in the circulation of humans of the washed retainer showed the stable and appropriate drug levels for more than 3 days. Wearable personalized 3D printed drug-loaded orthodontic retainers are a promising drug-device for sustained release of drugs.

Development and Evaluation of a Once-Daily Controlled Porosity Osmotic Pump of Tapentadol Hydrochloride

The present study aimed to prepare, optimize, and evaluate Tapentadol hydrochloride controlled porosity osmotic pump (CPOP) and to achieve the drug release at nearly zero-order. The CPOP was prepared by the coating of polymers (Eudragit RSPO and RLPO) on a directly compressed core tablet. A Box-behnken experimental design was applied to optimize the parameters for CPOP. The optimized batch was characterized for in vitro drug release study, effect of pH, osmolarity and agitation intensity, and surface morphology and stability study. In vivo pharmacokinetic studies were performed on New Zealand white rabbits for CPOP and marketed tablet. All the batches showed a drug release ranging from 29.87 to 56.92% after 12 h; and from 59.64 to 99.96% after 24 h. There was no change in the drug release pattern at different pH and agitation intensities. The drug release was found to decrease with increasing osmolarity of dissolution media.An in vivo study showed a higher mean residence time, area under the curve, and biological half-life (T 1/2) than the marketed tablet with low rate of elimination (Ke) and a 2.35-fold increase in relative bioavailability. The result showed that the amounts of sodium chloride and PEG 400 were contributing positively while the number of coats was negatively affecting the drug release. The drug release was found to be independent of physiological conditions. The stability testing showed that the prepared CPOP was stable for 3 months at accelerated conditions. The prepared CPOP was found to deliver Tapentadol hydrochloride at zero-order for up to 24 h.

Model drug as pore former for controlled release of water-soluble metoprolol succinate from ethylcellulose-coated pellets without lag phase: opportunities and challenges

The objective of the present study was to evaluate the feasibility of using model drug metoprolol succinate (MS) as a pore former to modify the initial lag phase (i.e., a slow or non-release phase in the first 1-2 h) associated with the drug release from coated pellets. MS-layered cores with high drug-layering efficiency (97% w/w) were first prepared by spraying a highly concentrated drug aqueous solution (60% w/w, 70°C) on non-pareils without using other binders. The presence of MS in ethylcellulose (EC) coating solution significantly improved the coating process by reducing pellets sticking, which often occurs during organic coating. There may be a maximum physical compatibility of MS with EC, and the physical state of the drug in the functional coating layer of EC/MS (80:20) was simultaneously crystalline and non-crystalline (amorphous or solid molecule solution). The lag phase associated with hydroxypropylcellulose (HPC) as a pore former was not observed when MS was used as a pore former. The drug release from EC/MS-coated pellets was pH independent, inversely proportional to the coating levels, and directly related to the pore former levels. The functional coating layer with MS as a pore former was not completely stabilized without curing. Curing at 60°C for 1 day could substantially improve the stability of EC/MS-coated pellets. The physical state of the drug in the free film of EC/MS (85:15) changed partially from amorphous to crystal when cured at 60°C for 1 day, which should be attributed to the incompatibility of the drug with EC.

In vitro, ex vivo and in silico mechanistic elucidation of the performance of an optimized porosity-controlled multi-elemental transbuccal system

PURPOSE

To elucidate the mechanisms of construction and performance of a porosity controlled, multi-elemental transbuccal system employing experimental and computational approaches.

METHODS

The production of the formulation was guided through a Box-Benkhen design employing homogenization coupled with lyophilization. The physicochemical and physicomechanical properties of the experimental design formulations were quantified with relevant analytical techniques. The influence of changes in porosity measures on the magnitude of these physical properties were explored mathematically. Furthermore, experimental outputs from the Box-Behnken design formulations were fitted into set limits and optimized using the response surface method. The optimized porosity-controlled formulation was subjected to mechanistic experimental and computational elucidations.

RESULTS

In general, the changes in magnitudes of studied porosity quantities had significant impact on formulation physicochemical and physicomechanical properties. The generation of an optimized formulation validated the stability and accuracy of the Box-Behnken experimental design. Experimental investigations revealed that the construction of this formulation is as a result of non-destructive physical interactions amongst its make-up compounds while its mechanism of performance is anchored mainly upon a gradual collapse of its ordered porous structure. Furthermore, the molecule mechanics simulations quantitatively predicted the molecular interactions inherent to multicomponent matrix formation and the mucoadhesion mechanism.

CONCLUSIONS

The fabrication and performance mechanisms of the porosity-controlled transbuccal system was successfully explored.

Development and evaluation of oral osmotic pump of butorphanol tartrate

Butorphanol is potent analgesic useful in pain management. However, because of high first-pass metabolism butorphanol is not available in market as oral dosage form. Drugs that undergo extensive first-pass metabolism can be delivered orally if protected in the stomach, and proximal small intestine. An oral controlled porosity osmotic pump (CPOP) was designed to deliver butorphanol tartrate that can maintain therapeutic blood concentration up to 24 h. The target release profile for extended release formulation was calculated by Wagner Nelson de-convolution using published immediate release blood concentration data for oral route. Composition of the core and coating were optimized using USFDA approved ingredients by evaluation of the drug release. Drug release from the developed system was inversely proportional to the weight gain and directly related to the level of pore former. Scanning electron microscopy (SEM) confirmed the formation of pores in the coating membrane on contact with water which lead to drug to release. Kinetic models were applied to drug release data to establish the drug release mechanism. The developed osmotic system effectively delivers selected drug at a predetermined rate for extended period.

Osmotic drug delivery system as a part of modified release dosage form

Conventional drug delivery systems are known to provide an immediate release of drug, in which one can not control the release of the drug and can not maintain effective concentration at the target site for longer time. Controlled drug delivery systems offer spatial control over the drug release. Osmotic pumps are most promising systems for controlled drug delivery. These systems are used for both oral administration and implantation. Osmotic pumps consist of an inner core containing drug and osmogens, coated with a semipermeable membrane. As the core absorbs water, it expands in volume, which pushes the drug solution out through the delivery ports. Osmotic pumps release drug at a rate that is independent of the pH and hydrodynamics of the dissolution medium. The historical development of osmotic systems includes development of the Rose-Nelson pump, the Higuchi-Leeper pumps, the Alzet and Osmet systems, the elementary osmotic pump, and the push-pull system. Recent advances include development of the controlled porosity osmotic pump, and systems based on asymmetric membranes. This paper highlights the principle of osmosis, materials used for fabrication of pumps, types of pumps, advantages, disadvantages, and marketed products of this system.