Current Applied Polymer Science - Current Issue

BCL is a BCS Class III drug. It has a relatively low oral bioavailability of about 40% due to its short half-life (2-4 hours) and rapid clearance from the body. Developing gastroretentive technology can enhance its bioavailability by prolonging its retention in the stomach, ensuring more consistent absorption and therapeutic effects. It is well absorbed in the acidic environment of the stomach (pH 1-4). Due to the highly hydrophilic nature of BCL, the development of hydrocolloid-based floating beads for oral controlled release presents a significant challenge. To overcome this challenge, a blend of Sodium Alginate and Gelucire 43/01 was used which forms an intercalating structure network in situ that helps in controlling drug release in the stomach.

The aim of this study is to develop and optimize a gastro buoyant drug delivery system of Baclofen (BCL) using a Taguchi 3^2-factorial design assisted formulation. The formulation encompasses Gelucire 43/01 and sodium alginate to create gastro-buoyant multi-unit systems that provide controlled drug release in the gastric environment.

To develop and characterize BCL loaded beads matrixed with Gelucire 43/01 and Sodium Alginate to retain in the stomach for achieving site-specific drug delivery. The formulation were investigated to achieve a controlled release of BCL to maintain therapeutic drug level concentration over an extended period, reducing the frequency of dosing. Utilization of 3² factorial designs to investigate the effects of various formulation variables on the buoyancy time (Y1) and drug release (Y2) profile..

09 formulations were prepared as per 3² Taguchi factorial design studies using Minitab software.

From conducted optimization studies, it was found that Gelucire 43/01 is responsible for achieving buoyancy and retardation of Baclofen from the intercalating polymeric matrices in 0.1 N HCl. Drug excipient thermal analysis studies confirmed that there is development of polyelectrolyte complex. All the formulations remained buoyant till the time of drug release with 100% buoyancy. Entrapment efficiency ranges from 99.74-90.90 with a low standard deviation. The obtained polynomial quadratic equation indicates the synergistic effect for both the polymers for Y1 and Y2 response. % dissolution efficiency ranging from 92.78 to 99.62, which means formulations have potential to produce therapeutic response when given in vivo. By using topography studies using SEM, it was found that there is a generation of porous structure which leads to lesser density than the utility (1.04 g/cm³) and is responsible for achieving buoyancy. Formulations F2 and F3 were found to be optimized. Drug release kinetics suggested that all the formulations follow zero-order kinetics with low AIC values. Obtained Durbin-Watson statistics suggested that models are highly validated and the degree of error is less for both responses (Y1 and Y2).

It may be concluded that polymer matrices composed of Gelucire 43/01 and sodium alginate as release retardants may be an excellent carrier for stomach-specific delivery of model drug BCL.

Currently, the literature on amino acid delivery through microspheres is almost nonexistent. The present study was based on the development and characterization of hybrid microspheres of a polymeric matrix structured with palygorskite nanoclays. These microspheres are proposed to be used as controlled delivery systems of amino acids for agricultural applications.

Hybrid microspheres of Poly(lactic acid) (PLA) and Palygorskite (Pal) were prepared via the double emulsion method with solvent evaporation. Likewise, the amino acids Glycine (Gly) and Glutamic acid (Glu) were integrated in situ during the preparation of the microspheres, all of which were characterized through Scanning Electron Microscopy (SEM), Particle Size (TP) and X-ray Diffraction (XRD); the amino acids were detected through Ultraviolet (UV) spectrophotometry.

Microspheres with spherical morphology were obtained, and as the Pal content increased, they displayed irregular surfaces with particle sizes between 101 and 152 µm. Pal in the microspheres was detected with XRD. The microspheres that trapped a greater amount of amino acids were those containing 2.5% Pal, which presented longer delivery times compared to those microspheres with only the PLA matrix.

The mathematical modeling of the delivery kinetics demonstrated that the amino acid release depends on the diffusion mechanism through the microspheres; the study also demonstrated that the presence of nanoclays influences the diffusion speed.

To check the release efficacy of active pharmaceutical ingredients from tablet dosage form using synthetic and natural polymers.

Diclofenac sodium in sustained release manner tablets was created by Xanthan gum, HPMC, and mixed with both polymers to change the concentration ratio. The dosage form of the tablet was examined for the early stage formulation studies such as repose angle, apparent density, compressibility index, and some corporal properties like weight variant, friability, and content of the drug. For post-formulation studies, like in-vitro studies were implemented in a solution of phosphate buffer pH 7.4 for 8 hours. All the corporal properties of the diclofenac sodium tablets were within the limit of tolerance.

The study checked the Diclofenac Sodium release kinetics from synthetic and natural polymer-modified tablets.

Following the wet granulation method, we prepared a diclofenac sodium tablet using HPMC and Xanthan Gum Polymer.

The tablet that contained both HPMC and Xanthan gum (Batch C-I and C-II) shows the best drug content than other polymer-based batches like HPMC (Batch A-I, A-II) and Xanthan gum (Batch B-I, B-II). The great sustained drug release was shown in the HPMC and Xanthan gum mixed polymer-based matrix tablet (Batch C-I). The data showed that the mixing of polymers could lead to sustaining drug release from the formulation.

From the research, we can conclude that the diclofenac release % was maximum when we used a combination of both polymers in the tablet dosage form.

Hemp and other natural fibers are seeing greater use in industry due to their useful mechanical properties and sustainability. Natural fibers can reinforce or fill polymers to reduce cost and increase biodegradability. Ultra-high molecular weight polyethylene (UHMWPE) exhibits exceptional toughness and is capable of being mixed with natural fibers.

In this study, hemp fiber, in powder form, has been blended with UHMWPE powder and processed by compression molding to evaluate mechanical strength properties. The effects of adding low molecular weight polyethylene wax (PE-wax), a property modifier, were also examined. The hemp content of the compositions was 0, 20, 40, 60% w/w, with and without the wax.

Consistent with filler behavior, the addition of hemp significantly reduces the ultimate and yield tensile strengths as well as the elongation at break; the effect increases with more hemp. PE-wax improves performance at 40% and 60% w/w hemp, compared to the no wax condition. The presence of hemp increases the elastic modulus for 20% and 40% w/w hemp, and PE-wax improves the elastic modulus at all hemp concentrations. Compressive strength declines as hemp content increases, and the wax raises the performance at all hemp levels, nearly doubling the 20% w/w hemp strength. Shore type D hardness values steadily decline with hemp content, with a 60% loss in hardness, from the pure UHMWPE baseline to the 60% w/w hemp sample.

The simplified process outlined in this study produced materials that are fit for use in engineered applications. The process was also much simpler than traditional hand lay-up techniques, making it attractive for use in industrial applications.