The aim of this study was to prepare tamoxifen citrate loaded cylindrical polymeric implants for application at tumor sites. The implant was based on poly (sebacic acid-co-ricinoleic-ester anhydride) 70 : 30 w/w [poly(SA-RA) 70 : 30 w/w], a low-melting, biodegradable, and biocompatible polymer. Implants were prepared by a standardized melt manufacturing method. Differential scanning calorimetry and scanning electron microscopy were used for implant characterization. In vitro drug release studies were performed in phosphate-buffered saline (pH 7.4) at 37 6 28C. The drug content was estimated by high-performance liquid chromatography. The differential scanning calorimetry studies showed that the tamoxifen citrate in the implants was in the amorphous state. The cumulative percentage of drug release from 10 and 20 wt % drug-loaded poly(SA-RA) 70 : 30 w/w implants after 30 days was found to be 42.36 and 62.60%, respectively.

This study was aimed to develop an injectable polymeric drug delivery system for tamoxifen citrate (TC) using poly(sebacic acid-co-ricinoleic acid) [poly(SA-RA) 70 : 30 w/w] as a drug carrier for the treatment of estrogen receptor positive breast cancer. Injectable biodegradable microparticles of TC were produced by solvent displacement technique of microencapsulation and were characterized by surface morphology (scanning electron microscopy), particle size, size distribution, physical and chemical interaction (Fourier transform infrared), nature and physical state of drug [DSC and X-ray diffraction (XRD)], and in vitro release studies. TC loading over different concentrations was analyzed by high performance liquid chromatography (HPLC) technique. Polyanhydride microparticles obtained after lyophilization were nearly spherical in shape with smooth surface and size less than 2.5 lm. TC was dispersed in the form of amorphous state, and TC remains intact and stable during the process of microencapsulation. In vitro drug release studies demonstrated prolonged controlled release of TC with zero-order kinetics. Stability studies revealed that the production process of microparticles itself did not affect the chemical stability of the drug and polymer forming the particle matrix. Significant difference in drug release capacity was observed in microparticles with different drug loadings, and the drug release was more sustained in microparticles prepared with high TC.

The objective of this study was to develop paclitaxel (PTX) loaded poly(ε-caprolactone) (PCL) based tiny implants. β-Cyclodextrin (β-CD) and polyethylene glycol (PEG 6000) were used to enhance solubility and release of the drug in the phosphate buffer saline pH 7.4. Implants were evaluated in terms of color, shape, thickness, surface area, weight, drug content. Developed implants were characterized for their surface morphology (SEM analysis), drug physical state by thermal analysis (DSC studies), crystalline nature (XRD studies) and drug excipients compatibility (FT-IR spectroscopy). Macroscopically all the tiny implants were white in color and cylindrical in shape with smooth surfaces. PTX was entrapped within implants in the polymeric amorphous form. In vitro drug release studies showed prolonged and controlled release of PTX with zero order and Korsmeyer-Peppas model being exhibited. Excipients and method of preparation did not affect chemical stability of PTX.

Mucoadhesive nanoparticles represent a potential drug delivery strategy to enhance the therapeutic efficacy in oral therapy. This study assessed the prospective of developing HPMC- and PLGA-based nanoparticles using a nanospray drier as a mucoadhesive extended release drug delivery system for sitagliptin and evaluated their potential in an animal model. Nanoparticles were prepared using a Buchi® B-90 nanospray drier. Optimization of particle size was performed using response surface methodology by examining the influence of spray-drying process variables (inlet temperature, feed flow, and polymer concentration) on the particle size. The prepared nanoparticles were characterized for various physicochemical characteristics (yield, drug content, morphology, particle size, thermal, and crystallographic properties) and assessed for drug release, stability, and mucoadhesive efficacy by ex vivo and in vivo studies in rats. A linear model was suggested by the design of the experiments to be the best fit for the generated design and values. The yield was 77 ± 4%, and the drug content was 90.5 ± 3.5%. Prepared nanoparticles showed an average particle size of 448.8 nm, with a narrow particle size distribution, and were wrinkled. Thermal and crystallographic characteristics showed that the drug present in the nanoparticles is in amorphous dispersion. Nanoparticles exhibited a biphasic drug release with an initial rapid release (24.9 ± 2.7% at 30 min) and a prolonged release (98.9 ± 1.8% up to 12 h). The ex vivo mucoadhesive studies confirmed the adherence of nanoparticles in stomach mucosa for a long period. Histopathological assessment showed that the formulation is safe for oral drug delivery. Nanoparticles showed a significantly higher (p < 0.05) amount of sitagliptin retention in the GIT (gastrointestinal tract) as compared to control. The data observed in this study indicate that the prepared mucoadhesive nanoparticles can be an effective alternative delivery system for the oral therapy of sitagliptin.

Sitagliptin (MK–0431) is a widely and commonly used oral hypoglycemic drug in the treatment of type 2 diabetes mellitus; patients typically take higher doses of this drug (50 mg, twice daily). One drawback is that only 38% of the drug is bound reversibly to plasma proteins and 79% is excreted in urine without being metabolized. To overcome this issue, there is a need for a better drug-delivery method to improve its efficacy in patients. It has been found that in existing formulations, the drug content is 72.5% ± 5% and the percentage yield is 84.9% ± 3%. In this study, sitagliptin nanoparticles (sizes ranging from 210 to 618 nm) were developed. The bioadhesion properties of the nanoparticles, as well as the swelling of the nanoparticles on the mucus membrane aided in sustained drug release. The pattern of drug release was in accordance with the Peppas model. Fourier-transform infrared (FTIR) spectroscopy demonstrated that there were no significant interactions between sitagliptin and chitosan. Differential scanning calorimetry (DSC) results showed an absence of drug peaks due to the fact that the drug was present in an amorphous state. Mucoadhesive nanoparticles were formulated using sitagliptin and were effective for about 12 hours in the gastrointestinal tract. When compared to conventional sitagliptin administration, use of a nanoparticle delivery system demonstrated greater benefits for use in oral delivery applications. This is the first time that a drug-delivery method based on the mucoadhesive properties of nanoparticles could prolong the drug-release time of sitagliptin.

We tested the solubility and dissolution of tamoxifen citrate to ascertain the optimal conditions for faster dissolution. Using the solvent evaporation method and hydrophilic carriers, we formulated tamoxifen citrate (TC) that contained solid dispersions (SDs). We increased the solubility and dissolution rate of TC with a solid dispersion system that consisted of polyethylene glycol (PEG-6000), beta-cyclodextrin (β-CD), and a combination of carriers. Physicochemical characteristics of solubility (mg/ml) were found to be 0.987±0.04 (water), 1.324±0.05 (6.8pH PBS), and 1.156±0.03 (7.4 pH PBS) for F5 formulation, percentage yield was between 98.74 ± 1.11% and 99.06 ± 0.58%, drug content was between 98.06±0.58 and 99.06±1.10, and dissolution studies binary complex showed a faster release of TC as compared to a single polymer and pure drug. Furthermore, thermal properties, physicochemical drug and polymer interaction, crystal properties, and morphology were determined using differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), X-ray differential studies, and scanning electron microscopy. We used the same proportion of carrier concentrations of the formulations to calculate the solubility of TC. Our results demonstrated that increased concentrations of β-C yielded an improved solubility of TC, which was two times higher than pure TC. The uniformity in drug content was 97.99 %. A quicker drug release occurred from the binary complex formulation as seen in the dissolution profile. FTIR demonstrated an absence in the physicochemical interaction between the drug and carriers. The drug was also found to be dispersed in the amorphous state as revealed by DSC and XRD. The drug concentration did not vary during various storage conditions. Our in vivo studies demonstrated that SD displayed significantly higher values of Cmax (p < 0.05) and AUC0-24 (p < 0.05) as compared to free TC. Furthermore, Tmax in SD was significantly lower (p < 0.05), as compared to free TC.

Background: Chronic diseases such as diabetes, asthma, and heart disease are the leading causes of death in developing countries. Public health plays an important role in preventing such diseases to improve individuals' quality of life. Conventional dosage schemes used in public health to cure various diseases generally lead to undesirable side effects and renders the overall treatment ineffective. For example, a required concentration of drug cannot reach the lungs using conventional methods to cure asthma. Microspheres have emerged as a confirmed drug-delivery system to cure asthma. Method: In this paper, a salbutamol-loaded poly lactic acid-co-glycolic acid-polyethylene glycol (PLGA-PEG) microsphere (SPP)-based formulation was prepared using a Buchi B-90 nanospray drier. Face-centered central composite design (CCD) was applied to optimize the spray-drying process. Results: The drug content and product yield were found to be 72%±0.8% and 86%±0.4%, respectively; drug release (91.1%) peaked for up to 12 hrs in vitro. Microspheres obtained from the spray dryer were found to be shriveled. The experiments were carried out and verified using various groups of rabbits. In our study, the particle size (8.24 µm) was observed to be an essential parameter for drug delivery. The in vivo results indicated that the targeting efficacy and drug concentration in the lung was higher with the salbutamolloaded PLGA-PEG SPP formulation (1,410.1±10.11 µg/g, 15 mins), as compared to the conventional formulation (92±0.56 µg/g, 10 min). The final product was stable under 5°C±2°C , 25°C±2°C, and 40°C±2°C/75%±5% relative humidity. In addition, these co-polymers have a good safety profile, as determined by testing on human alveolar basal epithelium A549 cell lines. Conclusion: Our results prove that microspheres are an alternative drug-delivery system for lung-targeted asthma treatments used in public health.

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