Co-milling of telmisartan with poly(vinyl alcohol)--An alkalinizer free green approach to ensure its bioavailability

Relaxation time of amorphous telmisartan: Bridging the gap between experiment and theory

Telmisartan is a crucial angiotensin receptor blocker in treating high blood pressure. However, there is a wide gap between experimental measurements and theoretical calculations for telmisartan in the amorphous form. Herein, we present how to overcome this challenge via the elastically collective nonlinear Langevin equation theory. First, we utilize a hard-sphere fluid model to rapidly analyze local and nonlocal effects on the molecular dynamics of telmisartan. A nonuniversal coupling parameter is introduced to capture physicochemical complexity via dynamic fragility. Then, a chemical mapping is created to evaluate the impact of temperature on the relaxation of telmisartan. The difference between supercooled and glassy states is encoded in thermal expansion coefficients. The above strategy allows us to determine the primary relaxation time over 30 decades and its secondary counterpart over 12 decades. From there, we can satisfactorily explain previous broadband-dielectric-spectroscopy observations without fitting procedures. Our results promise to enhance the applicability of amorphous telmisartan to health protection and promotion.

Study on the Scale-Up Possibility of a Combined Wet Grinding Technique Intended for Oral Administration of Meloxicam Nanosuspension

Background/Objectives: This article reports on the scalability of a combined wet grinding technique applying planetary ball mill and ZrO2 pearls as the grinding medium. After the determination of the parameters in a laboratory scale, the tenfold scale-up method was set. Meloxicam (MEL) was used as a nonsteroidal anti-inflammatory drug (NSAID) intended for per os delivery. During grinding, the PVA solution was used as a dispersion medium. Methods: The influence of the scaling-up on the particle size, morphology, crystallinity, and intra- and interparticulate phenomena has been studied. Formulation investigations of the milled suspensions were carried out. The dissolution test and the cytotoxicity analyses were accomplished. Results: Submicron MEL particle-containing samples were produced in both grinding scales. After the particle size determination was achieved from the suspensions, the wet milled, dried products were studied. The particle size of the dried products fell into the same range for both scales of milling (the maximum particle size was about 580 nm). There was no significant difference in drug crystallinity after the grindings; 70% of MEL remained crystalline in both cases. A remarkable interaction between the components did not develop as a result of milling. The polarity of the products increased, which resulted in a better dissolution, especially in the case of intestinal fluid (~100% in the first 5 min). The products were not found to be toxic. Conclusions: This research demonstrates that the scaling-up of combined wet grinding technique is feasible by adjusting the milling parameters and the adequate amount of excipient.

Electrospun orally disintegrating film formulation of telmisartan

Telmisartan (TEL) is an antihypertensive BCS class II drug with low solubility at physiological pH. However, the solubility of TEL increases with the presence of an alkalizer. Electrospinning is one of the most recent techniques for the solubility enhancement studies. In this study, an electrospun orally disintegrating film (ODF) formulation of TEL was developed with L-arginine and polyvinylpyrrolidone K90 (PVP), and its characterization studies were performed. Preformulation studies were performed to investigate possible incompatibilities in the components of formulation with differential scanning calorimetry (DSC) and Fourier transform infrared spectrometer (FT-IR) analyses. ODFs were characterized in terms of drug content and uniformity, mechanical properties, fiber shape and diameter and in vitro dissolution profile. Smooth nanofibers without any beads were obtained. The dissolution rate of the TEL significantly increased. The chosen formulation had acceptable mechanical properties with much faster dissolution compared to the commercially available product. Developed ODF and marketed product were compared with a dissolution study in phosphate-buffered solution (pH 7.4). ODF and marketed product both reached 100% release in the 45th minute, and ODF results showed that ODF had much faster release than marketed product. In this study, TEL ODF formulation was successfully produced and characterized.

Preparation and Evaluation of Co-amorphous Formulations of Telmisartan-Amino Acids as a Potential Method for Solubility and Dissolution Enhancement

Telmisartan (TLM) is a potent antihypertensive drug with pH-dependent aqueous solubility. This work aimed to enhance the solubility and dissolution rate of TLM by the co-amorphous drug amino acid (AA) approach by combining TLM, with different types and ratios of AAs. The co-amorphous TLM-AA blends were prepared by freeze-drying and investigated for solid-state characteristics like the dissolution rate enhancement of TLM. Among the prepared co-amorphous formulations, TLM-arginine (ARG) exhibited the greatest enhancement in solubility with increasing the molar ratio of ARG. The TLM-ARG at 1:2 ratio showed about a 57-fold increase in solubility of TLM and the highest dissolution percentage in phosphate buffer (pH7.5) (100% in 20 minutes) compared to both crystalline TLM (20% in 60 min) and physical mixture. Powder XRD, DSC, FTIR analysis and SEM demonstrated the formation of amorphous form within the co-amorphous formulations. Only TLM:ARG (1:0.5) were stable at (40°C, 75% RH) for a minimum of 90 days. In conclusion, ARG was able to stabilize the amorphous form of TLM and enhances its aqueous solubility and dissolution. The 1:2 w/w ratio of TLM-ARG co-amorphous showed the best solubility and dissolution rate while the 1:0.5 w/w ratio showed the best stability.

Effect of co-milling on dissolution rate of poorly soluble drugs

Co-milling of a drug with a co-former is an efficient technique to improve the solubility of drugs. Besides the particle size reduction, the co-milling process induces a structural disorder and the creation of amorphous regions. The extent of drug solubility enhancement is dependent on the proper choice of co-milling co-former. The aim of this work was to compare the effects of different co-formers (meglumine and polyvinylpyrrolidone) on the dissolution rates of glass forming (indomethacin) and non-glass forming (mefenamic acid) model drugs. A positive impact of the co-milling on the dissolution behavior was observed in all co-milled mixtures, even if no substantial amorphization was observed. While meglumine exhibited pronounced effects on the dissolution rate of both drugs, the slightest enhancement was observed in mixtures with polyvinylpyrrolidone. The evaluation of specific release rate revealed the surface activation of drug particle is responsible for improving the dissolution rate of both drug types, but for the glass former, this surface activation could be persistent while maintaining a high dissolution rate even until a high fraction of drug is released. Our results, therefore, indicate that adequate co-former choice and consideration of drug glass forming ability are important for a successful co-milling approach to poorly water-soluble drugs.

Formulation and In Vitro Evaluation of Telmisartan Nanoparticles Prepared by Emulsion-Solvent Evaporation Technique

Objectives

Telmisartan (TLM) is an antihypertensive drug that has been shown to have antiproliferative effects on cancer cells. It has low solubility and suboptimal oral bioavailability. To investigate the potential anticancer effect of TLM on breast cancer cells, poly (D, L-lactide) (PLA) nanoparticles were formulated with the benefit of improving its solubility.

Materials and Methods

TLM-loaded PLA nanoparticles were prepared by emulsion solvent evaporation. The effects of sonication time and polymer:drug ratio on nanoparticle size and drug encapsulation were investigated. TLM-loaded nanoparticles were tested against MCF-7 and MD-AMB-231 breast cancer cell lines for antiproliferative effects.

Results

Nanoparticles with mean particle size 272 nm and 79% encapsulation efficiency were obtained. Sustained release TLM nanoparticles (40% in 24 h) decreased cell viability to 45% for MCF-7 cells at 72 h, even at the lowest TLM concentration, indicating better anticancer efficiency than TLM solution.

Conclusion

TLM nanoparticles could be potential anticancer agents for breast cancer and deserve further studies.

Implication of Coformer Structural Diversity on Cocrystallization Outcomes of Telmisartan with Improved Biopharmaceutical Performance

Crystal engineering approach was utilized for the development of different multicomponent solid forms of telmisartan (TEL) to improve its oral bioavailability. In this context, two cocrystals, gentisic acid (GA) and maleic acid (MA), while two eutectic mixtures, para-aminobenzoic acid (PABA) and adipic acid (AA), were successfully prepared and characterized by different analytical tools. Both the cocrystals exhibited characteristic heterosynthons, viz. OH_acid⋯N_arom and OH_acid⋯O, to propagate new network. Structural features of coformers has been correlated with the outcomes of cocrystallization approach. Coformers having auxiliary functionality in addition to complementary functional groups have high propensity to generate cocrystals. However, multicomponent where auxiliary functionality is lacking, such combinations, is shown to form eutectic mixtures owing to strong homomeric interaction. Besides, the developed cocrystals and eutectic mixtures showed higher aqueous solubility (3-5.5-fold) and intrinsic dissolution rate (1-2.6-fold) over pure TEL. In vivo studies also revealed significant improvement in relative bioavailability (2-2.6-fold). The study also shed light on the implications of eutectic mixtures in mitigating the solubility issues of drugs which are often considered negative results of cocrystallization strategy.

Enhanced Solubility of Telmisartan Phthalic Acid Cocrystals within the pH Range of a Systemic Absorption Site

Telmisartan (TLM), a nonpeptide angiotensin II antagonist, is widely prescribed for treating arterial hypertension and marketed by the innovator with the trade name of Micardis and Micardis plus. Telmisartan exhibits low aqueous solubility in the pH range of 3-7, which is the physiological pH. For addressing the issue of poor solubility of TLM, its commercial form makes use of inorganic alkalinizers. The present work illustrates the attempt to improve the solubility of telmisartan via a crystal engineering approach. A novel solid form of telmisartan with phthalic acid was obtained through the solution crystallization method (TPS) and the reaction crystallization method (TPR). Both the forms (TPS and TPR) were thoroughly characterized by powder diffraction X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and ¹H NMR and were identified to be two different crystalline forms. Solubility studies of TPS and TPR were conducted at varying pH of phosphate buffer, and they exhibited 11-fold and 22-fold increased solubility, respectively, when compared to that of the pure drug at pH 5, which is within the pH of small intestine at which telmisartan is best absorbed orally from the systemic circulation.

Preliminary study of nanonized lamotrigine containing products for nasal powder formulation

The nasal delivery of drugs offers a great alternative route to avoid adverse events and to increase patient compliance due to its advantageous properties. Besides nasal application, topical, systemic and central effects are also available. Nasal powders (NPs) have better adhesion due to the additive polymers that may be, eg, gelling or good wettability agents; thus, their bioavailability is better compared to the liquid formulations. Using nanoparticles, innovative and more efficient products can be achieved, which may lead to the improvement of different therapies. The aim of this study was to produce NP formulations containing lamotrigine (LAM) as interactive physical mixtures and nanosized LAM-based formulations. After risk assessment of the preliminary tests, the micrometric properties (particle size and morphology) and the structural properties (differential scanning calorimetry [DSC], X-ray powder diffraction [XRPD]) were investigated; thereafter, physicochemical properties (solubility, polarity) and in vitro dissolution and diffusion profiles were also examined. These product samples showed an appropriate particle size ranging 10–25 µm, while the particle size of LAM in the products was between 120 and 230 nm and the dissolved amount of drug was >60% after 5 minutes in these cases.

Thermal behavior and molecular mobility in the glassy state of three anti-hypertensive pharmaceutical ingredients

Good agreement was found between the thermodynamic and kinetic fragilities of these APIs. DSC analysis of irbesartan showed the possibility of transformation A → B between the two monotropic polymorphic forms.