Microenvironmental pH-modified Amisulpride-Labrasol matrix tablets: development, optimization and in vivo pharmacokinetic study

Transdermal application of diacerin loaded-terpene enriched invasomes: an approach to augment anti-edema and nociception inhibition activity

This study aimed to formulate diacerein loaded terpene-enriched invasomes (DCN-TINV) to fulfill a fruitful management of osteoarthritis. A 23 factorial design was adopted, including A: cholesterol concentration (%w/v), B: ethanol volume (mL) and C: phosphatidylcholine: drug ratio as the studied factors. Invasomes were constructed using the thin film hydration technique. Herein, percent entrapment efficiency (EE%), particle size (PS), poly-dispersity index (PDI) and zeta potential (ZP) were statistically analyzed using Design-Expert® software to select the optimum formula. The selected criteria for detecting the optimum formula were restricting PS (<350 nm), dismissing PDI, magnifying ZP (as absolute value) and EE%. The selected formula was further scrutinized through multiple in-vitro studies, including Fourier-transform infrared spectroscopy, differential scanning calorimetry, pH measurement, stability study, release profile and transmission electron microscopy. Furthermore, the ex-vivo performance was evaluated through ex-vivo skin permeation and deposition. Finally, it was subjected to an array of in-vivo tests, namely Draize test, histopathology, In-vivo skin penetration, edema size, and nociception inhibition measurements. The optimum formula with desirability (0.913) demonstrated EE% (89.21% ± 2.12%), PS (319.75 ± 10.11 nm), ZP (-55 ± 3.96 mV) and a prolonged release profile. Intriguingly, revamped skin permeation (1143 ± 32.11 µg/cm2), nociception inhibition (77%) and In-vivo skin penetration (144 µm) compared to DCN suspension (285 ± 21.25 µg/cm2, 26% and 48 µm, respectively) were displayed. The optimum DCN-TINV exhibited plausible safety and stability profiles consolidated with auspicious efficacy for better management of osteoarthritis.

Bioequivalence of 200 mg Amisulpride Tablets in Healthy Chinese Volunteers under Fasting and Fed Conditions

In this study, we compared the pharmacokinetics and safety of a new generic product and a branded reference product of amisulpride tablets. Additionally, we assessed the bioequivalence of the 2 products in healthy Chinese volunteers to acquire sufficient evidence for the marketing approval of the generic drug. Thirty volunteers under fasting and fed conditions were randomly administered a single dose of the test or reference drug orally, followed by a 7-day washout period. The pharmacokinetic parameters were obtained by the concentration-time profiles, including the area under the plasma concentration-time curve (AUC) over the dosing interval, AUC from time zero to infinity, maximum plasma concentration, time to achieve maximum plasma concentration, and elimination half-life. AUC from time zero to infinity of amisulpride in the postprandial group was reduced by approximately 25%, suggesting that a high-fat diet can affect this parameter. In the aspect of safety, no serious adverse events occurred. This study demonstrated that generic and reference products of amisulpride tablets were bioequivalent in healthy Chinese volunteers under fasting and fed conditions.

Development of canagliflozin nanocrystals sublingual tablets in the presence of sodium caprate permeability enhancer: formulation optimization, characterization, in-vitro, in silico, and in-vivo study

Canagliflozin (CFZ) is a sodium-glucose cotransporter-2 inhibitor (SGLT2) that lowers albuminuria in type-2 diabetic patients, cardiovascular, kidney, and liver disease. CFZ is classified as class IV in the Biopharmaceutical Classification System (BCS) and is characterized by low permeability, solubility, and bioavailability, most likely attributed to hepatic first-pass metabolism. Nanocrystal-based sublingual formulations were developed in the presence of sodium caprate, as a wetting agent, and as a permeability enhancer. This formulation is suitable for children and adults and could enhance solubility, permeability, and avoid enterohepatic circulation due to absorption through the sublingual mucosa. In the present study, formulations containing various surfactants (P237, P338, PVA, and PVP K30) were prepared by the Sono-homo-assisted precipitation ion technique. The optimized formula prepared with PVP-K30 showed the smallest particle size (157 ± 0.32 nm), Zeta-potential (-18 ± 0.01), and morphology by TEM analysis. The optimized formula was subsequently formulated into a sublingual tablet containing Pharma burst-V® with a shorter disintegration time (51s) for the in-vivo study. The selected sublingual tablet improved histological and biochemical markers (blood glucose, liver, and kidney function), AMP-activated protein kinase (AMPK), and protein kinase B (AKT) pathway compared to the market formula, increased CFZ's antidiabetic potency in diabetic rabbits, boosted bioavailability by five-fold, and produced faster onset of action. These findings suggest successful treatment of diabetes with CFZ nanocrystal-sublingual tablets.

Syringeable atorvastatin loaded eugenol enriched PEGylated cubosomes in-situ gel for the intra-pocket treatment of periodontitis: statistical optimization and clinical assessment

Atorvastatin calcium (ATV) is a well-known anti-hyperlipidemic drug currently being recognized for possessing an anti-inflammatory effect. Introducing it as a novel remedy for periodontitis treatment necessitates developing a syringeable modified delivery system capable of targeting inflammation within the periodontal pockets. Thus, a 3³ Box-Behnken design was used to generate eugenol enriched PEGylated cubosomes. Based on the desirability function, the optimized formulation (OEEPC) was selected exhibiting a solubilization efficiency (SE%) of 97.71 ± 0.49%, particle size (PS) of 135.20 ± 1.11 nm, polydispersity index (PDI) of 0.09 ± 0.006, zeta potential (ZP) of -28.30 ± 1.84 mV and showing a sustained drug release over 12 h. It displayed a cubic structure under the transmission electron microscope, furthermore, it was stable upon storage for up to 30 days. Hence, it was loaded into an optimum syringeable in-situ gel (ISG) which displayed the desired periodontal gelation temperature (34 ± 0.70 °C) and an adequate gelation time (46 ± 2.82 sec), it also released approximately 75% of the drug within 72 h. Clinical evaluation of the ISG showed a promising percentage reduction of about 58.33% in probing depth, 90% in the bleeding index, 81.81% in the plaque index, and 70.21% in gingival levels of transforming growth factor-β1. This proved that the formulated syringeable intra-pocket delivery system of ATV is an efficient candidate for diminishing inflammation in periodontitis.

Flexosomes as a promising nanoplatform for enhancing tolnaftate ocular delivery: Formulation, in vitro characterization, statistical optimization, ex vivo and microbial in vivo studies

The eye is a complex organ with a unique physiology and anatomy. Using novel nanosystems is expected to enhance ocular drug permeation and retention. Hence, this work aimed to study the potential of flexosomes as an ocular delivery system to enhance the corneal permeation and antifungal activity of Tolnaftate (TOL). Different flexosomes formulae were formulated using ethanol injection method, employing a 31.22 full factorial design. The studied formulation variables were: X1: amount of stearyl amine, X2: hydration volume and X3: type of edge activator. Encapsulation efficiency, particle size and zeta potential were selected as dependent variables. FX5 was selected as the optimal TOL flexosomes and showed encapsulation efficiency of 66.08 ± 11.38%, particle size of 154.99 ± 29.11 nm and zeta potential of 42.95 ± 0.64 mV. FX5 was subjected to further ex vivo and in vivo studies which showed that TOL flux was significantly increased through FX5 compared to TOL suspension. Draize test and histopatholoigal tests assured that FX5 is safe to be used for eye.. The in vivo fungal susceptibility testing using Aspergillus niger demonstrated the superior and more durable antifungal activity of FX5 than TOL suspension. Hence, FX5 can be considered as promising nanocarrier for safe and efficient ocular TOL delivery.

Hair regrowth boosting via minoxidil cubosomes: Formulation development, in vivo hair regrowth evaluation, histopathological examination and confocal laser microscopy imaging

Minoxidil has been used as an effective and cost-efficient topical treatment for androgenic alopecia. However, due to its poor water solubility, commercially available formulations contain alcohol and propylene glycol in a concentration that causes skin reactions such as irritation and dryness. Therefore, nanotechnology-based formulations can offer an alternative that might increase penetration and deposition of the drug in the skin while minimizing its adverse reactions. Minoxidil cubosomes (MXD-CUB) were prepared by melt dispersion emulsification technique according to full 2³ factorial design. Three independent variables, namely, the dispersed phase concentration, glyceryl monooleate: Poloxamer 407 ratio and Tween 80 concentration were tested. Particle size, polydispersity index and the zeta potential were the dependent variables. The optimized formula was investigated by transmission electron microscopy, X-ray diffractometry and in vitro release test. In vivo study included Draize test, histopathological examination, hair regrowth efficacy and confocal laser scanning microscopy (CLSM). Particle size, zeta potential and polydispersity index of the optimal MXD-CUB were measured to be 131.10 ± 1.41 nm, -23.5 ± 0.42 mV and 0.185 ± 0.0, respectively, and its entrapment efficiency was 80.4 ± 4.04 %. Draize test and histopathological testing proved safety and tolerability of MXD-CUB. In vivo hair regrowth study revealed greater hair growth boosting effect of the prepared cubosomes compared to minoxidil solution. CLSM proved superior penetration and retention of rhodamine B-loaded cubosomes in the skin compared to rhodamine B solution. Therefore, MXD-CUB can be a safe and effective dosage form for minoxidil that overcome the drawbacks of the commercial formulations.

Microenvironmental pH Modification in Buccal/Sublingual Dosage Forms for Systemic Drug Delivery

Many drug candidates are poorly water-soluble. Microenvironmental pH (pH_M) modification in buccal/sublingual dosage forms has attracted increasing interest as a promising pharmaceutical strategy to enhance the oral mucosal absorption of drugs with pH-dependent solubility. Optimizing drug absorption at the oral mucosa using pH_M modification is considered to be a compromise between drug solubility and drug lipophilicity (Log D)/permeation. To create a desired pH_M around formulations during the dissolution process, a suitable amount of pH modifiers should be added in the formulations, and the appropriate methods of pH_M measurement are required. Despite pH_M modification having been demonstrated to be effective in enhancing the oral mucosal absorption of drugs, some potential risks, such as oral mucosal irritation and teeth erosion caused by the pH modifiers, should not been neglected during the formulation design process. This review aims to provide a short introduction to the pH_M modification concept in buccal/sublingual dosage forms, the properties of saliva related to pH_M modification, as well as suitable drug candidates and pH modifiers for pH_M modifying buccal/sublingual formulations. Additionally, the methods of pH_M measurement, pH_M modification methods and the corresponding challenges are summarized in the present review.

The overall assessment of simultaneous photocatalytic degradation of Cimetidine and Amisulpride by using chemical and genotoxicological approaches

Pharmaceutical Active Compounds (PhACs) are of particular interest among the emerging contaminants detected in the aquatic environment. Commonly, PhACs exist as complex mixtures in aquatic systems, causing potential adverse effects to the environment and human health than those of individual compounds. Based on the increasing interest in the contamination of water resources by PhACs, the photocatalytic degradation of Cimetidine and Amisulpride as a mixture in combination with their toxic and genotoxic effects before and after the treatment were evaluated for the first time. The toxic, genotoxic and cytotoxic effects were investigated using the Trypan Blue Exclusion Test and the Cytokinesis Block MicroNucleus (CBMN) assay in cultured human lymphocytes. The photocatalytic degradation of the PhACs was studied in ultrapure water and environmentally relevant matrices using UV-A and visible (Vis) irradiation and C-TiO₂ (TiO₂ Kronos vlp 7000) as photocatalyst. High removal percentages were observed for both compounds under UV-A and Vis irradiation in ultrapure water. In lake and drinking water a slower degradation rate was shown that could be attributed to the complex composition of these matrices. Scavenging experiments highlighted the significant role of h⁺ and O₂^●- in the degradation mechanisms under both irradiation sources. Oxidation, dealkylation and deamination were the main degradation pathways. Regarding the individual compounds, Amisulpride was found to be more cytotoxic than Cimetidine. No significant differences of the genotoxic effects during the treatment were observed. However, a slight increase in cytotoxicity was observed at the first stages of the process. At the end of the process under both UV-A and Vis light, non-significant cytotoxic/toxic effects were observed. Based on the results, heterogeneous photocatalysis can be considered as an effective process for the treatment of complex mixtures without the formation of harmful transformation products.

Development of an enhanced formulation to minimize pharmacokinetic variabilities of a weakly basic drug compound

Formulating poorly water soluble, weakly basic drugs with consistent exposure is often a challenge due to pH dependent solubility. When the oral formulation is exposed to different pH ranges in the gastrointestinal (GI) tract, drug precipitation or incomplete dissolution may occur resulting in decreased drug absorption and higher intra-and inter-patient pharmacokinetic variabilities.In the present study, a series of enhanced formulations containing organic acids and/or surfactants were developed and compared with conventional formulations with respect to their in vitro dissolution performance. The formulation containing 5% citric acid and 1% sodium lauryl sulfate (SLS) showed much less variations in dissolution performance at different pH conditions than a conventional formulation. The combination of citric acid and SLS demonstrated a synergistic effect as compared to use of citric acid alone or in combination with PEG4000 as a precipitation inhibitor.When compared with a conventional formulation and a spray-dried amorphous solid dispersion (ASD) formulation in a dog pharmacokinetics study, the enhanced formulation demonstrated the least AUC and C_max variability between the two gastric pH-controlled groups. In conclusion, an enhanced formulation using a combination of organic acid and surfactant is recommended for weakly basic drug compounds to minimize drug pharmacokinetic variabilities in clinical studies.

Scalable flibanserin nanocrystal-based novel sublingual platform for female hypoactive sexual desire disorder: engineering, optimization adopting the desirability function approach and in vivo pharmacokinetic study

Flibanserin (FLB) was approved by FDA for the treatment of pre-menopausal female hypoactive sexual desire disorder (HSDD). FLB suffers from low oral bioavailability (33%) which might be due to hepatic first-pass metabolism in addition to its poor aqueous solubility. The sublingual route could be a promising alternative for FLB due to the avoidance of enterohepatic circulation. However, the drug needs to dissolve in the small volume of saliva in order to be absorbed through the sublingual mucosa. Therefore, FLB nanocrystals were prepared by sono-precipitation technique according to 2³ full factorial design. FLB-nanocrystals were formulated using two surfactants (PVP K30 and PL F127) in two different amounts (200 and 400 mg) and the volume of ethanol was either 3 or 5 mL. Nanocrystal formulation was optimized according to the desirability function to have a minimum particle size, zeta potential, polydispersity index, and maximum saturated solubility. The optimized formula had a particle size of 443.12 ± 14.91 nm and a saturated solubility of 23.27 ± 4.62 mg/L which is five times the saturated solubility of FLB. Nanocrystal dispersion of the optimized formula was solidified by freeze-drying and used to prepare rapidly disintegrating sublingual tablets containing Pharmaburst^® as superdisintegrant. Sublingual tablet formulation with the shortest disintegration time (36 s) was selected for the in vivo study. FLB nanocrystal-based sublingual tablets exhibited a two-fold increase in bioavailability with a faster onset of action compared to the commercially available oral formulation. These findings prove the potential application of FLB nanocrystal-based sublingual tablets in the treatment of HSDD.