Fast-dissolving sublingual solid dispersion and cyclodextrin complex increase the absorption of perphenazine in rabbits

Investigation of Stabilized Amorphous Solid Dispersions to Improve Oral Olaparib Absorption

In this study, we investigated the formulation of stable solid dispersions to enhance the bioavailability of olaparib (OLA), a therapeutic agent for ovarian cancer and breast cancer characterized as a BCS class IV drug with low solubility and low permeability. Various polymers were screened based on solubility tests, and OLA-loaded solid dispersions were prepared using spray drying. The physicochemical properties of these dispersions were investigated via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier Transform Infrared Spectroscopy (FT-IR). Subsequent dissolution tests, along with assessments of morphological and crystallinity changes in aqueous solutions, led to the selection of a hypromellose (HPMC)-based OLA solid dispersion as the optimal formulation. HPMC was effective at maintaining the supersaturation of OLA in aqueous solutions and exhibited a stable amorphous state without recrystallization. In an in vivo study, this HPMC-based OLA solid dispersion significantly enhanced bioavailability, increasing AUC0-24 by 4.19-fold and Cmax by more than 10.68-fold compared to OLA drug powder (crystalline OLA). Our results highlight the effectiveness of HPMC-based solid dispersions in enhancing the oral bioavailability of OLA and suggest that they could be an effective tool for the development of oral drug formulations.

Role of Cyclodextrins and Drug Solid State Properties on Flufenamic Acid Dissolution Performance from Tablets

Flufenamic acid (FFA) is a non-steroidal anti-inflammatory drug characterised by a low solubility and problems of variable dissolution rate and bio-inequivalence. Different FFA batches, obtained by different suppliers, showed different powder characteristics (particle size, shape and surface properties) that may affect its dissolution behaviour from solid dosage forms. Aim of this work was the improvement of FFA solubility and dissolution rate by the use of cyclodextrins (CDs) and the obtainment of an effective tablet formulation by direct compression. Several CDs have been tested, both in solution and in solid state and several binary systems drug-CDs have been obtained with different techniques, with the scope to select the most effective system. Grinding technique with randomly methylated-β-cyclodextrin (RAMEB) was the only one that allowed the complete drug amorphization, together with the highest improvement in drug dissolution rate, and was then selected for tablets formulation. Conventional and immediate release tablets were obtained and fully characterised for technological properties. In both cases an improved and well reproducible drug dissolution performance was obtained, independently from the FFA supplier and thus no more affected by the differences observed between the original FFA crystalline samples.

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.

Development of Perphenazine-Loaded Solid Lipid Nanoparticles: Statistical Optimization and Cytotoxicity Studies

OBJECTIVE

Perphenazine (PPZ), as a typical antipsychotic medical substance, has the same effectiveness compared to atypical antipsychotic medications for the treatment of schizophrenia. Despite the lipophilic essence, PPZ encounters limited bioavailability caused by the first-pass metabolism following oral administration. In the present study, PPZ-containing solid lipid nanoparticles (PPZ-SLNs) were prepared and optimized based on different factors, including lipid and surfactant amount, to develop appropriate and safe novel oral dosage forms of PPZ.

METHODS

The solvent emulsification-evaporation method was utilized to form SLNs by using soybean lecithin, glycerol monostearate (GMS), and Tween 80. Statistical optimization was done by the Box-Behnken design method to achieve formulation with optimized particle size, entrapment efficiency, and zeta potential. Also, transmission electron microscopy, in vitro release behavior, differential scanning calorimetry (DSC), and powder X-ray diffractometry (P-XRD) studies and cytotoxicity studies were assessed.

RESULTS

Optimization exhibited the significant effect of various excipients on SLN characteristics. Our finding indicated that the mean particle size, zeta potential, and entrapment efficiency of optimized PPZ-SLN were, respectively, 104 ± 3.92 nm, -28 ± 2.28 mV, and 83% ± 1.29. Drug release of PPZ-SLN was observed to be greater than 90% for 48 h that emphasized a sustained-release pattern. The DSC and P-XRD studies revealed the amorphous state of PPZ-SLN. FTIR spectra showed no incompatibility between the drug and the lipid. Performing cytotoxicity studies indicated no significant cytotoxicity on HT-29 cell culture.

CONCLUSION

Our study suggests that PPZ-SLNs can make a promising vehicle for a suitable therapy of schizophrenia for the oral drug delivery system.

Preparation, characterization, and in vivo evaluation of perphenazine-loaded nanostructured lipid carriers for oral bioavailability improvement

OBJECTIVE

The main scope of the present investigation was to improve the bioavailability of perphenazine (PPZ) by incorporating it into the nanostructured lipid carriers (NLCs).

SIGNIFICANCE

As a result of lipophilic nature and poor aqueous solubility, as well as extensive hepatic metabolism, PPZ has low systemic bioavailability via the oral route. NLCs have shown potentials to surmount the oral delivery drawbacks of poorly water-soluble drugs.

METHODS

The PPZ-NLCs were prepared by the emulsification-solvent evaporation method and subjected for particle size, zeta potential, and entrapment efficiency (EE) analysis. The optimized NLCs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Besides, in vitro release behavior, storage stability, and pharmacokinetic studies followed by a single-dose oral administration in rats were performed.

RESULTS

Optimized PPZ-NLCs showed a particle size of less than 180 nm with appropriate EE of more than 95%. Microscopic images captured with SEM and TEM exhibited that NLCs were approximately spherical in shape. DSC and PXRD analysis confirmed reduced crystallinity of PPZ after incorporation in NLCs. FTIR spectra demonstrated no chemical interactions between PPZ and NLC components. In vitro release studies confirmed the extended-release properties of NLC formulations. PPZ-NLCs exhibited good stability at 4 °C within three months. The oral bioavailability of NLC-6 and NLC-12 was enhanced about 3.12- and 2.49-fold, respectively, compared to the plain drug suspension.

CONCLUSION

NLC can be designated as an effective nanocarrier for oral delivery of PPZ.

Pharmacokinetics and brain distribution studies of perphenazine-loaded solid lipid nanoparticles

BACKGROUND

Perphenazine (PPZ) is a typical antipsychotic that is mainly administrated for the treatment of schizophrenia. Due to its highly lipophilic nature and extensive hepatic first-pass metabolism, its oral bioavailability is low (40%).

OBJECTIVE

The novel nanocarriers like solid lipid nanoparticles (SLN) have been reported to be highly effective for improving the therapeutic effect of drugs. Therefore the main scope of the present investigation was the evaluation of in vivo characteristics of PPZ-SLN in terms of pharmacokinetic parameters and brain distribution.

METHODS

The PPZ-SLN was prepared by the solvent-emulsification and evaporation method. The storage stability of PPZ-SLN and empty SLN powders was studied for 3 months. In vivo pharmacokinetic studies and brain distribution evaluations were performed following a single oral dose administration of PPZ and PPZ-SLN suspensions on male Wistar rats. An HPLC method was established and validated for the quantitative determination of PPZ in plasma and brain samples.

RESULTS

The storage stability studies revealed the good storage stability of the both PPZ-SLN and empty SLN at 4 °C. Compared to PPZ suspension, the relative bioavailability and the brain distribution of PPZ-SLN were increased up to 2-fold and 16-fold, respectively. Mean residence time (MRT) and half-life (t_1/2) of PPZ-SLN were significantly (p value < 0.01) increased in both plasma and brain homogenate compared to PPZ suspension.

CONCLUSION

The significant improvement in the pharmacokinetic properties of PPZ following one oral dose indicates that SLN is a promising drug delivery system for PPZ and shows a high potential for successful brain delivery of this antipsychotic.

Epinephrine in Anaphylaxis: Preclinical Study of Pharmacokinetics after Sublingual Administration of Taste-Masked Tablets for Potential Pediatric Use

Epinephrine is a life-saving treatment in anaphylaxis. In community settings, a first-aid dose of epinephrine is injected from an auto-injector (EAI). Needle phobia highly contributes to EAI underuse, leading to fatalities—especially in children. A novel rapidly-disintegrating sublingual tablet (RDST) of epinephrine was developed in our laboratory as a potential alternative dosage form. The aim of this study was to evaluate the sublingual bioavailability of epinephrine 30 mg as a potential pediatric dose incorporated in our novel taste-masked RDST in comparison with intramuscular (IM) epinephrine 0.15 mg from EAI, the recommended and only available dosage form for children in community settings. We studied the rate and extent of epinephrine absorption in our validated rabbit model (n = 5) using a cross-over design. The positive control was IM epinephrine 0.15 mg from an EpiPen Jr^®. The negative control was a placebo RDST. Tablets were placed under the tongue for 2 min. Blood samples were collected at frequent intervals and epinephrine concentrations were measured using HPLC with electrochemical detection. The mean ± SEM maximum plasma concentration (C_max) of 16.7 ± 1.9 ng/mL at peak time (T_max) of 21 min after sublingual epinephrine 30 mg did not differ significantly (p > 0.05) from the C_max of 18.8 ± 1.9 ng/mL at a T_max of 36 min after IM epinephrine 0.15 mg. The C_max of both doses was significantly higher than the C_max of 7.5 ± 1.7 ng/mL of endogenous epinephrine after placebo. These taste-masked RDSTs containing a 30 mg dose of epinephrine have the potential to be used as an easy-to-carry, palatable, non-invasive treatment for anaphylactic episodes for children in community settings.

Direct comparison between millifluidic and bulk-mixing platform in the synthesis of amorphous drug-polysaccharide nanoparticle complex

Amorphous drug-polysaccharide nanoparticle complex (or drug nanoplex) had emerged as an ideal supersaturating delivery system of poorly-soluble drugs attributed to its many attractive characteristics. Herein we presented for the first time direct comparison between two nanoplex synthesis platforms, i.e. millifluidics and bulk mixing, representing continuous and batch production modes, respectively. They were compared by the resultant nanoplex's (1) physical characteristics (size, zeta potential, and payload), (2) preparation efficiency, (3) storage stability, (4) dissolution rate/supersaturation generation, and (5) production consistency. The effects of key variables in drug-polysaccharide complexation (pH, charge ratio) were investigated in both platforms. Perphenazine and dextran sulfate were used as the drug and polysaccharide models, respectively. The results showed that both platforms shared similar dependences on pH and charge ratio with similar optimal preparation conditions, where the pH was the governing variable through its influence on size and zeta potential, Nanoplexes having mostly similar characteristics (size ≈70-90nm, zeta potential ≈-50mV) were produced by both platforms, except for the payload where bulk mixing resulted in lower payload (65% versus 85%). The lower payload, however, resulted in its superior supersaturation generation. Nevertheless, millifluidics was favored attributed to its superior production consistency and scalability.

Amorphous nanoparticle complex of perphenazine and dextran sulfate as a new solubility enhancement strategy of antipsychotic perphenazine

OBJECTIVE

The objective of this study is to develop a new solubility enhancement strategy of antipsychotic drug - perphenazine (PPZ) - in the form of its amorphous nanoparticle complex (or nanoplex) with polyelectrolyte dextran sulfate (DXT).

SIGNIFICANCE

Poor bioavailability of PPZ necessitated the development of fast-dissolving PPZ formulations regardless of delivery routes. Existing fast-dissolving formulations, however, exhibited low PPZ payload. The high-payload PPZ-DXT nanoplex represents an attractive fast-dissolving formulation, as dissolution rate is known to be proportional to payload.

METHODS

The nanoplex was prepared by electrostatically driven complexation between PPZ and DXT in a simple process that involved only ambient mixing of PPZ and DXT solutions. We investigated the effects of key variables in drug-polyelectrolyte complexation (i.e. pH and charge ratio R_DXT/PPZ) on the physical characteristics and preparation efficiency of the nanoplex produced. Subsequently, we characterized the colloidal and amorphous state stabilities, dissolution enhancement, and supersaturation generation of the nanoplex prepared at the optimal condition.

RESULTS

The physical characteristics of nanoplex were governed by R_DXT/PPZ, while the preparation efficiency was governed by the preparation pH. Nanoplex having size of ≈80 nm, zeta potential of ≈(-) 60 mV, and payload of ≈70% (w/w) were prepared at nearly 90% PPZ utilization rate and ≈60% yield. The nanoplex exhibited superior dissolution than native PPZ in simulated intestinal juice, resulting in high and prolonged apparent solubility with good storage stabilities.

CONCLUSIONS

The simple yet efficient preparation, excellent physical characteristics, fast dissolution, and high apparent solubility exhibited by the PPZ-DXT nanoplex established its potential as a new bioavailability enhancement strategy of PPZ.

Sublingual Priming with a HIV gp41-Based Subunit Vaccine Elicits Mucosal Antibodies and Persistent B Memory Responses in Non-Human Primates

Persistent B cell responses in mucosal tissues are crucial to control infection against sexually transmitted pathogens like human immunodeficiency virus 1 (HIV-1). The genital tract is a major site of infection by HIV. Sublingual (SL) immunization in mice was previously shown to generate HIV-specific B cell immunity that disseminates to the genital tract. We report here the immunogenicity in female cynomolgus macaques of a SL vaccine based on a modified gp41 polypeptide coupled to the cholera toxin B subunit designed to expose hidden epitopes and to improve mucosal retention. Combined SL/intramuscular (IM) immunization with such mucoadhesive gp41-based vaccine elicited mucosal HIV-specific IgG and IgA antibodies more efficiently than IM immunization alone. This strategy increased the number and duration of gp41-specific IgA secreting cells. Importantly, combined immunization improved the generation of functional antibodies 3 months after vaccination as detected in HIV-neutralizing assays. Therefore, SL immunization represents a promising vaccine strategy to block HIV-1 transmission.

Effect of storage on the dissolution rate of a fast-dissolving perphenazine/β-cyclodextrin complex

OBJECTIVE

In general, the chemical and physical stability of amorphous cyclodextrin complexes and how storage affects their dissolution rate have not been widely reported. The aim of this study was to evaluate the solid-state stability of a fast-dissolving perphenazine/β-cyclodextrin (β-CD) complex, which has been found to be well absorbed after sublingual administration to rabbits. In addition, the dissolution rate of plain β-CD in crystalline and amorphous forms was determined.

METHODS

The amorphous perphenazine/β-CD complex powders were prepared by spray-drying and freeze-drying, and their stability was examined after storage at 40°C, 75% relative humidity (RH) or at room temperature, 60% RH for up to 82 days.

KEY FINDINGS

Perphenazine was found to be chemically stable in all samples. The dissolution rate of perphenazine remained practically unchanged at both storage conditions, although partial crystallization was observed in both spray-dried and freeze-dried samples at 40°C, 75% RH. Interestingly, it was also observed that the dissolution rates of crystalline and amorphous β-CD were similar.

CONCLUSION

The results suggest that CD complexation may represent a suitable alternative for preparing intraorally dissolving formulations because the fast dissolution rate of the drug was maintained even though changes in the crystal structure were observed during storage.

Development of orally disintegrating tablets of Perphenazine/hydroxypropyl-β-cyclodextrin inclusion complex

The aim of the present work was to prepare perphenazine (PPZ) orally disintegrating tablets (ODTs) based on the use of hydroxypropyl-β-cyclodextrin (HP-β-CD) forming inclusion complex with PPZ to improve the solubility and dissolution of this practically insoluble drug. Phase solubility studies were performed to evaluate the complexation of PPZ with HP-β-CD in three aqueous systems. The inclusion complex prepared by evaporation method was characterized by different physicochemical techniques, including the dissolution studies. The prepared complex was incorporated into ODTs containing different fillers and disintegrants. The ODTs prepared by direct compression were evaluated for drug content, hardness, porosity, friability, in vitro disintegration time (DT), wetting time (WT) and dissolution profiles. The solubility and dissolution rate were substantially improved compared with that of PPZ. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses suggested that PPZ could form true inclusion complex with HP-β-CD. The optimized formulation F6 exhibited short DT (15.5 ± 1.9 s) and WT (34.2 ± 2.3 s), sufficient hardness (30.4 ± 1.6 N/mm) and rapid drug dissolution. The developed tablet formulation could be a promising drug delivery system with improvements in PPZ bioavailability and patient compliance.