Development of a Novel Controlled-Release Tablet of Pregabalin: Formulation Variation and Pharmacokinetics in Dogs and Humans

A phase 4 randomized active-controlled clinical study to compare the efficacy and safety of sustained-release pregabalin with immediate-release pregabalin in type 2 diabetic patients with peripheral neuropathic pain

AIMS

The objective of this study was to demonstrate that sustained-release (SR) pregabalin is non-inferior to immediate-release (IR) pregabalin in attenuating diabetic peripheral neuropathic (DPN) pain along with patient satisfaction and compliance.

METHODS

This was an 8-week, randomized, active-controlled, open-label, phase 4 study. Eligible subjects who had been on IR pregabalin for 4 weeks were randomized to 1:1 ratio to either continue with twice-daily IR pregabalin (75 mg), or to switch to once-daily SR pregabalin (150 mg). Primary efficacy endpoint was the change in visual analogue scale (VAS) scores after 8 weeks of treatment compared to baseline in both SR and IR pregabalin groups.

RESULTS

Among 130 randomized subjects, 125 patients were included in full analysis set. For the change in VAS pain score, the least squares (LS) mean were -17.95 (SR pregabalin) and -18.74 (IR pregabalin) and the LS mean difference between both groups was 0.79, with the upper limit of the 95 % confidence interval [-5.99, 7.58] below the pre-specified non-inferiority margin of 9.2 mm.

CONCLUSIONS

This study demonstrates that the new once-daily SR pregabalin formulation is not different to the twice-daily IR pregabalin in alleviating DPN pain, indicating its potential as a promising treatment for DPN pain with a comparable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05624853.

Facile fabrication of an extended-release tablet of Ticagrelor using three dimensional printing technology

The objective of the study was to fabricate tailored extended-release tablets of blood thinner Ticagrelor as once-daily dosing using additive manufacturing for better compliance in heart failure therapy. The solid work design of the tablet was printed using hot melt extrusion (HME) based 3D printing by optimized mixture of Eudragit RS-100, plasticizer and drug for producing extrudable and printable filaments. FTIR and TGA results showed no covalent interaction among ingredients and no decomposition during HME process, respectively. Friability, weight variation, assay and content uniformity tests met USP requirements, while the mean hardness of the tablets was calculated in a value between 40 and 50 kg. According to DSC and XRD results, the crystallinity state of the Ticagrelor was converted to an amorphous one in the tablet matrix. Smooth surfaces with multiple deposited layers were observed using SEM. In comparison, the maximum Ticagrelor release of 100% after 120 min from Brilinta® tablets was decreased to 97% in 400 min from the 3D tablet at infill of 90%. Korsmeyer-Peppas kinetic model showed the drug release mechanism is affected by diffusion and swelling. In general, fabrication of the extended-release 3D printed tablet of Ticagrelor using HME-based-additive manufacturing has the potential to provide specific doses with tailored kinetic release for personalized medicine, improving adherence at point-of-care.

Analytical Quality by Design-Based Robust RP-HPLC Method for Quantitative Estimation of Pregabalin and Etoricoxib in Fixed-Dose Combination Tablet Formulation

Background

The Central Drugs Standard Control Organization approved a bilayered, uncoated, fixed-dosage combination tablet formulation containing pregabalin (75 mg) and etoricoxib (60 mg) in November 2019 to control prolonged back pain with neuropathic components.

Objective

This research aims to create an analytical quality by design-assisted reversed phase (RP)-HPLC method for quantifying pregabalin and etoricoxib in tablet formulation.

Methods

The best chromatographic conditions were a Phenomenex C8 column (250 × 4.6 mm, 5.6 μm) and a mobile phase of 0.35% orthophosphoric acid –acetonitrile (1 + 1, by volume). A flow rate of 1 mL/min was used with a detection wavelength of 220 nm.

Results

The optimized reversed phase HPLC method was successfully validated by the International Conference on Hormonization guideline Q2(R1). Moreover, the percentage assay of pregabalin and etoricoxib tablet formulation was 99.05 and 100.02% w/w, respectively, using the validated RP-HPLC method.

Conclusion

The newly developed analytical quality by design-assisted RP-HPLC method has several advantages, including shortened analytical time (2.65 min and 7.45 min pregabalin and etoricoxib, respectively), efficient separation in terms of well-defined peaks, and a simple mobile phase combination.

Highlights

The use of analytical quality by design principles and the design of the experiment tool allowed the detection of influential parameters critical for achieving the most favourable chromatographic conditions for accurately quantifying individual drugs using the RP-HPLC method. The compliance of the results with the ICH criteria validated the method. As a result, adopting the analytical quality by design methodology ensured the development of a more robust method that can generate consistent, dependable, and quality data throughout the process while also saving time.

An Integrative QbD Approach for the Development and Optimization of Controlled Release Compressed Coated Formulation of Water-Soluble Drugs

Controlled release dosage forms maintain regulated pharmacokinetic profile of drug substance within its therapeutic window by ensuring constant plasma concentrations. Controlled release formulations not only increase the therapeutic efficacy of drug substances but also reduce their dose-related side effects. Present investigation was conducted to develop, optimize, and validate compressed coated controlled release tablet formulation for highly water-soluble drug substances which have no rate-controlling factor towards its release from dosage form. Drug dispersed waxy core tablet, press coated within the swellable hydrophilic polymeric barrier layer, was developed and optimized via quality by design approach (QbD) using Box-Behnken design. The optimized formulation was characterized and validated using in vitro quality control parameters. Attributes identified under SUPAC guidelines, such as drug release rates at 30 min, 6 h, and 12 h, were considered as the critical quality attributes (CQAs) that significantly affected efficiency of the compressed coated controlled release tablets. CQAs screened using risk assessment and Pareto chart analyses were used for optimizing controlled release dosage form. Findings revealed that tablets containing drug to wax ratio of 1:1, hydrophilic swellable polymer concentration of 200 mg, and prepared using compression pressure of 6.5 kg/cm² exhibited the highest desirability indices in terms of controlling the release rate of drug substance. Optimized formulation was also evaluated for swelling rate, erosion rate, and other post-compression parameters, including release kinetics. Fickian diffusion-based zero-order controlled release of BCS class I drug substance was achieved through the developed dosage form.

The Effects of Prenatal Exposure to Pregabalin on the Development of Ventral Midbrain Dopaminergic Neurons

Pregabalin is widely used as a treatment for multiple neurological disorders; however, it has been reported to have the potential for misuse. Due to a lack of safety studies in pregnancy, pregabalin is considered the last treatment option for various neurological diseases, such as neuropathic pain. Therefore, pregabalin abuse in pregnant women, even at therapeutic doses, may impair fetal development. We used primary mouse embryonic neurons to investigate whether exposure to pregabalin can impair the morphogenesis and differentiation of ventral midbrain neurons. This study focused on ventral midbrain dopaminergic neurons, as they are responsible for cognition, movement, and behavior. The results showed that pregabalin exposure during early brain development induced upregulation of the dopaminergic progenitor genes Lmx1a and Nurr1 and the mature dopaminergic gene Pitx3. Interestingly, pregabalin had different effects on the morphogenesis of non-dopaminergic ventral midbrain neurons. Importantly, our findings illustrated that a therapeutic dose of pregabalin (10 μM) did not affect the viability of neurons. However, it caused a decrease in ATP release in ventral midbrain neurons. We demonstrated that exposure to pregabalin during early brain development could interfere with the neurogenesis and morphogenesis of ventral midbrain dopaminergic neurons. These findings are crucial for clinical consideration of the use of pregabalin during pregnancy.

Pathogenic Mechanism of Dry Eye-Induced Chronic Ocular Pain and a Mechanism-Based Therapeutic Approach

Purpose

Dry eye–induced chronic ocular pain is also called ocular neuropathic pain. However, details of the pathogenic mechanism remain unknown. The purpose of this study was to elucidate the pathogenic mechanism of dry eye–induced chronic pain in the anterior eye area and develop a pathophysiology-based therapeutic strategy.

Methods

We used a rat dry eye model with lacrimal gland excision (LGE) to elucidate the pathogenic mechanism of ocular neuropathic pain. Corneal epithelial damage, hypersensitivity, and hyperalgesia were evaluated on the LGE side and compared with the sham surgery side. We analyzed neuronal activity, microglial and astrocytic activity, α₂δ–1 subunit expression, and inhibitory interneurons in the trigeminal nucleus. We also evaluated the therapeutic effects of ophthalmic treatment and chronic pregabalin administration on dry eye–induced ocular neuropathic pain.

Results

Dry eye caused hypersensitivity and hyperalgesia on the LGE side. In the trigeminal nucleus of the LGE side, neuronal hyperactivation, transient activation of microglia, persistent activation of astrocytes, α₂δ–1 subunit upregulation, and reduced numbers of inhibitory interneurons were observed. Ophthalmic treatment alone did not improve hyperalgesia. In contrast, continuous treatment with pregabalin effectively ameliorated hypersensitivity and hyperalgesia and normalized neural activity, α₂δ–1 subunit upregulation, and astrocyte activation.

Conclusions

These results suggest that dry eye–induced hypersensitivity and hyperalgesia are caused by central sensitization in the trigeminal nucleus with upregulation of the α₂δ–1 subunit. Here, we showed that pregabalin is effective for treating dry eye–induced ocular neuropathic pain even after chronic pain has been established.

Preclinical Evaluation of Polymeric Nanocomposite Containing Pregabalin for Sustained Release as Potential Therapy for Neuropathic Pain

This study offers a novel oral pregabalin (PG)-loaded drug delivery system based on chitosan and hypromellose phthalate-based polymeric nanocomposite in order to treat neuropathic pain (PG-PN). PG-PN has a particle size of 432 ± 20 nm, a polydispersity index of 0.238 ± 0.001, a zeta potential of +19.0 ± 0.9 mV, a pH of 5.7 ± 0.06, and a spherical shape. Thermal and infrared spectroscopy confirmed nanocomposite generation. PG-PN pharmacokinetics was studied after a single oral dose in male Wistar rats. PG-PN showed greater distribution and clearance than free PG. The antinociceptive effect of PG-PN in neuropathic pain rats was tested by using the chronic constriction injury model. The parameter investigated was the mechanical nociceptive threshold measured by the von Frey filaments test; PG-PN showed a longer antinociceptive effect than free PG. The rota-rod and barbiturate sleep induction procedures were used to determine adverse effects; the criteria included motor deficit and sedative effects. PG-PN and free PG had plenty of motors. PG-PN exhibited a less sedative effect than free PG. By prolonging the antinociceptive effect and decreasing the unfavorable effects, polymeric nanocomposites with pregabalin have shown promise in treating neuropathic pain.

Delirium After Pregabalin Withdrawal

Pregabalin is a γ-amino butyric acid analogue drug that is used in fibromyalgia, neuropathic pain associated with diabetic peripheral neuropathy, spinal cord injury, and postherpetic neuralgia. Symptoms reported in association with pregabalin withdrawal include insomnia, gastrointestinal distress, tachycardia, and headache. This case report describes a 68-year-old patient who developed delirium after experiencing pregabalin withdrawal. Clinicians should be aware of the possibility of pregabalin withdrawal delirium.

A Critical Review on Analytical Methods for Recently Approved FDC Drugs: Pregabalin and Etoricoxib

Fixed-dose combinations (FDCs) refer to products containing two or more active ingredients combined in a single dosage form. The FDCs are justified because of several advantages. These are a) potentiating therapeutic efficacy, b) reducing the incidences of adverse drug effects, c) having pharmacokinetic advantages, d) reducing pills burden, e) reducing the dose of individual drugs and f) decreasing the drug resistance development. A recently approved FDC of Pregabalin IP (75 mg) and Etoricoxib (60 mg) recommended to control neuropathic chronic back pain. Analytical methods are available for individual quantitation of pregabalin (PGB) and etoricoxib (ETC), but an effective and reliable analytical method has not been reported for their combination. Thus, the objective of this literature survey was to gather information on various analytical instrumental methods used so far for the individual quantitation of PGB and ETC in various matrices. Such data would be useful to the scientific community to develop a novel analytical method for the analysis of recently approved FDC of PGB and ETC. Various scientific databases were explored to meet the objectives, and the information is synchronized. The reported methods are high-performance liquid chromatography (48% & 53%), hyphenated techniques (54% & 21%), spectroscopy (50% & 34%), and high-performance thin-layer chromatography, or thin-layer chromatography (6% & 13%) for pregabalin and etoricoxib, respectively. All these methods were specific and selective for the analysis of individual drugs.