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Pharmacokinetic and anti-colon cancer properties of curcumin-containing chitosan-pectinate composite nanoparticles

Alkhader E, Roberts CJ, Rosli R, Yuen KH, Seow EK, Lee YZ, et al.

J Biomater Sci Polym Ed, 2018 12;29(18):2281-2298.
PMID: 30376409 DOI: 10.1080/09205063.2018.1541500

Curcumin, the active ingredient of the rhizome curcuma longa has been extensively studied as an anticancer agent for various types of tumours. However, its efficacy as an anticancer agent is restricted due to poor absorption from the gastrointestinal tract, rapid metabolism and degradation in acidic medium. In the present study, we encapsulated curcumin in chitosan-pectinate nanoparticulate system (CUR-CS-PEC-NPs) for deployment of curcumin to the colon, whereby curcumin is protected against degradative effects in the upper digestive tract, and hence, maintaining its anticancer properties until colon arrival. The CUR-CS-PEC-NPs was taken up by HT-29 colorectal cancer cells which ultimately resulted in a significant reduction in cancer cell propagation. The anti-proliferative effect of the encapsulated curcumin was similar to that of free curcumin at equivalent doses which confirms that the encapsulation process did not impede the anticancer activity of curcumin. The oral bioavailability (Cmax, and AUC) of curcumin in CUR-CS-PEC-NPs was enhanced significantly by 4-folds after 6 hours of treatment compared to free curcumin. Furthermore, the clearance of curcumin from the CUR-CS-PEC-NPs was lower compared to free curcumin. These findings point to the potential application of the CUR-CS-PEC-NPs in the oral delivery of curcumin in the treatment of colon cancer.
Fulltext A gastrointestinal transit study on amphotericin B-loaded solid lipid nanoparticles in rats

Amekyeh H, Billa N, Yuen KH, Chin SL

AAPS PharmSciTech, 2015 Aug;16(4):871-7.
PMID: 25588365 DOI: 10.1208/s12249-014-0279-4

The gastrointestinal (GI) transit behavior of and absorption from an amphotericin B (AmB) solid lipid nanoformulation (SLN) in rats was investigated. We aimed to estimate the gastric emptying time (GET) and cecal arrival time (CAT) of AmB SLN in rats as animal models. From these two parameters, an insight on the absorption window of AmB was ascertained. Three types of SLNs, AmB, paracetamol (PAR), and sulfasalazine (SSZ), were similarly formulated using beeswax/theobroma oil composite as the lipid matrix and characterized with regard to size, viscosity, density, migration propensity within agarose gel, in vitro drug release, morphology, gastrointestinal transit, and in vivo absorption. The GET and CAT were estimated indirectly using marker drugs: PAR and sulfapyridine (SP). All three types of SLNs exhibited identical properties with regard to z-average, viscosity, relative density, and propensity to migrate. PAR was absorbed rapidly from the small intestine following emptying of the SLNs giving the T50E (time for 50% absorption of PAR) to be 1.6 h. SP was absorbed after release and microbial degradation of SSZ from SLN in the colon with a lag time of 2 h post-administration, serving as the estimated cecal arrival time of the SLNs. AmB within SLN was favorably absorbed from the small intestine, albeit slowly.
Effect of Food Status on the Gastrointestinal Transit of Amphotericin B-Containing Solid Lipid Nanoparticles in Rats

Amekyeh H, Billa N, Yuen KH, Lim SC

AAPS PharmSciTech, 2015 Oct 28.
PMID: 26511938

Amphotericin B (AmB) is poorly absorbed from the gastrointestinal tract. Recent studies have suggested enhanced drug absorption from solid lipid nanoparticles (SLN). Little is known of the fate of AmB absorption within the gastrointestinal tract, and no gastrointestinal transit study has yet been performed on AmB-containing nano-formulations. We aimed to investigate the effect of food on the gastrointestinal transit properties of an AmB-containing SLN in rats. Three SLNs containing AmB, paracetamol, or sulfasalazine were formulated using cocoa butter and beeswax as lipid matrices and simultaneously administered orally to Sprague-Dawley rats. Paracetamol and sulfapyridine were used as marker drugs for estimating gastric emptying and cecal arrival, respectively. The pharmacokinetic data generated for paracetamol and sulfapyridine were used in estimating the absorption of the AmB SLNs in the small and large intestines, respectively. A delayed rate of AmB absorption was observed in the fed state; however, the extent of absorption was not affected by food. Specifically, the percentages of AmB absorption during the fasted state in the stomach, small intestine, and colon were not significantly different from absorption within the respective regions in the fed state. In both states, however, absorption was highest in the colon and appeared to be a combination of absorption from the small intestine plus absorption proper within the colon. The study suggests that AmB SLN, irrespective of food status, is slowly but predominantly taken up by the lymph, making the small intestine the most favorable site for the delivery of the AmB SLNs.
Formulation variables affecting drug release from xanthan gum matrices at laboratory scale and pilot scale

Billa N, Yuen KH

AAPS PharmSciTech, 2000;1(4):E30.
PMID: 14727895

The purpose of this research was to study processing variables at the laboratory and pilot scales that can affect hydration rates of xanthan gum matrices containing diclofenac sodium and the rate of drug release. Tablets from the laboratory scale and pilot scale proceedings were made by wet granulation. Swelling indices of xanthan gum formulations prepared with different amounts of water were measured in water under a magnifying lens. Granules were thermally treated in an oven at 60 degrees C, 70 degrees C, and 80 degrees C to study the effects of elevated temperatures on drug release from xanthan gum matrices. Granules from the pilot scale formulations were bulkier compared to their laboratory scale counterparts, resulting in more porous, softer tablets. Drug release was linear from xanthan gum matrices prepared at the laboratory scale and pilot scales; however, release was faster from the pilot scales. Thermal treatment of the granules did not affect the swelling index and rate of drug release from tablets in both the pilot and laboratory scale proceedings. On the other hand, the release from both proceedings was affected by the amount of water used for granulation and the speed of the impeller during granulation. The data suggest that processing variables that affect the degree of wetness during granulation, such as increase in impeller speed and increase in amount of water used for granulation, also may affect the swelling index of xanthan gum matrices and therefore the rate of drug release.
Gamma-scintigraphic study of the gastrointestinal transit and in vivo dissolution of a controlled release diclofenac sodium formulation in xanthan gum matrices

Billa N, Yuen KH, Khader MA, Omar A

Int J Pharm, 2000 May 15;201(1):109-20.
PMID: 10867269

A xanthan gum matrix controlled release tablet formulation containing diclofenac sodium was evaluated in vitro and was found to release the drug at a uniform rate. The gastrointestinal transit behaviour of the formulation as determined by gamma scintigraphy, using healthy male volunteers under fasted and fed conditions, indicated that gastric emptying was delayed with food intake. In contrast, the small intestinal transit remained practically unchanged under both food statuses. Therefore, the delay in caecal arrival observed in the fed state can be attributed to the delay in gastric emptying. Rate of diclofenac sodium absorption was generally higher in the fed state compared to the fasted state, however the total amount absorbed under both food statuses remained practically the same. The rate of in vivo dissolution of the drug in the fed state was faster compared to that in the fasted state. Thus, at the time of caecal arrival, in vivo dissolution was complete in the fed state, unlike in the fasted state, where almost 60% of the drug was delivered to the colon.
Diclofenac release from eudragit-containing matrices and effects of thermal treatment

Billa N, Yuen KH, Peh KK

Drug Dev Ind Pharm, 1998 Jan;24(1):45-50.
PMID: 15605596

Ethyl acrylate-methyl methacrylate copolymer (Eudragit NE40D) was evaluated as matrix material for preparing controlled-release tablets of diclofenac sodium. Drug release could be modified in a predictable manner by varying the Eudragit NE40D content, but was pH dependent, being markedly reduced at lower pH. This could be attributed to the low solubility of the drug at these pH values. Thermal treatment of the tablets at 60 degrees C was also found to affect the rate of drug release, which was found to decrease with an increase in the treatment duration, but could be stabilized after 96 hr of treatment. This was also associated with a corresponding increase in the tablet tensile strength. However, treatment of the granules for 5 hr prior to compaction into tablets could shorten the stabilizing time of the drug release to 48 hr and that of the tensile strength to 24 hr. The effect of thermal treatment may be ascribed to better coalescence of the Eudragit particles to form a fine network, resulting in matrix of higher tortuosity and lower porosity.
A high-performance liquid chromatography analysis of plasma artemisinin using a glassy carbon electrode for reductive electrochemical detection

Chan KL, Yuen KH, Jinadasa S, Peh KK, Toh WT

Planta Med, 1997 Feb;63(1):66-9.
PMID: 9063097

A high-performance liquid chromatography assay equipped with a glassy carbon electrode for electrochemical detection (HPLC-ECD) was developed at reductive mode for the analysis of artemisinin, the antimalarial drug from Artemisia annua (Asteraceae) in human plasma. This method was selective, sensitive, and produced satisfactory recovery, precision, and accuracy. Analysis of plasma samples from 8 male volunteers given 10 mg kg-1 of artemisinin orally as an aqueous suspension showed a mean peak plasma concentration (Cmax) of 580.89 ng ml-1 +/- 88.64 SD at 2.5 h +/- 0.5 SD after dosing, and the mean area under the plasma concentration-time curve (AUC0-infinity) was 2227.57 ng h ml-1 +/- 677.22 SD. In addition, the elimination rate constant (Ke), elimination half-life (t1/2), and apparent volume of distribution (Vd) were calculated to be 0.2971 h-1 +/- 0.0644 SD, 2.42 h +/- 0.46 SD, and 16.26 l kg-1 +/- 3.44 SD, respectively.
Bioequivalence and pharmacokinetic comparison of two fixed dose combination of Metformin/ Glibenclamide formulations in healthy subjects under fed condition

Chang CT, Ang JY, Wong JM, Tan SS, Chin SK, Lim AB, et al.

Med J Malaysia, 2020 05;75(3):286-291.
PMID: 32467546

AIM: This study is conducted to compare the pharmacokinetic profiles of two fixed dose combination of metformin/glibenclamide tablets (500mg/5 mg per tablet).
MATERIALS AND METHODS: This is a single-center, single-dose, open-label, randomized, 2-treatment, 2-sequence and 2- period crossover study with a washout period of 7 days. All 28 adult male subjects were required to fast for at least 10 hours prior to drug administration and they were given access to water ad libitum during this period. Thirty minutes prior to dosing, all subjects were served with a standardized high-fat and high-calorie breakfast with a total calorie of 1000 kcal which was in accordance to the EMA Guideline on the Investigation of Bioequivalence. Subsequently, subjects were administered either the test or reference preparation with 240mL of plain water in the first trial period. During the second trial period, they received the alternate preparation. Plasma levels of glibenclamide and metformin were analysed separately using two different high performance liquid chromatography methods.
RESULTS: The 90% confidence interval (CI) for the ratio of the AUC0-t, AUC0-∞, and Cmax of the test preparation over those of the reference preparation were 0.9693-1.0739, 0.9598- 1.0561 and 0.9220 - 1.0642 respectively. Throughout the study period, no serious drug reaction was observed. However, a total of 26 adverse events (AE)/side effects were reported, including 24 that were definitely related to the study drugs, namely giddiness (n=17), while diarrheoa (n=3), headache (n=2) and excessive hunger (n=2) were less commonly reported by the subjects.
CONCLUSION: It can be concluded that the test preparation is bioequivalent to the reference preparation.
Acute effects of a single dose of tocotrienols on insulinemic and inflammatory responses in metabolic syndrome subjects after a high-fat challenge

Che HL, Kanthimathi MS, Loganathan R, Yuen KH, Tan AT, Selvaduray KR, et al.

Eur J Clin Nutr, 2017 01;71(1):107-114.
PMID: 27759074 DOI: 10.1038/ejcn.2016.200

BACKGROUND/OBJECTIVES: Evidence shows that tocotrienols potentially reverse various chronic disease progressions caused by the metabolic syndrome. We aimed to investigate the acute effects of a single-dose supplementation of gamma and delta tocotrienols (γδ-T3, 1:4 ratio) compared with those in placebo on the insulinemic, anti-inflammatory and anti-thrombogenic responses in metabolic syndrome subjects.
SUBJECTS/METHODS: Thirty metabolic syndrome subjects (15 men and 15 women) were recruited to a randomized, double-blinded and crossover study. The subjects were administered a single dose of 200 mg or 400 mg γδ-T3 emulsions or placebo incorporated into a glass of strawberry-flavored milkshake, consumed together with a high-fat muffin. Blood samples were collected at 0, 5, 15, 30, 60, 90, 120, 180, 240, 300 and 360 min after meal intake.
RESULTS: Plasma vitamin E levels reflected the absorption of γδ-T3 after treatments. Postprandial changes in serum C-peptide, serum insulin, plasma glucose, triacylglycerol, non-esterified fatty acid and adiponectin did not differ between treatments, with women displaying delayed increase in the aforementioned markers. No significant difference between treatments was observed for plasma cytokines (interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha) and thrombogenic markers (plasminogen activator inhibitor type 1 and D-dimer).
CONCLUSIONS: Supplementation of a single dose of γδ-T3 did not change the insulinemic, anti-inflammatory and anti-thrombogenic responses in metabolic syndrome subjects.
Fulltext A randomized single-dose, two-period crossover bioequivalence study of two fixed-dose Paracetamol/Orphenadrine combination preparations in healthy volunteers under fasted condition

Cheah KY, Mah KY, Pang LH, Ng SM, Wong JW, Tan SS, et al.

BMC Pharmacol Toxicol, 2020 06 23;21(1):45.
PMID: 32576287 DOI: 10.1186/s40360-020-00416-3

BACKGROUND: Paracetamol/Orphenadrine is a fixed dose combination containing 35 mg orphenadrine and 450 mg paracetamol. It has analgesic and muscle relaxant properties and is widely available as generics. This study is conducted to investigate the relative bioavailability and bioequivalence between one fixed dose paracetamol/orphenadrine combination test preparation and one fixed dose paracetamol/orphenadrine combination reference preparation in healthy volunteers under fasted condition for marketing authorization in Malaysia.
METHOD: This is a single-center, single-dose, open-label, randomized, 2-treatment, 2-sequence and 2-period crossover study with a washout period of 7 days. Paracetamol/Orphenadrine tablets were administered after a 10-h fast. Blood samples for pharmacokinetic analysis were collected at scheduled time intervals prior to and up to 72 h after dosing. Blood samples were centrifuged, and separated plasma were kept frozen (- 15 °C to - 25 °C) until analysis. Plasma concentrations of orphenadrine and paracetamol were quantified using liquid-chromatography-tandem mass spectrometer using diphenhydramine as internal standard. The pharmacokinetic parameters AUC0-∞, AUC0-t and Cmax were determined using plasma concentration time profile for both preparations. Bioequivalence was assessed according to the ASEAN guideline acceptance criteria for bioequivalence which is the 90% confidence intervals of AUC0-∞, AUC0-t and Cmax ratio must be within the range of 80.00-125.00%.
RESULTS: There were 28 healthy subjects enrolled, and 27 subjects completed this trial. There were no significant differences observed between the AUC0-∞, AUC0-t and Cmax of both test and reference preparations in fasted condition. The 90% confidence intervals for the ratio of AUC0-t (100.92-111.27%), AUC0-∞ (96.94-108.08%) and Cmax (100.11-112.50%) for orphenadrine (n = 25); and AUC0-t (94.29-101.83%), AUC0-∞ (94.77-101.68%) and Cmax (87.12-101.20%) for paracetamol (n = 27) for test preparation over reference preparation were all within acceptable bioequivalence range of 80.00-125.00%.
CONCLUSION: The test preparation is bioequivalent to the reference preparation and can be used interchangeably.
TRIAL REGISTRATION: NMRR- 17-1266-36,001; registered and approved on 12 September 2017.
Initial, long-term, and durable responses to terazosin, placebo, or other therapies for chronic prostatitis/chronic pelvic pain syndrome

Cheah PY, Liong ML, Yuen KH, Teh CL, Khor T, Yang JR, et al.

Urology, 2004 Nov;64(5):881-6.
PMID: 15533470 DOI: 10.1016/j.urology.2004.06.041

OBJECTIVES: To evaluate the initial, long-term, and durable response rates to terazosin, placebo, or other therapies in patients with chronic prostatitis/chronic pelvic pain syndrome.
METHODS: A total of 100 subjects, aged 20 to 50 years, who met the National Institutes of Health criteria for chronic prostatitis/chronic pelvic pain syndrome and had not previously been treated with alpha-blockers, were entered in a 14-week, double-blind comparison of terazosin or placebo therapy. Nonresponders and responders with subsequent relapse were treated with terazosin or other medications (open label). The criterion for response was a score of 0 to 2 on the National Institutes of Health Chronic Prostatitis Symptom Index quality-of-life item. The initial response was evaluated at week 14, and the long-term response was evaluated after a median of 38 weeks (range 34 to 42), regardless of any additional treatment. A durable response was defined as an initial response without additional treatment.
RESULTS: Of the 43 patients in the terazosin group, 24 (56%) had an initial response compared with 14 (33%) of 43 subjects in the placebo group (P = 0.03). Long-term responses were noted in 23 (56%) of 41 assessable subjects treated with terazosin initially compared with 12 (32%) of 38 assessable subjects treated with placebo (P = 0.03). Of the nonresponders and initial responders with relapse, 7 (41%) of 17 subjects responded to terazosin compared with 7 (21%) of 34 given other treatment (P = 0.12). Durable responses occurred in 18 (44%) of the 41 assessable patients treated initially with terazosin and in 6 (16%) of 38 treated initially with placebo (P = 0.01).
CONCLUSIONS: Patients treated with terazosin were more likely to have initial, long-term, and durable responses than those treated with placebo.
Chronic prostatitis: symptom survey with follow-up clinical evaluation

Cheah PY, Liong ML, Yuen KH, Teh CL, Khor T, Yang JR, et al.

Urology, 2003 Jan;61(1):60-4.
PMID: 12559266

OBJECTIVES: To determine the prevalence of chronic prostatitis/chronic pelvic pain syndrome (National Institutes of Health Category III prostatitis) in Penang, Malaysia and estimate the proportion of cases ascertained by population survey that met consensus clinical criteria for "chronic prostatitis."
METHODS: One percent of 20 to 50-year-old men in Penang, Malaysia were surveyed using the National Institutes of Health Chronic Prostatitis Symptom Index. A clinical evaluation that included lower urinary tract localization studies was recommended for symptomatic subjects who met the survey definition to identify bacterial prostatitis and other diagnoses that would exclude them from the consensus clinical definition for chronic prostatitis (Category III).
RESULTS: Of 3147 subjects surveyed, 275 (8.7%) met the survey criteria for chronic prostatitis. The prevalence of chronic prostatitis was 8.0% among Malays, 8.9% among non-Malays, and 16% among noncitizens (P = 0.025). The prevalence increased with age: 6.3% in 20 to 30-year-old men, 8.9% in 31 to 40-year-old men, and 12.6% in 41 to 50-year-old men (P <0.001). Of 87 subjects evaluated clinically, 65 (75%) met the consensus clinical criteria for chronic prostatitis.
CONCLUSIONS: Chronic prostatitis represents an important, international healthcare problem. A thorough clinical evaluation is necessary to verify that chronic prostatitis is indeed responsible for a patient's pelvic pain and lower urinary tract symptoms.
Terazosin therapy for chronic prostatitis/chronic pelvic pain syndrome: a randomized, placebo controlled trial

Cheah PY, Liong ML, Yuen KH, Teh CL, Khor T, Yang JR, et al.

J Urol, 2003 Feb;169(2):592-6.
PMID: 12544314 DOI: 10.1097/01.ju.0000042927.45683.6c

PURPOSE: We evaluate terazosin therapy for chronic prostatitis/chronic pelvic pain syndrome.
MATERIALS AND METHODS: The study included 100, 20 to-50-year-old subjects who met the consensus criteria for chronic prostatitis/chronic pelvic pain syndrome and had not received previous alpha-blockers. Subjects were randomized to receive terazosin with dose escalation from 1 to 5 mg. daily or placebo for 14 weeks. The primary criterion for response was scoring 2 or less ("delighted-to-mostly satisfied") on the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) quality of life item. The secondary criterion for response was greater than 50% reduction in NIH-CPSI pain score at 14 weeks. Other outcomes included total and NIH-CPSI domain scores, International Prostate Symptom Score, peak urinary flow rate, post-void residual urine and adverse effects.
RESULTS: Using the primary criterion 24 of 43 evaluable subjects (56%) responded in the terazosin group compared to 14 of 43 (36%) in the placebo group (p = 0.03). Using the secondary criterion 26 of 43 subjects (60%) responded in the terazosin group compared to 16 of 43 (37%) in the placebo group (p = 0.03). The terazosin group had greater reductions (p <0.05) in NIH-CPSI total score, individual domain scores and International Prostate Symptom Score than the placebo group. There was no difference in peak urinary flow rate or post-void residual. In the terazosin group 18 patients (42%) had side effects compared to 9 (21%) in the placebo group (p = 0.04).
CONCLUSIONS: Terazosin proved superior to placebo for patients with chronic prostatitis/chronic pelvic pain syndrome who had not received alpha-blockers previously.
Improved high-performance liquid chromatographic analysis of terazosin in human plasma

Cheah PY, Yuen KH, Liong ML

J Chromatogr B Biomed Sci Appl, 2000 Aug 18;745(2):439-43.
PMID: 11043762

A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method was developed for the determination of terazosin in human plasma. The method involves a one-step single solvent extraction procedure using dichloromethane with a 0.25 ml plasma sample. Recovery values were all greater than 90% over the concentration range 0.25-100 ng/ml. Terazosin was found to adsorb to glass or plastic tubes, but this could be circumvented by using disposable plastic tubes. Also, rinsing the injector port with methanol after each injection helped to prevent any carry-over effect. The internal standard, prazosin, did not exhibit this problem. The method has a quantification limit of 0.25 ng/ml. The within- and between-day coefficient of variation and accuracy values were all less than 7% over the concentration range 0.25-100 ng/ml and hence the method is suitable for use in pharmacokinetic studies of terazosin.
Reliability and validity of the National Institutes of Health: Chronic Prostatitis Symptom Index in a Malaysian population

Cheah PY, Liong ML, Yuen KH, Lee S, Yang JR, Teh CL, et al.

World J Urol, 2006 Feb;24(1):79-87.
PMID: 16465553 DOI: 10.1007/s00345-005-0037-z

The objective of the study is to determine the short- and long-term utility of the Chinese, Malay and English versions of the National Institutes of Health--Chronic Prostatitis Symptom Index (NIH-CPSI) in our ethnically diverse population. The NIH-CPSI was translated into Chinese and Malay, and then verified by back translation into English. Subjects included 100 new chronic prostatitis/chronic pelvic pain (CP/CPPS) patients, 71 new benign prostatic hyperplasia patients and 97 healthy individuals. Reliability was evaluated with test-retest reproducibility (TR) by calculating intraclass correlation coefficients (ICC). Internal consistency was evaluated by calculating Cronbach's alpha (alpha). Validity assessments included discriminant and construct validity. (Presented in the order of Chinese, Malay then English). ICC values for short-term (1 week) TR were 0.90, 0.80 and 0.89, while ICC values for long-term (14 weeks) TR were 0.54, 0.61 and 0.61. Cronbach's alpha values were 0.63, 0.62 and 0.57. The NIH-CPSI total score discriminated CP/CPPS patients (P<0.001) from the control groups with receiver operating curve values of 0.95, 0.98 and 0.94, respectively. Construct validity, reflected by the correlation coefficient values between the International Prostate Symptom Score and the NIH-CPSI of CP/CPPS patients were 0.72, 0.49 and 0.63 (all P<0.05). The Chinese, Malay and English versions of the NIH-CPSI each proved effective in our population. Short-term TR and discriminant validity were excellent for all three versions. However, long-term TR was only moderate, which might reflect variation in patients' perceptions of symptoms over time.
Fulltext Cytoprotective and enhanced anti-inflammatory activities of liposomal piroxicam formulation in lipopolysaccharide-stimulated RAW 264.7 macrophages

Chiong HS, Yong YK, Ahmad Z, Sulaiman MR, Zakaria ZA, Yuen KH, et al.

Int J Nanomedicine, 2013;8:1245-55.
PMID: 23569374 DOI: 10.2147/IJN.S42801

Liposomal drug delivery systems, a promising lipid-based nanoparticle technology, have been known to play significant roles in improving the safety and efficacy of an encapsulated drug.
Significance of lipid matrix aging on in vitro release and in vivo bioavailability

Choy YW, Khan N, Yuen KH

Int J Pharm, 2005 Aug 11;299(1-2):55-64.
PMID: 15955645

A polyglycolised glyceride carrier, Gelucire 50/13, was incorporated with paracetamol as a model drug, filled into hard gelatin capsules and stored at three different temperatures for various lengths of time. The resultant solidified matrix within the capsule was subjected to thermal analysis using differential scanning calorimetry (DSC) to ascertain its supramolecular structure. Polymorphic transformations towards more stable gelucire forms were observed upon aging the matrices, with samples stored at a temperature near the melting range of the lower temperature gelucire melting fraction showing the most profound changes. The increase in the rate of drug release from aged samples could be correlated to the alterations to the supramolecular structure of the gelucire. Accelerated drug release from aged samples could also be seen from in vivo studies using healthy human volunteers, although the extent of absorption was not affected. Therefore, even though the sustainability of release may be compromised by aging the gelucire matrices, the bioavailability of the incorporated drug is unlikely to be affected.
Agrowaste-based nanofibers as a probiotic encapsulant: fabrication and characterization

Fung WY, Yuen KH, Liong MT

J Agric Food Chem, 2011 Aug 10;59(15):8140-7.
PMID: 21711050 DOI: 10.1021/jf2009342

This study explored the potential of soluble dietary fiber (SDF) from agrowastes, okara (soybean solid waste), oil palm trunk (OPT), and oil palm frond (OPF) obtained via alkali treatment, in the nanoencapsulation of Lactobacillus acidophilus . SDF solutions were amended with 8% poly(vinyl alcohol) to produce nanofibers using electrospinning technology. The spinning solution made from okara had a higher pH value at 5.39 ± 0.01 and a higher viscosity at 578.00 ± 11.02 mPa·s (P < 0.05), which resulted in finer fibers. FTIR spectra of nanofibers showed the presence of hemicellulose material in the SDF. Thermal behavior of nanofibers suggested possible thermal protection of probiotics in heat-processed foods. L. acidophilus was incorporated into the spinning solution to produce nanofiber-encapsulated probiotic, measuring 229-703 nm, visible under fluorescence microscopy. Viability studies showed good bacterial survivability of 78.6-90% under electrospinning conditions and retained viability at refrigeration temperature during the 21 day storage study.
Characterization of fibrous residues from agrowastes and the production of nanofibers

Fung WY, Yuen KH, Liong MT

J Agric Food Chem, 2010 Jul 14;58(13):8077-84.
PMID: 20568772 DOI: 10.1021/jf1012506

Oil palm trunk (OPT), oil palm frond (OPF), and okara are agrowastes generated abundantly by the palm oil and soy industries. There are vast potentials for these fibrous biomass rather than disposal at landfills or incineration. Fibrous materials (FM) and alkali-treated fibrous residues (FR) were produced from the selected wastes and subsequently characterized. Functional properties such as emulsifying properties, mineral-binding capacity, and free radical scavenging activity were also evaluated for possible development of functional products. Supernatants (FS) generated from the alkaline treatment contained soluble fractions of fibers and were also characterized and used for the production of nanofibers. Okara FM had the highest (P < 0.05) protein (31.5%) and fat (12.2%) contents, which were significantly reduced following alkali treatment. The treatment also increased total dietary fiber (TDF) in okara by 107.9%, in OPT by 67.2%, and in OPF by 25.1%. The increased fiber fractions in FR enhanced functional properties such as water-holding capacities and oil-holding capacities. Okara displayed the highest (P < 0.05) emulsifying properties compared to OPT and OPF. High IDF content of OPT and OPF contributed to high antioxidant activities (377.2 and 367.8% higher than that of okara, respectively; P < 0.05). The soluble fraction from alkali treatment of fibers was successfully electrospun into nanofibers, which can be further developed into nanoencapsulants for bioactive compound or drug delivery.
Preparation, in-vitro and in-vivo characterisation of CoQ10 microparticles: electrospraying-enhanced bioavailability

Fung WY, Liong MT, Yuen KH

J Pharm Pharmacol, 2016 Feb;68(2):159-69.
PMID: 26730452 DOI: 10.1111/jphp.12502

OBJECTIVES: This study aimed to prepare Coenzyme Q10 (CoQ10) microparticles using electrospraying technology, and evaluate the in-vitro properties and in-vivo oral bioavailability.
KEY FINDINGS: Electrospraying was successfully used to prepare CoQ10 to enhance its solubility and dissolution properties. In-vitro evaluation of the electrosprayed microparticles showed bioavailability-enhancing properties such as reduced crystallinity and particle size. The formulation was evaluated using dissolution study and in-vivo oral bioavailability using rat model. The dissolution study revealed enhanced dissolution properties of electrosprayed microparticles compared with physical mixture and raw material. The absorption profiles showed increasing mean plasma levels CoQ10 in the following order: raw material < physical mixture < electrosprayed microparticles.
CONCLUSION: Based on the findings in this study, electrospraying is a highly prospective technology to produce functional nano- and micro-structures as delivery vehicles for drugs with poor oral bioavailability due to rate-limiting solubility.

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