3D Printing Technology in Customized Drug Delivery System: Current State of the Art, Prospective and the Challenges.

BACKGROUND: 3D printing/Additive Manufacturing seems a pragmatic approach to realize the quest for a truly customized and personalized drug delivery. 3DP technology, with innovations in pharmaceutical development and an interdisciplinary approach to finding newer Drug Delivery Systems can usher a new era of treatments to various diseases. The true potential of this is yet to be realized, and the US-FDA is focusing on the regulatory science of 3D printed medical devices to help patients access this technology safely and effectively. The approval of the first 3D printed prescription medicine by FDA is a promising step in the translation of more research in this area. METHODS: A web-search on PubMed, ScienceDirect, and Nature was performed with the keywords Customized 3D printing and Drug delivery, publications dealing with the aspects of drug delivery using 3D printing for personalized or customized delivery were further considered and analyzed and discussed. RESULTS: We present the advantages offered by 3DP over conventional methods of formulation development and discuss the current state of 3DP in pharmaceutics and how it can be used to develop a truly customized drug delivery system, various 3DP technologies including Stereolithography (SLA), Selective Laser Sintering (SLS), Fused Deposition Modelling (FDM), Pressure Assisted Microsyringe (PAM) that have been used to develop pharmaceutical products have been discussed along with their limitations and also the regulatory considerations to help formulation scientists envisaging research in this area with the necessary information. CONCLUSION: 3D printing has the potential to fabricate a customized drug delivery system. Presence of many drug formulation and the devices are already in the regulatory approval process indicating its success.

Serum gamma glutamyl transferase: a novel biomarker for screening of premature coronary artery disease.

BACKGROUND: We aimed to elucidate the association between gamma glutamyl transferase (GGT) activity with prevalence of premature coronary artery disease (CAD) in young Pakistani patients undergoing diagnostic coronary angiography. METHODS: A total of 218 young adults (age ≤ 45 years) underwent diagnostic angiography. Serum samples were taken from all the patients and analyzed for serum GGT activity, cholesterol and triglycerides. RESULTS: Coronary artery disease patients had significantly increased GGT activity (P = .001) and exhibited a significant positive correlation with blood pressure, cholesterol, blood glucose, and smoking and negative correlation with total antioxidant status (P < .01). CONCLUSION: The study revealed good diagnostic accuracy at cutoff of 35 U/L with a sensitivity of 92%, specificity of 81%, and diagnostic odds ratio of 48 in estimation of premature CAD in young Pakistanis.

Deferiprone challenge test for monitoring iron overload in hepatitis positive thalassemic major patients.

Viral hepatitis is common among beta-thalassemia major (BTM) children in Pakistan. Transfusional iron overload in BTM is usually monitored by serum ferritin. But its levels are falsely raised in viral hepatitis and do not reflect the true iron body burden in thalassemic patients. The objective of the study was to develop a test for monitoring iron overload in 'Hepatitis B&C' positive BTM patients by urinary iron excretion (UIE) after oral deferiprone chelation as compared to serum ferritin. We recruited 130 BTM patients from the registry of Thalassaemia centre at Rawalpindi, Pakistan. The patients were grouped into Hepatitis positive and Hepatitis negative based on ELISAtest. Serum ferritin levels were analyzed by kit on Access II. Each patient was given 75mg/kg of deferiprone at morning. Baseline UIE before deferiprone, and 4, 8 12 hours (hrs) UIE after deferiprone were analyzed on Selectra E. One hundred and thirty BTM patients aged 3 to 23 years comprising of Hepatitis positive (n=69) and Hepatitis negative (n=61) participated in the study. Hepatitis positive thalassemic patients had significantly high serum ferritin median (IQ) 4349 (2782-5927) mug/Lthan 3338 (2189-5506) mug/Lin the Hepatitis negative (p=0.001). We did not find any significant change in UIE at 4, 8, and 12 hours between two groups after Deferiprone intake (p=NS). We observed significant positive correlation between serum ferritin and 4 hours UIE in Hepatitis negative patients (r=0.57; p=0.01) but not in the Hepatitis positive patients (r=0.16; p=NS). Deferiprone challenge with measurement of 4 hours UIE is cost effective and non-invasive test rather than serum ferritin for monitoring iron overload in Hepatitis' positive BTM patients.

Adverse effects of pesticides residues on biochemical markers in pakistani tobacco farmers.

Tobacco is an important cash crop of Pakistan and tremendous amount of irrational pesticides are being used to control insect growth. The frequency of plasma pesticide residues above acceptable daily intake (ADI) and its correlation with biochemical markers for assessment of adverse health effects in the tobacco farmers at district Sawabi, Pakistan was determined. Total 109 adult males consisting of 55 tobacco farmers exposed to pesticides and 54 controls were included. Pesticides residues in blood were analyzed on HPLC and GC-NPD. Plasma butyrylcholinesterase (BChE) was analyzed by Ellman's method. Biochemical markers including serum calcium, phosphorus, urea, creatinine, bilirubin and liver enzymes were measured on Selectra-E auto analyzer. The tobacco farmers had multiple pesticides residues above ADI in their blood consisting of 35 (63%) methomyl; 31 (56%) thiodicarb; 34(62%) cypermethrin; 27 (49%) Imidacloprid; 18 (32%) Methamidophos and 15 (27%) endosulfan. BChE activity was significantly decreased in the pesticides exposed farmers as compared to controls (P<0.001). Plasma biochemical markers including ALT, AST, CK, LDH and phosphate were significantly raised in the pesticides exposed farmers as compared to control group (P<0.001). Total pesticides residues revealed a significant positive correlation with AST (r=0.42), LDH(r= 0.47), ALT (r=0.20) and phosphorus (r=0.51). Excessive exposure to pesticide caused cytotoxic changes in the hepatic and renal biochemical markers which were positively correlated with pesticide residue. Hence these biomarkers might be used in addition to BChE activity for monitoring of adverse effects of pesticides on the health of farm workers.

Efficient low-temperature oxidation of carbon-cluster anions by SO2.

Carbon-cluster anions, CN-, are very reactive toward SO2 (sticking probability of 0.012 +/- 0.005 for C27- at 25 degrees C), in contrast to their inertness toward other common atmospheric gases and pollutants. In flow reactor experiments at ambient temperature and near atmospheric pressure, primary adsorption of SO2 by the carbon cluster anions, N = 4-60, yields CNSO2- or CN-1S-. The inferred elimination of neutral CO2 is also detected as meta-stable decay in collision-induced dissociation. At higher temperatures, the reaction of SO2 with nascent carbon clusters yields CN-1SO- as well as undetected CO. The size-dependent initial reactivity reflects the previously established structural transitions (i.e., from chain to cyclic to cage structures). Such carbon clusters are formed in sooting flames and may act as nuclei for the formation of primary soot particles and serve as models for the local structural features of active soot particle sites for black-carbon soot. The facile generation of reactive carbon-sulfide and -sulfinate units may therefore have implications for understanding the health and environmental effects attributed to the coincidence of soot and SO2.

The total percentage of biopsy cores with cancer improves the prediction of pathological stage after radical prostatectomy.

OBJECTIVE: To examine whether the simple variable 'percentage of cancer-positive biopsy cores' is a significant predictor of true pathological stage after radical prostatectomy and can be used to improve pathological stage prediction by simple means. PATIENTS AND METHODS: In all, 375 patients had a radical prostatectomy for localized prostate cancer in two UK centres; 260 had complete preoperative staging information. Logistic regression was used and predicted probability graphs constructed to assess predictors of pathological stage. RESULTS: In this study, only PSA (P = 0.004) and percentage cancer-positive biopsy cores (P < 0.001) were significant predictors of pathological stage. The final model was an acceptable classifier for pathological stage (area under the receiver operating characteristic curve 0.76, specificity 85%, sensitivity 47%). A patient with a PSA of 10 ng/mL and one of six cores positive for cancer would have a predicted probability of extraprostatic disease of 20%, whereas the same patient with all six biopsy cores positive would have a predicted probability of extraprostatic disease of 80%. CONCLUSIONS: The percentage of cancer-positive biopsy cores significantly predicts the disease stage after radical prostatectomy. This variable is easy to obtain by the clinician and avoids the need to estimate the percentage of biopsy tissue infiltrated by cancer. This readily available information can easily be computed and may help to counsel patients about realistic expectations of organ-confined disease in relation to surgery as a treatment option.

Dose-dependent suppression of serum cholesterol by tocotrienol-rich fraction (TRF25) of rice bran in hypercholesterolemic humans.

Tocotrienols are effective in lowering serum total and LDL-cholesterol levels by inhibiting the hepatic enzymic activity of beta-hydroxy-beta-methylglutaryl coenzymeA (HMG-CoA) reductase through the post-transcriptional mechanism. alpha-Tocopherol, however, has an opposite effect (induces) on this enzyme activity. Since tocotrienols are also converted to tocopherols in vivo, it is necessary not to exceed a certain dose, as this would be counter-productive. The present study demonstrates the effects of various doses of a tocotrienol-rich fraction (TRF25) of stabilized and heated rice bran in hypercholesterolemic human subjects on serum lipid parameters. Ninety (18/group) hypercholesterolemic human subjects participated in this study, which comprised three phases of 35 days each. The subjects were initially placed on the American Heart Association (AHA) Step-1 diet and the effects noted. They were then administered 25, 50, 100, and 200 mg/day of TRF25 while on the restricted (AHA) diet. The results show that a dose of 100 mg/day of TRF25 produce maximum decreases of 20, 25, 14 (P<0.05) and 12%, respectively, in serum total cholesterol, LDL-cholesterol, apolipoprotein B and triglycerides compared with the baseline values, suggesting that a dose of 100 mg/day TRF25 plus AHA Step-1 diet may be the optimal dose for controlling the risk of coronary heart disease in hypercholesterolemic human subjects.

Effects of stabilized rice bran, its soluble and fiber fractions on blood glucose levels and serum lipid parameters in humans with diabetes mellitus Types I and II.

Stabilized rice bran (SRB), a source of complex carbohydrates, tocols, gamma-oryzanols, and polyphenols, was treated with carbohydrases and heat to yield two fractions, rice bran water solubles (RBWS), and rice bran fiber concentrates (RBFC). Stabilized rice bran and its fractions were fed for 60 days to insulin-dependent and noninsulin-dependent diabetes mellitus (IDDM = Type I and NIDDM = Type II) subjects to determine possible effects on serum hemoglobin, carbohydrate and lipid parameters. The Type I subjects (n = 22, 26, and 20) fed Stabilized rice bran, rice bran water solubles, and rice bran fiber concentrates plus AHA Step-1 diet reduced glycosylated hemoglobin 1%, 11%, and 10%, respectively. The fasting serum glucose levels were also reduced significantly (P < 0.01) with stabilized rice bran (9%), rice bran water solubles (29%), and rice bran fiber concentrates (19%).The Type II subjects (n = 31, and 26) fed rice bran water solubles and rice bran fiber concentrates plus AHA Step-1 diet had decreased levels of glycosylated hemoglobin (15% and 11%) and fasting glucose (33% and 22%; P < 0.001), respectively. Serum insulin levels were increased (4%) with rice bran water solubles in both types of diabetes. The reduction of glycosylated hemoglobin and a slight increase in insulin levels indicate that consumption of rice bran water solubles can control blood glucose levels in human diabetes. Serum total cholesterol, LDL-cholesterol, apolipoprotein B, and triglycerides levels were reduced with rice bran fiber concentrates in the Type I (10, 16, 10, 7%) and Type II groups (12, 15, 10, 8%), respectively. These results indicate that rice bran water solubles significantly reduces hyperglycemia (P < 0.01), whereas rice bran fiber concentrates reduces hyperlipidemia (P < 0.05) in both types of diabetes. Therefore, these natural products can be used as nutritional supplements for the control of both types of diabetes mellitus in humans.