Formulation and optimization of Enalapril Maleate-loaded floating microsphere using Box–Behnken design: in vitro study

The objective was to prepare an Enalapril Maleate (EnM)-loaded floating microsphere with minimum particle size,maximum drug loading, and drug entrapment efficiency. Formulations were prepared by varying drug-to-polymerratio (A), solvent ratio (B), and stirring time (C). The solvent evaporation method was used to prepare the microsphere.“Box–Behnken’s design” (3 factors × 3 levels) was utilized for optimization. The independent variables were polymerto-drug ratio (A), solvent ratio (B), and stirring time (C), while particle size (R1), drug loading (R2), and entrapmentefficiency (R3) were considered as dependent variables. EnM-loaded alcohol microsphere (Formulation-A) wasprepared and optimized. Both Formulation-A and EnM-loaded acetonitrile microspheres (Formulation-B) weresubjected to morphological, micrometric, characterization, and in vitro release studies. The particle size, drug loading,and entrapment efficiency of Formulation-A and Formulation-B were 143 ± 27.75 µm, 37.31% ± 5.73%, and 76.89%± 4.97%, and 158.13 ± 25.1 µm, 40.13% ± 6.12%, and 99.19% ± 1.14%, respectively. The cumulative drug releasesof Formulation-A and Formulation-B were 90.52% ± 4.11% and 86.23% ± 3.81%, respectively. Both formulationsfollowed the Higuchi model of drug release. EnM-floating microsphere was effectively prepared and both formulationsshowed excellent continuous release properties for more than 12 hours.

Factors associated with high prevalence of pulmonary tuberculosis in HIV-infected people visiting for assessment of eligibility for highly active antiretroviral therapy in Kathmandu, Nepal.

Background: Tuberculosis is the leading cause of deaths among HIV patients. In this study, we estimated the prevalence of pulmonary tuberculosis (PTB) and identified the factors/co-morbidities associated with active PTB in HIV-infected people visiting the national public health laboratory to assess their eligibility to receive highly active antiretroviral therapy. Methods: A cross-sectional study was conducted to measure the prevalence of pulmonary tuberculosis. Data on probable risk factors in patients with and without PTB were compared, calculating the odds ratio as a measure of association. Factors showing significant association in univariate analyses were included in a stepwise backward logistic regression model to adjust for confounding. Results: The prevalence of pulmonary tuberculosis was 32.4 % (95% confidence interval (CI) 30.25–34.56). In the univariate analysis, patients with PTB were more likely to be older, married, and have a longer duration since the diagnosis of HIV, diarrhoea, parasitic infection, lower CD4 T-cell counts, and lower CD4/CD8 ratio. However, the backward stepwise logistic regression revealed that only the CD4 T-cell count < 200/μL (AOR 11.69, 95% CI 6.23–21.94), CD4 T-cell count 200–350/μL (AOR 2.52, 95% CI 1.30–4.89), diarrhoea (AOR 2.77, 95% CI 1.78–4.31), parasitic infection (AOR 3.34, 95% CI 2.02–5.50) and ‘sex with partner’ as probable modes of transmission (AOR 0.44, 95% CI 0.20–0.93) were independently associated with pulmonary tuberculosis. Conclusion: A high prevalence of pulmonary tuberculosis was observed. Participants with tuberculosis were significantly more likely to have lower CD4 counts, diarrhoea, and parasitic infections. HIV treatment programmes should consider these factors for better outcomes.

Seroprevalence of HIV and hepatitis C co-infection among blood donors in Kathmandu Valley, Nepal.

We assessed the seroprevalence of human immunodeficiency virus (HIV) in different categories of blood donors and the hepatitis C virus (HCV) co-infection rate. A total of 33,255 blood samples were screened for HIV using a third generation ELISA test at the Central Blood Transfusion Service, Nepal Red Cross Society, Kathmandu from December 2006 to September 2007. The seroprevalence of HIV was 0.19% (95% CI= 0.15-0.25) and co-infection with HCV was found in 10.8% (95% CI= 4.4-20.9). There were no significant differences in HIV seroprevalence among the different categories of age, sex, type of donation and time of donation. The study revealed a relatively lower seroprevalence of HIV among blood donors in Kathmandu Valley than reported earlier but a higher HCV co-infection rate. The similar seroprevalence between first time and repeat donors suggests the need for more improved donor education and counselling.

Acute bacterial meningitis in Nepal.

This study was conducted at Tribhuvan University Teaching Hospital, a tertiary care hospital in Nepal from January 2001 to March 2002. The prevalence of bacterial meningitis, its causative organisms and their antibiotic sensitivity patterns were studied in cerebrospinal fluid of 448 suspected cases. The prevalence of acute bacterial meningitis was 8.3%. There was no significant association (p > 0.05) of the disease with gender (X2 = 0.0234) and among different age groups (X2 = 6.07875) studied. The causative bacteria were Pseudomonas aeruginosa (24.3%), Klebsiella pneumoniae (16.2%), Staphylococcus aureus (16.2%), coagulase negative staphylococci (10.8%), Escherichia coli (10.8%), Streptococcus pneumoniae (8.2%), Neisseria meningitidis (5.4%), Acinetobacter spp. (5.4%) and Aeromoanas spp. (2.7%). Imipenem was the most effective antibiotic, however, 11.1% of P. aeruginosa, 25.0% of E. coli and 50.0% of Acinetobacter spp. were resistant to the drug.

Factors associated with intestinal parasitic infection among school children in a rural area of Kathmandu Valley, Nepal.

We studied predisposing factors of enteric parasitic infections in school children [n=340 (Boys: 177 and Girls: 163)] in a rural area in Kathmandu Valley, Nepal. Fecal samples were examined by formal-ether concentration technique. A total of 71.2% children had parasite. Altogether nine types of parasites were recovered; Trichuris trichiura was the commonest one followed by hookworm and others. A structured questionnaire regarding various predisposing factors was used. No significant differences in the infection rate between the sexes, age groups (< or = 10 years, 11-14 years and > or = 15 years) and family sizes (< or = 5 and > or = 6) were observed (P>0.05). The positive rates were significantly low in children with the history of taking antihelminthic drugs in the past six months (P<0.05). A marginally higher positive rate was found among Dalits children compared to Tibeto-Burmans and Indo-Aryans (P>0.05) and children from farming family (P>0.05). No difference in the infection rate was found in children having different types of toilet facility: open-field defecation, pit latrine and modern toilet at their houses (P>0.05). Slightly higher positive rate was associated with drinking water from Kuwa (shallow well) compared to natural spout, piped water and Khola (river) (P>0.05). Children were infected despite of their awareness regarding the safe water and geophagy.

Purification and partial characterization of PfHRP-II protein of Plasmodium falciparum.

The human malarial parasite Plasmodium falciparum secretes various intra-and extra-cellular proteins during its asexual life cycle in human RBC. Histidine rich protein-II (HRP-II) is one of the most prominent proteins, found to be secreted by P. falciparum throughout the asexual cycle with the peak during mature schizont stage of the parasite development in human IRBC. The high histidine content (35% of the total amino acids in protein) of this protein suggested the potential to bind divalent metal ions. We have demonstrated by metal chelate chromatography, an extraordinary capacity of HRP-II to bind nickel ions (Ni++) and employed this characteristic to purify the extra-cellular HRP-II protein secreted by P. falciparum from culture supernatant. The identity of the purified protein was verified by the relative molecular weight on SDS-PAGE, by reacting with polyclonal antibodies directed against it using Western blot technique.