Optimization and Quest of HPMC loaded Stavudine Controlled Release Dosage Development by Central Composite Design utilizing Reduced Factorial Screening Technique

Abstract The current research focused on screening and finding the significant independent variables in stavudine loaded tablet, followed by optimizing the best formulation using central composite design. The objective of the study to develop stavudine loaded controlled release tablet utilizing reduced factorial design, followed by optimization technique as well as characterization of prepared tablets. Preliminary trial batches were prepared using different grades of hydroxypropyl methylcellulose. The resolution-IV reduced factorial design was selected to screen the significant independent variables in the dosage form design. A total number of eight runs were prepared and responses were recorded. The signified factors identified by half-normal and Pareto chart. The prepared tablets are evaluated for various physiochemical characterizations. Three dependent responses such as hardness, dissolution at 6 hour and 12 hours are considered in optimization process. Later on, drug-polymer interaction study was carried out. The principal of the study design based on finding the best formulation with prefixed set parameter values utilizing the concept of screening technique. It observed that HPMC K15M (57.18 %), HPMC K100 (66.32 %) and PVP K30 (7.97 %) as best composition in a formulation batch would fulfill the predetermined parameter with specific values.

In vivo interactive effect of garlic oil and vitamin E against stavudine induced genotoxicity in Mus musculus.

Stavudine (Zerit, d4T) is widely used as an anti HIV infection drug. It prevents HIV by altering the genetic material of healthy cells but causes mutations in mitochondrial and nuclear DNA. It also produces clastogenic effects in mice. In the present investigation, comet assay test was applied to evaluate the possible genomic damage caused by stavudine and also the ameliorating effects of garlic oil and vitamin E against its genotoxicity in different organs of mice. Two different doses of garlic oil (low and high dose) and vitamin E were administered to mice separately and in combination for six consecutive days followed by a dose of stavudine. The mice were sacrificed after 24, 48 and 72 h of stavudine administration. Both the antioxidants (vitamin E and garlic oil) separately and in combination reduced the genotoxicity of stavudine. The protective effects of high doses of garlic oil were more pronounced as compared to vitamin E administered group.

Fixed dose combination of lamivudine, stavudine and nevirapine in the treatment of pediatric HIV infection: a preliminary report.

To assess efficacy and safety of fixed-dose combination (FDC) of lamivudine, stavudine and nevirapine in the treatment of pediatric HIV- infection, it was administered in the form of oral suspension (Group-A) or dispersible tablet (Group-B). Assessment of improvement in symptoms, CD4 count and adverse drug reactions was done every three months. Baseline CD4 count/mm3 in Group-A (n = 13) patients aged < or =1 yr, 1 to 5 yr and > or = 6 yr increased by 79, 152, 342, 988; 422.8, 514.2, 711.6, 832.6; and 205, 332.7, 516.8, 761.6 after 3, 6, 9 and 12 months of therapy, respectively. The corresponding baseline CD4 count/mm3 in Group-B (n = 8) patients in the three age categories increased by 370, 644.5 and 314 after 3 months, respectively. Improvement in the clinical category was observed in all the patients taking study medication, including weight gain; and decreased incidence of fever, diarrhea, infections and hospitalization. None of the patients had any drug-related adverse effect. Adherence to the regimen was < 95 % and there were no treatment failures.

Antiretroviral therapy in children: Indian experience.

BACKGROUND : There is a paucity of reports on Highly Active Antiretroviral therapy (HAART) in children. We studied feasibility and effectiveness fixed dose combination (FDC) of lamivudine, nevirapine and stavudine in HIV infected children. DESIGN: Interventional study. SETTING: A Tertiary care center. SUBJECTS: Twenty five consecutive HIV positive antiretroviral naive children older than 18 months. METHODS: The study subjects were started on weight-appropriate doses of the FDC and followed up for 6 months. Weight, CD4 counts, absolute lymphocyte count (ALC) and number of episodes of illness were assessed before and after HAART. Adherence and barriers to adherence were studied. RESULTS: Mean weight increased from 15.2 to 16.8 kg (P < 0.001) while mean CD4 counts increased from 488/cmm to 765/cmm (P < 0.001). Only 2 cases of drug associated adverse event were encountered. Improvement in Center for Disease Control (CDC) immunological classification of the subjects was significant while that in World Health Organization (WHO) clinical staging was not statistically significant. Follow up visits were 95% of the expected 175 visits. The average distance traveled by the patient for every visit was 72 km (one way). CONCLUSIONS: Use of FDC in weight specific dosages is feasible and effective for treatment of Pediatric HIV in resource scarce setting. These preliminary results need to be tested in a different setting.

Efficacy of a generic fixed-dose combination of stavudine, lamivudine and nevirapine (GPO-VIR) in Thai HIV-infected patients.

BACKGROUND: GPO-VIR, fixed-dose combination of stavudine 30/40 mg, lamivudine 150 mg, and nevirapine 200 mg are widely used in Thailand. OBJECTIVE: Determine the efficacy and tolerability of GPO-VIR in naive HIV-infected patients. MATERIAL AND METHOD: Primary outcome was the time of initiation to achieve the goal of therapy, which was HIV RNA < 50 copies/mL or 50% increased of CD4 cell count. Ninety patients were eligible for the present study. Mean +/- SD age was 35 +/- 7 years and 51% were male. Median baseline CD4 and HIV RNA were 52 cells/ mm3 and 280,000 (5.4 log10) copies/mL, respectively. Sixty-two (69%) patients had previous opportunistic infections. RESULTS: In a median follow-up period of 15 weeks, 49 (54%) patients achieved the goal of therapy. The probability of goal achievement showed that 12-, 24-, 36- and 48- weeks success rates were 8.5% [95% confidence interval (CI): 3.9-18.0%], 62.7% (95% CI: 50.8-74.6%), 80.0% (95% CI: 67.3-90.1%), and 93.3% (95% CI: 76.3-99.4%), respectively. The median success time to achieve the goal was 21 weeks. Eleven (12%) patients needed to discontinue GPO-VIR because of adverse drugs reaction. CONCLUSION: GPO-VIR may be one of the antiretroviral regimens for HIV-infected patients in Thailand and other resource-limited countries. Its efficacy is good in patients with advanced HIV infection.

Plasma nevirapine levels and 24-week efficacy of a fixed-dose combination of stavudine, lamivudine and nevirapine (GPO-VIR) among Thai HIV-infected patients.

BACKGROUND: A fixed-dose combination of stavudine, lamivudine, and nevirapine (GPO-VIR) is the most affordable antiretroviral therapy (ART) regimen in Thailand. The data of nevirapine (NVP) level and efficacy of this fixed-dose combination is limited. MATERIAL AND METHOD: Patients who were initiated GPO-VIR in 2004 were enrolled NVP levels at 12 weeks were determined. Patients were followed for 24 weeks. RESULTS: Fifty-nine patients with a mean age of 36.4 years and 54% male were enrolled. Mean body weight was 54.7 kgs. Median baseline CD4 and HIV-RNA were 29 cells/mm3 and 270,000 (5.4 log10) copies/mL, respectively. Mean plasma NVP levels at 12 weeks was 6.4 mg/L. By linear regression, female gender (p = 0.042), and higher weight (p = 0.020) were associated with lower NVP levels. At 24 weeks, 78% achieved undetectable HIV-RNA and median CD4 was 156 cells/mm3. CONCLUSION: NVP levels and 24-week efficacy of GPO-VIR are favorable. According to the affordable cost, GPO-VIR should be an appropriate initial regimen for naïve HIV-infected patients in resource-limited settings.

Efficacy and safety of generic fixed-dose combination of stavudine, lamivudine and nevirapine (GPO-vir) in advanced HIV infection.

OBJECTIVES: To assess the efficacy and safety of generic fixed-dose combination of stavudine, lamivudine and nevirapine; GPO-vir in advanced HIV infection. MATERIAL AND METHOD: Open-label combined prospective and retrospective study involving 102 HIV infected patients with baseline CD4 cell count < 100 cells/mm3. All patients received GPO-vir for 48 weeks. The CD4 cell count and plasma viral load (pVL) was measured at 48 weeks. RESULTS: The median baseline CD4 cell count and pVL were 13 cells/mm3 and 363,500 copies/ml, respectively. At 48 weeks, the median CD4 cell count increased to 191 cells/mm3 and 63.7% in intention-to treat and 82.3% in on-treatment analysis had pVL < 50 copies/ml. There was no significant difference in pVL between patients with baseline pVL > 100,000 or < or = 100,000 copies/ml (p = 0.312). The incidence of hepatotoxicity, rash and peripheral neuropathy was 4.9%, 14.7% and 6.9%, respectively. CONCLUSION: GPO-vir was well tolerated and effective in increasing CD4 cell count and suppressing plasma viremia in advanced HIV infection during the 48 weeks follow-up period.

Aplastic anemia in an HIV infected child.

Hematologic manifestations of HIV in children are common and include anemia, neutropenia, lymphocytopenia, thrombocytopenia that may occur due to many reasons. However, aplastic anemia due to HIV infection is rare and even more so in children. Though anemia is seen with advanced disease and associated with poor prognosis it is treated with various therapeutic modalities. Our patient with aplastic anemia due to HIV infection responded to antiretroviral therapy.

Safety and efficacy of a simplified fixed-dose combination of stavudine, lamivudine and nevirapine (GPO-VIR) for the treatment of advanced HIV-infected patients: a 24-week study.

OBJECTIVE: To determine the efficacy and safety of the fixed-dose combination of stavudine (d4T), lamivudine (3TC) and nevirapine (NVP) in the treatment of antiretroviral naive HIV-infected Thai adults. PATIENTS AND METHOD: An open-label, single arm trial was conducted Baseline clinical assessment and blood test was done on 10, antiretroviral naive HIV-infected patients, who then received a fixed dose combination of d4T, 3TC and NVP (GPO- VIR, Thai Government Pharmaceutical Organization, Bangkok, Thailand). Nevirapine was given as 200 mg once daily for the first 2 weeks. The patients were followed up at 2, 4, 8, 12 and 24 weeks. A CD4 cell count and HIV-RNA assay were done at 12 and 24 weeks. RESULTS: One hundred and one patients were enrolled The mean baseline CD4 cell count and mean HIV RNA were 58.7 (57.7) cells/mm3 and 5.3 (0.5) log10, copies/mL respectively. At week 24th, the mean decrease in log HIV RNA was 3.6 (0.7) log10 copies/mL [P < 0.001; 95% confidence interval (CI), 2.70-3.03]. Eighty one (80.2%) patients had HIV RNA < 400 copies/mL by intention-to-treat analysis (ITT) and 97.6% had HIV RNA < 400 copies/mL by on-treatment analysis (OT). Sixteen (84.2%) patients with baseline HIV RNA < or = 100,000 copies/mL and 65 (82.3%) patients with baseline HIV RNA > 100,000 copies/mL had viral load < 400 copies/mL by ITT (P = 0.842; 95% CI, -20.9%-16.2%). Sixteen (94.1%) patients with baseline HIV RNA < or = 100,000 copies/mL and 65 (98.5%) patients with baseline HIV RNA > 100,000 copies/mL had viral load < 400 copies/mL by OT (P = 0.295; 95% CI, -25.5%-3.8%). The mean CD4 cell count at week 24 was 155.1 (89.0) cells/mm3 (range 13-402). The mean increase in CD4 cell count from baseline was 96.5 (63.5) cells/ mm3 (P < 0.001). A total of 12% of the patients receiving d4T + 3TC + NVP developed skin rashes. Grade 3 or 4 hepatotoxicity was recognized in 7% of the patients. CONCLUSION: Fixed-dose combination of d4T + 3 TC + NVP (GPO- VIR) is safe, well tolerated and effective in increasing CD4 cell counts and suppression of HIV RNA at 24 weeks in advanced HIV-infected patients in Thailand.

AIDS-related primary central nervous system lymphoma: prolonged remission associated with highly active antiretroviral therapy.

A 36-year-old HIV-seropositive man developed progressive confusion and unilateral tremor of the hand. His medical history included cryptococcal meningitis and CMV colitis. CT scan revealed a single hyperdense mass with minimal peripheral enhancement at the region of the cerebral peduncle and pons, causing obstructive hydrocephalus. He was treated with ventriculo-peritoneal shunt and cranial radiotherapy. He also received treatment with highly active antiretroviral therapy (HAART). A CD4+ cell count was increased from 2 to 345 cells/mm3. He returned to normal function for about 32 months after treatment.